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Anthropology

- The Real Magic of Rituals

Anthropology

The Real Magic of Rituals

We might call them superstitions or spells, but they genuinely drum anxiety away.

By Dimitris Xygalatas    September 14, 2022

Tennis star Rafael Nadal performs an elaborate repertoire of rituals before and during every match. When he arrives at the stadium, he enters the court holding a racket in his hand, taking great care never to step on the lines and always crossing each line right-foot first. He places his bag on the bench and turns his tournament ID face up. His chair must be perfectly perpendicular to the sideline. He checks his socks to make sure they are perfectly even on his calves. During the coin toss he faces the net and starts jumping until the coin falls, then runs to the baseline, where he drags his foot across the entire line in a single sweeping motion before hitting each shoe with his racket.

When the game begins, Nadal starts performing repetitive hand gestures that resemble those of Catholics crossing themselves. With his right hand he touches the back and front of his shorts, then his left shoulder, then the right, then his nose, left ear, nose again, right ear and finally his right thigh. At each changeover he picks up two towels. He waits for the other player to cross the line, and then he crosses right-foot first to take his seat. He carefully folds one towel and puts it behind him without using it. Then he folds the second towel and places it on his lap. He takes one sip from a bottle of water, then another sip from a second bottle. Very carefully, he returns the two bottles to the exact same position, the labels facing the same way.

Nadal insists he is not superstitious. In his autobiography, he writes, “Some call it superstition, but it’s not. If it were superstition, why would I keep doing the same thing over and over whether I win or lose? It’s a way of placing myself in a match, ordering my surroundings to match the order I seek in my head.” Who could deny that Nadal’s rituals don’t help him manage his anxiety and find order on the court? He is one of the greatest tennis players of all time.

Over the decades, anthropological studies, including my own, have shown that ritual practices come naturally to us, regardless of our cultures, and further, we expect them to have an effect. But is ritual really an effective stress-management strategy? Or is it simply an illusion, a waste of time or, worse, a dangerous distraction from our real problems?

Field observations suggest that ritual may indeed help people cope with anxiety. In a study conducted in Israel, researchers interviewed local women during the Lebanon War of 2006. They found that among those women who lived in war zones and experienced the stress of war, reciting psalms was associated with lower overall stress levels.1 No similar association was found for women living outside the war zones. While participants in this study were the judges of their own anxiety, similar effects were found at the physiological level.

“It’s a way of ordering my surroundings to the order I seek in my head.”

In my lab at the University of Connecticut, my colleagues and I observed a group of students during the midterm exams, one of the most stressful periods of the year. In addition to surveys, we collected hair and saliva samples, which we used to measure levels of cortisol, a hormone associated with stress. Salivary cortisol changes over the course of a few minutes, so it can be used to measure stress around a specific activity. But traces of the hormone also accumulate in our hair, and they can be used to track long-term anxiety. We found that students who participated in more rituals had lower anxiety across all these measures.

But these are correlational findings. They help us point to an association but cannot establish a causal relationship. For that, we need to turn to experimental studies. Fortunately, several experiments have been conducted on this topic in recent years.

In one of these studies, Matthew Anastasi and Andrew Newberg randomly assigned Catholic college students to either reciting the Rosary (a set of repetitive prayers) or watching a religious film, and measured anxiety levels before and after those tasks. They found that those who recited the Rosary experienced a greater decrease in anxiety.2

Alison Brooks and her colleagues found similar results when they asked participants to enact an artificial ritual that resembled a magical spell. As it turned out, performing this ritual helped people engaged in various stressful tasks such as taking a math test or participating in public karaoke to cope with anxiety.3 In another study, Michael Norton and Francesca Gino asked participants to think about a loss they had experienced—someone who had passed away, a broken relationship or even a monetary loss. They found that, when they asked some of them to perform a ritual, they were better able to cope with the anxiety caused by the loss.4

FORTUNE TELLER: Our brains are prediction machines. They look for patterns and statistical regularities everywhere. But when they can’t make sense of something, we experience anxiety. That’s where ritual comes in. Its repetitive actions help us cope. Illustration by Ekosuwandono / Shutterstock.

Moving from the lab into the real world, my colleagues and I designed a field experiment on the Indian Ocean island of Mauritius.5 To see whether some of the traditional local rituals helped people reduce anxiety, we measured a property of the autonomic nervous system known as heart-rate variability. A healthy heart does not beat evenly like a metronome. When we have a heart rate of 60 beats per minute, this does not mean that our heart ticks exactly once every second. Rather, it means that all the slightly different periods between each two successive beats average out as one second. This variance in the timing between beats is known as heart-rate variability. When it is high, the nervous system is more balanced, and the body is better able to respond to changing circumstances. But when we are stressed, this balance is disrupted and the heart beats in a more rigid way—it has low variability. As a result, the body maintains a state of high alert, which is experienced as anxiety.

Our study took place in a small fishing village called La Gaulette. As is often the case with such villages, most public life took place near the coast. All restaurants, shops, and other commercial activities were arranged alongside the coastal road, and so were all public services, including a police station and two places of worship: a Catholic church near the south entrance, and a Marathi Hindu temple on the north side. Sitting at the cafe each morning, we could see many of the local Hindu women, dressed in colorful saris, walk to the temple to perform religious prayers. Those prayers involved making offerings to the statues of various Hindu deities and executing circular movements with an incense burner or incense stick. These were just the kind of repetitive action patterns that we were interested in and, importantly, ones that were culturally scripted rather than dictated by the experiment.

Whether the sense of control is illusory is of little importance.

We recruited 75 of these women and split them into two groups. We asked those in the first group to meet our team at the temple. The second group arrived at a makeshift lab we had set up in a non-religious building of similar size and arrangement to the temple. This would be our control group. Participants wore a small monitor that recorded their heart beats before being invited to engage in a task that was designed to be stressful: We asked them to write an essay describing the kinds of precautions they would take when faced with an impending flood or cyclone. Such natural disasters regularly plague the island, often with catastrophic consequences, and are a constant source of anxiety for the locals. To create additional stress, we also told them that their essay would be evaluated by a group of public safety experts. After the stressor task, those who were in the temple were asked to go to the prayer room and perform their rituals in the same way as they always did. They entered the room in privacy, lit the incense, and made their offerings to the deities. Those in the control group went through the exact same procedure but performed no rituals. Instead, they were told to sit and relax.

As we predicted, the ritual had beneficial results. Reflecting on natural disasters caused a rise in anxiety for both groups. But those who performed the ritual were faster to recover from that anxiety. Their heart-rate variability increased by 30 percent, suggesting that they were better able to cope with the stress. This was also consistent with how they felt: Subjective ratings of anxiety were twice as high for those who had not performed the ritual. These are no trivial differences: Clinical studies have documented effects of similar magnitude between healthy individuals and people suffering from major depression.6 Ritual, it turns out, can be as effective in reducing stress as some of our best anxiety medications.

How can we explain these findings? Rituals are highly structured. They require rigidity (they must always be performed the “correct” way), repetition (the same actions performed again and again) and redundancy (they can go on for a long time). In other words, they are predictable. This predictability imposes order on the chaos of everyday life, which provides us with a sense of control over uncontrollable situations.

Studies show that, when people experience uncertainty and lack of control, they are more likely to see patterns or regularities where there are none. These patterns can range from visual illusions (such as seeing faces in the clouds) to seeing causality in random events and forming conspiracy theories.7 Under these circumstances people are also more likely to turn to ritualized behaviors. This is known as the compensatory control model: We compensate for lack of control in one domain by seeking it in another.8 Whether this sense of control is illusory is of little importance. What matters is that ritual can be an efficient coping mechanism, and this is why those domains of life that involve high stakes and uncertain outcomes are rife with rituals.

In the experiments conducted by Brooks and her colleagues, engaging in rituals helped participants to perform better in mathematics contests and sing more accurately in karaoke competitions. And in Israel the women who recited more psalms felt less need to take other precautions, which might have impeded them from going about their normal life. In contrast, those who did not perform as many rituals seemed overcome by anxiety. This led them to avoid public places, buses, restaurants,  and large crowds after rocket attacks. This sounds very sensible until you learn that, even at the height of the conflict, the chances of getting killed in a terrorist attack in Israel were lower than those of dying in a car accident. Living in fear could do more harm than good, and rituals helped those women deal with their fears and live a normal life in the face of the conflict.

Our predictive brain does not like unpredictability.

Similar effects extend to a variety of other domains. A group of German psychologists found that people who used lucky charms and rituals such as keeping their fingers crossed performed better in an assortment of skill games and puzzles.9 Other studies have found that ritualization may help athletes perform better. Basketball and golf players are more successful after performing pre-shot rituals.10 Stopping them from performing these rituals can be detrimental to their performance, leading them to miss more shots.11 The reason for these remarkable effects appears to be that these rituals allow the athletes to ease their own anxiety, regaining a sense of control.

In recent years, philosophers, psychologists, and neuroscientists have revised their models of the human mind. The classical view was that our cognitive apparatus functions as a data-processing device: It receives input from the environment and reacts by producing the appropriate responses. But evidence has been mounting that our brain is much more sophisticated than that. It is a predictive device. Rather than passively absorbing information about the state of the world, it actively works to make inferences (predictions) about what types of stimuli it is most likely to encounter at any given situation. Those predictions are based on information derived from our prior experience and socialization, our surroundings, as well as hard-wired knowledge.

Take the blind spot in our vision. The optic nerve, a bundle of nerve fibers that carry information from the eye to the brain, passes through the retina itself. Consequently, the spot where the optic nerve enters the eyeball has no photoreceptor cells to detect light. This is why it is called a blind spot: Whatever part of our visual field falls on to that spot becomes invisible to us. If you had never noticed that you have a blind spot, that is because your brain makes up the missing part of the image by using information from the surrounding environment to fill in the gap.

Our brain makes similar types of inferences in all sorts of other domains. Imagine that you live on the outskirts of San Francisco, and as you wake up you feel your bed shake. Fearing it might be an earthquake, your immediate response might be to try to get out of the building as quickly as possible. But now imagine that you live in New York, which does not experience many earthquakes, and that an elevated train line runs alongside your building. Perhaps the first time that you wake up to the vibration you rush to the door, only to embarrass yourself as you run down the hallway in your underwear. But once you know what to expect when you feel the shake, it will no longer cause you to panic. As your brain has now updated its prior knowledge, it can predict with greater confidence that the shaking will not cause the roof to fall on your head. The situation is no longer stressful. In fact, over the years, the familiar sensation of the train going by at regular intervals may even start to feel comforting.

Because our brain never stops making these kinds of predictions, we tend to look for patterns and statistical regularities everywhere around us. This is extremely important, because any computational device (and the human brain is no exception) becomes dramatically more efficient when it can build on prior knowledge. This way, we do not have to learn everything from scratch. But one consequence of this cognitive architecture is that when our predictive potential is limited—that is, when there is high uncertainty—we experience anxiety. Our predictive brain does not like unpredictability.

This is where ritual comes in. The repetitive action patterns found in ritual function as cognitive gadgets that help us cope with stress. By embedding these gadgets into our cultures, all human societies—and its individuals—can capitalize on their potential.

Just ask Rafael Nadal.

Dimitris Xygalatas is an anthropologist and cognitive scientist who studies some of the things that make us human. Most of his research has focused on rituals and their ability to soothe, excite, unite, and divide us. To study these effects, he combines ethnographic field work with scientific experiments. He is based at the University of Connecticut, where he directs the Experimental Anthropology Lab.

Excerpted from Ritual: How Seemingly Senseless Acts Make Life Worth Living, by Dimitris Xygalatas. Copyright © 2022 by Dimitris Xygalatas. Used with permission of Little, Brown and Company, an imprint of Hachette Book Group. New York, NY. All rights reserved.

Lead image: Sipa USA via AP Images

References

1. Sosis, R. & Handwerker, P. Psalms and coping with uncertainty. American Anthropologist 113, 40–55 (2011).

2. Anastasi, M.W. & Newberg, A.B. A preliminary study of the acute effects of religious ritual on anxiety. Journal of Alternative and Complementary Medicine 14, 163–165 (2008).

3.  Brooks, A.W., et al. Don’t stop believing: Rituals improve performance by decreasing anxiety. Organizational Behavior and Human Decision Processes 137, 71–85 (2016).

4.  Norton, M.I. & Gino, F. Rituals alleviate grieving for loved ones, lovers, and lotteries. Journal of Experimental Psychology: General 143, 266–272 (2014).

5. Lang, M., Krátký, J., & Xygalatas, D. The role of ritual behaviour in anxiety reduction: An investigation of Marathi religious practices in Mauritius. Philosophical Transactions of the Royal Society B 375, 20190431 (2020).

6. Udupa, K., et al. Alteration of cardiac autonomic functions in patients with major depression: A study using heart rate variability measures. Journal of Affective Disorders 100, 137–141 (2007).

7.  Whitson, J.A. & Galinsky, A.D. Lacking control increases illusory pattern perception. Science 322, 115–117 (2008).

8. Hockey, G.R.J. Compensatory control in the regulation of human performance under stress and high workload: A cognitive–energetical framework. Biological Psychology 45, 73–93  (1997).

9.  Damisch, L., Stoberock, B., & Mussweiler, T. Keep your fingers crossed! How superstition improves performance. Psychological Science 21, 1014–1020 (2010).

10. Gayton, W.F., Cielinski, K.L., Francis-Keniston, W.J., & Hearns, J.F. Effects of preshot routine on free-throw shooting. Perceptual and Motor Skills 68, 317–318 (1989).

11. Foster, D.J., Weigand, D.A., and Baines, D. The effect of removing superstitious behavior and introducing a pre-performance routine on basketball free-throw performance. Journal of Applied Sport Psychology 18, 167–171 (2006).

Astronomy

- A Step-by-Step Guide to Our Solar System’s Demise

Astronomy

A Step-by-Step Guide to Our Solar System’s Demise

First the oceans boil off. Then things really get serious.

By Sean Raymond    September 17, 2022

Our solar system is on its way out. Slowly. Over the next several billion years, a series of unfortunate events will take place, spanning from the not-so-great to the truly tragic. Afterward, our solar system will be gone: All of the planets will be lost and the sun will be a solitary white dwarf.

(Pause to wipe away tears.)

I will guide us through our solar system’s future, one step at a time. Since Earth is our home base, I’ll include a key event affecting life on Earth. Here are the five steps to come:

1. 1. Earth’s oceans will boil off.

2. The rocky planets’ orbits may go unstable, leading to a potential giant collision between planets.

3. The sun will become a red giant and swallow the rocky planets.

4. A passing star will trigger a dynamical instability among the remaining planets.

5. A passing star will strip away the final planet.

It is a near certainty that each of these events will happen, with the exception of number 2 (which has only a relatively small probability). But it will take about 100 billion years to reach the end.

Let’s get to it.

The End of Liquid Water (and Life) on Earth

The sun is ever-so-slowly heating up. Today, it’s about 30 percent brighter than right after it formed. As the sun converts hydrogen to helium in its core, the mean molecular weight increases, thus increasing the core’s temperature and the rate of the fusion reaction (called the proton-proton chain). This slowly increases the sun’s energy output.

SOLAR EVOLUTION: Each curve shows one of the sun’s characteristics compared with the current sun. The red curve shows its luminosity (brightness). Credit: Wikicommons

Life as we know it requires liquid water. In order to maintain liquid water on a planet’s surface, there must be a balance between the energy coming in and the energy going out that maintains the right temperature range.

The energy balance is always adjusting itself. If the amount of greenhouse gases in Earth’s atmosphere increases (as it is doing today), the “blanketing” effect of greenhouse gases creates a new energy balance with a hotter surface.

Earth does have a built-in thermostat: the carbonate-silicate cycle, which regulates the amount of carbon dioxide in the atmosphere, thus maintaining a stable climate. Unfortunately for us humans, it operates on about a million-year timescale so it is much too slow to help us with the current global warming problem.

HOT BLANKET: The greenhouse effect basically makes our atmosphere act like a blanket, by slowing down the loss of energy to space. More greenhouse gases means a thicker blanket. Credit: Time Scavengers

Another way for a planet to heat up is if the amount of incoming energy increases. This is exactly what is happening as the sun’s brightness slowly increases. And, although there are much shorter-term variations in Earth’s climate from seasons, changes in atmospheric composition (both from human-made greenhouse gases and sometimes from volcanic dust), and Milankovitch cycles, Earth’s surface is slowly but inexorably heating up due to the increasing solar brightness.

At some point, Earth’s atmosphere will no longer be able to maintain a stable energy balance and the greenhouse heating will enter a runaway phase. In a runaway greenhouse, there is a positive feedback loop. The planet’s surface becomes hotter, which causes more water to evaporate into the atmosphere. Water is a strong greenhouse gas, so this increases the strength of the greenhouse effect, which further heats the planet’s surface.

Credit: Sean Raymond

Once the greenhouse effect goes runaway, it will heat up Earth’s surface to the point that the oceans will entirely vaporize. This will just make the planet hotter and hotter until a new balance is reached, with a scorching hot surface and all of the water trapped in the atmosphere (likely in a “supercritical” state, meaning there is no distinction between liquid and gas). There will be more water vapor close to Earth’s surface but no liquid ocean.

Another way to think of this is in terms of the “habitable zone”—the region of orbits around a star inside which a planet can maintain liquid water, provided it has an appropriate atmosphere. The inner edge of the habitable zone is the distance from the star inside which a planet’s atmosphere will undergo runaway greenhouse heating. Right now, the inner edge of the sun’s habitable zone is at about 95 percent of the Earth-sun distance.

IT’S NICE HERE: Current location of the sun’s habitable zone. The inner edge is located at about 95 percent of the Earth-sun distance. Credit: Mythic Scribes

With the brightening sun, that inner edge of the habitable zone is slowly marching outward. Exactly when the inner edge of the habitable zone will cross Earth’s orbit is a little tricky to pinpoint, but estimates point to about a billion years from now.

From that point on, there won’t be any more liquid water on Earth. No more liquid water means no more life, at least as we know it. In the words of the great Mel Brooks: “There goes the planet!”

Chaotic Destabilization of the Rocky Planets’ Orbits

The planets’ orbits are chaotic. In a mathematical sense, this means that we cannot predict their exact positions in the distant future (beyond about 10 to 100 million years).

When thinking of the future, it’s easy to imagine the worst. When my kids were still crawling around, I would find myself imagining horrific futures in which they crawled off the edge of, well, anything tall. Luckily, nothing like that ever happened. But the prospect terrified me.

Given that the rocky planets’ orbits are chaotic, we cannot know their future. Should we just assume that their orbits will remain nice and stable for all time? Or, like a young parent, should we assume the worst, that things will somehow go terribly wrong?

Computers can help us find an answer, albeit a probabilistic one. Using codes designed to follow the orbits of the planets forward in time, we can simulate many possible futures for the solar system. Each simulation starts from very slightly different positions for the planets today, then projects those into the future. We know the positions of the planets quite accurately, but there are uncertainties at the level of millimeters to meters, and those uncertainties are magnified by chaos.

Some simulations find that Mercury’s orbit will become extremely stretched-out, or eccentric. This can happen if Mercury enters a “secular resonance” with Jupiter. The resonance causes an orbital alignment between the two planets in which the planets’ apsidal lines—the line connecting the sun to the position of closest approach—start to precess together, maintaining their alignment over many thousands of years. This acts to progressively stretch out Mercury’s orbit in dramatic fashion:

Credit: Greg Laughlin / Nature (2009)

Once Mercury’s orbit becomes so stretched-out that it crosses the orbit of Venus, all sorts of crazy things can happen. Mercury can come so close to the sun that it is engulfed. Another possibility is that Mercury collides with Venus. Perhaps the most dramatic (and tragic) outcome seen to date is that it is possible for Mercury to end up perturbing the other rocky planets’ orbits to the point of triggering a collision between Earth and Mars, as you can see in this image:

What is the likelihood of this happening? Is Earth really going to collide with Mars in 3 billion years? The most rigorous study to date, from 2009, showed that there is about a 1 percent probability of Mercury entering the secular resonance with Jupiter and wreaking havoc in the next 5 billion years. Even if Mercury enters the resonance, there is only a small chance of a collision with Earth. It is much more likely that Mercury will simply fall into the sun or collide with Venus.

In other words, there is a 99 percent chance that the rocky planets’ orbits will continue to zoom around the sun like clockwork, at least until the sun itself starts to change …

The Sun Will Evolve Into a Red Giant, Swallow the Inner Planets, and Become a White Dwarf

In about 5 billion years, the sun’s core will run out of hydrogen, the fuel of its fusion reactor. The sun will continue to fuse hydrogen in an expanding shell, and this will puff the sun up into a red giant.

A SUNNY LIFE: Red giants are cooler than sun-like stars (hence their redness) but are extremely bright due to their very large sizes. Credit: Unuplusunu / Wikicommons

Betelgeuse, Orion’s bright right shoulder, is a good example of a red giant. The sun will be a red giant for about half a billion years. It’ll increase in brightness, shifting the habitable zone outward to encompass Jupiter and Saturn. During this phase, the giant planets’ large moons may have the conditions for liquid water on their surfaces. Many of those moons have a lot of water in their interiors, including some (most famously, Europa) with liquid oceans under icy shells. Ganymede, the solar system’s largest moon, has a mass about 40 times smaller than Earth, yet is thought to be about half water! That makes Ganymede’s water budget significantly larger than Earth’s, since our planet is only about 1 part water in 1000 by mass. Ganymede will make quite the ocean moon in about 7 billion years.

ZONE SHIFT: Top: the habitable zone around the sun today. Bottom: the habitable zone around the sun once it becomes a red giant in about 7 billion years. Credit: Wendy Kenigsberg

The planets’ orbits will adjust to the changing sun. The inner planets will be engulfed when the sun is a red giant. Planets far from the sun will expand onto wider orbits as the sun loses mass to powerful winds flowing out from its surface. As the sun’s gravity weakens, a planet’s orbit naturally widens, like a slinky losing its tension and stretching out with age.

Now, a red giant is big. The sun will expand by about a factor of 100 to become a red giant, and will extend out about as far as Earth’s current orbit. Our planet is at the brink: We don’t know whether it will be swallowed by the sun or escape onto a larger orbit.

Meanwhile, the sun’s core will contract until the increased temperature and pressure enable the fusion of helium. There will be a few flashes, then the sun will puff off its outer layers as a “planetary nebula” (which has nothing to do with planets—it’s just an old name that stuck around). What will remain of the sun is its core, a small white dwarf that does nothing but slowly cool off for eternity.

Courtesy of Sean Raymond

White dwarfs are almost as massive as the sun but only about the size of Earth. This gives them extremely strong surface gravities, and any material heavier than hydrogen or helium settles out of their atmospheres and into the stars themselves in days to months—an astronomical blink of the eye.

When we look at white dwarfs, a large fraction of them appear to be “polluted”: Instead of having pure hydrogen or helium spectra, their outer layers are contaminated with rocky (or sometimes ice-rich) material. Because it should settle out very quickly, this rocky material must have collided with the white dwarf quite recently.

White dwarfs might be polluted by a slow trickle of material falling onto their surfaces from disks of debris on very close orbits. The debris comes from small bodies that were gravitationally sling-shotted by the planets during and after their orbital shift. Since a white dwarf is a tiny target, small bodies do not crash into the star but instead are torn apart by its gravity, spinning out disks of rocks that are ground to dust as they orbit very close to the white dwarf.

In about 7 billion years, the sun will be a white dwarf. Earth will have either been swallowed by the red giant sun or just thoroughly roasted. Viewed by a distant observer, the only hint that a pale blue dot once orbited this dime-a-dozen white dwarf will be a few distinctive spectral lines—the blood spatter from a long-dead planetary system.

To this point, our story looks like this:

But this is not the end. Five (or maybe six, if Earth is lucky) planets will survive to see the sun as a white dwarf.

A Passing Star Triggers a Dynamical Instability Among the Planets

Nothing lasts forever (even cold November rain).

After the sun becomes a white dwarf, its planetary system will be almost twice its current size. Not in terms of the number of planets, of course (bye-bye, inner rocky planets), but in terms of the sizes of the surviving planets’ orbits. The sun will have lost about 40 percent of its mass, much of it going to create a beautiful planetary nebula on its way to becoming a white dwarf. The planets’ orbits will widen in response by about 85 percent. Neptune’s orbit will grow from 30 to about 55 astronomical units, marking the outer edge of the planets.

It should be just smooth sailing from here to eternity, right? The planets will be on nice, nearly circular orbits around a white dwarf. And that pesky inner, chaotic part of the solar system will have been swallowed by the sun.

Only one thing could possibly endanger the solar system now: other stars.

Stars only spend a lot of time close to each other when they’re babies. In their birth clusters, stars frequently pass relatively close to each other. (The exact number depends on the size and density of the birth cluster.) Sometimes stars pass so close that their gravity affects what’s in orbit around each star. For instance, a passing star can destabilize the very outermost parts of another star’s planet-forming disk. And in some cases, a passing star can even steal a very wide-orbit planet. (This is a possible origin for the hypothetical Planet 9.)

One model proposes that the orbits of very distant objects in the Kuiper belt were shaped early in solar system history, when a star came within a few hundred to a thousand astronomical units of the sun. (It’s a contentious model.) This is a typical distance for the closest encounter that a star like the sun would experience in a birth cluster like the sun’s. This encounter may even have been the closest encounter the sun ever underwent, at least from its birth to its becoming a white dwarf.

Once their birth clusters dissipate, stars generally stay far away from each other. This is just because space is really big. Given the density of stars in the sun’s neighborhood and how fast they move around, we can calculate the typical time it takes for a star to pass within a given distance of the sun. On average, another star passes within 10,000 astronomical units of the sun every 20 million years or so, within 1,000 astronomical units every billion years, and within 100 astronomical units every 100 billion years.

Let me describe a fantastic 2020 study by Jon Zink, Konstantin Batygin, and Fred Adams that really improved our understanding of the solar system’s far future. They performed 10 simulations of the solar system’s orbital evolution for a trillion years, starting from the present day and then following the planets as the sun becomes a red giant, then a white dwarf, and continues into the distant future. The Big Bang was only 14 billion years old, so Zink and colleagues’ simulations stretch to about 70 times the current age of the universe. Each simulation represents a possible future for the solar system. In this case, the futures differ mainly in terms of the passages of stars close to the sun and planets.

A planetary system is only strongly affected when a star passes very close-by, within three to five times the size of the largest planetary orbit. With Neptune at 30 astronomical units, a star would need to pass within about 100 astronomical units to have a strong impact on the present-day solar system. But with Neptune at 55 astronomical units around the white dwarf sun, a star passing within about 200 astronomical units will have a strong effect on the planets. Even a flyby at 500 astronomical units gives Neptune a noticeable gravitational kick.

In Zink and his colleagues’ simulations, within about 30 billion years, a star passed within a few hundred astronomical units, triggering a dynamical instability. This will be a much stronger instability than the one that happened early in solar system history, because it will include gravitational scattering between Jupiter and Saturn. Instead of relatively gentle spreading of the giant planets’ orbits, this will look like the dynamical instabilities that astrophysicists think are commonplace among systems of giant exoplanets (and that often destroy their rocky planets):

This dynamical instability will eject all of the remaining planets but one. The gravitational kicks between planets will give each planet (but one) enough orbital energy to be launched into interstellar space to become free-floating planets. In most of Zink’s simulations, Jupiter was the last planet standing, surviving on a stretched-out orbit similar to those of giant exoplanets.

From this point on, the solar system will consist simply of the white dwarf sun and Jupiter. This is fitting in an odd way because, if we were to search for solar systems around nearby sun-like stars using present-day technology, Jupiter is still the only solar system planet that could be detected (for now).

The Close Passage of a Star Strips Away the Sun’s Last Planet

Just like every rope has a breaking point, any planet can be stripped away from its star if another star passes close enough.

At this stage Jupiter, the solar system’s last planet standing, will be on a wide, stretched-out orbit.

Distant flybys of stars can gently nudge Jupiter toward ejection, but the effect of very rare, very close encounters is actually what dominates. Zink’s simulations need to wait about 100 billion years for a star to pass within about 200 astronomical units. The star gives Jupiter the gravitational energy it needs to escape from the white dwarf sun and never come back. (Zink’s simulations had a range in the timing of the ejection of the last planet standing, from about 40 billion years in the future to a little over 300.)

So here are what the last phases of the solar system’s lifetime will look like:

When all is said and done, five or six of the sun’s eight original planets will still be intact, just not in orbit around the sun. Those planets will survive as free-floating, or “rogue” planets (the other two or three having been swallowed during the red-giant phase). Of course, those planets won’t be alone: The abundance of free-floating planets will be constantly increasing, as many other stars lose their planets to interstellar space.

This marks the end of the solar system. Wraps it all up. I hope you’ve enjoyed its story.

Sean Raymond is an American astrophysicist working at the Bordeaux Astrophysical Laboratory in France. He also writes a blog at the interface of science and fiction (planetplanet.net), and recently published a book of astronomy poems.

Additional Resources

- The Solar System’s story (with links to all chapters)

- Reading Earth’s destiny in the blood spatter around white dwarf stars (Nautilus article)

- How Planets Die: Roasted, Toasted and Swallowed by their evolving stars (from the How Planets Die) series

- Second chance planets: Iceball worlds that thaw out when their stars go red giant (the positive spin from the How Planets Die series, including the ultimate Second-Chance Solar System!)

- Some key technical papers: Koparappu et al 2013 (habitable zone limits), Ramirez and Kaltenegger 2016 (habitable zones of evolving stars) Laskar and Gastineau 2009 (about the possibility for chaos-driven dynamical instability among the rocky planets in the next 5 billion years), Veras 2016 (about how planetary systems respond to their evolving stars, Zink et al 2020 (about late instability and loss of the planets from stellar encounters over 100 billion years).

- The MOJO videos (in case you want to see me blabbing about planet formation live).

Lead image: Naeblys / Shutterstock

Reprinted with permission from Sean Raymond’s blog PlanetPlanet.net.

Communication

- How Shannon Entropy Imposes Fundamental Limits on Communication

- The Trouble With “The Big Bang”

Communication

How Shannon Entropy Imposes Fundamental Limits on Communication

What’s a message, really? Claude Shannon recognized that the elemental ingredient is surprise.

By Kevin Hartnett    September 15, 2022

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If someone tells you a fact you already know, they’ve essentially told you nothing at all. Whereas if they impart a secret, it’s fair to say something has really been communicated.

This distinction is at the heart of Claude Shannon’s theory of information. Introduced in an epochal 1948 paper, “A Mathematical Theory of Communication,” it provides a rigorous mathematical framework for quantifying the amount of information needed to accurately send and receive a message, as determined by the degree of uncertainty around what the intended message could be saying.

Which is to say, it’s time for an example.

In one scenario, I have a trick coin—it’s heads on both sides. I’m going to flip it twice. How much information does it take to communicate the result? None at all, because prior to receiving the message, you have complete certainty that both flips will come up heads.

In the second scenario I do my two flips with a normal coin—heads on one side, tails on the other. We can communicate the result using binary code: 0 for heads, 1 for tails. There are four possible messages—00, 11, 01, 10—and each requires two bits of information.

So, what’s the point? In the first scenario you had complete certainty about the contents of the message, and it took zero bits to transmit it. In the second you had a 1-in-4 chance of guessing the right answer—25 percent certainty—and the message needed two bits of information to resolve that ambiguity. More generally, the less you know about what the message will say, the more information it takes to convey.

Shannon was the first person to make this relationship mathematically precise. He captured it in a formula that calculates the minimum number of bits—a threshold later called the Shannon entropy—required to communicate a message. He also showed that if a sender uses fewer bits than the minimum, the message will inevitably get distorted.

“He had this great intuition that information is maximized when you’re most surprised about learning about something,” said Tara Javidi, an information theorist at the University of California, San Diego.

The term “entropy” is borrowed from physics, where entropy is a measure of disorder. A cloud has higher entropy than an ice cube, since a cloud allows for many more ways to arrange water molecules than a cube’s crystalline structure does. In an analogous way, a random message has a high Shannon entropy—there are so many possibilities for how its information can be arranged—whereas one that obeys a strict pattern has low entropy. There are also formal similarities in the way that entropy is calculated in both physics and information theory. In physics, the formula for entropy involves taking a logarithm of possible physical states. In information theory, it’s the logarithm of possible event outcomes.

The logarithmic formula for Shannon entropy belies the simplicity of what it captures—because another way to think about Shannon entropy is as the number of yes-or-no questions needed, on average, to ascertain the content of a message.

For instance, imagine two weather stations, one in San Diego, the other in St. Louis. Each wants to send the seven-day forecast for its city to the other. San Diego is almost always sunny, meaning you have high confidence about what the forecast will say. The weather in St. Louis is more uncertain—the chance of a sunny day is closer to 50-50.

FATHER OF INFORMATION THEORY: Claude Shannon at Bell Labs in 1954. Photo courtesy of the Estate of Francis Bello/Science Source.

How many yes-or-no questions would it take to transmit each seven-day forecast? For San Diego, a profitable first question might be: Are all seven days of the forecast sunny? If the answer is yes (and there’s a decent chance it will be), you’ve determined the entire forecast in a single question. But with St. Louis you almost have to work your way through the forecast one day at a time: Is the first day sunny? What about the second?

The more certainty there is around the content of a message, the fewer yes-or-no questions you’ll need, on average, to determine it.

To take another example, consider two versions of an alphabet game. In the first, I’ve selected a letter at random from the English alphabet and I want you to guess it. If you use the best possible guessing strategy, it will take you on average 4.7 questions to get it. (A useful first question would be, “Is the letter in the first half of the alphabet?”)

In the second version of the game, instead of guessing the value of random letters, you’re trying to guess letters in actual English words. Now you can tailor your guessing to take advantage of the fact that some letters appear more often than others (“Is it a vowel?”) and that knowing the value of one letter helps you guess the value of the next (q is almost always followed by u). Shannon calculated that the entropy of the English language is 2.62 bits per letter (or 2.62 yes-or-no questions), far less than the 4.7 you’d need if each letter appeared randomly. Put another way, patterns reduce uncertainty, which makes it possible to communicate a lot using relatively little information.

Note that in examples such as these, you can ask better or worse questions. Shannon entropy sets an inviolable floor: It’s the absolute minimum number of bits, or yes-or-no questions, needed to convey a message.

“Shannon showed there is something like the speed of light, a fundamental limit,” said Javidi. “He showed that Shannon entropy is a fundamental limit for how much we can compress a source, without risking distortion or loss.”

Today, Shannon entropy serves as a yardstick in many applied settings, including information compression technology. That you can zip a large movie file, for example, owes to the fact that pixel colors have a statistical pattern, the way English words do. Engineers can build probabilistic models for patterns of pixel colors from one frame to the next. The models make it possible to calculate the Shannon entropy by assigning weights to patterns and then taking the logarithm of the weight for all the possible ways pixels could appear. That value tells you the limit of “lossless” compression—the absolute most the movie can be compressed before you start to lose information about its contents.

Any compression algorithm’s performance can be compared to this limit. If you’re far from it, you have an incentive to work harder to find a better algorithm. But if you’re close to it, you know that the information laws of the universe prevent you from doing much better.

Lead image: To communicate a series of random events, such as coin flips, you need to use a lot of information, since there’s no structure to the message. Shannon entropy measures this fundamental constraint. Credit: Kristina Armitage/Quanta Magazine.

This article was originally published on the Quanta Abstractions blog.

- Kevin Hartnett

Posted on September 15, 2022

Kevin Hartnett is a senior writer at Quanta Magazine covering mathematics and computer science. His work has been collected in the the “Best Writing on Mathematics” series in 2013 and 2016. He also writes “Brainiac,” a weekly column for the Boston Globe’s Ideas section.

Communication

The Trouble With “The Big Bang”

A rash of recent articles illustrates a longstanding confusion over the famous term.

By Sabine Hossenfelder    September 11, 2022

Did the Big Bang happen? Has the James Webb Space Telescope found evidence against the Big Bang? If astrophysicists are sure the Big Bang happened, why do they also think the universe was born from a quantum fluctuation? And what does this have to do with dark matter?

I can’t blame readers for being confused by recent news stories about the Big Bang. The article that kicked them off, “The Big Bang Didn’t Happen,” is bad enough. But some of the rebuttals also don’t get it right. The problem is that writers conflate ideas in astrophysics and use the term “Big Bang” incorrectly. Let me set the record straight.

Let’s call Big Bang #1 the beginning of the universe. It’s what most people think the expression means. This Big Bang is what we find in the mathematics of Einstein’s general relativity if we extrapolate the current expansion of the universe back in time. The equations say that matter and energy in the universe becomes denser and hotter until, eventually, about 13.7 billion years in the past, both density and temperature become infinite. We cannot extrapolate any further back in time, so it’s fair to say that this event, if it happened, would be the beginning of the universe.

I can’t blame readers for being confused by recent news stories about the Big Bang.

This Big Bang is sometimes more specifically called the Big Bang Singularity. This word has somewhat fallen out of favor among physicists, partly because it’s clumsy, but also because I don’t know anyone who thinks this singularity is physically real. Its appearance almost certainly tells us that Einstein’s theory breaks down under extreme conditions. If energy density becomes very large, then space and time curve very strongly, and eventually quantum effects of spacetime become important. To describe those correctly, we would need a theory of quantum gravity—a theory for the quantum properties of space and time—which we don’t have. If we had it, it would probably remove the singularity.

This is what happens in all other theories in which we have singularities popping up: They are mathematical artifacts that stem from using a theory in a range where it should no longer be applied. An example may be the singularity in the surface curvature of a water drop, as it pinches off a tap. This singularity disappears if one considers that the water is made of molecules. What was formerly a point of infinite curvature is now a molecule like all the others.

Einstein’s theory breaks down about 10-43 seconds before the mathematical singularity, a unit also known as the Planck time. Since physicists don’t believe the singularity is real, the phrase “Big Bang” has come to refer to whatever event might replace the singularity in the to-be-found theory of quantum gravity in this Planck time. Let’s call it just that—the Big Bang Event.

We have no evidence the Big Bang Event happened. We cannot look back in time anywhere near that long ago. The earliest direct observation we have is the formation of the cosmic microwave background, which was formed about 400,000 years after the hypothetical Big Bang Event. Be careful: If you Google for the time at which the microwave background was formed, you will get the answer that it was formed 13.7 billion years ago and that might look like it was formed at the Big Bang Event. But that’s because the figure is rounded.

The James Webb Space Telescope doesn’t tell us anything about the Big Bang Event.

We understand quite well how matter behaves at energy densities somewhat above those at which the microwave background must have formed, so we trust that our extrapolations back in time are correct until we reach an energy density that roughly corresponds to that which the Large Hadron Collider probes, which brings us to about 10-12 seconds before the hypothetical Big Bang Event. We know nothing about what matter does at higher energy density—even the density in neutron stars is lower than that.

Now, 10-12 seconds isn’t much in human terms, but to get from there to the Big Bang Event, we’d still have to extrapolate over more than 50 orders of magnitude in energy density. That’s 50 orders of magnitude for which we have only speculation. This means the Big Bang Event might happen in our mathematics, but we have no observations that can tell us it happened in reality. Indeed, I think we will never have any observations that confirm the Big Bang Event. Some of my colleagues in astrophysics may disagree. But be that as it may, at least for now we just don’t know how the universe began.

That we have no evidence for (or against) the Big Bang Event is the reason why physicists have a large number of different hypotheses for the beginning of our universe. Besides the Big Bang Event, our universe could have been born out of a black hole; or it could have come about in a collision of higher-dimensional membranes; or it could have started as a big network in a non-geometric phase; or our universe could cycle through eons, as Roger Penrose has proposed. The most popular idea now is that our universe was born out of a fluctuation in a quantum field. All these alternative ideas to the Big Bang Event are possible because we cannot look back in time far enough to tell them apart.

The James Webb Space Telescope is an amazing instrument. It looks at young stars and galaxies that were formed long after the cosmic microwave background, at about 200 million years. That’s impressive, but it doesn’t tell us anything about the Big Bang Event, or its alternatives.

The problem has long been that the term Big Bang is used to refer to the expansion of the universe in general, and not to the event of the creation of the universe in particular. These are, however, two separate scientific hypotheses. We have overwhelmingly strong evidence that the universe expands (call it Big Bang #2), and we are confident about its history back to about the time of the electroweak phase transition, which is what the Large Hadron Collider probes. We have to date zero evidence for the beginning of the universe, whether it was a Big Bang Event or something else.

Historically, the first evidence for the expansion of the universe was Edwin Hubble’s observation that the light from other galaxies is systematically shifted to the red, indicating that they all recede from us. While this may have been the first evidence, the decisive evidence for the expansion of the universe was the discovery of the cosmic microwave background that ruled out the competing hypothesis, the “steady state” universe. As it often goes, the steady state hypothesis was then revised to accommodate the new data, but it is today considered summarily falsified, not just by the microwave background but also by what we know about the formation of structures in the universe.

This confusion between the expansion of the universe and the Big Bang Event becomes apparent, for example, just by looking at the Wikipedia entry for Big Bang. It starts out in the first paragraph referring to something called the “Big Bang theory,” and explains that this is the theory for the expansion of the universe. In the second paragraph, the Big Bang theory is distinguished from its extrapolation to the Big Bang singularity. But by the fourth paragraph the distinction has gotten lost, and we are informed, “A wide range of empirical evidence strongly favors the Big Bang, which is now essentially universally accepted.” The reader is misled to think that evidence for the expansion of the universe is evidence that the universe began with the Big Bang Event, which is incorrect.

It only adds to the confusion that the expansion of the universe is often conflated with a particular model for the expansion of the universe. In most cases, that’s the concordance model of the universe, sometimes also called the standard model of cosmology or ΛCDM—Λ being the cosmological constant and CDM standing for cold dark matter (call it Big Bang #3). However, there are a number of alternative models that give rise to a very similar expansion, for example a modification of gravity, which uses equations different from those of general relativity, but similar enough to reproduce the expansion.

So now the term Big Bang refers to three different hypotheses: The Big Bang Event that is the initial singularity, or whatever replaces it (no evidence); the expansion of the universe (extremely strong evidence); and a particular model for the expansion of the universe (largely compatible with evidence, but currently in some tension with data). Again, this confusion is exemplified on Wikipedia. If you scroll down in the Wikipedia article on the Big Bang, it turns into a discussion of the concordance model.

I have not seen or heard the term “Big Bang Theory” being used by a physicist in a seminar or paper for the expansion of the universe. If they refer to the expansion of the universe, they will either, well, just say “expansion of the universe,” or spell out which model for the expansion they are using.

Although the Webb telescope cannot tell us anything about the Big Bang Event and has not shed any doubt on the fact that the universe expands, it can tell us whether the formation of early galaxies is compatible with the concordance model, in particular with the hypothesis of dark matter. That’s because galaxy formation in a universe with dark matter is expected to proceed slowly and gradually. In this case, one does not expect young galaxies to be large. In a scenario with modified gravity, to the contrary, galaxies grow much faster—one does expect large galaxies at early times.

The tentative first evidence from the Webb telescope seems to show large galaxies at early times, which is a problem for the concordance model. However, the error bars on this data are currently large, and quite possibly the situation will change in the coming months. But at least for now, that’s the situation: Astrophysicists are both excited, and upset, that the Webb telescope data seem to cause trouble for the concordance model.

In the attention-grabbing article, “The Big Bang Never Happened,” Eric Lerner questions that the universe expands in the first place. His article was published in August by the Institute of Art and Ideas, a British organization that, by my own experience, prioritizes debate over scientific rigor.

Wikipedia exemplifies the confusion between the expansion of the universe and the creation event.

Lerner argues against the “cosmological establishment [that] has circled the wagons to protect this failed [Big Bang] theory with censorship,” presumably because Lerner has faced some difficulties in getting his alternative theory published. Under normal circumstances, an article that throws out a scientific theory that’s as well established as the expansion of the universe would have sunk to the bottom of the internet in about no time. But because of the confusion around the term “Big Bang,” Lerner’s claim has gathered traction. Lerner writes, for example, that the “images are blatantly and repeatedly contradicting … the Big Bang Hypothesis that the universe began 14 billion years ago in an incredibly hot, dense state and has been expanding ever since.” The images do no such thing.

It becomes clear, later in Lerner’s essay, that he is not attacking the Big Bang Event (which can reasonably be questioned) but the expansion of the universe. And because it is true that the Webb telescope has delivered data in tension with the concordance model, the reader (or editor) who does not know the difference, may get away finding Lerner’s piece reasonable.

But at least one popular article that debunks Lerner doesn’t clarify the debate but falls into the trap of conflating ideas. I can’t disagree with the headline, “No, James Webb Space Telescope Images Do Not Debunk the Big Bang,” but the explanation just contributes to the confusion.

“How did the universe come to be?” the article starts out. “The prevailing theory is everything that is began with the Big Bang. In a nutshell, the theory suggests everything, everywhere, all at once suddenly burst to life … The Big Bang theory is currently the best model we have for the birth of our universe.”

From the beginning, the article conflates the expansion of the universe with the creation event. Later in the article, the reader learns, “One of the chief reasons the Big Bang theory stands up is because of the cosmic microwave background.” But the cosmic microwave background emerged long after the Big Bang Event, if the Big Bang Event happened. The cosmic microwave background is merely evidence for the expansion of the universe, and that is, by itself, not enough evidence to single out a particular model for the expansion.

I am not particularly surprised by this debacle, having flagged this terminology confusion years ago. It can be cleared up by writers and scientists with a single rule. If you want to talk about the expansion of the universe, or a particular model for this expansion, then just spell out what you mean. And reserve the phrase “Big Bang” for the Big Bang Event. I understand the need to replace math with words when writing for non-experts, and “Big Bang” is a catchy term for sure. But we shouldn’t replace several different mathematical concepts with the same word. Using clear terminology benefits science communication and makes it harder for pseudoscience to gain hold.

Sabine Hossenfelder is a Research Fellow at the Frankfurt Institute for Advanced Studies where she works on modifications of general relativity, phenomenological quantum gravity, and the foundations of quantum mechanics. Her latest book is Existential Physics: A Scientist’s Guide to Life’s Biggest Questions. Follow her on Twitter @skdh.

Lead image: “Tarantula Nebula,” captured by the James Webb Space Telescope. (Learn more here.) Courtesy of NASA.

Evolution

- The Wizards of Mind Control

Evolution

The Wizards of Mind Control

How parasites manipulate the behavior of their hosts.

By Laith Al-Shawaf    September 7, 2022

What if some outside force could control your mind and make you act against your own interests? It’s a terrifying prospect—one that captures our imagination and recurs frequently in our fiction. It’s the goal of one of the three Unforgivable Curses in Harry Potter. It’s the purpose of Newspeak, the fictional language in George Orwell’s 1984. It enthralls in classics such as Brave New World and The Manchurian Candidate. In the 1950s, the CIA was so concerned that the communists had developed mind-control techniques that they launched their own secret program called MK-ULTRA, whose purpose was to use hallucinogenic drugs and biological manipulation to achieve mind control in ways that could be used against the United States’ enemies. It didn’t work—but mind control is real, and it can be observed in nature. Parasites do it all the time.

Parasites are organisms that live in or on other creatures, feeding on their hosts and taking their resources. They infect animals and pull their behavioral strings, manipulating them like marionettes. Such parasites are “essentially neuroengineers,” as one recent paper puts it, “capable of controlling the central nervous systems of the hosts they infect.”1 Their tactics are astonishing.

Neurochemical mind control is not just the stuff of science fiction.

Consider the fluke parasite Dicrocoelium dendriticum. It masterminds a cycle that starts in the liver of a hoofed animal—a cow or sheep. First, it lays eggs that end up in the animal’s digestive system. When the eggs are pooped out, a snail feeds on them. The parasite’s eggs hatch inside the snail’s intestines. Once the larvae are able, they drill through the snail’s gut into its digestive tract, where they become juveniles. The parasites exit when the snail excretes a ball of slime.

Ants then swallow the slime balls loaded with flukes. The parasite now needs its ant host to be eaten by a hoofed animal to restart the cycle—but this is a problem because hoofed animals eat grass, not ants. The parasite’s solution? Make the ant climb to the tip of a blade of grass and immobilize it there—in the exact location where it has the highest likelihood of being eaten by a grazing cow or sheep. But being in full view of the midday sun might scorch and kill the ant before it has a chance to get eaten. To solve this problem, the parasite makes the ant retreat down the blade of grass when it gets too hot. When the weather cools, D. dendriticum drives the ant back to the top after the risk of death by scorching has passed.

Not all parasites are microbial. Take brood parasites—birds that leave their eggs in other birds’ nests so that these abandoned eggs can be raised by unwitting foster parents. Some brood parasites use mafia-like manipulation strategies: If the host parents reject the foreign egg, the brood parasite will come back and punish the hosts by destroying their entire nest. In one study, researchers experimentally manipulated whether parasite (cowbird) eggs were rejected from host (warbler) nests, and found that cowbird parasites came back and destroyed 56 percent of rejector nests compared to only 6 percent of acceptor nests.2 The point of this parasite strategy is that it incentivizes compliance in the host parents: If the host tolerates one foreign egg, it will be allowed to raise several of its own offspring. If it rejects the foreign egg, it will lose all of its own offspring. The host is therefore pressured into tolerating parasite eggs. Researchers don’t yet know whether regular, non-brood parasites ever use similar “mafia-like” strategies to make their hosts fall in line.

ZOMBIE ANT: The fungus growing out of this dead ant’s head had taken over the insect’s mind, directing it to chomp down on a plant positioned over an ant trail, so that its spores might infect more victims. Photo by David Hughes.

The parasitic flatworm Euhaplorchis californiensis takes a more bizarre approach. Its mission: Infect a fish, hijack the fish’s mind, and coerce it into getting eaten by a bird, where the flatworm can complete its life cycle. The flatworm manipulates the fish into spending more time at the surface of the water—the perfect location for a fish who wants to become bird dinner.3 The parasite also has a second trick up its sleeve: It makes the fish repeatedly roll to the side and display its belly, which gives off a conspicuous silvery glint that catches the attention of predatory birds overhead.

How does E. californiensis do it? It sets up shop in the fish’s brain and alters its neurochemistry.4 Although the exact mechanisms remain to be discovered, evidence shows that the parasite modulates the fish’s levels of dopamine and serotonin—related to arousal and locomotion—inhibiting its natural response to stress. In essence, the parasite encourages the fish to remain mobile and conspicuous, which makes it more likely to get eaten by its predators. Neurochemical mind control is not just the stuff of science fiction. It’s a successful strategy that some parasites have turned into a finely tuned art.

Like E. californiensis, the flatworm Leucochloridium also manipulates its host into getting devoured by predators. This wily flatworm infects snails with artistic flair. To make its host look more like a tasty caterpillar—extra juicy and attractive to birds—the parasite turns the snail’s eye stalks into a throbbing, pulsating dance of color.

Parasites have more than one method of getting their way. Sometimes they manipulate their host into seeking the environment that they need to breed or to release their eggs. When a hairworm parasite infects a cricket, it spurs the cricket to do something shocking: commit suicide by jumping into water. This kills the cricket but benefits the worm: The parasite can now emerge from its cricket host and begin the next stage of its life cycle, which involves finding a mate and releasing its parasite eggs into the water. If you think this sounds too bizarre to be real, trust me, I’m sympathetic. But the evidence shows that this strategy—driving one’s host to a watery suicide—is so effective that it has evolved more than once among different lineages of parasites.

Parasitic fungi have a similar trick. Their manipulation doesn’t involve water, but it is equally dramatic. The fungus forces its infected ant host to climb to an elevated branch on a tree so that the ant can die where conditions are better for the parasite. From the parasite’s perspective, an elevated branch is the perfect vantage point from which to rain down fungal spores onto new hosts.

To appreciate how sophisticated this tactic is, it helps to know that ants are masters at stopping the spread of infectious disease. They quarantine diseased members of their group, and when a nestmate dies, they quickly remove the cadaver from the nest. By forcing infected ants to leave the nest and die elsewhere, the fungus manages to circumvent the ants’ quarantining practices. Because the infected ant dies outside home base, it becomes impossible for its nestmates to safely dispose of its corpse. Amazingly, this tactic—manipulating hosts into deserting their colony so they can die in a location that better suits the parasites’ needs—is so successful that it has evolved at least four times independently among living organisms.

Parasites outperform our most cutting-edge neuroscience when it comes to behavioral manipulation.

“There is something both unnerving and entrancing in the spectacle of an animal moving against its instinct to the drumbeat of a parasite inside its body,” write neuroethologist Frederic Libersat and his co-author David Hughes in a 2019 paper in Current Biology.1 “For biologists, the fact that such machinations have evolved repeatedly in the natural world offers us great opportunities to understand the why and how of manipulation and include such impressive adaptations into our framework for understanding evolution by natural selection.” Natural selection: the most marvelous of algorithms.

Another way for parasites to get from host to host is to infect an organism and use it as a vehicle or vector to help the parasite spread. The malaria-causing parasite Plasmodium has mastered this tactic. When it settles in mosquitoes, it interferes with their ability to drink properly. The point of this is that if the mosquito remains thirsty, it will need to draw blood from a greater number of hosts, which enables the parasite to get into more hosts.5

As for us, the parasite impairs our blood’s ability to clot, which helps it pass from our bloodstream into mosquitoes. Some studies suggest that the malaria parasite may even make infected people smell more attractive to mosquitoes. If true, it wouldn’t be the only species to do something like this: The parasite that causes Leishmaniasis, a tropical disease that can cause skin sores, alters the odor of its hosts, and the virus that causes Dengue fever manipulates genes in the mosquito’s antenna that affect its olfactory receptors, improving the mosquito’s sense of smell.6 Parasites may be small and invisible to the naked eye, but they are powerful manipulators.

THE SLY DR. WASP: The jewel wasp Ampulex compressa can perform neurosurgery on a cockroach to make it docile, which allows the wasp to walk the roach back to its den, to use as food for its hatchlings. Photo by Scadidi / Shutterstock.

Another parasitic route is a favorite among wasps: Spend some time maturing inside your host, emerge when you’re ready, lay your eggs nearby, then manipulate the host into taking care of you and your offspring.7 Parasitoid wasps use this classic strategy, or a variant of it, with their spider and caterpillar hosts. In some cases, the wasp makes its host act like a bodyguard. A 2008 study finds that after the wasp larvae leave the host to pupate, “the host stops feeding, remains close to the pupae, knocks off predators with violent head-swings, and dies before reaching adulthood.”8

In other cases, the wasp turns its host into a zombie construction worker. The hijacked spider or caterpillar works hard to weave a web or a cocoon that protects the wasp and its offspring rather than the host—only to be killed as soon as it’s done weaving! In a 2000 study published in Nature, behavioral ecologist William Eberhard shows “the mechanism employed by the larva to manipulate the spider’s behavior is fast-acting, apparently chemical, and has long-term effects.”9

An important caveat: When infected hosts engage in weird behavior, it isn’t always due to parasitic manipulation. Consider a host that gets infected and then moves to a new microhabitat. This could be manipulation: The parasite might need the new habitat to enter its next life stage, as with the hairworm that emerges from the cricket in water. However, infected hosts often seek hotter microhabitats in order to kill the parasites infecting them.10 To kill foreign invaders, warm-blooded animals will often run a fever, whereas cold-blooded animals use external heat sources to raise their body temperature—by seeking a hot rock in the sun, for example. Both strategies successfully kill parasites.11

The upshot is that when infected hosts behave strangely, we can’t automatically infer parasitic manipulation. Weird post-infection behavior could be one of three things: parasitic manipulation, a simple byproduct of illness, or an adaptive host response to infection, as in the fever example above.7 Because all three possibilities are real, biologists try to be as careful as possible when disentangling the alternative interpretations.

It’s pretty clear, though, that the jewel wasp Ampulex compressa is achieving mind control with the little act of neurosurgery it perpetrates on its cockroach victim. The wasp locates a specific region of its cockroach host’s brain and injects it with a neurochemical cocktail that seems crafted for a specific purpose. The wasp’s precise injection doesn’t paralyze the roach, but it does rob it of its will to escape—a distinction crucial to the parasite’s success.12 If the roach were paralyzed, it would be too big for the wasp to drag. Because the roach is not paralyzed, the tiny wasp is able to drag it, and the victim moves along helpfully like a trained animal on a leash. In this way, the wasp takes the zombie roach to its den, lays an egg on its victim, and buries it alive. Throughout this entire macabre process, the roach shows no interest in escaping. By using neurosurgery to rob the roach of its will to escape—but refraining from physically paralyzing it—the wasp has crafted the exact solution it needs.

The solution is so precise it’s shocking. But maybe it shouldn’t surprise us that parasites outperform our most cutting-edge neuroscience when it comes to behavioral manipulation. After all, evolution has given them a millions-of-years-long head start.

Laith Al-Shawaf is an associate professor of psychology at the University of Colorado in Colorado Springs. Follow him on Twitter @LaithAlShawaf.

Lead image: Rvector / Shutterstock

References

1. Hughes, D.P. & Libersat, F. Parasite manipulation of host behavior. Current Biology 29, R45-R47 (2019).

2. Hoover, J.P. & Robinson, S.K. Retaliatory mafia behavior by a parasitic cowbird favors host acceptance of parasitic eggs. Proceedings of the National Academy of Sciences 104, 4479-4483 (2007).

3. Lafferty, K.D. & Morris, K.A. Altered behavior of parasitized killifish increases susceptibility to predation by bird final hosts. Ecology 77, 1390-1397 (1996).

4.  Shaw, J.C., et al. Parasitic manipulation of brain monoamines in California killifish (Fundulus parvipinnis) by the trematode Euhaplorchis californiensis. Proceedings of the Royal Society B 276, 1137-1146 (2009).

5. Lefèvre, T., et al. Chapter 3 Invasion of the Body Snatchers: The diversity and evolution of manipulative strategies in host-parasite interactions. Advances in Parasitology 68, 45-83 (2009).

6. Staniek, M.E. & Hamilton, J.G.C. Odour of domestic dogs infected with Leishmania infantum is attractive to female but not male sand flies: Evidence for parasite manipulation. PLoS Pathogens 17, e1009354 (2021).

7. Poulin, R. Chapter 5 – Parasite manipulation of host behavior: An update and frequently asked questions. Advances in the Study of Behavior 41, 151-186 (2010).

8. Grosman, A.H., et al. Parasitoid increases survival of its pupae by inducing hosts to fight predators. PLoS One 3, e2276 (2008).

9. Eberhard, W.G. Spider manipulation by a wasp larva. Nature 406, 255-256 (2000).

10. Moore, J. The behavior of parasitized animals. BioScience 45, 89-96 (1995).

11. Neese, R.M. & Williams, G.C. Why We Get Sick: The New Science of Darwinian Medicine Vintage Books, New York, NY (1996).

12. Al-Shawaf, L. The why is not the same as the how: Levels of analysis and scientific progress in psychology. Areo (2020).

Genetics

- A Universal Cancer Treatment?

Genetics

A Universal Cancer Treatment?

A medicine that disrupts the DNA replication of cancer cells may be within reach.

By Lina Zeldovich    October 5, 2022

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Himanshu Brahmbhatt was staring at the results of a clinical trial that looked too good to be true. A co-founder and CEO of EnGeneIC, a biopharmaceutical company, Brahmbhatt was running a small trial that was testing a fundamentally different approach to fighting cancer. Patients in the group had grim prospects. They had exhausted all other options. With nothing left to lose and not expecting any miracles, they enrolled in the trial. They wanted to give it one more chance. Now their scans showed their tumors had stopped progressing. Even more remarkable was they didn’t have the same type of tumors. They had malignancies affecting different organs—lungs, bladders, colons, pancreases—and yet, they uniformly did well.

“These people were facing death,” Brahmbhatt says. “Then we started seeing that they were actually succeeding. You could see in the scan that the tumor has stopped growing. It was a feeling of such extreme internal joy that it’s very difficult to describe.”

The results may have appeared miraculous, but they were anything but. They stemmed from fundamental research into cell division that forms the basis of the EnGeneIC process. A longtime advisor to the company, Bruce Stillman, professor of biochemistry and president and CEO of Cold Spring Harbor Laboratory, has been studying the process of DNA replication, which plays a key role in cell division and cancer progression.

DNA DETECTIVE: Bruce Stillman has devoted his career to studying DNA replication. He believes that cell division, and DNA replication in particular, are key targets for treating cancer. Photo courtesy of Cold Spring Harbor Laboratory.

“Cancer cells multiply out of control,” says Stillman, who has devoted his career to studying DNA replication. “When a cell becomes a cancer cell, the very first thing that happens is the cells begin to divide without the normal controls. And the first thing that has to happen before the cell has to divide into two daughter cells is to copy the genome. So, the path that leads to cancer is in part dysregulation of the process that controls DNA replication.” The abnormal DNA replication causes the accumulation of mutations in the genome that advances cancer. Interfering with the process of cell division has long been a focus for treating cancer, but because normal cell division is unavoidably affected also, many of these chemotherapies are toxic. EnGeneIC has figured out a way around this problem by combining a novel method of drug delivery with a way to stop DNA replication.

Stillman was a graduate student when he understood that cell division, and DNA replication in particular, were key targets for treating cancer. That insight inspired him to switch careers from medicine to medical research. At the time, the science of DNA was a burgeoning field and there was a lot to discover; Stillman was a pioneer. He uncovered many of the mysteries of the genome replication process and what sets the copy machinery in motion. He has spent 40 years putting together the pieces of the molecular puzzle. “I wanted to understand how this process really works,” he says. And he did.

Deep inside the tens of trillions of cells that comprise your body, the DNA replication machinery is constantly speeding along in many tissues. In the bone marrow alone, 500 million red and white blood cells are produced every minute. There’s about two meters of DNA in each cell, neatly woven inside the nucleus. To keep the blood cell supply steady, about a billion meters of DNA must be copied every minute. “You could wrap that around the Earth along the equator about 25 times,” Stillman says. It is inevitable that over the course of a person’s lifetime, this process will make mistakes—some harmless, but others leading to malignant mutations. So, understanding the cogs of this complex machinery may hold the key to combating many cancers.

Stillman and his team discovered that the replication process starts with a set of six specific proteins called Origin Recognition Complex, or ORC. The proteins bind to the DNA at specific locations and recruit more proteins to help, forming what’s called the pre-replicative complex. This pre-replicative complex “gives permission” to start DNA replication and many proteins begin copying the genetic material from their respective starting points. Once the job is finished, the pre-replicative complex is destroyed. Once the cell is ready to divide again, the complex is formed anew.

They sent a Trojan horse into cells and turned cancer’s own trickery against it.

Stillman’s group first discovered the ORC in yeast, experimenting with a strain called Saccharomyces cerevisiae, normally used to make bread, wine, and beer. (Notably, in 2020, he won a Heineken Prize for Biochemistry and Biophysics for his work, although it didn’t have anything to do with brewing—the prizes are awarded to the leading figures in the above disciplines as well as in art, medicine, history, and environmental and cognitive sciences.) As Stillman’s team kept studying the ORC phenomenon, they realized this ancient process works very similarly in humans. “It’s remarkable to think that yeast and humans share the same process of DNA replication,” Stillman says. “We started off with yeast cells and we were able to walk through evolution and eventually get to the human genes.”

Another key player in DNA replication is an enzyme called DNA polymerase. DNA polymerases synthesize the new DNA by adding nucleotides—the gene building blocks—one by one to the growing DNA chain. “There are about 15 polymerases involved in this procedure,” Brahmbhatt says. “Each of these polymerases does a different job inside that DNA replication process.” If some of them stop working, the cell won’t be able to divide.

Knowing the key points in DNA replication has allowed scientists to ponder ways to jam the copying gears inside the rogue cells. At the biochemical level, gear-jamming isn’t an insurmountable task—today scientists can forge a small molecule that can bind to some of the players and “disable” them. The real challenge was to deliver these molecules inside the cancer cells and no others. If these molecules ended up inside healthy cells, they would halt the normal replication processes, killing the cells—and the person with them.

Scientists know cancers have an uncanny ability to travel through the body by slipping in and out of blood vessels to hitch a ride through the bloodstream. They do it by loosening the arterial walls and squeezing through. “Normally, our blood vessel walls are all sealed pipes,” Brahmbhatt says. “But around wherever the cancer is growing, the blood vessels are known to be very defective. They have got a lot of holes in them.”

Brahmbhatt and his collaborator Jennifer MacDiarmid devised a clever ploy. They would send a Trojan horse into malignant cells and turn cancer’s own trickery against it.

The Trojan horse, in this case, is a product of a harmless bacteria that’s been genetically engineered to have specific qualities. When this genetically engineered bacteria divides, it yields a tiny non-living cell of 400 nanometers in diameter—the right size to slip through the damaged vessels and mingle with the tumors. To the nano-cell, Brahmbhatt and MacDiarmid affixed a “molecular hook” that the tumor grasps and swallows. The nano-cell is also packaged with “interfering” RNA molecules—distant relatives of the RNAs used to create the first coronavirus vaccines. Known as siRNAs, the molecules interfere with the expression of specific genes. They can target some of the DNA replication enzymes and inhibit their function. Brahmbhatt says Stillman provided invaluable advice about which polymerases to target to kill malignant tumors.

It was a feeling of such extreme joy that it’s difficult to describe.

Brahmbhatt and MacDiarmid tested the nano-cell assassins in mice and then in a small human trial. “There was a big fear at first,” Brahmbhatt says. “Everybody was frightened because these molecules have never been sent specifically into a human, and everybody knew that if this thing gets into the wrong cells—meaning into the normal cells—it could be fatal.” That’s why the study’s first cohort included only people who had exhausted all other options.

When he looked at the first set of scans, Brahmbhatt recalls, “what we saw was something fantastic. With these molecules, which are inhibitors of DNA replication, we could extend their lives.” More surprising was the fact that—unlike systemic chemotherapies—there were no toxic side effects. Currently Brahmbhatt’s company, EnGeneIC, is preparing for the next phase of clinical trials.

Should the siRNA method prove its worth in larger trials, the public health impact will be much greater than just putting another anti-cancer compound on the market. Stunting DNA replication has the potential to become cancer’s universal treatment. The research Stillman did, as well as others who chose to study the fundamental biology of DNA replication, is now not only bearing fruit, but—combined with the right delivery system—has the potential to change the cancer treatment paradigm. And that’s the beauty and importance of the fundamental research, without which modern clinical applications would be impossible. “Today, those discoveries have become critical,” Brahmbhatt says. “If this works, we won’t just cure one type of cancer. We would cure cancer across the board.”

Lead image: Bawan / Shutterstock

- Lina Zeldovich

Posted on October 5, 2022

Lina Zeldovich grew up in a family of Russian scientists, listening to bedtime stories about volcanoes, black holes, and intrepid explorers. She has written for The New York Times, Scientific American, Reader’s Digest, and Audubon Magazine, among other publications, and won four awards for covering the science of poop. Her book, The Other Dark Matter: The Science and Business of Turning Waste into Wealth, was published in 2021 by Chicago University Press. You can find her at LinaZeldovich.com and @LinaZeldovich.

Health

- What Can Night-Shift Workers Do to Feel Better?

- Targeting Cancer’s Achilles Heel

Health

What Can Night-Shift Workers Do to Feel Better?

One question for Sarah Chellappa, a neuroscientist at the University of Cologne.

By Brian Gallagher    September 20, 2022

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One question for Sarah Chellappa, a neuroscientist at the University of Cologne who studies how sleep and circadian rhythms affect human mood, cognition, and brain activity.

Photo courtesy of Center of Environmental Therapeutics

What can night-shift workers do to feel better?

Our findings suggest that meal timing is important for mood. That’s why we titled our new study, published in the Proceedings of the National Academy of Sciences, “Daytime eating prevents mood vulnerability in night work.” It may be helpful if night workers reconsidered the amount of calories, and especially carbohydrates, consumed in the nighttime. Shift workers often experience circadian misalignment, the misalignment between their central circadian clock in the brain and daily behaviors, such as sleep/wake and fasting/eating cycles. They also have a 25 to 40 percent higher risk of depression and anxiety. Meal timing is important for physical health, and diet is important for mood. That’s why we wanted to find out whether meal timing can benefit mental health as well.

We used a stringently controlled 14-day laboratory protocol. Because of that, it is challenging to make a direct translation of our daytime meal intervention to meal schedules in real-life shift workers or patient populations. More is needed to establish if meal timing interventions can prevent depressed and anxious mood states in shift workers, who account for up to 20 percent of the workforce in industrial societies and are directly responsible for many hospital services, factory work, and other essential services.

We enrolled 19 participants (12 men and 7 women) in a laboratory study that included four 28-hour “days.” By the fourth “day” their behavioral cycles were inverted by 12 hours, simulating night work. That caused their circadian clocks to misalign. We put some of the participants in a control group, which had meals according to a 28-hour cycle. This resulted in them eating during the night and day, as night workers often eat. The other group had meals on a 24-hour cycle. So, eating only during the day. We found that during the simulated night shift (day 4), those in the first group, the control, had more depression-like and anxiety-like mood levels, compared to baseline (day 1). However, no such worsening of mood levels happened during the simulated night work in the group that ate only during the day. And those who had a greater degree of internal circadian misalignment, the misalignment between endogenous circadian rhythms in the body, experienced more depression- and anxiety-like mood.

What potential mechanisms might underlie that association, between daytime eating and mental health? We previously showed in the same laboratory experiment that participants who ate in the night and day had more glucose intolerance during the simulated night shift. No such changes happened during the simulated night work in the group that ate just during the day. Because high glucose levels are associated with depression, the beneficial effects of daytime eating on glucose tolerance may extend to mood perception.

Lead image: Mariusz Zawadzki / Shutterstock

- Brian Gallagher

Posted on September 20, 2022

Brian Gallagher is an associate editor at Nautilus. Follow him on Twitter @bsgallagher.

Health

Targeting Cancer’s Achilles Heel

Biden’s Cancer Moonshot aims to cut annual deaths in half. Scientists have the goal in their sights.

By Lina Zeldovich    September 9, 2022

Explore

Matthew Weiss dreams of the day when his oncology practice will operate very differently. A surgeon at the Northwell Health System in New York who treats pancreatic cancer—one of the deadliest malignancies known—he doesn’t have a lot of choices when it comes to saving his patients. Some people with pancreatic tumors die within a few weeks and others fight longer, but only 11 percent of them are still alive five years later.1 Current treatment options are limited. There are only two treatment paradigms, one based on a cocktail of two chemotherapy drugs and another one based on three, but doctors never know which one will work. “We may as well flip a coin when we decide which regimen to use,” says Weiss. “We have no way to predict who’s going to respond to what chemotherapy.”

Doctors can of course switch from one regimen to another if the initial performs poorly. But it takes a few months to determine whether tumors are shrinking or not, and patients don’t have that time. Moreover, the initial chemo may sicken some to the point that they are too weak to try the second approach. To make things worse, the incidences of pancreatic cancer, once considered rare, have increased in the past 20 years, now reaching over 60,000 cases annually in America alone.2 “About 1 in 50 to 60 people get it, and most of them don’t survive it,” says David Tuveson, cancer biologist at the Cold Spring Harbor Laboratory and director of CSHL’s Cancer Center. “It used to be rare, but it’s not anymore. It is now the third most common cancer, behind lung and colon, and predictions show that it’s going to take the number two spot soon.”

To battle cancer better, treatment should be tailored to patients’ individual needs.

Even more concerning is the fact that pancreatic cancer now strikes early, afflicting a greater number of young people, particularly women under 35.2 “I saw a patient yesterday morning who is 41 years old, with pancreatic cancer and three young children at home,” Weiss shares. With an average prognosis of about five years to live, it’s a family tragedy. “Five years is not enough, so to me pancreatic cancer is an emergency,” Weiss says. “We have to do things radically different.” Treatment must take guessing out of the process.

Weiss dreams of having a way to test the regimens before placing people on them. For the past few years, he has been working on making this a reality in collaboration with Tuveson. Their method involves trying the chemo cocktails on pancreatic tumors outside the patient who developed them. In scientific terms such outside tumors are called organoids. They’re grown from the small chunks of cancer cells biopsied from patients as part of the diagnosis. Because they retain the characteristics and mutations of the original tumor, their behavior when grown in a lab may predict their behavior inside their human host, including the reaction to the two chemo cocktails oncologists use to treat pancreatic cancer.

If the method works, it will improve patients’ current survival chances. But the idea has far-reaching potential. It may revolutionize how doctors treat cancers in the 21st century.

Cancers are tricky. Patients respond differently to the same treatments. One beats cancer and the other dies quickly. To battle cancer better, the treatment should be tailored to patients’ individual needs—the so-called personalized medicine concept that has taken a center stage in cancer care. Organoids, combined with the genomic data from patients, might provide that much-needed personalized care. These little living tumors can also inform scientists how cancer develops, what changes it causes in the body in early and late stages, and how it plays out in people of different ethnic origins. That can shift not only the treatment approaches, but the entire cancer care paradigm.

In February 2022, President Joe Biden rekindled his Cancer Moonshot effort, which aims to end cancer as we know it. The initiative set several goals, including reducing death rates by at least a half in the next 25 years while improving the quality of life for those battling the disease. Currently, cancer kills about 600,000 Americans a year, so cutting it in half is a multi-pronged challenge. “The White House announcement makes you think, ‘What do we need to do to achieve that?’” Tuveson says. He sees the three pillars of success as better prevention, better detection, and better treatment.

WATCH ITS BEHAVIOR: This human tumor “organoid” line was derived from a biopsy of a liver metastasis of a pancreatic cancer. Because an organoid retains the characteristics and mutations of the original tumor, its behavior when grown in a lab is opening a new window for scientists on how a tumor functions in a body, and how to better treat cancer. Image courtesy of Caitlin Tsang.

Better prevention begins with understanding cancer triggers, which in case of the pancreas can begin in the complex interplay of the digestive organs. Your stomach digests food and absorbs the nutrients needed to sustain the body, but it can’t do all this hard work alone. It does it in concert with the other neighboring organs, including the pancreas and the liver. The banana-shaped pancreas produces the hormones insulin and glucagon, which regulate levels of blood sugar. It also makes the digestive enzymes amylase, protease, and lipase, which respectively break down starches, proteins, and fat. Once made, these enzymes pour through the pancreatic ducts and into the upper part of the small intestine, called the duodenum, where they help digest food. The liver aids with fat breakdown by producing bile, which accumulates in the gallbladder, and then trickles into the stomach via bile ducts. “Bile is like soap, a green, greasy material that dissolves fat,” explains Tuveson.

This normally well-oiled machinery can get thrown off track by inflammatory processes. One of them is pancreatitis—an inflammation of pancreatic tissues, which can be caused by solidified bile, more commonly called gallbladder stones. “Sometimes when a stone passes from the gallbladder into the intestines, it may go the wrong way and get stuck in the pancreatic ducts, making the pancreas swell like a balloon,” Tuveson explains. “Now the enzymes can’t get out, so they start digesting the pancreas itself. And we don’t know why, but almost everybody who develops pancreatic cancer has had either symptomatic or silent pancreatitis before it happens.” Other things like alcohol overuse, smoking, obesity, and certain medicines can trigger pancreatitis also, which can increase cancer risk. “Many more patients develop pancreatitis than pancreatic cancer, so if we can prevent pancreatitis, we will probably also decrease the number of people who develop pancreatic cancer,” Tuveson says.

Organoids might help decipher the differences in cancer behavior between various ethnic groups, says Jeff Boyd, who directs the Northwell Health Cancer Institute’s Center for Genomic Medicine, while also holding a professorship at Cold Spring Harbor Laboratory. For example, pancreatic cancer outcomes are worse for African American and Latino people compared to those of European descent. It could be because of diets, pollution, or lifestyle—or due to some biological differences in the pancreatic cells. Organoids may hold the answers. “We’ve been trying to study the disparity of pancreatic cancer by culturing pancreas cancer organoids from individuals of European ancestry, African ancestry, and Hispanic ancestry,” Tuveson says. “So that we could investigate if there’s any fundamental difference in the biology of tumors from patients of different racial and ethnic backgrounds.”

Better detection requires better imaging procedures or specialized blood tests, neither of which clinicians have right now. Scientists know that an intraductal papillary mucinous neoplasm (IMPN)—a tiny growth arising from the duct lining—can be a precursor for pancreatic cancer, but spotting them early is difficult. Hidden behind the intestines, the pancreas is very hard to image, even with the modern MRI and CT machinery. It doesn’t help that the pancreatic tumors are usually microscopically small, compared to, for example, an intestinal polyp that gastroenterologists can identify with a naked eye. “An early pancreas tumor is the size of a grain of rice or even smaller,” Tuveson says, so they are easy to miss on a digital image. Inserting a camera scope into the pancreas through its very narrow ducts is an impossible feat because it would stop the flow of enzymes, which would immediately start digesting the pancreas’ own tissues. A smarter way would be to develop a blood test that checks for certain compounds which a precancerous pancreas may produce, but so far scientists don’t know of any.

Organoids give clinicians the flexibility to experiment.

That’s another problem Tuveson is trying to solve with organoids. His team grows IPMN organoids of these “early cancers” and implants them into the pancreatic ducts of mice, trying to see if this would spark any changes in the animals’ blood composition. Tuveson is also using mice implanted with IPMN cells to test new ways to image tiny tumors. “We’re growing early human cancers inside the duct of a mouse pancreas, so that we can find new ways to look for evidence in blood or develop new ways to image the cancer,” he says. “We use organoids in these futuristic kinds of approaches as a way to develop early detection methods.”

Better treatment is where organoids really get their chance to shine. And to some extent they are shining already, as a part of a bigger multi-institute and international effort—a clinical trial called PASS-01, which stands for Pancreatic Adenocarcinoma Signature Stratification for Treatment. When Weiss takes a biopsy, he sends the little cancerous bits to Tuveson’s laboratory where they are grown into organoids in petri dishes. Then, Tuveson’s lab subjects the patient’s organoids to both chemo regimens, noting which one kills cancer more efficiently. Meanwhile, Weiss’s colleagues treat the patient on the chemo regimens. After a while, they compare results and see whether the patients’ tumors and the organoids reacted to treatment the same way. The team hopes to use this clinical trial to show the first scientific proof that organoids can indeed predict how tumors will respond inside the human body.

At this early clinical stage, the two collaborators aren’t using the organoids to decide which treatment to prescribe—they are only trying to establish the correlation. But so far, the results are encouraging. “We have a series of anecdotes that are promising,” Tuveson says. “And when you line up a bunch of anecdotes, you suddenly have a trend.” When the trend continues, and there are enough cases to undergo rigorous statistical analysis, one now has a case for the next level of a clinical trial: Using organoids to predict the best therapy and then treating the patient with it.

Another gift that organoids would give clinicians is the flexibility to experiment. With cancers in a dish, doctors can experiment all they want. They can alter drug ratios, such as decreasing the dose of a more toxic drug and see if the cocktail works just the same. They can swap one drug for another, including those not normally used in the current regimens, and see if it works better. And they can add another medication that’s not typically used for pancreatic cancer at all—and see if that does any miracles.

Tuveson likens the approach to shooting arrows at the enemy and finally finding its most vulnerable spot. “What we are doing is essentially looking for the cancer’s Achilles heel,” he says. And with the ability to test all kinds of approaches on organoids grown in a dish, there’s no limit to the number of arrows scientists can shoot. Oncologists will be able to do all the trial and error in a dish, sparing their patients from the chemo side effects, lost time, and diminishing recovery chances.

Weiss and Tuveson hope to see the decades-old treatment concepts change within a few years. “Treating cancer should work similar to treating infections,” Tuveson says. If you have a bad infection, the doctors may prescribe broad-spectrum antibiotics at first, but at the same time they also send your blood and urine tests to the lab and wait to see what bug you have. Once they know the exact culprit, they often change the meds to the most efficient antibiotic against it. “I’d like for the organoids to do the same—use them as a kind of a bacteriology test for cancer that will tell us the best way to kill it,” Tuveson says. “I’m optimistic that they can point us to cancer’s Achilles heel.”

Lead image: Le Panda / Shutterstock and Hunky / Shutterstock

References

1. Post, E. Five-year pancreatic cancer survival rate increases to 11%. pancan.org (2022).

2. Gaddam, S. Incidence of pancreatic cancer by age and sex in the US, 2000-2018. Journal of the American Medical Association 326, 2075-2077 (2021).

- Lina Zeldovich

Posted on September 9, 2022

Lina Zeldovich grew up in a family of Russian scientists, listening to bedtime stories about volcanoes, black holes, and intrepid explorers. She has written for The New York Times, Scientific American, Reader’s Digest, and Audubon Magazine, among other publications, and won four awards for covering the science of poop. Her book, The Other Dark Matter: The Science and Business of Turning Waste into Wealth, was published in 2021 by Chicago University Press. You can find her at LinaZeldovich.com and @LinaZeldovich.

Microbiology

- What We Really Are Is an Agglomeration of Cells

- The Big Thinker

Microbiology

What We Really Are Is an Agglomeration of Cells

Siddhartha Mukherjee sings the praises of the cell to offer us a holistic portrait of life.

By Michael Denham    October 12, 2022

During a “mid-pandemic limbo,” Siddhartha Mukherjee decided to build his own microscope. He had to see what the 17th-century Dutch cloth merchant Antonie van Leeuwenhoek saw when he looked at a raindrop under one of his self-built microscopes and found tiny creatures he called “animalcules.” Simply writing about the founder of microbiology in his new book, The Song of the Cell: An Exploration of Medicine and the New Human, wasn’t enough. After scrapping dozens of prototypes, he finally constructed a workable contraption. Mukherjee—a Pulitzer Prize-winning author, medical oncologist, and associate professor of medicine at Columbia University—used his homemade device to glimpse cells in a drop of rainwater. “The drop came sharply into view,” he writes in The Song of the Cell, “and then a whole world within it.”

The Song of the Cell, out on October 25, is Mukherjee’s fourth book. His first book, The Emperor of All Maladies: A Biography of Cancer, won the 2011 Pulitzer Prize in General Nonfiction as well as the Guardian First Book award. The renowned filmmaker Ken Burns adapted The Emperor of All Maladies into a documentary, and when Mukherjee wrote The Gene: An Intimate History, in 2016, Burns adapted that, too. When he’s not writing stories for The New Yorker, Mukherjee works clinically and conducts research in cancer cell biology and treatment, including ongoing clinical trials examining how dietary management may play a role in cancer care.

So naturally our conversation ranged widely over Mukherjee’s many occupations. Sporting a head of tousled hair and a slightly unbuttoned black shirt, he spoke to me over Zoom about how his new book explores, in a series of scientific, historical, and personal narratives, the role cells play as a primary element of life. We also discuss what motivated him to train his attention on cells, the relationship between lowbrow tinkering and highbrow science, whether science writing is a form of literature, the limits of cancer genetics, the impact his popular writing has had on his colleagues, and how often it is that useful scientific ideas come up informally and spontaneously at the dinner table.

FANTASTIC VOYAGE: Siddhartha Mukherjee says that as you get deeper and deeper into the workings of the cell, “you begin to realize what a fantastic thing there is in this integrating machine.”

How did you decide that cells would be the focus of your new book?

From The Gene onward, I’ve been thinking more and more about how to move upward—and by upward I mean from a more reductive approach to a more holistic approach. The gene and DNA have been iconographic elements of ourselves for a century. But a gene is lifeless without a cell. It’s a molecule. It’s the cell that allows the integration of information, that emerges from the genome and integrates that information to create function. And function is the basis of physiology.

The cell is many machines. The first thing is that it’s an information-decoding machine. The second is that it’s an information-integrating machine. And then it’s a dividing machine. It integrates information, divides, and perpetuates that so that you can form a multicellular organism.

And the time had come to pan back even more beyond that iconographic description of human beings as an agglomeration of genes and DNA, to what we really are, which is agglomerations of cells, which interpret DNA, integrate signals, and create everything that’s functional about ourselves, our metabolics and our capacities.

So I’m climbing toward a more accurate and complete description of human biology and human physiology. I draw from Rudolf Virchow’s statement that until you understand this all this way upward, you will never be able to locate or understand the locus of disease. And if you can’t understand the locus of disease, you will always be behind in your understanding of how to cure, treat, or prevent it.

You tell us that statement by Virchow is pinned to a board in your office. “Every disease depends on an alteration of a larger or smaller number of cellular units in the living body, every pathological disturbance, every therapeutic effect, finds its ultimate explanation only when it’s possible to designate the specific living cellular elements involved.”

Cancer is one example of this. We’ve been somewhat monomaniacally focused on cancer genetics, which has a very important place in all of this. But cancer isn’t just mutated genes. There is a cell biology, there’s a cell behind it, and there’s a human beyond that cell. And there are mysteries of cancer that you cannot solve by decoding the cancer genome. Why the spleen isn’t a site of metastases, whereas the liver—which is just next to it, is the same size, has the same flux of blood—is among the most frequently cited metastases. There’s nothing in the genome, as far as I can tell, that will tell you that by reading the code, and yet that question is of great clinical importance. There’s nothing in the genome, that I can read at least, or we can read now, that tells you how a brain figures out its multiple functions—regulation, sentience, cognizance. The answer lies somewhere in cell biology and maybe beyond cell biology.

It’s wonderful we know so much about genetics. But there is a post-genetic world. Which brings me back to the word “holism.” I mean the word holism very carefully. I mean that we need to integrate all the information that we’ve gathered from genetics, from ecology, from other kinds of biological investigation. It’s only when we integrate that information that we can understand how the human body is built in normalcy, and how the human body goes wrong in the context of illness.

DNA has been our iconographic element. But a gene is lifeless without a cell.

The Song of the Cell progresses from an understanding of the cell as a building block to examining what they construct, such as organs, tissues, and blood. What’s important about this concept of no cell being an island?

It’s structurally organized in a very unusual way. When you write about medicine, chronology is your friend. And you write a story chronologically because you can. These discoveries follow on discoveries, and then there’s a kind of intellectual chronology that you can construct.

But this book is organized differently. In every chapter there’s a historical prelude, and there is a future postlude or interlude. But in the middle, every chapter builds on some property that is acquired by cells and systems of cells. That is my broad takeaway message. The cell in its environment becomes a unit, acts as a unit, but also acts in collaboration and cooperation with other cells to create physiology, to create the things that we find so magical and fantastical about organisms. And as you get deeper and deeper into it, you begin to realize what a fantastic thing there is in this integrating machine.

You’ve written articles in The New Yorker touching on this theme in different ways. Did they lead to The Song of the Cell?

Yes. When I wrote a piece about cellular therapy, I kept coming back to the idea that it was the cell that was the integrator of all this physiology. And so that’s where I began to really think about the cell as that master integrator, and cell-cell interactions as the basis of physiology. I began to think about the future and the new human. You have people who are being infused with modified cells, altered cells, cells whose behaviors we’ve changed, cells whose physiologies we’ve changed in order to effect new ways of thinking about cancer. So in terms of medicine describing human life, it felt as if all of these were pointing to the same direction, which is the direction of the cell.

If you’re moving up the ladder of complexity, what’s the next rung?

That rung is metabolism, integration, and potentially behavior. And how understanding those, how cells interact with each other, and how, at the largest level, how humans interact with each other, will perhaps be the last of these rungs. Gene-cell-environment-behavior would be the last step. Dissecting that last piece is going to be the hardest because it’s the least known. Questions like why, even after we know that smoking cessation causes enormous health benefits, can we not get half the world to stop smoking? Obviously, there’s an addictive component to that. But there are social components to that. There are network effects in that. Same for metabolism—metabolism isn’t something that happens as a consequence of one gene.

Writing is a mechanism to understand and express ideas. I write to think.

You write, “Highbrow science was born from lowbrow tinkering.” Is there still a place for lowbrow tinkering in the practice of modern science?

For me, it’s very much about beginning with very lowbrow things, just looking at cells, looking at how they interact. The first experiments that I design when I design a new experiment are usually extraordinarily simple. Let’s put this and this together and see what happens. And then we go into much more complex things like data analysis, genomics, and proteomics. But it’s not as if I’m coming home and thinking, Oh gosh, let’s apply proteomics to this cell. What I’m coming home thinking is something very simple, like how can we genetically manipulate an immune cell to make a cell that becomes super phagocytic? We’re studying bone a lot. What does it look like? What does an arthritic bone look like under the microscope? That’s where I begin all my experiments. As a cell biologist or virologist, I begin just by looking. And the first thing I do is try to see, what is it about these things? What is special? What’s different? And, how can I manipulate it if I can? And what will be the result of manipulating any of this?

You might argue that there’s still a seamless transition from dinner table conversation to actual work going on in the laboratory.

It’s very important to have that dinner table conversation. That’s why scientists still meet in person. There’s a saying that most of the best science in the meetings is done off the meetings. That’s when people really begin to think about ideas and collaborations, that wheels begin to turn. It’s certainly been true for me.

Faeth, a company that I launched with Lew Cantley, which uses metabolism as a mechanism to deal with cancer, was launched because we’re out to dinner and Lew took a paper napkin, and started drawing. And we were drawing together. It’s not like Lew said to me, “Gosh, you know, I’ve done this massive transcriptomic blah, blah, blah, blah, blah, on cells. And I think that this is the case.” It was just a doodle. We did experiments after that. We started with simple experiments, went on to very complex experiments, and finally went on to do transcriptional analysis and find mechanisms and so forth. Again, different scientists are different. But for me it begins at a very simple place.

The golden goal is always going to be, “How can we alleviate suffering?”

How do you understand your role as a science communicator?

In some ways, I don’t think of myself as a science communicator, although of course I am. I like communicating about science. I think of myself as someone who tries to describe the process. And of course, that’s a form of communication—it would be silly to say that it was not—but I try to describe the process. And the hope is that in describing the process, I capture something about the way science is done, the human affair of it—the frustrations of it, but also the wonder of it—in a way that you couldn’t do otherwise. It’s not like I sit down and say, “I’m going to communicate this idea.” It’s more like, “Here’s something that I’m very excited about. And if I’m very excited about it, I’m pretty sure other people will be, too.” I can’t write about things that I myself am not excited about. That is the source and the beginning and the end of how I write.

Does your popular writing affect your relationships with research colleagues?

Virtually all my research colleagues know about my second, secret life, as it were. I collaborate heavily with people like Jim Manley on RNA, with Lew Cantley on metabolics, with physicians like Azra Raza on acute myeloid leukemia and myelodysplastic syndromes, with a whole team of people working on chimeric antigen receptor T-cell therapies in India. They all know about what I do in this other life. And they are respectful of it, but it somehow doesn’t enter the conversation because when we’re talking about the science, we’re talking about the science. And they know that somehow maybe they’ll end up in a book somewhere. And they are almost always fine with it.

In your chapter on in vitro fertilization, you talk about Landrum Shettles, a professor of obstetrics and gynecology at Columbia University, who neglects to tell his department about his plans to create a human embryo in vitro for implantation. Why do you describe him as “tone-deaf to the scientific and moral crossings required to produce a human embryo in a glass jar?”

In medicine, the golden goal is always going to be, “How can we alleviate suffering?” And what is suffering? What does suffering mean? In science, of course, the ultimate goal is also to alleviate human suffering, but it also includes understanding nature. But then, in the middle of understanding nature, we very quickly make a crossing into tampering with nature, and what is natural. And that’s where I think there requires a lot of acuity in non-tone-deafness, so that we can understand nature, but also understand where we stop tampering with nature so that we don’t get into deeper trouble.

Do you think science writing can be considered literature?

I don’t really make a distinction between “big L” literature and writing about science. If you read Leonardo’s books, or if you read Lewis Thomas or others, you’ll quickly realize that that distinction is an arbitrary distinction. They were writing as much literature as the next person. So I think there’s no “big L” literature. Writing is writing. Writing is a mechanism for us to understand and express ideas. I write to think.

How do you construct a story? What does a story mean? Where do pieces of a story fit in? How do you not give away the punchline before a certain point? How do you build a sense of wonder, a sense of suspense, a sense of achievement or failure? Those ideas cross all boundaries of disciplines. So I think of literature as just a mechanism—as I said, I’m a big reader, I love to read—to cross those boundaries.

Michael Denham is a medical student at the Columbia University Vagelos College of Physicians and Surgeons. Follow him on Twitter @MichaelWDenham.

Lead image: Vilmos Varga / Shutterstock

Microbiology

The Big Thinker

Nick Lane is asking—and answering—the vital questions about life.

By Philip Ball    September 7, 2022

There is a black hole at the heart of biology,” Nick Lane writes at the start of his 2015 book The Vital Question. “Bluntly put, we do not know why life is the way it is.” It takes some chutzpah to lay down the gauntlet to the life sciences so starkly—to suggest they are engaged more in documenting life than in explaining it.

Lane, a professor of evolutionary biochemistry at University College London, doesn’t seem the kind of person you might expect to make such a provocative challenge. He’s disarmingly modest, explaining his own answer for why life is the way it is with enthusiasm and conviction but also with frequent disclaimers and frank recognition that he could be wrong. “I’ve come to realize that being wrong is actually really good fun,” he says.

But then his self-assurance kicks back in. Sure, he could be wrong on the details, but on the big picture, “I can’t possibly be, because at bottom all I am saying is that energy is important to life, and that the peculiar method by which it works surely tells us something important about how life operates.”

It takes chutzpah to lay down the gauntlet to the life sciences so starkly.

Lane and I are sitting in the Wellcome Collection in London, the flagship public space of the Wellcome Trust medical charity set up in 1936 from the legacy of Victorian pharmaceutical entrepreneur and collector Henry Wellcome. We are surrounded by Wellcome’s collection of bone saws, religious relics, and medical-themed paintings—an apt setting for talking about how life began, how it proceeds, and ends.

Lane displays the curious and perhaps even contradictory mindset that seems to characterize many creatively provocative scientists: open to being wrong, but convinced he is fundamentally right. He is eclectic in his sources of inspiration but focused on his personal vision. His independent turn of mind is reflected in his unconventional career path, which—along with the breadth of his vision—puts one in mind of the late James Lovelock, who also thought deeply about the relationship between life and the planetary environment it inhabits and transforms. And like Lovelock, Lane has the gift of being a clear communicator, which has allowed him to bring to wider attention a new perspective on living organisms that might otherwise have languished in the corners of specialist journals.

By asking questions about life that few others seem to be asking—and then offering ingenious answers—Lane has earned wide recognition, praise, and admiration. His 2010 book Life Ascending won the Royal Society Book Prize for science books, and in 2016 he was given the Royal Society’s prestigious Michael Faraday award for communication of science to the public. Bill Gates has said The Vital Question “blew me away”—and has funded Lane’s work to the tune of $1.2 million.

DEEP HISTORY: Nick Lane at the Wellcome Collection in London, a museum that ventures through the corridors of health and human history. The museum was an apt setting for the evolutionary biochemist to describe his compelling research into how life began. Photo by Philipp Ammon.

Through scientific and popular publications as well as lab experiments, Lane has been steadily developing an unconventional narrative about how life works and how it began and evolved. At its core, it is a tale not of genetic inheritance of information but of how life harnesses energy from its environment and uses it to build complex molecular systems. “The difference between being alive or dead,” he writes in his new book Transformer: The Deep Chemistry of Life and Death in an aphoristic summary of his central concept, “lies in energy flow.”

Transformer presents an explanation for the origin of the Krebs cycle, the central biochemical process of metabolism in all organisms that live by respiration, whereby large molecules are broken down into small ones and energy is generated in the process. Both prokaryotic organisms like bacteria and eukaryotes like us use the Krebs cycle, which was identified in 1937 by the British biochemist Hans Krebs (it is sometimes called the citric acid cycle). It generates cellular energy while producing the precursors of amino acids and other vital cell ingredients via a cyclic series of enzyme-catalyzed reactions.

The Krebs cycle is often seen as an important but extremely dry piece of textbook biochemistry. When I chatted to Lane a year ago at a science reception and he told me that this was the topic of his next book, he wore a wry grin that implied he was on a fool’s errand. “The Krebs cycle is basically extremely dull even to the people who work on it,” he tells me now. “And yet somehow it’s making me excited. I remember reading [the Italian chemist and writer] Primo Levi, who said a good writer should be able to make any subject interesting. And maybe I took that as a challenge.”

It’s no surprise that as gifted an expositor as Lane meets that challenge in style. The story in Transformer is not just lively and engaging but filled with stimulating ideas about life’s origins and evolution, about what regulates health and disease, and about the fundamental nature of life itself. “It’s about metabolic biochemistry, but also it’s about the origin of life, it’s about the origin of animals, it’s about cancer, it’s about consciousness,” Lane says. “These are really big ideas.”

In his position as leader of the largest group in UCL’s biology and biochemistry departments, Lane conducts experiments that seem closer to the inventive and speculative chemical cookery of the 1950s than to the cutting-edge wizardry of much of today’s molecular and chemical biology. The ingredients could hardly be simpler: carbon dioxide (CO_2), hydrogen, iron minerals, salts. Out of them are coming, not exactly signs of life itself, but clues to how it began.

Lane got here along an unusual path. Having studied biochemistry at Imperial College London, he completed a Ph.D. at the Royal Free Hospital in London in the 1990s, which subsequently became part of UCL. “I got a good enough degree, but only just, and I had a big debt,” he says. “I got a job in a lab to pay off the debt, and it came with the opportunity to do a Ph.D.” The lab was run by a professor of surgery, Colin Green. Lane remembers Green as “an extraordinary man who set up the first medical school in Palestine and was director of the London City Ballet at the time.”

Lane worked on organ transplantation, trying to understand why transplants can lead to the condition called ischemia, where tissues are damaged by low levels of blood oxygen. A transplant can lead to a burst of free radicals in the body—reactive, oxidizing chemical agents with unpaired electrons. Lane tried introducing antioxidants to reduce the damage. “But nothing ever worked, and you think the dose is wrong or the timing is wrong or something,” he says. “In some ways, it was great fun and I realized that I love research. In other ways, it was frustrating.” Yet in retrospect, the essence of Lane’s grand vision of life was already contained in those failing experiments.

Lane’s bold hypothesis is life had to be this way.

Seeking a postdoctoral position in free-radical chemistry without knowing anyone in the field was never likely to be successful, but Lane found an alternative. “I had just been a runner-up in a newspaper writing competition, so I looked for writing jobs,” he explains. “Some of them were dreadful—writing up clinical trials reports for pharmaceutical companies, unbelievably dull.” He eventually landed a position working on medical animations. “It was basically soft marketing for pharmaceutical companies,” Lane says. “I did that for a couple of years, and I learned a lot about writing. First, tell a straight story. Second, use plain international English. And I found I could master a subject I knew little about; I could grasp the essence quickly. It turned out to be a useful skill.”

The job was only fun for so long. “My way out was that I’d try to write a book,” Lane says, as if it were the obvious option. In the 1990s, free-radical chemistry caused by oxygen-based respiration was thought to be central to many disease mechanisms. Why that is so was the organizing question for his first book, Oxygen: The Molecule That Made the World, published in 2002. “But I had no idea where the oxygen came from,” he says. “I didn’t know anything about the evolutionary history of life on Earth.” As he explored that question, “I kind of fell in love with science all over again.”

But he was left with a puzzling question. “Oxygen in evolutionary terms seems to have been a wonderful thing. The more oxygen in the atmosphere, the more profuse life has been. And yet here’s the medical profession saying too much oxygen is going to poison you with free radicals.” It all came down, he figured, to aerobic metabolism in the mitochondria: the compartments in cells where energy is generated in the form of the molecule ATP, via the Krebs cycle. That became the topic of his next book, Power, Sex, Suicide, published in 2005.

VISUAL AID: Nick Lane’s inclusion of illustrations like the Krebs cycle (above) in his books signals his mission to communicate without proselytizing or saying to readers, “Trust me, I’m a scientist.” “I’m not patronizing them,” Lane says. “I’m giving them the opportunity to see why it’s this way.”

Mitochondria are widely believed now to be the remnants of an entirely distinct single-celled organism that merged with another cell long ago in evolutionary history, perhaps around 1.5 billion years ago, in a process called endosymbiosis. This would explain, for example, why our mitochondria today contain a small number of their own genes, separate from the rest of the genome in the cell nucleus. (It’s the possession of this nucleus that defines the distinction between cells like ours, called eukaryotic, and those of single-celled organisms such as bacteria and archaea, which are prokaryotes.)

There remains an argument, some of it heated, about what this momentous merger consisted of. Some researchers believe it happened between an already extant eukaryotic cell and a prokaryote. Others argue that both cells were prokaryotic. Lane favors the latter, saying those who advocate for the “eukaryote-first” picture do so for “basically emotional reasons.” He says the idea that mitochondria appeared when a bacterial endosymbiont merged with an archaeal host cell is consistent with all we know about the evolution of eukaryotes.

At any rate, cells that acquired their own internal powerhouse were suddenly able to do entirely new things—like group together to make multicellular organisms. Lane sharpened his ideas in conversations with the microbiologist Bill Martin of the University of Düsseldorf in Germany. Martin had an unconventional view of what happened in the endosymbiosis that led to eukaryotes with mitochondria, in which a central role was played not by oxygen but by hydrogen. In this “hydrogen hypothesis,” the host cell was an archaeon that metabolized by using hydrogen, and the bacterium that became the mitochondria produced hydrogen (as well as carbon dioxide) via anaerobic respiration—so it supplied the fuel that the host needed.

“Around 2002, when Oxygen came out, I went to a discussion meeting at the Royal Society and Bill was there and gave a pretty amazing talk on the origin of life,” Lane says. There Martin laid out the hydrogen hypothesis and explained why in his view early life was much more about metabolism and energy flow than about genes and proteins. “It was all very radical, it still is radical, but back then it seemed crazy,” Lane says. Martin, he adds, “was one of the biggest influences on my thinking.”

Stimulated by such ideas, Lane found that the book he was developing, Power, Sex, Suicide, started to take a new direction. “It went from being a book about mitochondria to being a book about the origin of complexity,” he says. “It really boiled down to the fact that it wasn’t about oxygen after all—it was about mitochondria and the energetics of genomes. I still think it’s basically the right way of seeing the question.”

Later, Lane and Martin teamed up, and in 2010 they made the case that what changed with the acquisition of mitochondria was the “energy per gene.” By their calculations, eukaryotes have up to 200,000 times more energy per gene than prokaryotes. With those resources, eukaryotes could do things unavailable to prokaryotes, such as become multicellular and develop complex forms and collective behavior. Thanks to that energy boost, large animals—and eventually us—became possible, as did behaviors, such as sexual reproduction, that are inaccessible to bacteria and archaea.

With these ideas about the energetics of life’s origins arising in the mid-2000s, Lane realized he was at a turning point. He was doing fine with science writing. He was embarked on writing Life Ascending, which looked at “the ten great inventions of evolution” (including the endosymbiosis that he believes led to eukaryotes). But he had, almost by accident, found a hypothesis about a key stage in evolutionary history, with a welter of wide-ranging implications.

The question of how life began is often posed in terms of how to make its molecular ingredients, such as amino acids and nucleotides, the building blocks of proteins and the nucleic acids RNA and DNA, from simple inorganic compounds that might have been present on the early Earth—carbon monoxide, water, and cyanide. If you succeed in making, say, nucleotides in such prebiotic reactions, the next challenge is to link them up into chains and polymers—for example, to progress toward the “RNA World” hypothesized in the 1980s, where RNA molecules served the dual role of acting as catalysts and carriers of inheritable “genetic” information before proteins and DNA took over those respective roles.

“It’s so simple. It solves so many problems. It’s quite thrilling.”

That’s all very well, says Lane, but to make such molecules and to do anything with them, you need a source of energy. In early work on prebiotic chemistry, like that of Harold Urey and Stanley Miller, the energy source driving the chemical reactions was often assumed to be light or ultraviolet radiation from the sun, or lightning discharges in the atmosphere. But pretty much all the energy in living cells today, whether of bacteria or plants or animals, is ultimately “chemiosmotic”: The cell’s ubiquitous molecule, ATP, produces energy by harnessing the driving force created by differences in concentration of ions—especially hydrogen ions, which are merely lone protons—across biological membranes. Like dam water driving a hydroelectric turbine, this “proton-motive force” powers the enzyme ATP synthase, a protein that sits embedded in the membrane and churns out ATP molecules as its head rotates in a membrane-bound sleeve. ATP synthase is found in almost all bacteria, archaea, and eukaryotes, says Lane. “It is as universal as the genetic code itself,” Lane writes in The Vital Question, and “should be as symbolic of life as the double helix of DNA.” In other words, life is really all about the flow of electrical charge (electrons and protons) as a driving force for making biomolecules and powering metabolic pathways.

“I was actively trying to think, how can I test some of these ideas?” he recalls. “How can I get back into academia?” Then he got a lucky break.

In 2008, Lane met the author and scientist Don Braben, an advocate of “blue-skies research” that is curiosity-led rather than aimed at specific questions or applications. Braben was working at UCL, where he now holds an honorary position in the Office of the Vice-Provost for Research. “Don’s view is that some of the great breakthroughs in the 20th century would never have happened with the current funding model,” Lane says. Braben persuaded the provost at UCL to back research proposals with basically no peer review. “He wanted very short proposals on ideas that were potentially transformative,” Lane says. “It became clear that this was by far my best opportunity to get back into academia.”

After much back-and-forth, Lane’s application elicited a funded position called the Provost’s Venture Research Fellowship from 2009 until 2012. “It was strange for me to go back into the lab,” he says. “It was incredibly cack-handed and amateurish, and I didn’t have any equipment—I had to beg and borrow other people’s. I was doing amazingly stupid things, but some of it worked.”

Lane’s proposal was titled Chemiosmosis and the foundations of complex life. “It only took one or two meetings for me to be convinced that Nick is an exceptional scientist who might one day win a Nobel Prize,” says Braben. “He did not try to persuade me that his research would lead to this or that wonderful outcome but would concentrate entirely on the science involved.”

“Nick’s performance at our meetings convinced me that here was a scientist who would do something important and radically change the way we think,” Braben adds. “But with funding success rates running at about 20 percent, the chances of his winning support from normal sources would be negligible.”

Lane praises UCL as “an environment where people do give a damn about ideas and about other people’s work. It’s a really bottom-up, collaborative place, where you can easily infect people with your own enthusiasm.”

In The Vital Question, Lane offered a detailed and concrete scenario for how life might have got started on Earth. It builds on the idea proposed in the 1970s that it all began not in some prebiotic soup such as ponds or shallow oceans rich in organic molecules and warmed by sunlight, but deep down in the oceans at structures called hydrothermal vents, where volcanic activity sends mineral-rich hot fluids spewing from mineralized chimney-like structures on the seabed.

In the late 1980s, British chemist Mike Russell began to develop a detailed scenario for how the necessary chemistry could have arisen. Iron sulfide minerals might act as the source of the energy and electrons needed to drive the fixation of carbon, he said. Some vents are rich in such minerals, which can drive “redox chemistry” (for example, adding and subtracting oxygen and hydrogen atoms from carbon compounds) as the iron ions cycle between two states with differing electrical charge. Even today, clusters of iron and sulfur atoms are commonly found in some enzymes, including those that catalyze the reactions of respiration—a remnant, Russell suspected, of the early role played by iron sulfide minerals.

These things are where happiness in science lies.

This picture, called the chemoautotrophic origin of life, drew on work in the 1980s by the German chemist Günter Wächtershäuser, who argued that the Krebs cycle, running in reverse, could have been the first biochemical metabolic pathway, powered by iron-sulfur chemistry. In 1997 Russell and his colleague Allan Hall showed how the gradients in pH at alkaline vents could couple to iron sulfide redox chemistry to drive the emergence of the first living entities, which used a proton-motive force to power their metabolism.

To harness such a “chemiosmotic” concentration gradient, you need a membrane that partitions space into regions of different concentration, so that this difference is not just washed away by diffusion of the molecules or ions. At hydrothermal vents, Russell argued, such membranes can be inorganic—made from mineral compounds such as iron sulfides or hydroxides. Perhaps once such structures were producing pseudo-metabolic chemical processes that generated molecules like organic fatty acids, they could create their own organic membranes, the precursors to the phospholipid membranes of today’s cells. A system like this could act to transfer electrons from hydrogen molecules to carbon dioxide molecules (both are abundant in hydrothermal vents): the first step in generating more complex organic molecules such as formaldehyde, carboxylic acids, and ultimately the components of the Krebs cycle of metabolism.

In other words, rather than finding separate routes for making the biomolecular components of the first proto-cellular organisms and then having to hope they somehow all come together in an organized entity, redox chemistry at hydrothermal vents could have given rise to compartmentalized chemical reactors with a ready-made energy source, spinning out the complex organic ingredients needed for life to begin.

Russell’s scenario in which proton gradients and the proton-motive force operate in cell-like cavities at alkaline hydrothermal vents “really excited me,” says Lane. “Mike Russell was and is inspirational in linking geochemistry and structure with the beginnings of biochemistry.”

“An environment like hydrothermal events provide everything we think we need” to kickstart life, Lane says: the raw ingredients such as a carbon source (CO_2), a source of energy (pH gradients), agents that can catalyze redox chemistry (such as iron sulfides), and compartmentalization by membranes.

Indeed, in the mid 2000s Martin and Russell elaborated the theory of an origin of life at alkaline hydrothermal vents and how the inorganic chemistry happening there could have given rise to the beginnings of the Krebs cycle that fixes carbon from CO_2 into a form usable by early organisms. They developed a scenario in which these proto-organisms might have developed first into simple bacteria-like cells with an organic membrane, and then, about 2 billion years ago, merged to form eukaryotes with mitochondria.

Work by Martin and Russell is a foundation of Lane’s theory of the origin of life. Broadly speaking, Russell says, “Nick seems to have followed me in most of his ideas, although with a more biochemical grounding compared to mine, which was developed from geological exploration and geochemical knowledge and experience.” Martin is less sanguine. He says he has not been given enough credit for initiating some of the ideas described in Lane’s books (even though he is duly cited many times). Russell says he harbors no ill feelings about the way Lane has extended and popularized his ideas. “I, for one, am very happy about the way he proselytizes this work,” he says.

As Lane explains his vision in the gloom of the Wellcome exhibition room, while the occasional visitor wanders past, peering into the glass cases, I can see how convinced he is that this story, despite its chemical complexity, provides a coherent picture of the way life gained a foothold on the planet. Putting chemiosmotic energy and metabolic reactions at the heart of it all, he says, fits nicely with what genetic studies suggest the first organisms might have looked like. And his hypothesis “makes a terrifying prediction,” he says. “All of this biochemistry is just going to spontaneously happen. But what a beautiful prediction!” Now he’s trying to test it in the lab.

Transformer fleshes out this story by explaining how it could have led to the Krebs cycle itself. As Lane writes, this complex, cyclical series of reactions generates ATP “by stripping out hydrogen atoms from the carbon skeletons of food [molecules] and feeding them to the ravenous beast that is oxygen”: the process of cellular respiration. On paper it looks like a rather arbitrary sequence of conversions of molecules related to citric acid—a headache for biochemistry students to learn and understand. But Lane now believes that a consideration of what is needed to drive metabolism involving CO_2, oxygen, and hydrogen makes almost all this chemistry inevitable.

Five or six years ago, Lane says, he’d have conceded only that something vaguely resembling this sequence was bound to arise. “It kind of beggars belief that that level of reaction networks will happen spontaneously. But it looks more and more like they do.” Lane is referring to not just the cycle itself but the reactions that spin off from it, which form amino acids and the specific nucleotide bases found in DNA and RNA. “If you’ve got this molecule here in this context, you ask, what’s going to happen next? And you can see what it will be. You are going to form this one, and so on. You start drawing these things, and you think—Jesus, here’s the Krebs cycle! You almost can’t end up with anything else.”

“It was all very radical, it still is radical, but back then it seemed crazy.”

If Lane is right, it suggests that identical biochemistry will arise on any other planet with an environment something like that of the prebiotic Earth. In other words, the principles of chemical thermodynamics and kinetics dictate a kind of pre-Darwinian convergent evolution that creates something at least close to a Krebs cycle. “All it’s asking for is a wet rocky planet or moon with CO_2 in the atmosphere,” Lane says. “That’s not a big ask, right? There are probably billions of exoplanets in the Milky Way that fit that set of criteria.” And you need chemical disequilibrium like that found at hydrothermal vents. “What really matters is converting this environmental disequilibrium into living matter: CO_2 and hydrogen into cycling intermediates, and amino acids and nucleotides.” The bold hypothesis is that life had to be this way—and not just terrestrial life, but any life in Earth-like environments. “It’s so simple,” Lane says. “It solves so many problems. It’s quite thrilling.”

Where evolution might take it after the first primitive protocells have appeared is another matter. So far Lane has elaborated his picture to account for the production of the first nucleotides and their polymers, and recently he and his group have argued that the energetics of CO_2 fixation might explain why the genetic code, which relates the nucleotide sequence of DNA to the amino-acid sequence of proteins, takes the form it does. “I’ve just got up to the origins of information and evolvability,” Lane says, “but I’m a long way from molecular machines like ribosomes,” the multi-molecule assemblies that make proteins from the information in RNA. “So there’s an interesting next question: What’s the simplest possible molecular machine that you can imagine?”

But is there any proof that this is really how life began—and had to begin? “It makes a bunch of predictions that may or may not be true,” Lane admits. “It’s very easy to delude yourself into thinking that because it’s a beautiful idea, it’s got to be true. Maybe it’s not—maybe these associations are just not strong enough or there is some other explanation for it.”

The proposal needs to be tested in the lab—and that’s what Lane is now doing. He and his team are using microfluidic systems to see if, starting with CO_2, hydrogen, and simple inorganic ingredients such as silicates and iron salts, they can generate some of the Krebs cycle compounds. They’re getting somewhere, slowly. “We’re getting at least acetate, and possibly pyruvate,” he says—two of the key molecules in the cycle. They have also shown that “protocells”—closed compartments made from organic membranes composed of simply fatty acids—will form spontaneously under the conditions that exist at alkaline hydrothermal vents.

“I seem to have assembled around me a bunch of people who are very free thinkers,” he says. “I encourage them to disprove everything that I say, and they seem to try and do it with relish. It throws lots of googlies at you on an almost daily basis: Either this is wrong or what can we do next, how can we get out of this corner?”

For all the grand ideas about some of the most profound questions contemplated by science, Lane hasn’t lost sight of his early days working on disease. That’s all part of the picture too. “The issue with cancer is it’s about growth,” he says. “It’s about how a cancer cell can optimize metabolic flux so that it can make copies of itself.” Cancer is also about the Krebs cycle. “The cancer people have been thinking along these lines for a little while, and it links up with aging as well. It’s hooking up three different fields in a way which they should hook up.”

An interest in this chemistry of carbon fixation has also come from another unexpected direction. “Part of the reason it’s become more interesting to people is because of the issues with CO_2 capture and climate change,” Lane says. “People are now taking the idea that you can reduce CO_2 and convert it into something useful like hydrocarbons much more seriously than they were a few years ago.”

Lane is willing to take his ideas about the centrality of energy and electron flow in some speculative directions. Transformer ends with a discussion of its role in the evolution of thought and consciousness. “The electrical potential humming away on cell membranes is movement too, dancing charge, electrons and protons, the elementary particles of life,” Lane writes. “Moving charge generates electromagnetic fields that permeate our being. And clearly, the flux of metabolism generates electromagnetic fields on cells. Could feelings somehow be related to this dance of charge, the ephemeral states of cells?”

“I think the likelihood of that being completely true is probably quite small,” Lane admits. “But the possibility that it might be true is intriguing.”

This seems to be the next direction in which Lane’s fertile mind is taking him. “If you’d asked me a couple of years ago which question I’d like to see answered in my lifetime, I’d almost certainly say something to do with the origin of life,” he says. “But in a strange way, I feel as if conceptually I can almost understand it now. There’s an awful lot of work in the lab to do, but I think I can join the dots. So now I’d say it’s consciousness, because I think that’s more out there.”

Despite being head of a large research group, formulating and testing complex hypotheses, Lane retains his passion—indeed, almost a sense of urgent obligation—for communicating science to the widest possible audience. “Asking the big questions and trying to excite other people with them—these things are where happiness in science lies,” Lane says. “Somehow we’ve got to get across to people that science is a human activity, that it’s about finding out what we don’t know about the world.”

In a time when popular science can end up over-simplifying ideas for general consumption, Lane’s books might seem uncompromising. Transformer is filled with illustrations of the Krebs-cycle intermediates and their reactions: yes, molecules, a pretty reliable deterrent for those with bad memories of school chemistry classes. “It’s going to require patience,” he admits. “It’s going to require some commitment on the part of the reader. But I’m not patronizing them. I’m giving them the opportunity to see why it’s this way.”

This urge to communicate without proselytizing or saying simply “Trust me, I’m a scientist,” is at the core of Lane’s mission. “What keeps most scientists going most of the time is the excitement of the unknown,” he says. “Yet somehow that’s not transmitted through to the public very well. If we can do that, I think there will be much more excitement about and sympathy for science in society, and then better decisions about what we do about climate emergencies or pandemics. It’s not just a case of getting science across to people, it’s a case of getting people to participate, to be part of it, to feel that science is for them.”

Philip Ball is a science writer and author based in London. His most recent book is The Book of Minds.

Lead image: Philipp Ammon

Neuroscience

- The Afterlife Is in Our Heads

- How We Remember Last Weekend

Neuroscience

The Afterlife Is in Our Heads

The real meaning of near-death experiences.

By Kristen French    September 28, 2022

One Sunday evening in September, nearly 30 years ago, Xavier Melo, then 23, was driving home from his job as a private math tutor in Barcelona, Spain. It was one of his two weekend jobs, and his car was stacked with study notes and practice tests for an upcoming business school entrance exam. Melo retraced the familiar route home at a leisurely pace, to savor a gentle breeze and the satisfaction of a weekend’s work complete. As he pulled into an intersection, a Volkswagen Golf violently crashed into his car, destroying it. Melo himself suffered head trauma, lost consciousness, and fell into a coma. He woke up in his hospital bed, screaming, again and again, “I have been with God!”

Melo’s memory of the immediate aftermath of the crash is vivid and mysterious; it follows the familiar arc of the near-death experience. He recalls that he flew out of his body and hovered above it, that he observed a nurse in the ambulance who held his hand and called out, “We’re losing him, we’re losing him,” as he watched his papers swirl and scatter in the street. Then he began to rise, the ambulance receding from him in the distance, until he came to a tunnel, where scenes of his life as a child began to play out. He felt an overwhelming sense of belonging, of kinship with the trees, the wind, and the water, and saw an indescribable light that drew him in, a light he began to believe was a being. “It was like the magnetism of love, something that attracts the deepest part of you,” he told me. “I have never been more alive, I have never felt more lucid in my life.” Regaining awareness and sense of his physical body, Melo said, was traumatic.

As Melo relived his story for me over Zoom, from his home in Barcelona, he repeatedly became so overwhelmed with emotion that he had to stop to regain his composure. The experience, he said, transformed him, but not until 25 years after his accident. In 2017, after years in the insurance industry, and upon graduating from a business school program in management, he formed a foundation, Icloby, to promote socially responsible business practices. This fall, the foundation will also embark on a study of near-death experiences in cardiac arrest patients, including children, among Spanish speaking people across Spain, Cuba, Mexico, Colombia, and Argentina. The research project aims to replicate an earlier study of 344 cardiac arrest survivors published in the British medical journal The Lancet in 2001 and led by Pim Van Lommel, a cardiologist, author, and researcher in near-death studies from the Netherlands. “For us, it’s important to demonstrate that death is only for the material body,” said Luján Comas, vice-president of the Icloby foundation, who joined us on the Zoom call.

FREE FALLIN’: You don’t want to undermine someone convinced they had a glimpse of the other side, says neuroscientist Anil Seth. “If they experience flying through a tunnel of light, into a beautiful white open space, then that’s what they experience.” But that experience depends on brain activity. “No brain activity, no mental process.” Image by Fran_kie / Shutterstock.

The idea that near-death experiences, also known as NDEs, offer proof of an afterlife for the soul has been remarkably persistent, despite an accumulation of scientific evidence to the contrary. Such claims have existed in the historical record since at least Plato’s time; the earliest known account of near-death experiences appeared in the fifth century B.C. But they weren’t widely popularized until the 1970s, when American physician and philosopher Raymond Moody published his best-seller Life After Life, based on his collection of 150 coma survivor’s reports.1

Many studies and books that bear witness to life after life have sprung up since Moody’s book, none more notorious than Proof of Heaven: A Neurosurgeon’s Journey into the Afterlife, a New York Times bestseller in 2012, by neurosurgeon Eben Alexander. Increasingly, these supernatural claims have taken on a scientific veneer. Van Lommel, the cardiologist from the Netherlands, has made it clear in his many popular writings, public talks, and interviews that he believes NDEs serve as proof that consciousness exists independently of the brain, that it is “non-local.” And Sam Parnia, who researches resuscitation science and NDEs at New York University Grossman School of Medicine and was the lead researcher on a 2022 paper that proposes a framework for future study of NDEs, recently told me, “The [big] question that we’re trying to explore is, ‘What happens to consciousness when you die, does it die or continue?’ And the evidence so far is that it doesn’t die when you and I cross over into death.”

But neuroscientists who study consciousness and have weighed the decades of research into NDEs told me these claims that consciousness survives death are not supported by the research. Though they are highly personal and often transformative for those who experience them, NDEs are nonetheless explained by physiological processes, they said, which have been pieced together over the past 50 years. In the decades since Moody published Life After Life, advances in critical care medicine and resuscitation science have made it easier to revive patients whose hearts have stopped, which has made it easier to systematically identify and study people who have had an NDE. Some estimates now suggest that between 4 to 15 percent of the global population and 10 to 23 percent of cardiac arrest patients have had an NDE.2 We now have a better grasp of how they happen, what purpose they may serve and why they are so transformative for those who experience them. At the most basic level, neuroscientists say, when a person’s brain changes in profound ways—as happens when that person goes into cardiac arrest, for example—their perceptions and emotions change in profound ways, too.

“I have never felt more lucid in my life.”

“Having an out-of-body experience is not proof that the soul or the mind can leave the body and go floating about,” said Anil Seth, a professor of cognitive and computational neuroscience at the University of Sussex who studies consciousness and is the author of a recent book on the subject, Being You. Those who tout near-death experiences as something more than biological, Seth added, “are confusing the content of the experience with a claim about the nature of the universe. There’s a much more interesting explanation, which is that the location that we feel ourselves to be is something that is generated by the brain and can be changed when the brain is in a particular state.”

In 2019, a group of critical care specialists, anesthesiologists, and psychiatrists, as well as a neurologist from New York Medical College and a neurophysiologist specializing in sleep and epilepsy from Kings College in London, got together in New York to discuss the future of NDE studies. Sam Parnia, the resuscitation researcher from New York University Grossman School of Medicine, was among them. The result of that meeting was the 2022 paper in the Annals of the New York Academy of Sciences. Among other things, the authors proposed a new name for the NDE: “recalled experiences of death,” or REDs, to limit the field to the study of just those experiences that occur when someone is in critical condition, or a near-death state, such as cardiac arrest, when the brain no longer receives blood and oxygen.

Parnia told me the new name was meant to reflect the authors’ belief that near-death experiences actually happen after someone is dead. “What we’re saying is science is showing you that death is not the end that we thought,” Parnia said. “It’s almost like a new, uncharted, unexplored territory.”

The group also identified 51 core features, or themes, of REDs. These include “separating from the body,” “realization of having died,” “a higher purpose: I wish I had known,” and “loss of fear of death.” These experiences, the paper states, are characterized by “a paradoxical lucidity and a heightened sense of consciousness, awareness, and well-structured thought processes, typically without external or visible signs of consciousness.” In a supplement to the paper, the authors allow the possibility that consciousness “is a separate entity that, while undiscovered by science today, is not produced by conventional brain cell activities.”

NDEs have been reported under many circumstances, a list of which appeared in Van Lommel’s 2001 paper: cardiac arrest in myocardial infarction, shock in postpartum loss of blood or in perioperative complications, septic or anaphylactic shock, electrocution, coma from traumatic brain damage, intracerebral hemorrhage or cerebral infarction, attempted suicide, near-drowning or asphyxia, and apnea. According to Van Lommel, they are also reported by patients with serious but not immediately life-threatening diseases, and in those with major depression. Experiences that bear many similarities to NDEs can even happen in the terminal phases of illness or after situations in which death seemed inevitable, such as mountaineering accidents.

But NDEs can also occur in circumstances that do not bear any direct relation to imminent death or even fear of death, such as meditation or intense grief, according to numerous studies, said Renaud Evrard, a clinical psychologist and assistant professor at the University of Lorraine in France, who works with patients grappling with exceptional and paranormal experiences, including NDEs. In a response paper published a few months later in the same journal, the Annals of the New York Academy of Sciences, Evrard accused Parnia and his co-authors of ignoring the actual data on NDEs.3 “They focus too much on the interpretation of testimonies and not enough on the evidence,” said Evrard. Bruce Greyson, professor of psychiatry and neurobehavioral sciences at the University of Virginia and the creator of the Greyson scale used to identify and rate NDEs, agreed, even though he is listed as an author on the 2022 paper. The evidence suggests NDEs experienced by patients whose hearts have stopped are no different from those experienced by people who simply fear death—for example, if someone is falling off of a mountain, Greyson said.

Prior belief in god or an afterlife does not, perhaps surprisingly, seem to influence one’s propensity to have an NDE, according to the research, but there is a strong association between the “depth” of the NDE a person experiences—as measured by the Greyson NDE Scale^4—and the likelihood that they will experience a religious or spiritual transformation afterward, including reduced fear of death, greater empathy, and decreased interest in material possessions.5

NDEs are generally understood to begin with a feeling of detachment from the physical body—known as an out-of-body experience, or OBE—followed by deep feelings of peacefulness, entering a gateway or tunnel, seeing a bright light^6 and finally feeling a “return” to the body. It is the OBE that is perhaps the most defining element of the NDE: Some 80 percent of people who report experiencing an NDE have one, according to the research of Steven Laureys, a clinical professor of neurology who leads the Coma Science Group at the University of Liège in Belgium. His lab searches for behavioral and neural correlates of consciousness in patients with severe brain damage and studies non-ordinary states of consciousness.

But a wealth of neuroscience research describes how OBE-like experiences—a loss of the sense of self and disturbed body perception or ownership—can be triggered by brain damage, epilepsy, and migraine,7 as well as by stimulation of the part of the brain where the right temporal and parietal lobes meet. This region is known as the right temporal-parietal junction (TPJ), and it is understood to play an important role in multisensory integration, our sense of embodiment, feelings of agency and self-other distinction.8 Stimulation of this junction can disrupt the brain’s ability to coherently process the positioning of the body and the sense of body ownership, which can lead to the sensation of seeing oneself from above.

“No brain activity, no mental process.”

OBEs often also involve awareness of specific details of the scene that feature the body in a comatose state–doctors discussing one’s chances of survival, for example, or attempting CPR. In the past, accounts from people who have recovered from being unconscious or in a minimally conscious state, and have recalled sensory details of their environments, might have seemed miraculous. But recent studies of people who are in coma, or under anesthesia, and seem unresponsive, have shown these individuals can perceive things in their environment and respond physically to commands.9 For example, while higher-level semantic processes can be impaired in people with low levels of sedation or minimally impaired consciousness, a person’s ability to process speech more generally has been found to be resilient even during deep sedation.10

Cardiac arrest may be similar. How much activity is present in the brain under these conditions is not clear. Positron emission tomography scans suggest that there is about a 60 percent reduction in global activity compared to baseline following cardiac arrest, said Laureys, but it’s not zero.11 But if a brain has flatlined, showing no activity on an EEG monitor, it would most likely be incapable of forming a memory or having any other conscious experience, said Seth, who has been studying the neuroscience of consciousness for decades. He and many others believe that most NDEs are “false” or imagined memories—that the brain constructs a memory after the fact to fill in for an inexplicable series of mental events.

“You don’t want to undermine the person’s lived experience,” Seth said. “If they experience flying through a tunnel of light, into a beautiful white open space, then that’s what they experience. But memories, things that minds do, like remember things and talk about them, depend on brain activity. No brain activity, no mental process. If somebody with no brain activity were able to experience something and remember it later, then pretty much everything we know about the brain, about science, about physics is wrong.”

While no single overarching explanation for the NDE has yet been established, neuroscientists have discovered a series of neurophysiological mechanisms that could, together, account for many aspects of the phenomenon. One hypothesis is that NDEs are produced by the release in the brain of a natural hallucinogen with neuroprotective properties. London researcher Karl Jansen, a member of the Royal College of Psychiatrists, is a leading expert on the hallucinogen ketamine, which is used to treat depression and, during surgery, as an analgesic to induce loss of consciousness and reduce pain. Jansen proposed in the 1990s that a ketamine-like substance may play a role in the emergence of NDEs among patients with life-threatening injuries or disorders of the brain or spinal cord given the parallels between NDEs and ketamine trips, and the potentially protective properties of ketamine-like substances.

The “dissociative anesthetic ketamine can reproduce all aspects of the near-death experience,” Jansen wrote. That includes a sense of ineffability, timelessness, that what is experienced is “real,” that one is actually dead, a perception of separation from the body, vivid hallucination, rapid movement through a tunnel, and emerging “into the light.”

Although many psychedelic experiences bear some similarities to NDEs, recreational ketamine trips top the list. In a massive 2019 study comparing psychedelic experiences to NDEs, Laureys’ group used natural language processing tools to assess the semantic similarity between 15,000 accounts linked to the use of 165 different psychoactive substances and 625 NDE narratives. They found that accounts of ketamine trips^12 most closely resembled those of NDEs.

Ketamine is also an N-methyl D-aspartate (NMDA) receptor antagonist, and so could counter neurotoxic processes that are set into motion by NMDA receptors when blood flow and oxygen to the brain are cut off, “with a short lived, dissociative hallucinogenic state occurring as a side effect.” At least one naturally occurring substance that could play this role, called an endopsychosin, has been identified. In fact, critical conditions like hypoxia—oxygen deficiency—or temporal lobe epilepsy, have been shown to trigger NDEs or NDE-like experiences. And many studies and clinical trials have established that ketamine has neuroprotective and neuroregenerative effects in humans, even after stroke, brain injury, and epileptic seizures.13

There is likewise some experimental evidence that near-death experiences that occur at the time of a trauma might help to ward off post-traumatic stress disorder.14 Bruce Greyson, of the Greyson NDE Scale, led a study published in 2001 that showed that people who have NDEs report more intrusive memories of their close brushes with death but make fewer efforts to avoid reminders of the event, which is considered the more pathological dimension of PTSD.

“One feature that distinguishes NDEs from other forms of [traumatic] dissociation is the strong positive affect,” which might help defend against full-blown PTSD, Greyson wrote in the 2001 paper. “If so, we might speculate about the possible survival value of having NDEs when close to death.”15 (Of course, some NDEs have been documented to feature negative and even nightmarish features, though some question whether these are “true” NDEs.)

“Ketamine can reproduce all aspects of the near-death experience.”

Independently, serotonin, a neurotransmitter involved in mood, cognition, reward, learning, and memory, might play a role in certain features of the NDE. In a small placebo-controlled experiment with 13 individuals, Laureys’ group assessed the experiences induced by injection with a drug called DMT that stimulates serotonin production, which triggered feelings such as entering an unearthly environment, heightened senses, feelings of peace and harmony or unity with the universe. All participants scored above the cut-off score of seven on the most widely used reference scale for NDEs, the Greyson scale.16 Hypoxia itself has also been considered as a possible contributor. Hypoxia is sometimes experienced by fighter pilots during acceleration maneuvers, which have been documented to provoke tunnel visions, bright lights, OBEs, pleasant sensations, and visions of beloved ones.

To attempt to confirm this in a controlled study, one group induced temporary loss of consciousness via loss of blood pressure in 42 volunteer participants and found that 16 percent reported OBEs, 35 percent reported feelings of peace and pleasantness, 17 percent had a vision of a light, 47 percent felt they entered another world, 20 percent encountered preternatural beings, and 8 percent experienced a tunnel. Likewise, abnormally elevated levels of carbon dioxide in the blood, known as hypercarbia, can induce recollections of past memories, life reviews, visions of a light, OBEs, or mystical experiences, according to research conducted in 1950 and again in 2010.17 Yet another study showed higher prevalence of NDEs in people with REM sleep intrusions.

Other work suggests that some kind of last-gasp survival mechanism may be at work when near-death experiences occur, in which the brain marshals all of its remaining resources to try to keep itself alive. Recent EEG studies in humans and rodents seem to show highly coherent electrical activity in the brain just before death. This was first found in a small human case series in 2009 by researchers who identified transient electrical spikes in half of their sample of critically ill patients immediately before cardiac arrest. They speculated that critical hypoxia—loss of blood flow to the brain—unleashes a cascade of pathological neuronal activity. These findings were replicated on a larger sample of 35 patients in 2017.

Similar episodes of so-called paradoxical lucidity have been identified in patients with Alzheimer’s disease just before they die, despite irreversible degeneration in the cerebral cortex and the hippocampus and corresponding memory loss. Researchers who have studied brains in the throes of electrical surges just before death have posited that they represent “a last gasp attempt by the brain to survive a lethal loss of blood flow,” which could serve as an “evolutionary survival event.”18 Why some people experience these surges and others don’t, and how they are set into motion, is unknown.

Scientists haven’t assembled all the pieces to explain why brains in desperate throes generate feelings of peace and joy, ineffability, and the sense of being in the presence of something transcendent. “It’s always difficult for science to answer the big why questions,” Laureys said. Comas, of the Icloby Foundation, told me that by educating the public about near-death experiences, she and Melo hoped to “to eradicate the fear of death.” After all, she said, “The fear of death is the mother and father of all fears.” Who could argue with that? Scientific evidence says near-death experiences are directly linked to the workings of our brains. But evolution is a sly master. Perhaps our biology in its final hour is easing us gently into that good night.

Kristen French is a contributing editor at Nautilus.

Lead image: Lidiia / Shutterstock

References

1. Martial, C., Cassol, H., Laureys, S., & Gosseries, O. Near-death experience as a probe to explore (disconnected) consciousness. Trends in Cognitive Sciences 24, 173-183 (2020).

2. Ibid.

3. Evrard, R., Pratte, E.A., & Rabeyron, T. Sawing the branch of near-death experience research: A critical analysis of Parnia et al’s paper.” Annals of the New York Academy of Sciences 1515, 5-9 (2022).

4. Greyson, B. The near-death experience scale. The Journal of Nervous and Mental Disease 171, 369-375 (1983).

5. Greyson, B. Near-death experiences and spirituality. Zygon 41, 393-414 (2006).

6. Martial, C., Cassol, H., Laureys, S., & Gosseries, O. Near-death experience as a probe to explore (disconnected) consciousness. Trends in Cognitive Sciences 24, 173-183 (2020).

7. Blanke, O. & Arzy, S. The out-of-body experience: disturbed self-processing at the temporo-parietal junction. Neuroscientist 11, 16-24 (2005).

8. Blanke, O. & Mohr, C. Out-of-body experience, heautoscopy, and autoscopic hallucination of neurological origin: Implications for neurocognitive mechanisms of corporeal awareness and self-consciousness. Brain Research Reviews 50, 184-99 (2005); Blanke, O., Faivre, N., & Dieguez, S. Leaving body and life behind: Out-of-body and near-death experience. In Laureys, S, Gosseries, O., & Tononi, G. (Eds.) The Neurology of Consciousness (Second Edition), Academic Press, Cambridge, MA (2016).

9. Laureys, S., Perrin, F., Schnakers, C., Boly, M., & Majerus, S. Residual cognitive function in comatose, vegetative and minimally conscious states. Current Opinion in Neurology 18, 726-33 (2005).

10. Owen, A.M., et al. Detecting awareness in the vegetative state. Science 8, 5792 (2006).

11. Ibid

12. Jansen, K.L.R. The ketamine model of the near-death experience: A central role for the N-Methyl-D-aspartate receptor. Journal of Near-Death Studies 16, 5–26 (1997).

13. Fujikawa, D.G. Neuroprotective effect of ketamine administered after status epilepticus onset. Epilepsia 36, 186-195 (1995).

14. Greyson, B. Posttraumatic stress symptoms following near-death experiences. American Journal of Orthopsychiatry 71, 368-373 (2001).

15. Ibid.

16. Timmermann, C., et al. DMT models the near-death experience. Frontiers in Psychology, 9 (2018).

17. Klemenc-Ketis, Z., Kersnik, J., & Grmec, S. The effect of carbon dioxide on near-death experiences in out-of-hospital cardiac arrest survivors: a prospective observational study. Critical Care 14, R56 (2010).

18. Chawla, L.S., et al. Characterization of end of life electroencephalographic surges in critically ill patients. Death Studies 41, 385-392 (2017).

Neuroscience

How We Remember Last Weekend

High-frequency oscillations that ripple through our brains may generate memory and conscious experience.

By Marco Altamirano    September 28, 2022

One of the most difficult questions for the science of memory deals with the most obvious fact about memories: We can, well, recollect them. The problem is that no one knows exactly how we call to mind, and with such ease, that party last weekend, with all the samba dancing and clinking of ice in glasses, the scent of circulating hors d’oeuvres, the jolt up the spine from catching a lover’s eye across a crowded room. All these emotional and sensory elements, we know, are registered in distinct areas of the brain—but how is it that we can reminisce and conjure them all up at once, recalling the mental event as a single experience?

A group of scientists based at the University of California, San Diego, have found a promising mechanism that may explain not just how recollection works, but also, more broadly, conscious experience itself.

In a recent paper published in the Proceedings of the National Academy of Sciences, lead author and neurophysiologist Charles Dickey identified patterns of ripples—brief high frequency oscillations in neural activity—that synchronize across the human brain during spontaneous waking and memory recall.1 These ripples fan out across distant areas of the cerebral cortex (the wrinkly surface of the brain) that are responsible for the sensory elements involved in any mental event, and extend to the hippocampus, a seahorse-shaped structure key to memory. Many studies had previously investigated ripples in the rat hippocampus and their relationship to memory, but Dickey only recently identified ripples in the human cortex.

There are several competing theories about networks of neuronal activity that may facilitate communication between different areas of the brain to give rise to conscious experience.2 But this may be the first observed mechanism that could potentially solve the so-called “soft problem” of consciousness—the quest to identify the physical processes in the brain that underpin mental events. The soft problem is in contrast to the so-called “hard problem” of consciousness, the question of how something physical like the brain can possibly generate the rich, clearly mental quality of lived experience.

RIPPLE: Instead of a single ghost in the machine, we may host an infinite number of ghosts, in the form of an incredible procession of ripples, which fan out across the brain. Illustration by Kateryna Kon / Shutterstock

“We have to solve the soft problem of consciousness first, and the hard problem doesn’t really impede that search,” said Eric Halgren, senior author of the paper and director of the UC San Diego lab where Dickey did his graduate research.

The difficulty behind the soft problem of consciousness is that there isn’t a readily identifiable locus of consciousness, though many possibilities have been proposed over the centuries. Rene Descartes, the 17th-century philosopher, thought the seat of consciousness was the pineal gland, a small gland in the center of the brain, but we now realize it’s probably responsible for producing and regulating melatonin for our sleep cycles instead. Two hundred years later a German physiologist named Johannes Müller suggested the medulla oblongata, the stem-like structure at the bottom of the brainstem, was responsible for consciousness. (We now know it’s chiefly responsible for involuntary functions like heartbeat, breathing, vomiting, and sneezing.)

This mechanism could solve the “soft problem” of consciousness.

Later, the English physiologist William B. Carpenter nominated the thalamus, a boot-shaped structure in the middle of the brain, as the hub of consciousness, and then celebrated biologist Francis Crick considered the claustrum, a neural structure that appears like a crown of thorns around the cortex. It turns out that both the claustrum and the thalamus may indeed play important roles in certain features of consciousness, but their candidacies as coordinating centers for consciousness remains largely conjectural.

The largest hurdle for the search for consciousness in the brain was somewhat inadvertently discovered by 20th-century neurosurgeon Wilder Penfield, who was treating patients with severe epilepsy by lesioning the malfunctioning areas of the brain that were instigating seizures. During his surgical procedures, Penfield noticed that certain movements or perceptions could be manufactured by stimulating different areas of the cortex; stimulation via an electrode on your forehead could produce the smell of a bandage, while one on the back of your head might make you see the Buddha and wiggle your pinky. This presented a problem of brain geography that is sometimes called “the binding problem”: How do distant areas—the ones involved in, say, the smell of bandages and the ones involved in the throbbing pain of the wound under the bandage—communicate with one another to produce a seamless experience? Enter brain ripples.

Brain ripples are so named because these high-frequency oscillations of neural activity appear as ripples on stereogram readouts of the cortex called electroencephalograms.

“The cortex is where we have all our sensory areas, so experiences are primarily a cortical phenomenon,” Dickey said. “The idea is that an experience happens, and this affects the firing of synapses between specific sets of sensory neurons, strengthening their connections.” He added, “Ripples may modulate this synaptic activity to consolidate the memory within the cortex.”

Ripples unify our experience by the moment, playing a memory like a song.

“What’s really interesting about brain ripples as a mechanism for studying consciousness and memory is that they’re primarily temporal,” Halgren said. Ripples emanate and multiply across the cortex spatially, but in the way that music fills a room. Ripples form fleeting but repeated patterns. They come and go like memories and experiences themselves.

While these specific kinds of human cortical brain ripples are newly discovered, the purely theoretical underpinnings of them have been around since the late 1970s. One popular theory of consciousness is known as “binding-through-synchrony,” which postulates that a synchronization of neural activity is what organizes different sensory cues from different regions of the cortex into coherent experience. The theory has been  around for decades, but evidence for it (beyond some experiments with the visual systems of cats) was limited.3 Brain ripples are the first observable and testable mechanism that could corroborate the binding-through-synchrony hypothesis.

What could this mean for consciousness and the study of the mind? The mechanism of brain ripples seems to suggest that consciousness may not have a center, or a fixed unifying organ controlling it. Instead, they suggest a decentralized consciousness, where frequencies accompany and hold our thoughts like ghostly electrical consorts, appearing and disappearing as quickly as they do. Instead of a single ghost in the machine, we may host an infinite number of ghosts, in the form of an incredible procession of ripples, unifying the entirety of our experience by the moment, playing a memory like a song, taking its notes from the distributed and diverse functions of our sensory apparatuses.

In the end, perhaps the search for consciousness was impeded for so long because we were searching for the wrong kind of thing, something physical or structural rather than phenomenal—a pineal gland instead of an electric signature, a neuro-chemical ghost that pulses across the cortex.

The real test for whether brain ripples underpin conscious experience might include cortical stimulation experiments in humans to test if certain kinds of experiences can be induced by ripples (or, conversely, if conscious experiences can be interrupted by disrupting cortical ripples). If further research concludes that ripples do in fact coordinate the communication of all the different parts of the brain responsible for an experience of, say, a beach in August (with its hot sand everywhere, the blazing sun and cooling ocean, and drying off while waves whoosh nearby), then Dickey’s study could be an immense step forward for solving the soft problem of consciousness.

Marco Altamirano is a writer based in New Orleans and the author of Time, Technology, and Environment: An Essay on the Philosophy of Nature. Follow him on Twitter @marcosien and Instagram @cocomarquito.

Lead image: GoodStudio / Shutterstock

References

1. Dickey, C.W., et al. Widespread ripples synchronize human cortical activity during sleep, waking, and memory recall. Proceedings of the National Academy of Sciences 119 (2022).

2. Maillé, S. & Lynn, M. Reconciling current theories of consciousness. The Journal of Neuroscience 40, 1994–1996 (2020).

3. Fries, P., Schröder, J., Roelfsema, P.R., Singer, W., & Engel, A.K. Oscillatory neuronal synchronization in primary visual cortex as a correlate of stimulus selection. The Journal of Neuroscience 22, 3739–3754 (2002).

Philosophy

- What Is Misinformation Doing to Us?

Philosophy

What Is Misinformation Doing to Us?

One question for Daniel Williams, a philosopher at the University of Cambridge.

By Brian Gallagher    September 13, 2022

Explore

One question for Daniel Williams, a philosopher at the University of Cambridge who studies recent advances in psychology to understand how various forms of irrationality and bias are socially adaptive.

Courtesy of Cambridge University

What Is misinformation doing to us?

Since 2016, there’s been a growing panic about how much misinformation is affecting what people believe and do. But what I argue in a recent paper, published in Economics & Philosophy, is that the panic around misinformation is misguided. The share of misinformation in most people’s information diet, in countries like the United States and the United Kingdom and in Northern and Western Europe, is pretty negligible. (There’s much less research when it comes to other countries around the world.) The minority of the population that tends to consume a lot of misinformation tend to be people who are already extremely partisan or dogmatic on certain issues anyway, which suggests that the information is not really changing their behavior.

Before there’s any kind of policy-level decision making when it comes to things like censorship and banning, it’s really crucial to get that causal arrow correct: Is it the case that people are being misinformed by the misinformation, or are they seeking out evidence and arguments to rationalize those beliefs? People tend to be pretty vigilant when it comes to acquiring information from different sources—if anything, relying too much on their own intuitions than they do from information acquired from other people.

In his great book Not Born Yesterday, Hugo Mercier goes through an enormous amount of evidence showing how sophisticated people are when it comes to evaluating information that they encounter. The first thing people do, not always consciously, is a kind of plausibility checking. They also ask, “Can I hold this person accountable if they misinformed me? Have they got good arguments? Do I have good reason to believe that they’re a trustworthy source?” All of these different cues people use to weigh up the reliability of information. But the catch is they’re only vigilant in that way when their aim is to acquire accurate beliefs.

When, on the other hand, they’re engaged in motivated reasoning, when they’re motivated to form beliefs because it’s favored by their in-group, say, then people tend to be much more receptive to information if it confirms and rationalizes their favorite narrative. This is where the idea of a marketplace of rationalization comes in. This is any kind of social system in which certain individuals or firms stand to benefit either financially or socially from producing and disseminating information, not really to inform people but to rationalize what people are motivated to believe. There’s a widespread demand for rationalizations of the narratives of different political, cultural, and social groups. Certain ambitious media companies or people on social media stand to benefit from churning out intellectual ammunition conducive to justifying these favorite narratives.

Insofar as people are being “gullible,” it’s almost a strategic gullibility, whereby they’re letting their guard down to accept information because it supports and rationalizes what they’re motivated to believe. It’s not that people are pursuing the truth and then being duped by propaganda and demagogues—although again, I don’t want to say that never happens. For the most part, it’s that people have motivations to view the world in a particular way. And they’re highly receptive to, and indeed seek out evidence and arguments which support, that preferred way of seeing the world.

Membership in crosscutting communities, and also reducing your antipathy to those who belong to different communities—these will really weaken the motivation to engage in what the social scientist, Dan Kahan, called identity-protective cognition, where roughly speaking, you are prioritizing your attachment to a particular social group over forming accurate beliefs. I don’t know how optimistic we should be that people will actually pursue that strategy because especially in a country like the U.S., there is such intense political and cultural polarization. And one of the things that’s difficult about motivated reasoning is that it never feels like you’re engaged in it when you are.

Lead image: Pavlo Plakhotia / Shutterstock

- Brian Gallagher

Posted on September 13, 2022

Brian Gallagher is an associate editor at Nautilus. Follow him on Twitter @bsgallagher.

Physics

- They Probed Quantum Entanglement While Everyone Shrugged

- Are We Getting the Real Stuff in Popular Science?

- Lose Weight the Slow and Incredibly Difficult Way

Physics

They Probed Quantum Entanglement While Everyone Shrugged

This year’s winners of the Nobel Prize in Physics were driven by curiosity, skill, and tenacity.

By David Kaiser    October 5, 2022

Among the quirks that my wife chooses to find amusing, I have a habit of waking up extra early every year on the first Tuesday of October. That’s the time when the Royal Swedish Academy of Sciences announces new recipients of the Nobel Prize in Physics. I have been repeating this ritual every year for about a dozen years, waiting—hoping—to hear a particular announcement. This year it finally arrived.

The winners of the Nobel Prize in Physics for 2022, Alain Aspect, John Clauser, and Anton Zeilinger, have been pioneers in the study of quantum entanglement, one of the most beguiling features of quantum theory. Albert Einstein and colleagues helped to identify the notion back in the 1930s, only to reject the idea as too outlandish to be true. Thirty years later, physicist John Bell introduced an ingenious way to design an experimental test that might confirm or rule out such strange-sounding behavior.

Quantum theory predicts that if two or more particles are prepared in a particular way, their behavior should remain correlated, even after they have moved very far apart. Perform a measurement of some property of particle A and—wham!—particle B should display specific behavior, even if they are light-years apart. Stranger still, the particles’ properties should align even when physicists measure different properties of each particle, selecting the measurements to perform on each member of the pair at random.

DON’T GO CHASING PHILOSOPHY: When young physicist John Clauser told his Ph.D. advisor he wanted to test the quantum theory that the behavior of particles remains correlated (envisioned above), his advisor told him not to chase “philosophical” topics. Illustration by local_doctor / Shutterstock.

The experiments that Bell had in mind were clever, and they also seemed feasible. No need to build a huge particle accelerator or launch a massive new satellite. And yet years went by before other physicists even cited Bell’s article, let alone rolled up their sleeves to give it a go.

One of the first to reach out to Bell was a young John Clauser. Clauser had stumbled upon Bell’s article while browsing journals in the library as a graduate student. Excited by what he read, he rushed to his Ph.D. supervisor to suggest they conduct the type of experiment that Bell had proposed. To Clauser’s frustration, his advisor responded with (no doubt well-intentioned) advice: Stick with more mainstream topics for the dissertation, don’t chase such “philosophical” topics as entanglement.

Yet Bell’s idea stuck, and a few years later, as Clauser was preparing for his postdoctoral position at the Lawrence Berkeley National Laboratory, he wrote to Bell to ask if other physicists had conducted any such tests in the interim. As Bell later recalled, Clauser’s letter was the first time any experimental physicist had evinced interest in Bell’s work. Bell quickly responded: If Clauser did manage to measure behavior different than the quantum predictions—and hence more in line with Einstein’s expectations—that would “shake the world!”

I had the great luck to partner with Anton Zeilinger and his group on “Cosmic Bell” tests.

With Bell’s encouragement, along with critical input from a few like-minded colleagues, Clauser and Stuart Freedman (a graduate student at the time) set out to conduct the first Bell test. After scrounging for spare parts around the laboratory, they managed to collect data on thousands of pairs of particles, finding exactly the correlated behavior predicted by quantum theory. They published their results in a flagship journal in 1972, and then … nothing. The following year, citations to Bell’s work, previously just a trickle, dropped by more than half. Some academic leaders doubted whether investigations of entanglement counted as “real physics.”

An ocean away, just outside Paris, Alain Aspect had also become captivated by entanglement. Like Clauser, he aspired to conduct a Bell test in a laboratory. His main ambition was to perform an experiment that could home in on the instantaneousness of entanglement. He made a pilgrimage to CERN in Geneva, where Bell worked, to ask Bell himself whether such an experiment would be worthwhile. Bell’s first question: “Do you have a permanent position?” The topic still moldered on the margins.

Like Clauser, Aspect pressed on. In a virtuoso experiment with colleagues in 1982, Aspect used super-fast switches that could change each particle’s path en route to the measuring devices. The switches changed back and forth 100 million times per second. The detector toward which a given particle would be directed was determined while that particle was in flight. Moreover, the two measuring stations were far enough apart that information from one side of Aspect’s experiment couldn’t possibly be communicated to the other side before measurements on both particles had been completed. Aspect and his colleagues sent nearly a trillion pairs of particles through the apparatus and they, too, found the spooky correlations precisely as quantum theory predicted.

At first Aspect’s beautiful experiment, like Clauser’s a decade earlier, was met with a collective shrug. For the next several years he focused on other areas of physics, frustrated by many colleagues’ indifference to topics like entanglement.

They published their results in a flagship journal in 1972, and then … nothing.

The third recipient of this year’s prize, Anton Zeilinger, showed equal tenacity, ingenuity, and persistence. With several colleagues he extended Bell’s work to the case of three or more entangled particles. In the 1990s, he and his group first succeeded in teleporting an entangled state, transferring the special correlated behavior to a third particle. Soon after that, his group measured the tell-tale correlations among particles even after they had flown 100 miles apart.

Zeilinger, too, pressed on even when many colleagues considered entanglement to be a sideshow. In fact, for decades he worked tirelessly to shore up Bell tests, conducting several trailblazing experiments to address various “loopholes”—far-fetched but still logically consistent scenarios by which an Einstein-like scenario might account for all of those correlated measurements on pairs of particles.

My friends Andy Friedman, Jason Gallicchio, Alan Guth, and I had the great luck to partner with Zeilinger and his group on some of his most recent experiments. In our “Cosmic Bell” tests, we turned the universe itself into a pair of random-number generators, determining which measurements to perform on Earthbound particles based on split-second measurements of light from distant galaxies. Our goal was to ensure that the patterns in the Earthbound particles’ behavior could not be traced to information, obtained in advance, about which particular measurements would be performed on each particle.

Prior to experiments like ours, there had remained open the possibility that the correlated measurement outcomes might have been due to a prior correlation between the production of entangled particles and the choices of measurements to perform on each. That would be as if a student had received a copy of a pop quiz the night before it was handed out in class: She would know in advance which specific questions would be posed, and in which order.

So Zeilinger and our team took advantage of the huge distances to faraway galaxies to separate the production of entangled particles on Earth from the events that would decide which measurements would be performed on them. In the end—thanks to Anton’s prowess as a negotiator as well as a physicist—we were able to secure valuable telescope time at the beautiful mountaintop observatory on the island of La Palma, in the Canary Islands. By using light from high-redshift quasars, we managed to constrain any such pop-quiz-in-advance mechanism to need to have occurred no more recently than 8 billion years ago—eons before there was a planet Earth, let alone an Albert Einstein to ponder entanglement.

Remarkably, the achievements by Clauser, Aspect, and Zeilinger now stretch well beyond esoteric questions about how the world works. Around the world today, research expenditures in the field of quantum information science exceed $1 billion per year, spanning academic laboratories, government facilities, and industrial efforts. Next-generation technologies like quantum encryption and quantum computing are now being built by turning entanglement into a resource and not just a curiosity.

Max Planck, who helped to create quantum theory more than a century ago, famously quipped that new scientific ideas do not triumph by convincing the skeptics. Rather, Planck argued, the critics eventually die and a new generation grows up for whom the once-strange notions seem familiar. Thankfully Alain Aspect, John Clauser, and Anton Zeilinger did not have to wait quite that long. Nonetheless, their special recognition this week marks the tail end of a half-century journey. Driven by curiosity and skill—mixed with a bit of stubbornness—they dug in, did their best, and never lost sight of the long view.

David Kaiser is Germeshausen Professor at the Massachusetts Institute of Technology, where he teaches physics and the history of science. He wrote about the history of quantum entanglement and Bell tests in his book How the Hippies Saved Physics: Science, Counterculture, and the Quantum Revival. His latest book is “Well, Doc, You’re In”: Freeman Dyson’s Journey Through the Universe.

Lead art: From left, Alain Aspect, John F. Clauser, and Anton Zeilinger. Courtesy of nobelprize.org

Physics

Are We Getting the Real Stuff in Popular Science?

When it comes to physics, says Sean Carroll, you need the math.

By Kevin Berger    September 21, 2022

Sean Carroll is one of the best writing scientists in the business. He’s the paragon of a writer who understands his subject completely and can explain it with clarity and ingratiating authority. The physicist transforms concepts in his field into prose that makes lay readers like me think we can understand the emergence of spacetime and quantum mechanics and explain them to friends at dinner parties. Which I have done, thanks in part to two of Carroll’s books The Big Picture and Something Deeply Hidden.

GOOD SPORT: Sean Carroll says his goal to deepen people’s knowledge of the natural world by explaining key math equations is analogous to things he’s done in his personal life, notably learning more about poker and basketball. “When you’re watching people play basketball or poker, you ask, ‘Why did they just do that?’ Usually there’s a good reason. And knowing that reason provides new insights.”

Carroll has a felicitous phrase for his approach to describing “the world at its deepest level,” and that’s “poetic naturalism.” He adopted the phrase from poet Muriel Rukeyser, who wrote, “The universe is made of stories, not of atoms.” Throughout his career, for years as a research professor at Caltech, and now a professor of natural philosophy at Johns Hopkins University, Carroll, 55, has told stories about the ways of the natural world—poetic in how they ring true.

Which is why Carroll’s latest book, The Biggest Ideas in the Universe: Space, Time, and Motion—the first in a trio of books that verse readers in the laws of the universe—is a jolt. It exposes an anxiety lurking beneath the surface of popular science, which is we’re never getting the full picture. And why not? Because we’re missing math. In The Biggest Ideas in the Universe, Carroll sets out to rectify our wayward knowledge. You can read all the words you like about Einstein’s theory of general relativity, how mass and energy cause spacetime to curve, Carroll writes, “but until you understand this equation you won’t really understand Einstein’s theory”:

Carroll fleshes out the relatively short book with patient and cogent explanations of the equation’s symbols and the concepts behind them. Comprehension is challenging, for sure, for readers like me without a math background. But Carroll, as he explains with poise in our recent interview, is undaunted. He’s certain good readers will emerge, if not the next Fields Medal winners, new converts to calculus. What jolted me most about the new book, though, was its implication, seemingly in contrast to Carroll’s poetic naturalism, that readers will never grasp the world at its deepest level from prose alone. Carroll was revealing a crack in the popular science mission, and I was excited to ask him about it.

Let’s start with the first sentence of The Biggest Ideas in the Universe: “My dream is to live in a world where most people have informed and passionate views about modern physics.” That’s a very admirable dream, Sean.

Well, I’m someone who is a professional physicist, but I also have broader intellectual interests. I’m a little jealous of people in other fields whose work can be discussed knowledgeably by people outside their own disciplines, whether it’s economics, biology, or history. But there’s a barrier in physics and math. The way we speak about what we do to nonexperts is limited in a way the other fields aren’t. My strategy is to bite the bullet and teach people the equations.

You write, “You can read books, go to lectures, watch videos, listen to podcasts. The good news is that we do have a vibrant ecosystem of such resources, and it’s possible to learn quite a bit, albeit in a somewhat haphazard way. But at the end, you know you’re not getting the real stuff.” What is the real stuff?

The real stuff is precise, it’s rigorous, it’s clear, it’s unambiguous. What that means in practice is it takes the form of equations. It also means it’s not allegorical or analogical. It just says what it says.

My previous book, Something Deeply Hidden, was about quantum mechanics and the many worlds interpretation of quantum mechanics. Whenever you measure a little quantum system, different outcomes become real in different worlds. There are various objections to this view, and various arguments for it. Some of the objections are perfectly good objections. I get it. I don’t think they’re definitive, but I understand why you’re making that objection.

With other objections, I was like, “No, you don’t get it.” One objection was, “Where does the energy come from? Where does the energy come from when you make all these universes?” This is not a question that anyone who understands the equations would ask. If you don’t understand the equations, and you’re just talking about images, and intuitions, and metaphors, that question doesn’t go away.

The real stuff is precise, it’s rigorous, it’s clear, it’s unambiguous. It takes the form of equations.

There are other examples like Noether’s Theorem, the idea that if there’s a symmetry of nature, there’s a conserved quantity. How do you get those kinds of answers? There are a set of things which are crystal clear when you know the math, and utterly obscure when you don’t. I feel guilty if I’m forced to say, “Shut up and listen to the equations.” I never want to do that. I want to provide an explanation.

I understand concepts from physics pretty well when I read good science writers like you. But what am I missing if I don’t get the math?

You’re missing various implications and connotations of the words. I’ve written books without equations. I’m all in favor of it. But whenever you use an analogy, there’s a problem because unwanted implications go along with the analogy. Someone says the expanding universe is like a balloon with galaxies being little dots drawn on the surface of the balloon. You might ask, “What is it expanding into?” The answer is it’s not expanding into anything. You might respond, “But the balloon must be expanding into something.” No, the balloon is just an analogy. “OK, the dots expand. Does that mean galaxies expand?” No, the galaxies don’t expand. So that’s what I mean: The analogy doesn’t give you the real stuff about the expansion of the universe.

Are analogies for math always going to fail?

If we try to make perfect analogies, yes. There’s no reason why something like the expansion of the universe or the collapse of the wave function should have an analogy with anything in our everyday experience. It’s a different realm. It’s a realm that we didn’t know about thousands of years ago when language was invented.

There are times when I talk about the geometry of space, and I say, “Look, here is the formula. It works in any number of dimensions. It doesn’t matter whether space is three dimensional, four dimensional, five dimensional. If you get the equation, the concept is clear.” If you don’t get the equation, how do you visualize 10-dimensional spacetime? The answer is you don’t. You need the equation that tells you how spacetime behaves.

I admit that without a background in math, I struggled with the equations in The Biggest Ideas in the Universe, despite your fluid explanations of the symbols and what they mean. I did, though, gain a good sense of how universal principles are established in physics. The universe has foundational behaviors, regardless of the situation—the math says so.

I’m glad to hear you say that. And there are many examples. For instance, when the universe expands, light redshifts. Distant galaxies are redshifted. There was an early theory that was a competitor to that idea, the “tired light theory,” that idea that light just gets tired. No, it doesn’t. How do you know? Here’s the equation that says what light does. Light can propagate by itself, according to its equation. That’s its natural thing to do.

In science, we propose hypotheses, and we build theories in an attempt to fit the data. The data come in and we try to make a model from it. And when we succeed like Einstein did, the equations are much smarter than us. The equations that work can be extrapolated way beyond what we expected.

Einstein himself didn’t know about the Big Bang, but his equation did. And that’s just endlessly amazing. That’s why physics—even though I try to be ecumenical—is the most amazing science: These little ideas we come up with in our offices correctly describe things happening billions of years ago and billions of light-years away. And that’s only possible because of the equations.

So do we need to understand the language of math before we can touch the foundational truths about the universe?

Yes, I think that’s true. But I would emphasize that it’s a continuum, not a yes or no. When someone says A squared plus B squared equals C squared, Pythagoras’ theorem, most people don’t struggle with that. They get it. If you see a right triangle, and A, B, and C are drawn on the lines, and C is the hypotenuse, and you know what squared is, and you know what plus is, you’re not really going to struggle with that. To go from there to Einstein’s equation is a matter of degree, not of kind. And different people will be comfortable going different distances, but to pretend it’s an insuperable barrier is a mistake.

I appreciate what you’re saying about getting the “real stuff.” Knowledge deepens our appreciation. I was once traveling with a wolf biologist in Montana and I always remember something she said to me in the forest, “If you don’t understand ecology, nature is just scenery.” Are you saying something similar about physics? You can look up at the night sky and be awed. But it’s just scenery unless you know what you’re seeing. Would you agree?

I would completely agree. I’ve had similar experiences, but with geologists, not wolf biologists. If you go through the mountains with a geologist, it’s an entirely different experience. If you have a meal with a great chef, it’s an entirely different experience. There’s a depth of understanding if you go to a concert with a composer or a musicologist.

I have been to concerts with composers and musicologists and it’s an incredible experience to have them describe what we’ve heard. Though I’ve also been to concerts with people who don’t want the explanation, just the experience.

Right. It’s not for everybody. And no one person, no matter how ambitious they are, can be an expert in everything. So hopefully everybody has some pleasures that they just enjoy at a superficial level. I’m like that about classical music. I have no deep understanding of it, but I like it. I have a mildly deeper understanding of jazz, but I couldn’t tell you what mode someone was improvising in during their solo. And that’s fine.

The only reason we’re doing it is because humans are curious creatures and want to understand.

But with the things that I am an expert on, there’s no question that the character of the pleasure is different. That’s why I keep hammering on about the equations. In part, my hammering on about the equations is so people don’t feel cheated when they get The Biggest Ideas in the Universe. I’m not hiding the fact that there’s a lot of equations in there. But I try very hard to explain the principles behind them. I’m not just saying, here’s what a derivative is. I’m saying, here’s how physics works in the Laplacian paradigm, where you have the positions and velocities of everything, and you can predict the future. Why should you be able to predict the future from the positions and velocities of everything? That’s something that can be understood.

I’m not insisting that everyone become an expert in physics. What I’m trying to do is open a door for people who don’t want to become professional physicists but want to understand things better. I don’t think there should be this hard and fast wall between physicists and non-physicists.

Not all scientists agree, right? Even though I’m in the popular science business, I respect scientists who want to remain in their labs, do their work, and not feel they have to explain it to the lay public. Have you encountered scientists like that?

Sure.

What do you say to them?

I have a very consistent line. I don’t think every scientist has a duty to explain themselves to the wider world. I do think every scientific field has a duty to explain itself to the wider world. I don’t have an issue with people who don’t want to do it themselves, but with people who don’t value it when their colleagues do it. They should be extraordinarily grateful if they don’t want to talk to the public, but somebody else does. That’s taking a huge burden off them.

In fields like mine, where we’re thinking about dark matter and the birth of the universe, there’s no practical, technological, or economic application. The only reason we’re doing it is because human beings are curious creatures and want to understand. If we do the research and understand something, and don’t tell anybody, what’s the point? Why should we be supported by society? So I think the endeavor to explain what we’re doing to the public is extraordinarily valuable.

Did you have a Road-to-Damascus moment in your career when you realized you wanted to explain physics to people?

Not really. I always wanted to explain it to people. I am a physicist, technically, but also a philosopher. My job now is more about thinking and understanding and sharing and learning than it is about the subject matter of physics. The joy I’ve always had in physics was not only understanding new things but talking about them and explaining them to other people. And appreciating the good explanations I could get from other people. Do you know the famous dedication page of the general relativity textbook, Gravitation, by Misner, Thorne, and Wheeler?

No, I don’t.

I just unpacked it here in my new office. It’s 1,000 pages. It’s known as the phone book. Here’s the dedication. “We dedicate this book to our fellow citizens who, for love of truth, take from their own wants, by taxes and gifts, and now and then send forth one of themselves as dedicated servant, to forward the search into the mysteries and marvelous simplicities of this strange and beautiful universe, our home.”

So that’s the idea. We are supported by society. We’re not putting food on the table or anything like that. But a healthy society has enough resources to have some musicians and some artists and some scientists. Some scientists have direct economic, tangible benefits. Some don’t. Some of us are closer to musicians and artists. And so we have to give back as a field. It’s an absolutely central part of the endeavor.

You’re a great public defender of science against pseudoscientists, intelligent designers, religious figures—the whole parade. In my more cynical moments, I wonder, Why bother?

It’s true that there are plenty of people whose minds are made up. The closest correlation is, how old are they? You’re not going to reach some people of a certain age. But you do reach the young people. They are not hardened yet. I don’t see myself as a proselytizer or as a debater. I just want to help people understand and let them make up their own minds. And the good news is once you do that, they often are led in good directions.

Are science and religion “non-overlapping magisteria,” as Stephen Jay Gould believed?

I am not in any way a believer in the non-overlapping magisteria. I think these magisteria overlap seriously. There are ways of thinking about the world and what it’s made of, how it works, what its purpose is, that belong to both science and religion and spirituality. They overlap in certain places. And don’t overlap in others. Religion is a more comprehensive set of ideas, dealing with morality and community and behavior, about which science doesn’t say anything. But religion also says something about the nature of reality. And science also has something to say about that.

What are specific places where science and religion overlap?

Why does the universe exist? Why is there something rather than nothing? A scientific answer or even a modern philosophical answer, might be, “There need not be any answer to that question.” But that’s not what the religious arguments are going to tell you. They’re going to say, “No, we need an explanation for this.” There is a principle of sufficient reason, following Leibniz and so forth. It’s just very different.

I tell my colleagues this because it’s strange for modern physicists and philosophers to remain silent about religion, especially the physicists and philosophers who work in fundamental metaphysics, ontology, quantum mechanics, or spacetime. In those fields, as I said, we’re not building a better smartphone. We’re not curing cancer. What is the overlap we have with people’s everyday lives? Well, it’s the fundamental nature of reality. And the fact that the world works perfectly fine as a system obeying laws, without any support from anything supernatural. It’s much easier to understand natural selection or the origin of the universe at the Big Bang when you understand the science. And that might affect your views on the need for God.

Who was the first good popular science writer in physics?

We are in the special situation that one of the early pioneers was named Galileo. I mean, great popular physics writing was the invention of physics, and Galileo was really good at it. Even Einstein was pretty good at explaining things. And then people like Richard Feynman, George Gamow, and in a different way, Carl Sagan, came along. So we’ve always had that tradition. We didn’t have to invent it, but we do need to be reminded that it’s important and it needs to be rediscovered and appreciated.

Where does popular science go wrong?

Like popular anything, or media anything, it can sensationalize. It wants everything to be the latest and the greatest. The world has changed now with the internet. But it used to be that if you wanted to write something that would help explain some concept, you would need a news hook to explain it. Why would anyone care about science unless something had just happened? And I’m like, well, relativity is still true, even if nothing happened recently.

There’s something extra in science journalism that’s not there in other journalism.

There’s an ecosystem where researchers want to get attention. They want to get grant money. They have media relations departments at their universities. They want to over-claim what they do. And the journalist naturally must place some degree of credence in what the experts say. But you have to check against people who are not the ones doing the study, and you have to take their warnings seriously.

I’m a big believer in science writing and science journalism. As I said, I don’t think every scientist should be devoting their efforts to popularization. I think that some should, but almost every scientist has some interesting work that they’re doing.

So there’s plenty to be done by good journalists to think about what’s interesting that is going on, and not just what is the work being done by the most charismatic scientist out there. And they have to make it explicable, understandable, and tell some of the human story. I’m a big believer in the human story. That’s something that should be emphasized.

But you have to balance it. It defeats the purpose if it’s just the human story. There’s something extra in science journalism that’s not there in celebrity journalism. The other thing that is special about science journalism is the scientist can explain something and it’s the job of the journalist or the writer to translate it. That translation, as we were saying, often involves either analogies or extrapolation. And it’s possible to go wrong. So, to me, science journalism, more than political journalism or celebrity journalism, needs to be a back and forth.

I remember my very first experience with my own work being written about was when I was a graduate student. I was working on a project of whether you can build a time machine in a simplified three-dimensional spacetime. The journalists talked to us and got it right. At some point in the article, they mentioned a closed universe. And the editor, trying to clear things up, added a line saying, “A closed universe is one that will expand and then collapse.” But that’s not true in a three-dimensional spacetime. It’s true in a four-dimensional spacetime. They didn’t check with the scientist before putting it in.

Journalists are professionals at writing and explaining. Scientists are professionals at doing science. So it needs to be teamwork between them in a way that is different from economics or political science reporting.

Although we can’t always take you at your word. As you say, we have to check what you tell us against other scientists and perhaps contrary evidence, and use our own judgment about how best to inform readers.

That’s why you get paid the big bucks.

Kevin Berger is the editor of Nautilus.

Lead image: Tynyuk / Shutterstock

Physics

Lose Weight the Slow and Incredibly Difficult Way

Trying to answer a silly question can take you through some serious science.

By Randall Munroe    September 21, 2022

This seems simple enough. Your weight comes from the Earth’s gravity pulling you down. The Earth’s gravity comes from its mass. Less mass should mean less gravity. Remove mass from the Earth, and you’ll lose weight.

You decide to give it a try.

Removing lots of mass from the Earth will take a lot of energy, so you start by seizing the entire planet’s oil reserves.

You process the oil into fuel and use it to launch several hundred billion tons of rocks into orbit. This shaves off an average of 0.2 mm of rock from the Earth’s surface. You hop on the scale.

Okay, it didn’t work. But that makes sense; a few hundred billion tons is a tiny fraction of the Earth’s mass.

Burning the Earth’s other fossil fuels helps a little—especially coal, which there’s quite a lot of—and lets you remove almost a millimeter of the Earth’s surface.* You step back on the scale.

Darn.

You need more energy.

You cover the entire planet with highly efficient solar panels and spend a year soaking up all the sunlight that strikes the Earth and using it to power your rock launchers. Humanity lives in the shade under your panels. People are probably pretty mad at you at this point.

A year’s worth of sunlight would give you enough energy to remove nearly 100 trillion tons of rock—several inches of the planet’s surface. Sadly, that’s not enough.

Clearly, this incremental approach isn’t working.

You need more power. Rather than capturing only the small portion of the sun’s energy that hits Earth, you decide to capture all of its energy by building an energy-collecting enclosure around it—a Dyson sphere. Once you’ve harnessed the sun’s entire output, you have enough energy to start stripping away the Earth’s surface much more quickly.

The Earth’s rocks get hotter the deeper you go. After you strip away a few hundred meters of the crust, people start to notice the ground is warming up. By the time you remove a kilometer of rock, the surface is up to 40 degrees Celsius. That might feel nice on your feet when you get out of bed on a cold morning, but it will make life pretty uncomfortable. Also, since you’ve removed the tops of all the various hot spots, all the world’s volcanoes would erupt.

You check the scale.

Darn.

You use your Dyson sphere to remove more rock. You’ve now stripped away a 5-kilometer layer, which takes about 20 minutes. (For good measure, you spend another few minutes removing the oceans.) The Earth is no longer remotely habitable. Thanks to the exposed magma under the Yellowstone super volcano, northwestern Wyoming is a lake of lava. The ground in most places is hot enough to boil water and start fires.

You try the scale again.

That’s fine, you just need to remove more rock, perhaps with some kind of sun-powered vegetable peeler.

You slice away 20 kilometers of crust, which exposes the Earth’s mantle over much of the former sea floor.

Well, no one ever said losing weight was easy. You take off another 20 kilometers, removing layers of molten mantle and pockets of deep crust.

You keep going. After four hours of work with your planet peeler, you’ve removed 60 kilometers of mostly molten rock. When you step on the scale, you finally see a change.

You’re one pound heavier.

How could this be?

If the Earth were of uniform density, removing layers would make you lighter. But our planet gets denser the deeper you go, and the density cancels out the mass loss. The planet is getting a little lighter as you remove the surface, but you’re also getting closer to that dense core. The net effect is that removing the Earth’s outer layer makes its surface gravity stronger.

Gravity keeps increasing as you go deeper. It only levels off after you’ve shaved off about 3,000 kilometers, reducing the Earth’s diameter by half and ejecting two-thirds of its mass. (This takes your sun-powered planet peeler about a week.) Your weight peaks at about 207 pounds, after which it starts falling as you start removing the denser outer core.

Once you’ve removed 3,450 kilometers of rock, your weight gets back down to what it was when you started. After 3,750 kilometers of rock, you finally achieve your goal of losing 20 pounds. At this point, you’ve removed 85 percent of the Earth’s mass. But you’ve lost weight!

This plan has some flaws. It destroys the Earth, yes, but it’s also unnecessarily inefficient. There’s a much easier way to reduce the Earth’s gravitational pull on you without changing your mass or leaving the surface.

A spherical shell of matter doesn’t exert any gravitational force on objects inside it, which means that if you go underground, the layers of rock above you stop contributing to your weight. From a gravitational point of view, it’s as if they vanish. You didn’t actually need to remove mass from the Earth, you just needed to go under it. You could’ve avoided all that work with a comparatively simple tunnel.

Did you at least avoid exercise? Well, sort of. Your project ended up requiring you do an awful lot of work. Removing the Earth’s surface required 5 x 10^28 calories of energy, which is more calories than would be burned if the entire human population started doing intense workouts 24 hours a day from now until when the sun burned out and its remnant cooled to room temperature.

If your goal was to avoid work, you could not have failed more badly.

Randall Munroe is the author of the #1 New York Times bestsellers What If? and Thing Explainer, the science question-and-answer blog What If, and the popular webcomic xkcd. A former NASA roboticist, he left the agency in 2006 to draw comics on the internet full-time. He lives in Massachusetts.

Excerpted from What If? 2 by Randall Munroe. Copyright © 2022 by Randall Munroe. Excerpted by permission of Riverhead, an imprint and division of Penguin Random House LLC, New York. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.

* People might complain, but on the plus side, that millimeter probably includes all the grime and dirt on the floor. Maybe you can spin it as a free cleaning.

Psychology

- I Didn’t Know My Mind Was So Strange Until I Started Listening to It

- Should Social Psychologists Experiment with Psychedelics?

- Why Should We Delay Gratification?

Psychology

I Didn’t Know My Mind Was So Strange Until I Started Listening to It

I took part in an experiment to decipher my inner thoughts.

By Phil Jaekl    October 4, 2022

One fine spring afternoon this year, as I was out running errands in the small Norwegian town where I live, a loud beep startled me into awareness. What had just been on my mind? After a moment’s pause, I realized something strange. I’d been thinking two things at the same time—rehearsing the combination of a new bike lock and contemplating whether I should wear the clunky white beeper that had just sounded into a bank.

How, I wondered, could I have been saying two things simultaneously in my mind? Was I deceiving myself? Was this, mentally, normal? I silenced the beeper on my belt and pulled out my phone to make a voice memo of the bizarre experience before I walked into the bank; aesthetics be damned.

I was in the midst of an experiment that involved keeping a log of my inner thoughts for Russ Hurlburt, a senior psychologist at the University of Las Vegas. For decades, Hurlburt has been motivated by one question: How, exactly, do we experience our own mental life?

My career in cognitive neuroscience didn’t prepare me for this.

It’s a simple enough question. And, one might argue, an existentially important one. But it’s a surprisingly vexing query to try to answer. Once we turn our gaze inward, the subjective squishiness of our mental experience seems to defy objective scrutiny.

For centuries, philosophers and psychologists have presumed our mental life is composed primarily of a single-stream inner monologue. I know that’s what I had assumed, and my training in cognitive neuroscience had never led me to suppose otherwise.

Hurlburt, however, finds this armchair conclusion “dramatically wrong.”1 Sure, it’s relatively common to experience “brain chatter,” those voices in our head that keep us up at night or haunt us with things we should have said. But Hurlburt’s research suggests that inner speech is not nearly as consistent, frequent, or even as universal as many of us might assume.2 He takes a much broader perspective on our inner lives, one that goes way beyond the contents of what we say to ourselves to include experiences that are hard to put words to at all.

Emerging from engineering school in the 1970s, Hurlburt decided to forgo a career in his field and instead take up psychology to pursue his growing obsession with how we experience the mind. The best way to try to capture the intangible aspects of inner life, Hurlburt reasoned, was to sample people’s thoughts at random times throughout the day—“in the wild” as he calls it. To that end he created oversized beepers that prompt wearers to make a note of what they were experiencing at the moment right before a beep. Soon after, they share their experiences—with him or with trained members of his team—in more detail through careful interviews.

I had written about Hurlburt and his long-running experiment before, and I was intrigued. So I decided to try the experience out myself. When my beeper arrived, I put appearances aside, donned the unwieldy contraption—complete with its dangling, wired-earpiece—and embarked on my own journey into my inner experience.

Over the course of a few months, I made notes on 54 random moments, and I spoke with Hurlburt about each one in detail during nine separate interviews, all lasting at least an hour.

HEARING VOICES: Constantly monitoring and making notes about his mental life, writes Phil Jaekl, was like listening to a narration of his thoughts: “I felt like the words were somehow coming to mind, rather than my actively constructing phrases.” Illustration by VectorMine / Shutterstock.

Hurlburt calls his full approach Descriptive Experience Sampling.3 The process purports to reveal, in detail, the contents, forms, and nuances of our “pristine” inner experience. It requires considerable skill because there’s no ready vocabulary for the contents of inner life. Obtaining accurate descriptions requires being very delicate and careful not to unintentionally lead or persuade participants into a particular belief or assumption. Inner experiences can be dreamlike and elusive. They can include inner speaking, inner hearing, sensory stimulations, feelings, or even just a wordless sense of knowing or thinking something.4 Inside our heads, it seems, almost anything is possible.

According to decades of Hurlburt’s data from hundreds of participants, much of what we presumed about mental life appears incomplete—or just plain wrong.

Take fully formed inner speech, for example, which I had assumed made up much of my own inner life. As Hurlburt explained to me, “People come in thinking to themselves that they are talking to themselves all of the time.” On beeps where they reported inner speech he says, “I would ask them what exactly they are saying to themselves—a pretty reasonable, straightforward question. When they [consistently] can’t answer that question, they come to the conclusion, ‘Well, I wasn’t really talking to myself. I don’t really talk to myself.’” The DES data indicate that on average, inner speaking takes up only about a quarter of mental life.1

When I first started wearing the beeper, I was surprised that I often found it difficult to have any idea what my experiences were, even though they had just occurred. The beeper would go off at relatively mundane moments when there were no significant distractions: walking my dog, sitting at my desk, or eating lunch. Despite having the utmost enthusiasm for immediately describing the content of my inner life, only a moment ago, I found myself drawing complete blanks. Was my mind empty?

Perhaps it was. After slight embarrassment in revealing such inner vacancy, Hurlburt explained that although most participants are able to describe their experiences more easily, “There is no reason why there has to be inner experience at all.” At any wakeful moment, our brains are processing many things in parallel while skillfully keeping most of them out of our attentional focus—things like our body position, the temperature, the noise of an air conditioner. There is no reason why any one must be present in our experience.

As I got more practice with the beeper, I became more adept at identifying and describing my inner life. I began to see that my mind was often pursuing multiple avenues simultaneously.

I found myself drawing complete blanks. Was my mind empty?

One day a beep went off as I was eating lunch at home. In what seemed like an insignificant, ordinary moment, I realized I was having many different, disconnected inner experiences. I was contemplating what to make for dinner (yes, I like food) and was innerly beginning to say “I think I want …” hoping that an idea for a dish would suddenly spring into mind. At the same time, I was watching the bright leaves of a currant bush just outside a nearby window as they shook vigorously in the wind against the clear blue sky. What’s difficult to describe is that I also felt an awareness of the location of the bush relative to a cardboard box that had blown from my patio into a neighbor’s yard. I couldn’t see the box, but it drew my attention because I was planning to sneak into their yard to nab it before they noticed it. It’s difficult to describe the feeling, but the box felt somehow embodied with the leafy bush, and me. It was like a sense of the relevant, connective geometry.

As I reflected on this moment and the one by the bank where I caught myself with multiple simultaneous streams of inner speech, I realized they felt so strange because they challenge the common assumptions that mental life exists as a singular thread of experience^5 and that multiple thought streams typically arise only during altered states of consciousness. The bank incident was even weirder because it comprised two experiences within inner speech. Unlike, say, an audio-visual experience of hearing and seeing someone speaking, for which our brains integrate multisensory information,6 the notion of innerly speaking multiple phrases at once is basically unheard of in established science.

After I revealed these odd experiences with slight uneasiness, Hurlburt quelled my apprehension by one-upping me. Without hesitation he averred that these simultaneous occurrences are not infrequent and, in fact, often have an uncanny spatial element to them. He explained that some, perfectly normal people attribute varied locations to inner voices. “People can have two different inner speeches going on at the same time; one ‘in the back of their mind’ and one in the ‘front’ of their mind, about two different topics at the same time and somehow keep those things straight,” he explained to me. “And inner voices don’t have to be in your head. They can be in your chest or outside of your body.”

Submitting to this research, I also learned that I frequently experienced a kind of opposite feat of inner speech—the “feeling” or apprehension of having just executed non-vocalized speech, but without words. The first instance occurred while I was sitting on my back deck, watching the shadow of a huge cloud front swiftly covering a nearby mountainside. As I watched a portion of the shadow sweep completely across a snow-covered region it moved onto a large, dark, rocky area, where I could no longer see it. At the moment just prior to the beep I felt a notion of “can’t see it anymore” but without actually saying those words in my head. Was it possible to conceptualize specific thoughts without having called upon language at all?

There’s no agreement on what “thinking” actually is.

By this point my mind was starting to be more open about the strange world of inner life. Hurlburt maintains that there are many ways to experience even something as seemingly straightforward as inner speech. “It’s possible to have a sense of having spoken, a sense of speaking, but without any words: So I feel myself to be speaking and I actually know what I’m speaking. I’m speaking ‘I can’t see it anymore,’ even though I don’t experience the words,” he explained.

What Hurlburt found unique about my experiences was that I often had difficulty distinguishing my own inner speaking from inner hearing. Although I had true inner hearing experiences such as a song “in my head,” which felt similar to actually listening to the song, these other instances were somehow different. I felt like I was hearing a voice that was clearly mine yet it was somehow more passively apprehended. It wasn’t like true voice hearing, though, where the heard voice can attribute its own, separate identity and agency.7 As odd as it sounds, the experiences were remotely comparable to listening to a narration of my thoughts. That is, I felt like the words were somehow coming to mind, rather than my actively constructing phrases, as when explaining something difficult and choosing my words carefully. Like now.

When you think a lot about thinking, it gets complicated. Even the term is more ambiguous than one might think (contemplative pun intended). Hurlburt explained that dictionaries define it as a cognitive thing whereas many philosophers and psychologists equate it with inner speaking. After listening in on the inner experiences of so many people over the years, Hurlburt finds each of these assumptions at once partially correct and partially misguided. “Thinking” is a tricky term, it turns out, and, just like “consciousness,” its definition depends on who you ask.

Hurlburt explained further that people often assume that others experience inner life similarly to themselves. But DES reveals that’s not the case. How people experience inner life can be as unique as they are. Someone who innerly speaks only seldomly but visualizes often might believe thinking is a visual thing. And so on with other forms of inner experience. So there’s no agreement on what “thinking” actually is, according to Hurlburt.

As the days logging and describing my thoughts went on, I had lingering questions about the deeply subjective aspects of this approach. So I called Alain Morin, a psychologist at Mount Royal University in Calgary, who also researches inner life. He and many other psychologists have long relied on questionnaires to understand phenomena like inner speech. Recent analysis has found these types of retrospective assessments to be relatively reliable for capturing patterns of self-talk, although not immune to the influence of bias and presupposition.8 They also leave out a vast swath of the inner experience that is difficult to put words to, such as the emotional tone of one’s inner voice or other vague sensations, like my moment gazing at the currant bush. Which is where, Morin contends, DES has much greater power of depth. “It’s probably the best method we have, short of wearing a brain recording device,” Morin told me. “But that’s science fiction, obviously, for now.”

Yet without such advanced technology, Hurlburt’s humble beeper prompted me to learn things about my own mind that even 45 years of existence and a career in cognitive neuroscience had kept hidden from my perception. Multiple speech streams, wordless speech, a strange geometric sense … I would never have known about these capabilities of the mind because my common assumptions about what consciousness is and how we experience it precluded these possibilities. It was at once dispiriting and wondrous to realize just how unaware we are of what our minds are doing almost all of the time. I now can start to imagine the vast oceans of potential experiences within our inner worlds—and the utter uniqueness of those to individual minds. And I owe it all to the awkward white beeper, which I am supposed to ship back to Las Vegas next week, but which I’m tempted to keep.

Phil Jaekl is a freelance science writer and author with an academic background in cognitive neuroscience. His latest book is Out Cold: A Chilling Descent into the Macabre, Controversial, Lifesaving History of Hypothermia. He lives in the Norwegian Arctic in Tromsø.

Lead image: Sangoiri / Shutterstock

References

1. Hurlburt, R.T., Heavy, C.L., & Kelsey, J.M. Toward a phenomenology of inner speaking. Consciousness and Cognition 22, 1477-1494 (2013).

2. Krumm, A.E. & Hurlburt, R.T. A complete, unabridged, “pre=registered” descriptive experience sampling investigation: The case of Lena. Phenomenology and the Cognitive Sciences (2021).

3. Hurlburt, R.T. & Heavy, C.L. Exploring Inner Experience John Benjamins Publishing Company, Amsterdam, Netherlands (2006).

4. Hurlburt, R.T. & Akher, S.A. Unsymbolized thinking. Consciousness and Cognition 17, 1364-1374 (2008).

5. Fernyhough, C., Alderson-Day, B., Hurlburt, R.T., & Kühn, S. Investigation multiple streams of consciousness: Using descriptive experience sampling to explore internally and externally directed streams of thought. Frontiers in Human Neuroscience (2018).

6. Jaekl, P., Pesquita, A., Alsius, S., Munhall, K., & Soto-Franco, S. The contribution of dynamic visual cues to audiovisual speech perception. Neuropsychologia 75, 402-410 (2015).

7. Larøi, F., et al. The characteristic features of auditory verbal hallucinations in clinical and nonclinical groups: State-of-the-art overview and future directions. Schizophrenia Bulletin 38, 724-733 (2012).

8. Racy, F., Morin, A., & Hagerty, J. Concurrent validity and reliability of representative inner speech questionnaires. Psychological Reports0, 1-8 (2022).

Psychology

Should Social Psychologists Experiment with Psychedelics?

One question for Sonja Lyubomirsky, a psychologist at UC Riverside.

By Brian Gallagher    September 27, 2022

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One question for Sonja Lyubomirsky, a psychologist at UC Riverside studying the sources and benefits of happiness, and the author of The How of Happiness: A New Approach to Getting the Life You Want.

Photo courtesy of Sonja Lyubomirsky

Should social psychologists experiment with psychedelics?

Yes. That’s the premise of my recent paper, “Toward a New Science of Psychedelic Social Psychology: The Effects of MDMA (Ecstasy) on Social Connection.” I should add that some researchers put MDMA in a psychedelic category, but it’s usually called an empathogen or an entactogen. On MDMA, people report feeling understood, loved, and cared for—valued. So, it serves as a window into those processes.

For example, we know what brain pathways, and some of the psychological processes, that MDMA affects. There’s more eye contact. People disclose more about themselves. That reveals some of the key ingredients that are important for connection. The key to relationships, according to partner-responsiveness theory, is feeling understood, valued, and loved by your partner, or by the person that you have a relationship with. On MDMA, people who are lonely or socially anxious, or have experienced trauma, can feel like they really connect with other people, or with a particular person, and that carries over to their regular life. I’m not suggesting that people be on this drug all the time, obviously, but it’s a way to bolster this connection that will endure, maybe even have permanent impact.

Have I used it myself? I’ve been told that, in answering this, you are screwed either way. If you say, “No, I don’t use it,” whatever the drug you study, then people respond, “Well, you don’t know what you’re talking about.” And if you say you do use it—“Oh, you’re biased.” I don’t think it’s a magic drug. There’s a little bit of magic to it, I guess. The reason I’m studying it is not because I’ve used it, though I have. It’s because it’s incredibly relevant to what I study. I’ve never seen anything else that can boost connection as much. If that can happen on MDMA, maybe we can bring that into the non-drug world, and borrow the insights.

I’m not an evangelist for these substances. I’m not saying, “Everyone should go do it.” You don’t know what you’re getting on the street. In our studies, we get research-grade MDMA from, I think, Purdue University. So I’m saying, “Do research on it.” We are planning a study right now using a citizen-scientist approach. We’re going to ask people to get together with a friend and have a deep conversation. We’re going to have a placebo, which may be either a lower dose of the drug, or it could be another drug. We use a paradigm called Fast Friends, popularized actually by The New York Times in an article called “The 36 Questions That Lead to Love.” They increase in how deep and personal they are. You might start with asking, “If there’s a famous person you’d want to have dinner with, who would it be?” Later on, you’re asking, “When was the last time you cried in front of another person, and why?”

Psychedelics can be an important tool in social psychologists’ toolbox in studying connection. As well as other things, of course—the self, creativity, prejudice. I wrote the paper because it didn’t feel at all like MDMA and other drugs were on social psychologists’ radar. I wanted to put it on their radar. We’ll see what happens.

Lead image: Eskymaks / Shutterstock

- Brian Gallagher

Posted on September 27, 2022

Brian Gallagher is an associate editor at Nautilus. Follow him on Twitter @bsgallagher.

Psychology

Why Should We Delay Gratification?

One question for Yuko Munakata, a psychologist at the University of California, Davis and director of the Cognition in Context Lab.

By Brian Gallagher    September 7, 2022

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One question for Yuko Munakata, a psychologist at the University of California, Davis and director of the Cognition in Context Lab, where she uses behavioral, electrophysiological, computational, and cross-cultural approaches to study the variations in thinking that people show across contexts.

Courtesy of UC Davis

Why should we delay gratification?

The standard story has been that we delay gratification by calling on our higher-level cognitive processes that help us to inhibit impulsive behavior, plan for the longer-term, and achieve broad goals. There is truth to that. Early delaying in childhood, on the classic marshmallow task (where kids are told, “You can have one marshmallow now, or if you wait until I come back, you can have two marshmallows later”) has been linked to a variety of important life outcomes. Educational achievement. Social and emotional kinds of success and competence. And better health decades later. But our recent work, published in Psychological Science, highlights that there’s a lot more going on.

If you think about the kid in the marshmallow task, sitting on their hands, squirming in their seats—it doesn’t have to look like that. Delaying gratification can become more automatic, simple, based on cultural practice. I was inspired by recently spending time in Kyoto, Japan, for a six-month sabbatical. My kids came with me—at the time, they were in third and fifth grade in the Japanese school system, which I wasn’t familiar with. I was born and raised here, in the United States. My kids quickly learned that, when you sit down with your lunch, if you start eating it immediately, all the kids around you will start indicating, “No, no, no”—head shakes and hand waves that you’re doing it wrong.

In Japan, everyone waits to begin eating until everybody has sat down with their food. Only then does everybody say, “Itadakimasu” (sort of like bon appétit) in unison, and begin to eat. That is a massively different experience—day in, day out, meal after meal—that kids in Japan are getting in contrast with what we typically experience in the U.S.

We anticipated that this would be specific to these food contexts, and not translate to other areas of life. In our study, we tested kids in Japan and in the U.S. with two measures of delaying gratification. One was a classic marshmallow task. On average, the Japanese kids waited the maximum 15 minutes, sitting by themselves. The American kids, on average, ate the marshmallow within three or four minutes.

But on the other measure of delaying gratification, the pattern completely flipped. Instead of marshmallows, we gave American and Japanese kids presents, and the Americans waited, on average, the entire 15 minutes. It turns out that gift-giving traditions, like Christmas and birthdays, are different across the two countries in ways that could support the American kids waiting longer. In Japan, gifts are given across the year at more informal, casual kinds of occasions. You see someone and you give them a gift, and they can open it right then and there.

An intriguing thing we found is that, where there were these cultural routines around waiting, what predicted whether or not kids waited was not their self-control abilities, but their sensitivity to social conventions. That can support delaying gratification in the classic marshmallow task, and can support things like success in relationships and in school. Tuning in to what a teacher is asking you to do. Being sensitive and responsive to what doctors or health advisors are suggesting should be done for health. It’s not just about some general ability to resist impulses and work toward longer-term goals. That explains maybe half of the variance in these long-term outcomes. We’re missing some big chunk of the answer. And these kinds of social sensitivity to cultural expectations could be a part of that.

Lead image: Josie Garner / Shutterstock

- Brian Gallagher

Posted on September 7, 2022

Brian Gallagher is an associate editor at Nautilus. Follow him on Twitter @bsgallagher.

Technology

- A New Doorway to the Brain

- The Chess Cheat in the 21st Century

- Why Are People Biased Against New Technology?

- Is Tesla’s New Humanoid Robot “Optimus” an AI Gamechanger?

Technology

A New Doorway to the Brain

Neuroscientists can now explore the “wild west” in our heads in incredible detail—a boon to medicine and understanding what makes us tick.

By Elena Renken    October 11, 2022

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The brain’s lifeline, its network of blood vessels, is like a tree, says Mathieu Pernot, deputy director of the Physics for Medicine Paris Lab. The trunk begins in the neck with the carotid arteries, a pair of broad channels that then split into branches that climb into the various lobes of the brain. These channels fork endlessly into a web of tiny vessels that form a kind of canopy. The narrowest of these vessels are only wide enough for a single red blood cell to pass through, and in one important sense these vessels are akin to the tree’s leaves.

“When you want to look at pathology, usually you don’t see the sickness in the tree, but in the leaves,” Pernot says. (You can identify Dutch Elm Disease when the tree’s leaves yellow and wilt.) Just like leaves, the tiniest blood vessels in the brain often register changes in neuron and synapse activity first, including illness, such as new growth in a cancerous brain tumor.1, 2 But only in the past decade or so have we developed the technology to detect these microscopic changes in blood flow: It’s called ultrafast ultrasound.

The images show activity in deep regions of the brain where past imaging couldn’t reach.

Standard ultrasound is already popular in clinical imaging given that it is minimally invasive, low-cost, portable, and can generate images in real time.3 But until now, it has rarely been used to image the brain. That’s partly because the skull gets in the way—bone tends to scatter ultrasound waves—and the technology is too slow to detect blood flow in the smaller arteries that support most brain function. Neurologists have mostly used it in niche applications: to examine newborns, whose skulls have gaps between the bone plates, or to guide surgeons in some brain surgeries, where part of the skull is typically removed. Neuroscience researchers have also used it to study functional differences between the two hemispheres of the brain, based on imaging of the major cerebral arteries, by positioning the device over the temporal bone window, the thinnest area of the skull.

But ultrafast ultrasound is exponentially faster, more powerful, and more spatially sensitive than standard ultrasound: It can produce many thousands of detailed high-resolution images per second.3 If conventional ultrasound is like peeking through a keyhole, ultrafast ultrasound “opens the whole door,” says Peifeng Song, who researches ultrasound techniques at the University of Illinois Urbana-Champaign. Neuroscientists say it could not only help doctors make much earlier diagnoses of debilitating brain diseases, such as brain cancer or Alzheimer’s, but could also aid neuroscientists working with animal models in solving major research questions and accelerate the development of non-invasive brain-machine interfaces, such as robotic limbs.

“If you talk about neuroscience and how the brain works, there’s a lot of unknowns,” Song says. “It’s the wild west.” Ultrafast ultrasound could trace brain signaling with great precision, documenting how circuits and groups of cells interact as the brain performs functions from perception to decision-making.

Functional ultrasound imaging works by the process of echolocation, the same process bats use to navigate. Too high pitched for humans to hear, ultrasound waves collide with tissues or cells in the body and reflect out. Their echoes can then be captured and used to calculate the locations and velocities of blood cells. The frequencies of the returning ultrasound waves reveal where blood is flowing, supplying oxygen and glucose to brain regions that are working especially hard, or conversely, which parts of the brain are not receiving the blood and nutrients they need. These images allow researchers and clinicians to get a sense of what parts of the brain are active—for example, regions responsible for decision-making—or which ones might be at risk of damage.4

In the last decade or so, advances in computer processing power have allowed researchers to transform ultrasound technology. Instead of emitting individual beams, these newer ultrasound systems send out a series of plane waves—an array of ultrasound beams that together form a plane—that hit their target at different angles. The resulting images are composites that are multiple orders of magnitude sharper than conventional ultrasound, MRI, or CT scans, without the trade-offs faced by other imaging methods. MRI machines, for example, demand hugely powerful and expensive magnets to improve their resolution.5 The new forms of ultrasound can also work up to 100 times faster than conventional ultrasound tools, which is especially useful during medical emergencies, when time is of the essence. Such speeds allow ultrasound to track seizures as they happen, Pernot says.

“Even just a few years ago, that type of data throughput would have just been mountainous,” says Sumner Norman, a postdoc at Caltech. “So you wouldn’t have been able to do much with it.” But as computer capacity caught up with the demand, ultrafast ultrasound became more feasible. In Song’s lab, their 3-D ultrasound imaging requires around 10 terabytes of data to fully image the brain of each lab animal in 3-D—the same amount it would take to stream Netflix in standard definition for 10,000 hours.

Bubbles in the Brain: Ultrasound localization microscopy takes high resolution images of blood flow in the brain by bouncing ultrasound waves off of microscopic gas bubbles injected into the blood. Credit: Junjie Yao’s lab at Duke University.

Now that researchers have the computing power to create such high-speed, fine-grained images, they can also track the movement of cells over time. Research published in August by the lab of Mickael Tanter of PSL Research University in France depicted activity throughout the rat brain at a microscopic level.6 The images show activity in deep regions of the brain where light-based imaging can’t reach, and in stunning detail—much finer resolution than an MRI or CT scan. The pictures showed activity from second to second down to a scale of a few thousands of a millimeter.

In humans, ultrasound researchers are finding creative ways to work around the impediment of the skull. Fabienne Perren at the University of Geneva and colleagues, including Tanter, used a contrast agent—microbubbles of gas injected into patients’ blood.7 Some waves still collide with the skull and scatter, but the ones that make it through are more likely to reflect back out when they bounce off the bubbles. Where a CT scan showed only a blob, ultrasound imaging allowed the team to zoom in until they could pinpoint the turbulence inside a bulging blood vessel. Tanter’s lab has also sent ultrasound signals through the gaps between newborns’ skull plates to record brain activity during seizures and sleep.8

Scientists can also remove a small piece of the skull to facilitate working with ultrasound. Working with monkeys, Norman and his colleagues replaced a domino-sized piece of the skull with an ultrasound device. The images of activity in a part of the brain that plans movement revealed when a monkey intended to move an arm. In fact, they could predict the direction of the movement about 89 percent of the time.9 This is comparable to methods that implant electrodes in the scalp, which have been reported to accurately predict direction of movement roughly 70 to 90 percent of the time.

You can’t wheel an MRI machine onto a battlefield. But you can take a handheld device.

But ultrasound imaging does a better job detecting activity deep within the brain, which is harder for electrodes on the scalp to detect. Electrodes are also far more invasive and can cause tissue damage. And the rapidly accelerating capacities of ultrasound will bring improvements, researchers expect. These findings were published last year in Neuron and could pave the way for robotic limbs that translate thought into action: Ultrasound imaging could read brain activity, revealing how a person wants to move their hand to the left, and that data could be fed into a computer that controls a robotic arm, for instance. “We’re already moving toward humans,” Norman says.

Ultrafast ultrasound could also assist surgeons, who often remove pieces of bone before operating anyway. Zin Khaing, an assistant professor of neurological surgery at the University of Washington, is now testing enhanced ultrasound on spinal surgery patients. “If I were to get injured today,” she says, “you would do a CT or an X-ray.” Perhaps an MRI, too. But these only produce anatomical images. “It just shows you where all the bits and pieces are, and what’s squishing onto your soft spinal cord tissue,” Khaing says. Imaging that tracks blood flow is not part of the protocol.

In her pilot clinical trial, ultrafast ultrasound is used in the operating room so doctors can follow the movement of blood. Zhaing is aiming to map what tissue still has blood flow, so that doctors can know what will be salvageable, and what areas are still swollen—perhaps where the surgeon should relieve pressure. She hopes ultrasound could guide surgery even in geographies with fewer resources. “You can’t wheel an MRI machine to a war situation, right? But you can have a handheld ultrasound device,” she says. Plus, she imagines ultrasound technology that’s even easier to use than a probe: something more like a bandaid. MIT researchers have already developed thin ultrasound stickers that can monitor organs over time without a doctor holding an ultrasound wand.10

At the Physics for Medicine Paris Lab, Pernot is hopeful that scientists will be able to correct for the skull’s effects on ultrasound waves. In the same way that researchers can compensate for a flaw in the lens of a telescope, they could also use an algorithm to adjust for the way the skull scatters ultrasound signals, he says. X-rays that map the exact geometry of a skull can guide a model of exactly how the skull distorts ultrasound waves, says Junjie Yao, a researcher at Duke who develops technology that uses both ultrasound and light-based imaging. And that model can be used to correct ultrasound images so they appear undistorted, as though there weren’t any skull there at all. “I wouldn’t say it’s impossible to overcome the hurdle of the skull, but it will be an engineering challenge,” Yao adds.

Ultrasound imaging is still evolving rapidly. “New ideas are popping up every day,” Yao says. Norman was impressed by how quickly his work progressed—in only a few years, he moved from small animal tests to large animal experiments and showed the potential of ultrasound to read brain activity that could feed into a computer.9 “It was incredible how quickly it moved. Usually when you start a new technology, you’re in for a decades-long slog to make it work,” he says. But when computer processing accelerated, the benefits of ultrafast ultrasound became clear. Now researchers can follow rivulets of blood deep into the brain. “We are going to have an imaging technique to go into another world,” Tanter says.

Research into the use of contrast agents in ultrafast ultrasound by Fabienne Perren is funded by the Bertarelli Foundation.

Lead image: Paul Craft / Shutterstock

References

1. Guyon, J., Chapouly, C., Andrique, L., Bikfalvi, A., & Daubon, T. The normal and brain tumor vasculature: Morphological and functional characteristics and therapeutic targeting. Frontiers in Physiology 12, 622615 (2021).

2. Baloyannis, S. Brain capillaries in Alzheimer’s disease. Hellenic Journal of Nuclear Medicine 1:152 (2015).

3. Deffieux, T., Demené, C., & Tanter, M. Functional ultrasound imaging: A new imaging modality for neuroscience. Neuroscience 474, 110-121 (2021).

4. Montaldo, G., Urban, A., & Macé, E. Functional ultrasound neuroimaging. Annual Review of Neuroscience 45, 491-513 (2022).

5. Nowogrodzki, A. The world’s strongest MRI machines are pushing human imaging to new limits. Nature (2018).

6. Renaudin, N., et al. Functional ultrasound localization microscopy reveals brain-wide neurovascular activity on a microscopic scale. Nature Methods 19, 1004-1012 (2022).

7. Demené, C., et al. Transcranial ultrafast ultrasound localization microscopy of brain vasculature in patients. Nature Biomedical Engineering 5, 219-228 (2021).

8. Demené, C., et al. Functional ultrasound imaging of brain activity in human newborns. Science Translational Medicine 9 (2017).

9. Norman, S.L., et al. Single-trial decoding of movement intentions using functional ultrasound neuroimaging. Neuron 109, 1554-1566 (2021).

10. Wang, C., et al. Bioadhesive ultrasound for long-term continuous imaging of diverse organs. Science 377, 517-523 (2022).

- Elena Renken

Posted on October 11, 2022

Elena Renken is a science reporter focusing on the brain and medicine. Her work has been published by NPR, Quanta Magazine, and PBS NOVA.

Technology

The Chess Cheat in the 21st Century

If only the 18th-century hoaxer could see his “Mechanical Turk” now.

By Jim Davies    October 11, 2022

Wolfgang von Kempelen, the 18th-century inventor and author, once claimed to have created a chess-playing robot, called the Mechanical Turk. How was this possible, almost two centuries before computers were invented? Easy. By fraud.

The Turk was just a box containing a hidden chess master. Back then, the idea of an automaton that could play good chess was impossible. Even in 1997, when the IBM computer Deep Blue defeated the then-reigning chess champion Garry Kasparov, he suspected that one of the moves Deep Blue made during the game had actually come from a human.

How times have changed.

Since Deep Blue, the best chess playing entities have been computer programs, not humans. It’s trivially easy to cheat online, on platforms like Chess.com, where many people and some of the world’s best play. You simply have a chess program running off to the side and put your opponent’s moves in as your own, then move as the computer would against your opponent. You’re guaranteed to win. Unless, of course, they are cheating, too.

ALL THE (TOO) RIGHT MOVES: A chess analyst who examined games played by Hans Neimann (right) supported Magnus Carlsen’s suspicions: Niemann’s moves were too optimal. Photo courtesy of Saint Louis Chess Club, Crystal Fuller.

In September, Magnus Carlsen, the reigning five-time world chess champion, withdrew from an over-the-board match with Hans Niemann, a 19-year-old grandmaster, at the prestigious Sinquefield Cup in St. Louis. Carlsen accused Niemann of cheating. Niemann denied it, and admitted to cheating online just twice in his life—when he was 12 and 16 years old. An investigation by Chess.com, released on Oct. 4, states Niemann likely cheated in more than 100 online games.

In the Sinquefield Cup match, there was no hard evidence that Niemann had cheated against Carlsen. No device, speaker, computer, or wires have been discovered. How would it be possible? I’m reminded of the scene from Goldfinger, where someone cheats at cards with the aid of an accomplice with binoculars and an audio connection. You can fit a chess computer into a small, silicone-covered box the size of a small salt shaker. It buzzes to indicate where to move which piece, allowing one to have the chess computer on their person.

If Niemann cheated, he could have also recruited some conspirator to put Carlsen’s moves into a chess AI, and then communicate the recommended move via some device, hidden somewhere on Niemann’s person. Historically, others have cheated by having a vibrating device signal morse code from an accomplice watching the game or giving subtle hand signals from the crowd. This recent turmoil has caused some beefed-up security at chess tournaments, including allowing people to spectate only from another room with a 30-minute delay in the video, to thwart real-time assistance.

Chess.com found that Hans Niemann’s results in many online games were unlikely.

Many people seem sure that Niemann cheated somehow. Why? Carlsen’s suspicions carry weight. Niemann was playing unrealistically well, Carlsen said in a public statement. “Throughout our game in the Sinquefield Cup I had the impression that he wasn’t tense or even fully concentrating on the game in critical positions, while outplaying me as black in a way I think only a handful of players can do.”

If Niemann cheated, it may not have been on every move. For excellent chess players, the next best move is often relatively obvious. The player would only need to consult a chess AI at certain key points—as few as one or two—to beat their competitor. This is known as “selective cheating.” A savvy cheater might even make some low-cost moves they know are sub-optimal, just to throw cheater detectors off the scent.

In its report, Chess.com compared Niemann’s moves to that of Stockfish, the best chess AI out now. It’s so good it would probably beat Carlsen, or any other human player, every time. It can look over 40 moves ahead, far more than any human being. This means that chess AIs can make moves that humans never would—moves that look, to skilled chess players, like bad ideas in the short term but pay off further ahead in the game than human grandmasters can mentally simulate. Human chessmasters tend not to make such moves, and if they do, we might suspect them of cheating.

Chess.com found that Niemann’s results in many online games were extraordinarily unlikely, given his skill. They also looked at how long Niemann took to make the more difficult moves—if the moves are made too fast, it adds evidence to the idea that he was using an AI. This is similar to how “doping” is detected in sports: Contenders on drugs perform at inhuman levels of speed and strength.

In September, chess enthusiast Yosha Iglesias conducted an analysis of Niemann’s games using a program that estimates how close to optimal each move was. What Iglesias found supported Carlsen’s suspicions: Niemann’s moves were close to optimal. Most chess masters play at around 70 to 75 percent of optimality, and Niemann played at close to 100 percent over the course of several games. Clever Hans might be taking cues from outside his own mind.

Where once we had machines cheating at chess by using humans, now we have humans cheating by using machines.

An anti-Mechanical Turk.

Jim Davies is a professor at the Department of Cognitive Science at Carleton University. He is co-host of the award-winning podcast Minding the Brain. His latest book is Being the Person Your Dog Thinks You Are: The Science of a Better You.

Lead image: Humboldt University Library / Wikimedia Commons

Technology

Why Are People Biased Against New Technology?

One question for Matthew Fisher, a psychologist at Southern Methodist University.

By Brian Gallagher    October 10, 2022

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One question for Matthew Fisher, a psychologist at Southern Methodist University who studies the strategies people use to digest the overwhelming amount of information they encounter, and the effects technology has on how people perceive their own abilities.

Photo courtesy of Matthew Fisher

Why are people biased against new technology?

The big takeaway from what we found in our recent study, published in Psychological Science, is that people seem to have this status quo bias when it comes to technology. That’s why we titled it, “The Golden Age Is Behind Us.” In essence, technology invented before people were born gets granted this status, the status-quo status, so that it just is assumed to be a part of how the world works. People tend to have a more positive evaluation of that technology. They don’t really know a world where it didn’t exist, and therefore evaluate it more favorably, and that’s contrasted with technology invented after they were born. It’s for those technologies that people tend to be more skeptical.

The first thing we tried, which I think offers the cleanest evidence for our story, was dynamically presenting our subjects, whose ages we recorded, with a real but unfamiliar technology—aerogel. I think it was actually invented in the 80s, but no one’s really heard of it, or knows exactly what it does. We used that to our advantage. We either told them that this was invented 15 years before or after they were born. We’re holding fixed the actual properties of the technology. If the status-quo story is true, then they should be less skeptical of it if it was invented before they were born, and more skeptical of it if it was invented after they were born. Indeed, that’s exactly what we found. Tell people that it was invented earlier, they evaluated it more favorably. Say it was invented after they were born, now they’re a little more skeptical about its impact on society.

In follow-up studies, we showed people 60-plus different technologies, and then collected information about when they were born, their exposure to that technology, et cetera, and this same sort of pattern was emerging. Take the smartphone. If we think about who’s leading the charge on the discussions of the screen’s impact on our wellbeing and attention, it tends to be older folks. Of course, if you zero in on any particular technology, it can be hard to exactly tell what’s going on—is it just that older people are in a better position to critique the smartphone? But what really seems to matter is when people were born relative to each of those technologies. That trend emerges as you zoom out and look at the bigger picture.

The data we have suggests it’s a gradual increase, where the farther and farther away from you the advent of the technology gets, the more and more skeptical you are. That’s going forward. And then the farther it goes back in time, the more accepting, the less skeptical, you are. And, extrapolating out from our findings, it would suggest that this era of history, relative to others, would be especially cautious or discerning about technology being introduced, just based on the sheer demographics, where there’s more and more older people than younger people. Yet it’s not totally obvious to me how big of an impact that would have on the actual industries producing technologies. Plenty of people are skeptical about social media, for instance, and it seems to be getting more popular than ever.

If I were to speculate, I would say status-quo thinking can help in some regards by just essentially making sure that things that are time tested are preserved. Having a status-quo bias toward things that have been around for longer just lets the filter of time sort out what’s worth keeping and what’s not. There is a coherent logic to it, but of course, like any tendency, it could be overdone. If you overweight the value of the past and don’t allow any new innovation to come along, of course that’s going to be a problem. I think about myself growing up after certain inventions, like the television. That was a part of life that you didn’t really even question. Now I’m raising kids myself and looking back at my childhood, thinking of all the hours I sat in front of the TV. I was like, “If I could play piano right now and trade those hours out, I think I would swap it.”

Lead image: Elenabsl / Shutterstock

- Brian Gallagher

Posted on October 10, 2022

Brian Gallagher is an associate editor at Nautilus. Follow him on Twitter @bsgallagher.

Technology

Is Tesla’s New Humanoid Robot “Optimus” an AI Gamechanger?

One question for Animesh Garg, a computer scientist at the University of Toronto.

By Brian Gallagher    October 3, 2022

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One question for Animesh Garg, a computer scientist at the University of Toronto, director of the People, AI, and Robotics group, and a senior research scientist at Nvidia whose research vision is to enable robots to seamlessly interact and collaborate with humans in novel environments.

Photo courtesy of Animesh Garg

Is Tesla’s new humanoid robot “Optimus” an AI gamechanger?

Overall, the current design of the robot, which Tesla unveiled on September 29, is a very good first step. Interest in building such systems is welcome because Tesla and Elon Musk’s involvement brings attention, talent, and resources to the problem, setting in motion a flywheel of progress.

The goal of building humanoids is fascinating and divisive. A lot of academics, investors, and industry leaders would balk at the idea, arguing that simpler, non-anthropomorphic solutions, along with changes to the environment, are more practical. But this is akin to redoing the infrastructure to make autonomous cars work, instead of adapting autonomous cars to our current infrastructure.

The problem of a smart robot design lies equally in building more capable robot hardware—sensors, actuators, and power systems—as it does in building smarter brains. Tesla’s Optimus effort is, in a sense, no different from Asimo, Atlas, T-HR3, or Digit. All of them are backed by expert roboticists. Some of them are from car companies like Honda and Toyota, which have taken their manufacturing background and years of design experience to build humanoid robots. However, what’s different is that the Tesla robotics team has done a commendable job in fast iteration time for the design of the robot from the ground up—from a good experimental study on actuator requirements, designing new actuators, and creating the integrated system. This would allow meaningful power while conserving energy, unlike hydraulic actuators used by Atlas, from Boston Dynamics.

The hand also seems exciting—a metallic cable-driven system with four fingers and a thumb. In the brief demo, they showed it had a reasonably high-loading capacity (holding plant-watering water cans, lifting bars of aluminum in the factory). However, due to the cable-driven design, the system will have a slower response time, and it will be harder to do learning-based control. There’s also no back drivability in autonomous mode, which will make general-purpose autonomous hand manipulation slightly challenging.

Tesla would benefit a lot from collaborating with the community. Designing the whole stack of hardware, simulation, and data infrastructure is requiring Tesla to reinvent the wheel on many fronts. They could release limited encrypted designs which would enable a community to integrate Tesla Bot as an experimental platform and build around it. Yet, the challenges of learning-based control and behavior chart a long road, with a long tail of problems. Autonomous driving offered a mirage of being “just around the corner,” and we are still chasing the dream over a decade later.

Overall, we should learn a lesson in humility about the challenges of building deployable autonomy in the real world. Especially since making the Tesla bot work could be considered a harder problem, because along with perception and agent modeling, it also needs carefully controlled interactions with the environment. Autonomous vehicle stacks use rendering and procedural-scene creation with no physics at all, since there is no contact-based interaction, while robotics is built for controlled contact in addition to many of the challenges of autonomous vehicles.

The flip side, though, is that robots, in the short term, have use cases in places where they do not necessarily need to interact with humans, and the implications of failure are less severe. The community needs to find a revenue-positive pathway to support this development. And this could come from behind-the-scenes use cases for robot manipulation in warehouses, retail stores, food prep, and manufacturing.

This effort should be lauded with cautious optimism by the community, for the compass points in the right direction, and Elon brings with him the heft of Tesla engineers as we trek through the AI/Robotics jungle.

Adapted with permission from Animesh Garg’s original remarks here.

Lead image: Tesla / Youtube

- Brian Gallagher

Posted on October 3, 2022

Brian Gallagher is an associate editor at Nautilus. Follow him on Twitter @bsgallagher.

Zoology

- To Stop Illegal Fishing, Send a Seabird

- That Snapper You’re Eating Might Be 80 Years Old

- What Do Dolphins Talk About?

Zoology

To Stop Illegal Fishing, Send a Seabird

Illegal fishing is too big a problem for humans to handle alone.

By Claudia Geib    October 14, 2022

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Every year, as shifting currents pull cold, nutrient-rich waters up from the Pacific Ocean depths, the western coast of South America floods with fish. Billions of anchovies follow the currents in flickering silver masses, and in turn are followed by fleets of fishing vessels.

Conservation scientists follow this catch, too, trying to prevent overharvesting that will cause populations to plummet and jeopardize the many other creatures—larger fish, sea lions, dolphins and sharks, and seabirds—who also depend on the anchovies. This year, these monitors have some unusual assistants: As seabirds flock to the feast, they’ll be carrying GPS-equipped cameras to monitor the ships below.

“They are an independent, non-biased way to record fishing activities,” says Carlos Zavalaga, a seabird ecologist  at Peru’s Scientific University of the South, who leads a project that uses kitted-out Peruvian boobies to monitor the country’s anchovy fisheries. “They just go and feed.”

Those birds provided an unwitting view into illegal, unregulated, and unreported fishing

Scientists started sticking gauges and radio trackers on large-bodied animals back in the 1940s, but the advent of GPS, satellite transmission, and miniaturized electronics opened the field up to track smaller, lighter, and farther-traveling animals. Seabirds are stars of this research, and it has yielded extraordinary insight into the lives of creatures capable of drinking seawater, going weeks without food, and of flying halfway around the globe without ever touching land.

It was Henri Weimerskirch, a seabird researcher at the French National Centre for Scientific Research, who first thought to employ them as spies. While tracking how young albatrosses spend their first few months at sea, he realized that he could sometimes see the birds following and hunting around fishing vessels. Sometimes the boats were fishing in areas they were not supposed to be—or were not supposed to be fishing at all.

Those birds provided an unwitting view into illegal, unregulated, and unreported (IUU) fishing, which poses a threat to the sustainability of the ocean’s already-stressed fisheries. One estimate suggests that these catches annually amount to as much as 26 million tons of fish, or nearly one-third the total of all legal fisheries.1 Another puts the price tag of IUU fishing at $26 to $50 billion lost from the legitimate fishing industry.2 And neither of these numbers captures the additional scale of bycatch: fish, marine mammals, and seabirds caught accidentally and, often, killed in these fisheries.

Weimerskirch wondered whether seabirds might be used to track those vessels. To investigate the possibility, he fitted 169 albatrosses living on islands in the southern Indian Ocean with GPS trackers and devices that detected the radar signals boats use to navigate.

The birds ranged across more than 29 million square miles of ocean, including forays into the icy, storm-tossed Southern Ocean around Antarctica.3 They encountered 353 different boats, of which 28 percent were fishing without an Automatic Identification System (AIS). This radio-operated system automatically identifies a vessel and its position, speed, and direction; turning it off, or operating without one, is not only illegal within roughly 200 miles of land but is usually a sign that a boat is trying to hide something.

FLIGHT PLAN: The ocean-spanning flight paths (green, yellow, and orange lines) of albatrosses tagged by Henri Weimerskirch. Locations of boats they encountered are marked with yellow pins. Image courtesy of PNAS.

Weimerskirch was particularly encouraged by the possibility that these birds could, potentially, help tackle the thorny challenge of monitoring IUU fishing in the Southern Ocean, one of the most remote places on Earth. “In most places, you can use other ways to monitor illegal fishing—planes or drones or at-sea spotters,” he says. “But in the Southern Ocean, there is nothing.”

The possibilities don’t end there. “The risks of IUU fishing are in every ocean and across many different fleets,” says Elizabeth Selig, the deputy director of Stanford’s Center for Ocean Solutions. And even when planes or drones or spotters are available, the vast scale of their task is daunting. Seabirds may still have a role to play.

Luckily seabirds, like illegal fisheries, are found globally. While some species are better-suited than others to being fitted with trackers—albatrosses, for example, are known for being remarkably easy to work with—technological advances mean these devices are becoming even smaller and lighter, making it possible to tag seabirds as small as one-pound Atlantic puffins, lighter than a loaf of bread.

Since his initial study, Weimerskirch has connected with researchers in New Zealand, the United Kingdom, and the United States who have also adopted his technique. Researchers from BirdLife international, a global conservation group, are using it to figure out which legal fleets to target for bycatch mitigation measures.

If illegal fishing is not curbed then seabirds will face a grim future.

Selig notes that seabirds will never fully replace other monitoring systems. Their movements are not entirely predictable, so one can’t plan for them to visit a specific area at a specific time; and even if a boat looks suspicious, it’s not always possible to know whether they’re actively engaged in fishing. Nonetheless, she sees seabird monitors as “another piece of the enormous puzzle,” providing data that can be used to flag areas for further scrutiny.

More fine-grained information might yet be possible, though. The cameras that Zavalaga is fitting onto anchovy-eating Peruvian boobies are able to capture, so long as photographic conditions allow, the names and license numbers of boats.

Of 31 boats that Zavalaga’s tagged boobies spotted during the first phase of his research, five were unregistered. Two were fishing in marine protected areas where fishing is illegal. His latest project, monitoring both artisanal and commercial fisheries, will collect and transmit daily reports to fishing regulatory agencies, with the aim of providing more actionable day-to-day information. “What we want is not to replace the surveillance system, but to complement it,” Zavalaga says.

And what of the birds themselves?

Researchers have labored to make the technology as small as possible to avoid disrupting the lives of their sentinels. But this is still extra weight, carried sometimes for tens of thousands of miles. A 2019 review of tracking devices on birds found that the effects can vary widely, from increased preening at the low end to early mortality at the most extreme.4

Impacts were less severe when sensors were smaller relative to a bird’s weight. As a result, large-bodied seabirds—like Weimerskirch’s albatrosses and Zavalaga’s boobies, whose equipment amounts, respectively, to less than 1 and 2 percent of their weight—were least likely to have problems.

That did not mean there were none, though. Sensors had a tendency to decrease breeding success, and this had no relationship with body size. Managing these effects is a challenge—but if illegal fishing is not curbed then seabirds, already threatened by climate change, bycatch, and invasive species, will face a grim future. Using seabirds as monitors should ultimately help the birds, too.

Lead image: A wandering albatross fitted with a GPS tracker and sensors that detect the radar used by boats to navigate. Credit: A. Corbeau

References

1. Song, A.M., et al. Collateral damage? Small-scale fisheries in the global fight against IUU fishing. Fish and Fisheries 21, 831-843 (2020).

2. Sumaila, U.R., et al. Illicit trade in marine fish catch and its effects on ecosystems and people worldwide. Science Advances 6 (2020).

3. Weimerskirch, H., Collet, J., Corbeau, A., & Patrick, S.C. Ocean sentinel albatrosses locate illegal vessels and provide the first estimate of the extent of nondeclared fishing. Proceedings of the National Academy of Sciences 117, 3006-3014 (2020).

4. Geen, G.R., Robinson, R.A., & Baillie, S.R. Effects of tracking devices on individual birds—a review of the evidence. Journal of Avian Biology 50 (2019).

- Claudia Geib

Posted on October 14, 2022

Claudia Geib is a science journalist and editor based on Cape Cod. Her work covers marine and environmental science, wildlife, and how humans connect with the natural world.

Zoology

That Snapper You’re Eating Might Be 80 Years Old

Shouldn’t we respect our animal elders, too?

By Jonathan Balcombe    October 6, 2022

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On July 31, my mother celebrated her 88th birthday. Based on recent discoveries, it is quite possible—even likely—that a fish somewhere turned 88 on the same day.

It could have been a snapper. In one study of 476 snappers of three species caught along the Western Australian coast and the Chagos Archipelago in the Indian Ocean, 11 specimens were over 60 years old. One two-spot red snapper was 79, and a midnight snapper was 81.

They are the oldest tropical reef-dwelling fishes known to science, and they are not likely to be rare examples of longevity in these species. The 81-year-old midnight snapper was found in a sampling of just 11 fish, making it improbable that the researchers stumbled upon an exception. All were apparently healthy when they were caught. “Some of these fish are probably getting up close to 100 years old,” says Brett Taylor, a marine ecologist with the University of Guam and leader of the study, which was published in the journal Coral Reefs.1

I’m sure I’m not alone in feeling a deep respect for a being who can live so long.

Venerable as these snappers were, they are nowhere near to being the reigning marine Methuselahs. Two male orange roughies—an inhabitant of deep seamounts—caught off Tasmania were 230 and 245 years old. Greenland sharks can live longer still, with one female examined by researchers tipping time’s scales at 400 years, give or take a century. There might be Greenland sharks cruising slowly beneath Arctic ice today who began life before Columbus set foot on American shores.

How and why some fishes live so long isn’t known for certain, but older individuals tend to be larger, which slows down metabolism, as does living in deeper, colder water. Those slow metabolisms are useful in environments where food is scarce, and genomic studies of long-lived fishes have found genes associated with repairing damaged DNA and reducing inflammation, which may reduce cancer risk and improve immune system function.2

Regardless of how they achieve it, I’m sure I’m not alone in feeling a deep, reflexive respect for a being who can live so long. It’s an extension of the respect shown by human cultures toward our elderly citizens. The oldest among us have navigated life’s vicissitudes and accumulated a wealth of experience; as Andy Rooney said, “The best classroom in the world is at the feet of an elderly person.” When Queen Elizabeth II died, the subsequent outpouring of adoration and veneration was fueled in large part by her advanced age and the record-setting length of her royal tenure.

Might we extend these feelings toward elderly animals, too? At the moment, our treatment of elderly fishes runs quite contrary to the values we have about oldness.

OLD SCHOOL: Those orange roughies at your local fish market may have been born before Thomas Edison. Photo by Tony Moran / Shutterstock.

A case in point is the method of scientific choice for estimating the age of bony fishes like snappers and roughies. It entails examining their otoliths: bone-like structures floating in the inner ear that, much like tree rings, contain annual growth bands, leading some fish biologists to dub them “nature’s chronometers”—but in order to read one, the fish must be killed. Taylor, whose team caught snappers by angling and spearfishing in addition to studying archived specimens collected decades ago, says there are other, non-lethal ways to estimate a fish’s age, such as clipping off part of the dorsal spine, “but they are much less accurate, and more time-consuming.”

As for cartilaginous fishes like Greenland sharks, they can be aged by carbon-dating proteins that form before birth in their eyes’ lenses. The 28 specimens examined in the study that found the 400-year-old shark were not killed for that purpose, though; they were caught accidentally in fishing nets. This is not uncommon, and while Greenland sharks are no longer hunted for the liver oil once used to light lamps and lubricate machines, many other long-lived species are still caught commercially.

Consider the aforementioned orange roughies, once called “slimeheads.” When in the late 1970s their gastronomic potential was recognized, the species was given a more-palatable name and a feeding frenzy ensued. Within a decade the yearly global catch peaked at around 90,000 tons, then quickly declined. By 2000, three of the eight orange roughy fisheries in New Zealand, where most roughies are caught, had collapsed and were closed.

The collapse illuminated the unique vulnerability of long-lived fishes. Because they tend to be slow-growing and slow to mature—orange roughies don’t start reproducing until they are at least 20 years old—they tend to be susceptible to exploitation. “Longevity in fish is one of the reasons we have had major fisheries collapses,” says Taylor. A decimated population, even if left alone, may take a half century or more to recover.

Greenland sharks can tip time’s scales at 400 years.

Nowadays people can purchase sustainably caught orange roughy, secure in the knowledge that, at least according to the label, their populations will not be exploited to the point of destruction. But what about individuals? Might a very old fish stir sympathy? “When I started to get some over 200 years old, I was thinking, ‘Gosh, this thing had been tootling around in the ocean for two centuries, and suddenly it has a bad day and ends up on someone’s dinner plate,’” says Kyne Krusic-Golub, an Australian fish aging expert who has studied longevity in orange roughies.

Yet even the researchers’ reactions seem incommensurate with the death of such ancient beings—a 200-year-old bear, for example, would occasion far more sympathy. Perhaps this is a legacy of outdated ideas about fishes as cognitively primitive, lacking even the capacity for pain and living lives less rich than those of other animals.

Modern science, however, is revealing fishes to be so much more than just animated objects to be caught en masse and eaten. As I describe in What a Fish Knows: The Inner Lives of Our Underwater Cousins, fishes have minds; they learn, use tools, plan, and fall for optical illusions. Some have prodigious memories. Others can spot a familiar human face among 40 unfamiliar ones.

One common reef species, the bluestreak cleaner wrasse, has passed the vaunted mirror-self-recognition test, which suggests self-awareness comparable to our own. Fishes also demonstrate pain, pleasure, and distress; stressed-out surgeonfishes seek relief with soothing caresses from a cleaner wrasse or a trusted human. Living in societies has fostered cooperative behaviors and relationships, including communication between species, courtship, and parenting.

These are traits deserving of regard in fishes of any age, but of particular relevance to long-lived species is culture, which scientists define as behaviors passed on socially, not genetically, across generations. On land, for example, elephant clan matriarchs are repositories of important knowledge about herd migration routes, water sources, and when trees fruit. Scientists who study declining populations of elephants, and also long-lived whales, worry about the loss of knowledge accumulated through generations and passed on from elders to the young. That may partly explain why many whale populations have shown few signs of recovery in the half-century since large-scale whaling ceased.

Might removing the oldest individuals disrupt cultural transmission in long-lived fishes, too? In a review of fish learning skills led by Anders Fernö, a biologist at Norway’s University of Bergen, researchers considered that possibility.3 “We could wipe out whole cultural units of long-lived fish populations, and consequently important aspects of their adult behavior,” they wrote, “because there are no longer enough experienced fishes to copy.” In addition to the orange roughy, many other long-lived and commercially fished species, including cod, Patagonian toothfish—rebranded as “Chilean sea bass”—and Atlantic halibut, have not returned to anything like their historical abundance, even with improved management. Perhaps they miss the knowledge once possessed by older fish.

There’s much room for improvement in our relationships with fishes of any age, but the capacity of certain species to live for centuries makes our exploitation of them more poignant. Perhaps it would help if labeling programs, such as Monterey Bay Aquarium’s Seafood Watch, informed people about the longevity of species as well as their vulnerability. Knowing that fish in a supermarket freezer may have been born before Thomas Edison might make people think twice about eating them. Being a responsible consumer of fish could begin with respecting your elders.

Lead image: A 79-year-old two-spot red snapper. Credit: Dan Bayley.

References

1. Taylor, B.M., Wakefield, C.B., Newman, S.J., Chinkin, M., & Meekan, M.G. Unprecedented longevity of unharvested shallow-water snappers in the Indian Ocean. Coral Reefs 40, 15-19 (2021).

2. Kolora, R.R., et al. Origins and evolution of extreme life span in the Pacific Ocean rockfishes. Science 374, 842-847 (2021).

3. Brown, C., Laland, K., & Krause, J. (Eds.) Fish Cognition and Behavior Blackwell Publishing, Oxford, U.K. (2006).

- Jonathan Balcombe

Posted on October 6, 2022

Jonathan Balcombe, Ph.D, is a biologist and author of What a Fish Knows and Super Fly. He lives in Ontario.

Zoology

What Do Dolphins Talk About?

In the latest episode of the Ignorance podcast, Diana Reiss takes us behind the scenes with some chatty dolphins.

By Stuart Firestein & Leslie Vosshall    September 7, 2022

How can we tell if other animals have thoughts, desires, self-awareness? And if they do have all of those things, how can we communicate with them? Diana Reiss, a professor of cognitive psychology and director of the Animal Behavior and Conservation Graduate Program at Hunter College, has been working on these questions for decades.

In this episode of the Ignorance podcast—a series that investigates what scientists don’t yet know, what remains to be figured out—neuroscience professor Stuart Firestein and neurobiologist Leslie Voshall interview Reiss about the mirror test, computers for dolphins, and more.

The Ignorance podcast looks into what scientists don’t know, what remains to be figured out.

Listen to the full podcast here.

Partial transcript:

Leslie Vosshall: How did you ever believe you could learn anything about how animals think?

Diana Reiss: I was always interested in communication with animals because I thought when I was a kid, I was communicating with my dog. And I was, and we do communicate with our pets. With dolphins, it’s quite a different situation. They’re about as different from us as you can possibly get in terms of body form, in terms of evolution—we’ve evolved in totally separate domains. They’re totally aquatic. We’re land-based animals. They’re so different looking in terms of their body form, but like us, they have large complex brains. Like us, they learn their vocalizations and there are lots of other things we’ve been discovering that make them a lot more like us than we might have thought.

My real interest beyond that is in what ways are they also very different from us? I’m always intrigued by the probability or the possibility that perhaps we’re not seeing the nature of their real intelligence just because of our differences. What if they’re doing things and we just simply can’t understand it because it’s so different than what we know?

Leslie Vosshall: This brings up the fundamental question of how do you ask another animal what it’s thinking. I think Frans de Waal wrote a book that asked are we smart enough to know how smart animals are?

Diana Reiss: One of these studies that I did many years ago, back in 2001, was to ask: What happens if you put a mirror in front of a dolphin? Mirrors are really an interesting research tool to work with. They’re really simple, they’re relatively inexpensive and they let us provide dolphins with potential information. We present a dolphin with a mirror and we look at how they react when they first see a mirror. Would they react in any way like the way we act in front of a mirror? We recognize that there’s an external representation of ourselves in the mirror and we use mirrors as tools to examine parts of our body we can’t see, we watch ourselves move in different ways.

We used to think this was uniquely human, but in the 1970s, another scientist, Warden Gallup Jr. showed that our closest living relatives, the great apes, also shared this ability with us. For about 40 years there was a lot of speculation that, “Oh, it’s only the great apes that are going to show this because of our evolutionary connection.” Well, what about dolphins, which are really different from us? Would they show that same ability? They have big brains like us, they’re highly social like us. What happens?

We actually marked them with lipstick once. It wasn’t a good mark. That’s the next phase. So once they show this self-directed behavior, again, they’re using the mirror as a tool to view themselves, which may seem trivial to people because we do it so readily. But humans don’t realize young children don’t start showing this until they’re between 18 and 24 months of age—it really takes a good deal of cognitive processing to understand that that external representation is you. To be aware that you can see yourself in a mirror is not shared by many animals on this planet.

Stuart Firestein: So now, once you know that they have some sense of self, what’s the next question you ask them?

Diana Reiss: One of the next questions that came up after that was how does this emergence of self-awareness relate to other aspects of their cognitive ability? After we did this study, several years later, one of my students in my lab, Rachel Morrison, and I did a second study asking at what age does this emerge and how does it emerge in relationship to other cognitive abilities? Mirror self-recognition, interestingly, starts emerging with their growing social awareness, their growing motor skill, sensory motor development, their proprioreception, which is the ability to track your body movements, being aware of the movements of your body and space. Without that, it would be very hard for an animal to understand that’s itself in a mirror without knowing what you’re doing with your own body.

What we found, interestingly, was that young dolphins actually showed the emergence of self-directed behavior at the mirror, self recognition, even earlier than children. Children show it earlier than apes, but dolphins were showing it earlier than kids. Now, that doesn’t mean they’re smarter than kids. What it suggests is that their whole course of development is happening at a much more escalated rate. I mean, you’re a young dolphin, you’ve got to hit the water running—or I should say hit the water swimming—or you’re not going to make it. They’re very precocious.

Leslie Vosshall: So Diana, if we believe that animals are thinking, how do we get into the animal mind?

Diana Reiss: I think that’s a really provocative question. If we can find ways of giving animals more choice and control and more of a voice—I sort of say that I try to partner with the dolphins when I work with them. I’m trying to give them a way to communicate what they want, what their interests are. That’s, to me, a real breakthrough.

Many years ago, this was 1983, we built an underwater keyboard for dolphins. Imagine you’re underwater and you’re a dolphin. You have this keyboard in front of you and you touch a white triangle that’s in the middle of the keyboard. What happens is you hear a sound and somebody gives you a ball. That’s your favorite toy.

Then you might do it again. You touch it again, but this time it’s in another position, but it’s that white triangle. Again, you hear that sound and you get a ball and you do whatever you want with it. Then you touch a different symbol. It’s an H-shaped symbol and you hear a different whistle. The person standing behind the keyboard puts their hand in the water and tickles your belly. You also like to get a belly rub.

We created a keyboard that would let the dolphins touch what they wanted to and then when they touch those different symbols, they got different things, different contingencies. They heard a different whistle for each shape and they got a different reward, a ball or a rub or a ring or a float. The dolphins really seemed to enjoy this. They were fed. I never would work with a dolphin that wasn’t fed and had a full belly, because I wouldn’t want to work with children who were hungry, and they had toys all the time, but right before we put the keyboard in, we took out the toys and then we gave them a 30-minute session with this keyboard. It was interfaced by fiber optic cables to an old Apple 2 computer.

Stuart Firestein: I’m not sure the computer was up to this. The dolphins may have been.

Diana Reiss: Well, yeah, we could barely keep up—we were barely able to do this. We had this thing, this was so cool, it was called a vo-coder. So that when the dolphin hit a key, the dolphin heard the whistle and I in my headset would hear what I had to give the dolphin. So I would hear “ball,” “ring,” “rub” in this really horrible computer voice. I would also hear what the dolphins were doing in the pool. So this was like a sci-fi scenario, but the dolphins showed us so much, they did so much more than we have ever expected.

Now, let me just back up for one second. I forgot to tell you that dolphins use whistles in their communication. They echolocate, which is a kind of sonar. So they get sort of exquisite images, we think. They can see with sound basically and they use a variety of different kinds of calls, but they use a very complex set of whistles when they communicate socially. So we created computer-generated whistles that were different than the whistles the dolphins were doing themselves, but were within the time and frequency range that could be easily imitated by dolphins.

Leslie Vosshall: Sort of like in the dolphin-ish language.

Diana Reiss: Exactly, but different than their own. It’s like if we were going to give us new human words that we could reproduce, we just hadn’t heard them before. We had studied the development of these two young dolphins with their moms for the year prior to giving them the keyboard. Anyway, to cut to the chase, the dolphins very quickly started to imitate the sounds, and they did it with great fidelity. In fact, what they did was very much like the way babies start imitating human sounds. Sometimes they did what we call segmentation. They broke the sounds up. Sometimes they imitated the very end first, then put the whole sound together. They showed babbling in their own development like human kids do.

They also started using what we called facsimiles or their own imitations of these sounds while they were playing with the right objects. We would hear, coming from the pool, and record the ball whistle not from the computer, but from the dolphin and they’d be playing with balls. Or they would be whistling a ring signal while they were playing with rings. In the second year of a two-year study, they actually started combining ball and ring in one context in a new game that they had invented, which was playing with balls and rings at the same time. It sounds goofy to us, but it’s a dolphin game. What can I say?

Leslie Vosshall: What are the kinds of things that come out of playing these games? Let’s say someone breaks the rules, humans or dolphins. What happens?

Diana Reiss: We had one day where things really got screwed up, where, again, all they see is the keyboard. They have to hit a key to get a sound, and we forgot to turn the speakers on. Dumb us, right? What we got that day was more vocal production. They were imitating the sounds at a much higher rate than any other time. When we looked at it, we thought, “They’re trying to tell us something here.”

Leslie Vosshall: “Hey, I want my ball.”

Diana Reiss: Yeah. It’s often in these errors where you see these really interesting things happen. It makes sense when you think about it, but it’s unexpected.

Stuart Firestein is a professor of neuroscience in the Department of Biological Sciences at Columbia University. He is a fellow of the American Association for the Advancement of Science, a Guggenheim Fellow, and serves as an advisor to the Alfred P. Sloan Foundation.

Leslie Vosshall is an HHMI Investigator and the Robin Chemers Neustein Professor of Neurogenetics and Behavior at The Rockefeller University. She is also the director of the Kavli Neural Systems Institute at The Rockefeller University.

Lead image: Andrea Izzotti / Shutterstock

Table of Contents

Nautilus: 14 Oct, 2022

Anthropology

The Real Magic of Rituals

Astronomy

A Step-by-Step Guide to Our Solar System’s Demise

Communication

How Shannon Entropy Imposes Fundamental Limits on Communication

The Trouble With “The Big Bang”

Evolution

The Wizards of Mind Control

Genetics

A Universal Cancer Treatment?

Health

What Can Night-Shift Workers Do to Feel Better?

Targeting Cancer’s Achilles Heel

Microbiology

What We Really Are Is an Agglomeration of Cells

The Big Thinker

Neuroscience

The Afterlife Is in Our Heads

How We Remember Last Weekend

Philosophy

What Is Misinformation Doing to Us?

Physics

They Probed Quantum Entanglement While Everyone Shrugged

Are We Getting the Real Stuff in Popular Science?

Lose Weight the Slow and Incredibly Difficult Way

Psychology

I Didn’t Know My Mind Was So Strange Until I Started Listening to It

Should Social Psychologists Experiment with Psychedelics?

Why Should We Delay Gratification?

Technology

A New Doorway to the Brain

The Chess Cheat in the 21st Century

Why Are People Biased Against New Technology?

Is Tesla’s New Humanoid Robot “Optimus” an AI Gamechanger?

Zoology

To Stop Illegal Fishing, Send a Seabird

That Snapper You’re Eating Might Be 80 Years Old

What Do Dolphins Talk About?