The Reality Bubble

by Ziya Tong

  Life and death are a cycle. That’s just the way nature works. In Alaska’s Tongass rainforest, a similar process is visible. But here, what scientists are looking for are salmon in the trees. Typically, we picture animals eating plants, but in this instance it’s the trees that are feeding on animal remains.

  Each year, when hundreds of millions of salmon return to the rivers and streams to spawn, they die and decay there, becoming chemical nutrients for the forest. As biologist Anne Post notes, a spawning chum salmon contains an average of 130 grams of nitrogen, 20 grams of phosphorus, and more than 20,000 kilojoules of energy in the form of protein and fat. That means that in just one month, a 250-metre-long stream where salmon come to spawn and die receives more than 80 kilograms of nitrogen and 11 kilograms of phosphorus.

  Because of this, the Tongass is known as a “salmon forest.” Scientists tracking stream-side vegetation have found that anywhere from a quarter to three-quarters of the trees’ nitrogen comes from returning salmon. This can make a huge difference to their growth. Sitka spruce growing by these riverbanks take around eighty years to reach fifty centimetres in trunk diameter; their salmon-less counterparts in the interior require much longer, on average, three centuries to reach that size.

  The sitkas’ tree rings also show a record of the salmon’s return. In years where the salmon runs have been large, the marine-derived nitrogen-15 in the trees’ sap is highly correlated. As you may remember, nitrogen-15 is very rare in terrestrial environments, but it is common in the marine food web. The nitrogen-15 in the trees could only have come from one place: the returning fish. Meaning that the salmon’s spawning history is literally being written in the library of the forest.

  Humans are not exempt. We too are subject to the same death-to-life process. Though we may squirm to think of it, naturally buried human bodies also enrich the soil, and just like the salmon we leave our chemical signatures behind. After death, for every kilogram of dry body mass, the average human body releases thirty-two grams of nitrogen, ten grams of phosphorus, four grams of potassium, and one gram of magnesium into the soil of a gravesite. And while a burial will initially kill off some of the nearby vegetation, eventually a balance returns and our decomposing bodies begin to nourish the ecosystem.*10 Just as dying stars gave rise to life on Earth, our own scattered atomic remains re-form in new bodies. They become the ingredients of life again.

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  SINCE THE BIG BANG there has been no new matter in the universe, but over the past hundred years or so, scientists have discovered how to transform atoms in ways that are highly unlikely to occur in nature—some of them intentional, some less so. Of course, even something as familiar as burning a piece of toast, or baking bread in the first place, means changing molecular structure. (Which is pretty impressive, from an evolutionary perspective: one way of thinking of about human ingenuity is that we are an animal capable of modifying molecular structure.) But that’s not nearly the same thing as making new elements, the way a star does. That requires unimaginable amounts of energy, something far beyond what our ancestors could have dreamed of.

  Today though, we have that power. Of the 118 elements on the periodic table, 26 are synthetic, or human made. We make new elements by smashing atomic nuclei together in a process called fusion. The particles are made to collide at high speeds in a particle accelerator, fusing them into a heavier element.

  We have also developed the opposite superpower: the ability not only to fuse atoms but also to make them split. And we demonstrated this power at 5:29 A.M. on July 16, 1945. A photograph captured by the United States Department of Defense shows a bomb codenamed Trinity, a half-second after detonation: in it a dome three hundred metres wide, rises up over New Mexico’s Jornada del Muerto desert like a giant blister. Inside, a fireball ten thousand times hotter than the sun is set to explode into a deadly mushroom cloud.

  Trinity was the world’s first nuclear weapon. The power of the bomb unleashed the energy equivalent of 20,000 tons of TNT. As it did, smoke and debris erupted 11,600 metres into the sky, causing a downpour of radioactive confetti. At the surface, the shockwave blasted a crater into the earth, the heat liquefied the sand, and even 16 kilometres away, observers felt like they were “standing directly in front of a roaring fireplace.” For the first time, humanity held in its hands a power as awesome as the sun. And by daybreak, within a 1.5-kilometre radius of the test site, nothing remained alive.

  Once the United States unveiled this weapon of mass destruction, it was only a matter of time before everyone else wanted it too. Over the next two decades, the world’s most advanced militaries raced to build their own bombs, pockmarking the planet with over five hundred white-hot explosions and sending tons of radioactive debris up into the atmosphere until the Limited Test Ban Treaty was signed in 1963. Then things quieted down. Nuclear tests were banned in outer space, underwater, and in the atmosphere, but no one was aware that after detonation the remnants from nuclear bombs don’t just vaporize and disappear. Each blast injected radioactive particles into the atmosphere, rushing the molecules towards a new destiny. Just like exploding stars, the bomb blasts would become new life.

  For life to exist, however, the element of carbon is vital. All life on Earth is made of it. The same stuff that makes us up is also found in lumps of coal, pencil lead, and diamonds. In living things, it’s a primary element found in proteins, sugars, fats, muscle tissue, and DNA.*11 Plants inhale it directly from the atmosphere, and animals in turn absorb it from the plants they eat. For humans, like all plants and animals, the carbon we take in is used to build our bodies, which brings us back to the mystery of the two mummified sisters in Austria.

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  THE FORENSICS TEAM INVESTIGATING the sisters’ death approached nuclear physicists for help because they knew that radiocarbon dating was used to establish the age of Egyptian mummies. But natural atmospheric carbon-14, which is typically used in carbon dating, was useless here *12; with a half-life of 5,730 years, carbon-14 could certainly be used to date organic tissue, but the accuracy range was in the order of several hundred years. To find out which of the sisters died first, the physicists needed a measure on a human time scale.

  A light bulb went off when they realized there might be a different way to date the bodies. They could look for the artificial spike of carbon-14 that resulted from the fallout of Cold War nuclear testing. Combined with oxygen, carbon-14 becomes carbon dioxide, which is inhaled by plants. When animals eat plants, or eat other animals that feed on plants, they take in that carbon. And because cells don’t discriminate, these carbon isotopes work their way into the food chain. That’s how radiocarbon from nuclear bomb blasts became a building block of every living being.

  Carbon-14 is rare in the environment. It only makes up one-trillionth of the carbon on the planet. This special spike in radiocarbon can be detected in us because the amount of carbon-14 in the atmosphere doubled during the era of above-ground tests before abruptly plummeting again after the test ban. For physicists, this bomb-pulse curve can be read like an atomic calendar, because since that time the radiocarbon has diluted at a steady rate of 1 percent a year. If the scientists could measure the amount of “artificial radiocarbon” inside a cell, like a time-stamp, they could pinpoint the date that the cell appeared.*13

  The forensics team now had a way to unravel the mystery. What they needed next was a sample of cells from the sisters’ bodies that regenerated quickly, cells that were created in days or months rather than years.

  You may have heard the myth that every seven years all of your body’s cells have been replaced so essentially, you’ve become a brand new person. And while it is true that you lose, on average, about fifty billion cells a day, the cells in our bodies have vastly different lifespans and turn over at different rates. Some cells are like mayflies and die within a few days, while others are programmed to stay on with us for weeks, years, or even decades. And to fully bust the my
th: there are some cells so loyal, they stay with us our entire lifetimes.

  Skin cells are quick to go. Stationed on the front lines of our bodies, these cells are replaced every two to three weeks. The entire outer layer of our skin, the epidermis, is exchanged every second month or so. But not only the external parts of us are quickly renewed. Deep inside our guts, our intestinal cells known as villi have even shorter lifespans. Exposed to grinding stomach acids, they go through tremendous wear and tear, shedding and regenerating every couple of days. The speed at which cell turnover takes place also depends on the cells’ vulnerability. While the surfaces of our corneas come with the added protection of our eyelids, these cells are vital for focused vision and so we have a built-in emergency response, and if any damage occurs we can replace them in as little as twenty-four hours.

  Joining us for a longer ride are the cells in our bones. Our skeletons are broken down and gradually replaced every decade. Our heart cells stay with us even longer. In our twenties, we replace them at a rate of 1 percent a year, but this regeneration slows down, and we replace less than 0.5 percent of heart cells annually by the time we’re seventy-five. So, if you live to the ripe old age of one hundred, you will still have about half of the original heart you were born with.

  Because no new carbon is taken in after a body is dead, by examining skin and hair samples, some of the last new cells the sisters’ bodies had made, the scientists determined that one sister had died a year earlier than the other, in 1988. Her cells contained more carbon-14 from the bomb pulse. The last cells were formed in the other sister’s body in 1989, meaning she must have lived alongside her dead sister’s decomposing body before dying herself the following year.

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  WHERE DO WE END and where do we begin? As children, the answer seems simple: I am “me,” and everything else is separate. In fact, even infants have an intuitive understanding of physics. They understand, for instance, the notion of solids: that two solid objects cannot occupy the same space, and that most objects are persistent and have stable boundaries. This is common sense to most of us from our earliest years, but it is a natural blind spot. Given the scale we inhabit, we perceive as solid what is in fact porous, and what seems separate from our bodies is, at the atomic and subatomic levels, deeply interconnected to everything.

  The mystics have long understood this. As Lanza and Berman note, “Entire religions (three of the four branches of Buddhism, Zen, and the mainstream Advaita Vedānta sect of Hinduism, for example) are dedicated to proving that a separate independent self, isolated from the vast bulk of the cosmos, is a fundamentally illusory sensation.” In the practice of Zen Buddhism, the aim is to make the invisible visible. Much like science, the goal is for the Zen practitioner to realize that there is “no separation between the self and the ten thousand things.” The famed Buddhist monk Thich Nhat Hanh illustrates the idea in non-scientific terms by describing a simple flower. A flower, he explains, cannot exist as an isolated thing, because it is intimately connected to everything around it:

  Looking into a flower, you can see that the flower is made of many elements that we can call non-flower elements. When you touch the flower, you touch the cloud. You cannot remove the cloud from the flower, because if you could remove the cloud from the flower, the flower would collapse right away.

  You don’t have to be a poet in order to see a cloud floating in the flower, but you know very well that without the clouds there would be no rain and no water for the flower to grow. So cloud is part of flower, and if you send the element cloud back to the sky, there will be no flower. Cloud is a non-flower element. And the sunshine…you can touch the sunshine here. If you send back the element sunshine, the flower will vanish. And sunshine is another non-flower element.

  And earth, and gardener…if you continue, you will see a multitude of non-flower elements in the flower. In fact, a flower is made only with non-flower elements. It does not have a separate self.

  All living things are like this. We are not isolated; we are networks. Life could not exist otherwise. We are made of matter, and like all matter, we are bound by the second law of thermodynamics, which states that an isolated system will always tend towards a state of chaos and disorder. As living systems, as organized matter, we fight this entropy through constant inflow from the outside world. And we can do this because living things are not closed systems. We require energy from the world around us to maintain our existence. In a very real way, what we call death is the moment that this exchange stops and we dissolve back into chaos. We lose our solidity and become particles again.

  George Berkeley’s question of whether the material world is “real” or only an impression of the mind presupposed that our minds are made from some other “stuff.” Today, we know that our brains—our minds—are made of the very same primordial elements that we now observe. Our second blind spot is that we cannot see how intimately connected we are to the universe around us. That in reality, as astronomer Michelle Thaller has observed, “We are dead stars, looking back up at the sky.”

  *1 A hydrogen atom has one proton, no neutrons and one electron. A lead atom is much “busier.” It has eighty-two protons, eighty-two neutrons, and eighty-two electrons, which is why lead is a much denser element.

  *2 Sixty-five billion solar neutrinos pass through one square centimetre perpendicular to the sun per second.

  *3 Wilhelm Röntgen refused to take out any patents on X-ray technology. He believed that people should be free to benefit from his work.

  *4 DNA itself was first imaged using X-rays.

  *5 Our own sun fuses approximately 620 million metric tons of hydrogen into helium every second.

  *6 The astute reader will have noticed that we skipped from helium to carbon—and that the lighter elements of lithium, beryllium, and boron should be in between. These elements are cosmically created in a different fashion, when a heavier element is hit by cosmic rays.

  *7 Iron cannot release energy by fusion because it requires a larger input of energy than it releases.

  *8 Some elements, like gold, are made from the explosive collision of neutron stars.

  *9 MALDI-MS is a mass spectrometry system that uses a laser to sort atoms and other compounds, allowing scientists to see what an object is made of by looking at their mass and charge. Modern instruments charge an atom or molecule and the laser serves as a firing gun, starting a literal atomic race. The lightest ions are the fastest, and the heaviest the slowest. And so, based on their speed and atomic weight, you can develop a picture of the compounds present in a sample.

  *10 Not with embalming fluids or cremation though. Those are bad for both the soil and plants.

  *11 When DNA replicates, 30 percent is carbon.

  *12 The primary source of C14 is cosmic ray collisions.

  *13 As the bomb-pulse radiocarbon decreases by 1 percent per year, by 2030 the bomb pulse will die out. That’s because organisms born after this time will no longer have any significant spikes of the bomb pulse traces, and so their cells will not be able to be timed. That is, unless we set off more bombs.

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  I TO EYE

  When one does not see what one does not see, one does not even see that one is blind.

  — PAUL VEYNE

  FOR GÉZA TELEKI, it was a rare day off. The primatologist had set out for a scenic hike along one of the high ridges in Tanzania’s Gombe National Park. Towards late afternoon, he found a perfect spot looking out over lush rolling grasslands. There, he settled under a tree to await the evening spectacle: the big African sun would soon drop over the glittering waters of Lake Tanganyika.

  It was quiet above the valley forests, but as Teleki looked around, he realized that he was not alone. Climbing up from opposite directions were two adult male chimpanzees. As they reached the ridge crest, they spotted one another. They both got up on their hind legs, walked upright through the grass until they met eye to eye, and greeted each other by softly panting an
d clasping hands. Now just a few yards in front of Teleki, the chimpanzees sat down. All three sat together in silence. For the primatologist, it was an experience that was transformative and profound. The chimpanzees had come to the spot, just as he had, simply to sit and watch the beautiful sunset.

  What are we to make of this? Given that we are 99 percent chimpanzee, that we share largely the same DNA, is it really so impossible that they could appreciate something like a sunset? Or is that anthropomorphism? Are we projecting our thoughts and ideas onto another species, seeing the chimps’ behaviour through a human lens?

  There are at least two ways of looking at it, and both reveal that we have a blind spot with regard to how we view other species. On the one hand, we have to concede that we are not, as we might think, the planet’s only stargazers. Indeed, we are not the only problem-solvers, not the only communicators, and not the only animals capable of love or the appreciation of beauty.

  But the other way of looking at the chimps’ behaviour may be even more astonishing, because, though we can guess at the thoughts or emotions of our fellow primates on that hillside, the truth is their experience is completely unknowable to us. That is, even our closest evolutionary relative might see and perceive a world completely different from our own.

  Most of us spend little time thinking about how other animals perceive the world. But in Italy, a by-law came into effect in the city of Monza that made it illegal to keep a pet goldfish in a bowl. The ruling came about because the fish have good vision, and so keeping them in a warped environment that forces them to live with a “distorted view of reality” is considered cruel. City councillor Monica Cirinnà, quoted in the newspaper Il Messaggero, said, “The civilization of a city can be measured by this”—“this” being the still rather shocking idea that we could or should have respect for an animal’s perspective.