The Reality Bubble

by Ziya Tong

  Imagine a block of lead stretched out one light year in length, or nine and a half trillion kilometres long.*1 Now imagine shooting a stream of neutrinos through it at one end. Incredibly, half of the particles would sail through effortlessly, making a clear exit on the other side. At nearly zero mass, with no electric charge, neutrinos are so named because they are neutral and are not drawn to other subatomic particles. They are also unimaginably puny. For a neutrino, the space between lead atoms is like an immense chasm, as a result, zipping right through lead is a breeze.

  In everyday life, our eyes and stubbed toes deceive us into believing that matter is solid, but that is an illusion. As early as grade school, we learn that atoms are made up primarily of open space. For example, if you were to blow up a hydrogen atom’s nucleus to the size of a golf ball in your hand, the rest of the electron shell around you would be a kilometre away. But to understand how small a neutrino is, you would need to make the atom enormous—you’d have to inflate it to the size of the solar system. At that scale, the golf ball in your hand would be about the size of a neutrino; that’s how minuscule a neutrino is compared to the size of an atom.

  But these simple illustrations don’t give us the full picture. Because at the subatomic level, neutrinos don’t even have a “size” per se. According to physicists, neutrinos are “point-like particles with uncertain positions”; they are less than a millionth the mass of an electron, which is why they can move freely and relatively unencumbered even through the densest of space.

  At the subatomic scale, our bodies, like mountains, are also basically empty space. To neutrinos, we’re like ghosts: a hundred trillion neutrinos pass unnoticed through our bodies every second as if we’re not even here. But because we are bombarded by so many neutrinos—they are constantly being generated by the sun’s nuclear fusion and by the destruction of supernovas—every once in a while, given their immense volume, a neutrino will hit another subatomic particle, which allows a neutrino observatory to detect it.*2 At the Super-K facility, these rare collisions are what the scientists are waiting for. When a neutrino hits an electron in the ultra-pure water, it produces a tiny blue spark of neutrino light similar to an optical sonic boom. This results in a characteristic blue glow, called Cherenkov radiation.

  After 503 days of exposure, capturing about fifteen neutrino “pixels” a day, the Super-K had collected enough of these brief neutrino flashes, which had passed not only down through the mountain but also up through the earth, that it formed the image of the sun beaming brightly outside.

  The image created by the neutrinos is called a neutrinograph. And what makes the Super-K neutrinograph of the sun so remarkable is that it proves that what looks like the solid world around us, from stones to whole mountains, is indeed empty and porous. But as we’ll see next, there is another scientific imaging technique that can be used to look inside ourselves, and it reveals the same thing.

  Lord Londesborough, At Home,

  144 Piccadilly.

  A Mummy From Thebes to be unrolled at half-past Two

  —formal invitation, 1850

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  IN THE NINETEENTH CENTURY, British high society was gripped by Egyptomania. It was a legacy of Napoleon’s Egyptian campaign, which began archaeological excavations half a century earlier. Archaeologists and explorers were revealing the awe-inspiring power of an ancient empire, once as great as their own, that now lay in ruins. The desert expeditions pillaged Egypt’s ancient temples and tombs, while back in Europe private collectors snapped up the ancient artifacts which had rested undisturbed for thousands of years.

  As part of this fascination, wealthy collectors began hosting mummy “unrolling” parties. Guests gathered around the desiccated bodies, marvelling at the gems and amulets that were revealed as the linen bandages were theatrically unwound from the dead. The bodies were sought-after souvenirs. As French aristocrat Abbot Ferdinand de Géramb wrote in 1833, “It would be hardly respectable, on one’s return from Egypt, to present oneself without a mummy in one hand and a crocodile in the other.” And so the mummies were destroyed in afternoon spectacles so that the rich could entertain their friends.

  Towards the end of the century, however, a new craze emerged when in 1895 a German physics professor named Wilhelm Röntgen turned the public’s attention to a mind-blowing new discovery. He called them X-rays.*3 The mysterious rays could penetrate solid matter, allowing people to see through human skin right down to the bone.

  It was extraordinary. The images baffled Victorian society. People were so excited by the technology that, as one author has noted, X-rays became like the iPhones of the 1890s. Soon this new form of “super-vision” was everywhere. And for the mummies at least, the X-ray images, or radiographs, offered some reprieve. It was only months after the X-ray’s debut that physicist Walter König scanned the mummy of an Egyptian child, pioneering a non-invasive way to examine human remains, preserving them for posterity.

  X-rays weren’t only used on the dead, of course. Physicians in particular were quick to pick up on their benefits. If in the past determining the exact location of broken bones relied solely on a doctor’s best guess, now, with X-ray vision, problem areas could be identified before an operation. This ability to see through flesh became especially useful at the battlefront, as medics could spot the exact location of bullets and shrapnel lodged in the bodies of injured soldiers.

  The power of X-ray vision was also not limited to scientific or medical domains. It became hugely popular with the general public as well. At fun fairs and carnivals, “bone portraits” became a new attraction, and people lined up to see the shocking sight of their skeletons for the first time. X-rays also revealed the skeletal deformities prevalent in the Victorian era. For women dressed in the fashions of the day, X-rays revealed that a lifetime spent bound in tight hourglass corsets had bent their ribs and crushed their organs.

  But the new trend did not only reveal the side effects of the beauty industry, it caused them too. The British entrepreneur Max Kaiser developed what he called the Tricho system for hair removal. By 1925, he had expanded the business and set up shop in over seventy-five studios across the United States. Women coming in for hair removal treatment on their upper lips were subjected to up to twenty doses of radiation.

  As with any boom, the X-ray business was for a while a free-for-all, and anyone, whether they were a builder, pharmacist, or wine dealer, could open up their own lab and be considered competent enough to read a radiograph. The technology became so prevalent that until the 1950s shoe-fitting “fluoroscopes” were available at most department stores, casually offered up to shoppers who wanted to see their feet inside a pair of shoes to ensure they had a perfect fit. But it had not gone unnoticed that the powerful rays had side effects. The X-ray craze began to fall out of favour as more and more reports came in of unwanted hair loss, blisters, swelling, and burns, as well as cancer and even death. The irony being that despite being able to “see” better than ever before, we could not see the damage until it was too late.

  Radiation, scientists were discovering, is not all the same: there are different rays with different penetrating effects. Alpha radiation, for instance, is fairly weak and can be blocked by something as simple as an outstretched hand. Alpha rays cannot even penetrate the cells on the outer layer of your skin. Because of this, in cancer treatment, alpha radiation in the form of radium-223 is commonly used to destroy cancerous masses. Inserted into the tumour, the alpha particles kill the cancerous cells, but because they can’t penetrate very far, the healthy surrounding cells are left untouched.

  Beta radiation, on the other hand, goes a little farther. Emitting particles of a smaller mass, this form of radiation can penetrate a few centimetres into the human body but can be stopped by a relatively “solid” sheet of plastic or aluminum. Radioactive carbon-14 in the atmosphere is a form of beta radiation that barely penetrates the most outer layer of dead skin on our bodies. But as we’ll see sh
ortly, this form of beta radiation has other clever ways to make its way in.

  As for gamma rays and X-rays, these two types of radiation have the highest penetration; they are able to travel right through the body as if it isn’t even there. But they can’t filter through materials the way neutrinos can. Remember, a neutrino can travel unimpeded through nine and a half trillion kilometres of lead, while an X-ray will be stopped by a few centimetres. Still, the thickness and density of the calcium in our bones are enough to block X-rays, which is what creates the images of our skeletons. Soft tissues, like our fat, muscles, and skin, are more permeable, whereas materials made up of higher-atomic-numbered elements, like calcium, or bullets made of lead, block most of the X-ray beam, creating that now familiar white silhouette.

  As for our cells, for the most part X-rays shoot through them without damage, but as ionized radiation with enough energy to knock out an atom’s electrons, every once in a while they can rip a cell’s molecular structure, causing a mutation in the DNA.*4 That’s why large or frequent X-ray doses are dangerous, because they literally shower the cells with radiation. Like playing Russian roulette, with each shot you are increasing the odds of a damaging effect.

  You may have noticed that to protect radiologists and medical staff, the doors and walls of modern hospital X-ray rooms are lined with lead, and that during exams, patients must wear a lead vest to cover the parts of their body not being X-rayed. The expectation is not that none of the photons will make it through—some will—but with a high atomic number, the lead shield will block the vast majority of them.

  Similarly, the metal luggage scanning boxes at airport security are lined with lead. Because X-rays light up high-density objects, this alerts screeners to the potential presence of weapons or bombs. If you’ve ever wondered why passengers have to remove their laptops and cameras from their carry-on luggage at security, it’s because the X-rays can’t see through these impenetrable materials, making it difficult to detect objects that might be hidden behind them.

  It’s been more than a century since the discovery of X-rays, and today most of us take it for granted that X-ray machines allow us to see what we were once blind to. But in a way, each new form of sight reveals a different kind of blindness. Just as the X-ray machine can spot contraband but is blind to the baggage, the Super-K can see the sun but is blind to the mountain. Sometimes, to see one previously hidden thing, we lose sight of something else.

  At the heart of Johnson and Boswell’s debate back in 1763 was whether there is a real distinction between what is inside our minds and what is out there in the physical world. At the human scale, we tend to see “solid” and “real” as the same thing, but at the subatomic scale the world around us is in a constant dance of interchanging particles. What modern scientific tools have revealed to us is that not only is there no strong distinction between us and the stuff around us, our bodies are made of the stuff around us. That stone and Johnson’s toe, as we will soon discover, both have their origins in the same thing.

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  IN 1957, A SCIENTIFIC PAPER now known as the B2FH paper forever changed how we see ourselves on Earth. “B2FH” stood for the last names of its authors: astronomers Geoffrey and Margaret Burbidge, William Fowler, and Fred Hoyle. In it, they outlined the “stardust” theory of the origins of the living universe. And today, most of us have solid proof that all life, and all matter that makes up the stuff of our material reality is derived from elements created by the stars.

  In technical terms, it’s called stellar nucleosynthesis. What it means is that all of us are the physical resurrection of dead stars. That’s because every life on Earth, every body, is born from a galaxy of explosions. According to NASA astronomer Michelle Thaller, the iron that makes our blood red was made in the final moments before a star died. For all of us, then, our very life-blood began with a spectacular death in a solar system.

  Stars themselves are born in molecular nurseries. As gas clouds made up mostly of hydrogen spiral inward together under the force of gravity, the hydrogen atoms begin to fuse together in a blinding hot core. The fusion of four hydrogen nuclei creates a new element, helium, and it is this blasting outflow of energy generated from the massive nuclear reaction that supports the star, preventing it from collapsing inward under the pressure of its own weight.*5 A star remains stable as long as these two opposing forces—exploding outward and crushing in—balance each other out.

  Eventually, however, the hydrogen fuel runs out and the star begins using the only other fuel it has available: the shell of helium it produced from nuclear fusion. Fusing three helium atoms together, it begins to form the next element: carbon. The carbon then forms oxygen, and the oxygen turns into silicon and sulphur. This process of lighter elements fusing to form heavier elements is the chain reaction of “stellar nucelosynthesis,”*6 which continues all the way up the periodic table until the star reaches iron, whereupon the star becomes so heavy that the energy no longer burns outward and instead all of that power is absorbed.*7 The result is an explosion so massive and spectacularly violent that the dying star burns brighter than all the other stars in its home galaxy combined. This is the legendary supernova. It is from this stellar explosion that the primary elements in the periodic table are made: the carbon in our bodies, the silicon in our cell phones, the uranium we use to make bombs and power cities. Almost all of the matter that surrounds us came from the death of a star.*8

  Supernovas are so powerful, they can even eject atoms into other galaxies. The process is known as “intergalactic transfer,” and astrophysicists at Northwestern University have calculated that approximately half of the matter that makes up our bodies is not even from the Milky Way. Atomically, Earthlings are extragalactic beings, as half of the particles in our bodies were born in far-flung galaxies. As astrobiologist Caleb Scharf writes in The Zoomable Universe, “In simple terms, we are all condensed. The fundamental physical properties of the universe conspired to pull together a set of atoms and molecules that previously had been occupying a volume a billion trillion times larger….Five billion years ago, your atoms were about ten million times more widely spread across the cosmos than they are now.”

  And some of these atoms are as old as the Big Bang itself. In fact, 98 percent of the hydrogen atoms in your body date back to the universe’s beginnings.

  The molecules that surround us are ancient too. We like to think the water we drink is fresh, but scientists believe that water is older than the sun. When you next take a sip, take a moment to consider that the water you are drinking has been a cloud, an iceberg, and a wave, that it has drifted and meandered through canyons at the bottom of the sea. Before entering your body, it has spent, on average, three thousand years in the ocean and just over a week in the sky before falling as rain. Locked up in glaciers, it rests for longer, from thousands to hundreds of thousands of years. Then one day it finally melts, spending half a month in streams and rivers before draining back out to the sea. And this cycle has repeated many, many times in the four and half billion years that Earth has been orbiting our modest sun.

  It’s not just water that gets recycled. The majority of the carbon that makes up our bodies, approximately two-thirds, comes from the plants that we eat and from the carbon dioxide that they exhale, but the remaining one-third comes from carbon that was trapped in buried oil and gas deposits for hundreds of millions of years. As we burn up these fossil fuels, they release into the atmosphere the carbon atoms that made up the bodies of the first aquatic animals that existed 500 to 600 million years ago; the first land plants of 475 million years ago; the earliest reptiles, insects, and amphibians of 350 to 400 million years ago; and the dinosaurs that roamed as giants from 230 to 65 million years ago. So in some small sense, you are the atomic resurrection of a dinosaur.

  What this means is that while your body is constantly renewing itself, creating millions of new cells every second, the atomic materials from which those cells are made are as o
ld as time. Like microscopic Lego, the atoms that have been used to build your body have been used billions of times before, and the atoms that are in your body right now will be used billions of times again.

  At an intuitive level, we all know that life is a cycle, that “from ashes to ashes, dust to dust,” the nursery for new life is a literal deathbed of rot and decay. But scientists can now see this resurrection as it unfolds. At Sheffield Hallam University, Malcolm Clench, a professor of mass spectrometry, became the first to track atoms as they moved from an organism after its death to become visibly incorporated in the body of a new life.

  Producers at the BBC contacted Clench, as they were working on a documentary about the science of decay and wanted to find a visual way to show viewers the death-to-life process as it was taking place. So, Clench created an “After Life” garden, growing hydroponic plants which he fed with a special nutrient system containing chemically labelled nitrogen-15. Nitrogen is essential to life because it’s a fundamental building block of our DNA. And while nitrogen-14 is everywhere in the air and very common, nitrogen-15 is exceptionally rare and only 0.3 percent naturally abundant; that is, you’re unlikely to encounter it by accident.

  Clench’s donor plants were grown to be sacrificed. After mulching them, he turned the dead matter into a liquid compost. This “death soup” was fed to new seedlings which until that time had been grown with the abundant isotope of nitrogen-14. Then, using a mass spectrometer,*9 which sorts and isolates atoms and other compounds by mass, Clench was able to generate a photo of the nitrogen’s exact location, showing where it had been taken up in the young plants’ leaves. It was possible to see with special imaging tools that the nitrogen-15 in the leaves lit up and glowed a bright white. The atomic “death marks” of the rare isotopes could only have come from one place: it was the atomic resurrection of the dead donor plant.