Origin Story, page 3
It wasn’t until the early 1960s that the crucial pieces of the big bang story emerged. That’s when astronomers first detected the cosmic microwave background radiation (CMBR)—energy left over from the big bang and present everywhere in today’s universe. Though cosmologists still struggle to understand the moment when our universe appeared, they can tell a rollicking story that begins about (deep breath, and I hope I’ve got this precise) a billionth of a billionth of a billionth of a billionth of a billionth of a second after the universe appeared (around 10-43 of a second after time zero).
The bare-bones story goes like this: Our universe began as a point smaller than an atom. How small is that? Our species’ minds evolved to deal with things at human scales, so they struggle with things this tiny, but it might help to know that you could squeeze a million atoms into the dot at the end of this sentence.9 At the moment of the big bang, the entire universe was smaller than an atom. Packed into it was all the energy and matter present in today’s universe. All of it. That is a daunting idea, and at first it might appear plain crazy. But all the evidence we have at present tells us that this strange, tiny, and fantastically hot object really existed about 13.82 billion years ago.
We don’t yet understand how and why this thing appeared. But quantum physics tells us, and particle accelerators—which speed up subatomic particles to high velocities by means of electric or electromagnetic fields—show us, that something really can appear in a vacuum from nothing, though grasping what this means requires a sophisticated understanding of nothing. In modern quantum physics, it is impossible to determine precisely the position and motion of subatomic particles. This means you can never say for sure that a particular region of space is empty, and that means that emptiness is tense with the possibility that something might appear. Like the “neither non-existence nor existence” of the Indian Vedas, this tension seems to have bootstrapped our universe.10
Today, we refer to the universe’s first moment as the “big bang,” rather as if, like a newborn baby, the universe yelled out at its birth. This cute term was coined in 1949 by an English astronomer, Fred Hoyle, who thought the idea was ridiculous. In the early 1930s, when the concept of a big bang was first floated, the Belgian astronomer (and Catholic priest) Georges Lemaître called the newborn universe the “cosmic egg” or the “primordial atom.” It was clear to the few scientists who took the idea seriously that, with so much energy squashed up inside it, the primordial atom had to be inconceivably hot and had to be expanding like crazy to relieve the pressure. The expansion continues today; it’s as if a vast spring has been uncoiling for more than thirteen billion years.
A lot happened in the first seconds and minutes after the big bang. Most important of all, the first interesting structures and patterns appeared, the first entities or energies that had distinctive nonrandom forms and properties. The emergence of something with distinctive new qualities is always magical. We will see this happening over and over again in the modern origin story, although what appears to be magical at first may seem less so once we understand that the new thing and its new qualities did not arrive out of nowhere or from nothing. New things with new properties emerge from already existing things and forces that are arranged in new ways. It’s the new arrangements that yield the new properties, just as arranging tiles in a different way can generate a new pattern in a mosaic. Take an example from chemistry. We normally think of hydrogen and oxygen as colorless gases. But join two hydrogen atoms to a single oxygen atom in a particular configuration, and you get a molecule of water. Put lots of those molecules together, and you get the utterly new quality that we think of as “wateriness.” When we see a new form or structure with new qualities, we are really seeing new arrangements of what already existed. Innovation is emergence. If we think of emergence as a character in our story, it’s probably slinky, mysterious, and unpredictable, likely to pop up from the darkness unexpectedly and take the plot in new and surprising directions.
The first structures and patterns in the universe emerged in just this way, as things and forces that popped out of the big bang were arranged in new configurations.
At the earliest moment for which we have some evidence, a split second after the big bang, the universe consisted of pure, random, undifferentiated, shapeless energy. We can think of energy as the potential for something to happen, the capacity to do things or change things. The energies inside the primeval atom were staggering, many trillions of degrees above absolute zero. There was a brief period of super-rapid expansion known as inflation. Expansion was so fast that much of the universe may have been projected far beyond anything we will ever see. That means that what we see today is probably just a tiny part of our entire universe.
A split second later, rates of expansion slowed. The turbulent energies of the big bang settled down, and as the universe kept expanding, the energies were spread out and diluted. Average temperatures fell, and they have kept falling, so today, most of the universe is just 2.76 degrees Celsius above absolute zero. (Absolute zero is the temperature at which nothing even jiggles.) We don’t feel the chill, nor do any of the other organisms on planet Earth, because we are warmed by the campfire of our sun.
In the extreme temperatures of the big bang, almost anything was possible. But as temperatures dropped, possibilities narrowed. Distinct entities began to emerge like ghosts within the chaotic fog of the cooling universe, entities that could not exist in the violent cauldron of the big bang itself. Scientists call these changes of form and structure phase changes. We see phase changes in our daily lives when steam loses energy and turns into water (whose molecules move about a lot less than steam molecules) and when water turns into ice (which has so little energy that its molecules just jiggle in place). Water and ice can exist only in a narrow range of very low temperatures.
Within a billionth of a billionth of a billionth of a billionth of a second after the big bang, energy itself underwent a phase change. It split into four very different species. Today, we know them as gravity, the electromagnetic force, and the strong and weak nuclear forces. We need to get acquainted with their different personalities, because they shaped our universe. Gravity is weak, but it reaches across vast distances and always pulls things together, so its power accumulates. It tends to make the universe more clumpy. Electromagnetic energy comes in negative and positive forms, so it often cancels itself out. Gravity, though puny, shapes the universe on a large scale. But electromagnetism dominates at the level of chemistry and biology, so it’s what holds our bodies together. The third and fourth fundamental forces are known, unexcitingly, as the strong and weak nuclear forces. They reach over tiny distances, so they matter on a subatomic scale. We humans don’t experience them directly, but they shape every aspect of our world because they determine what happens deep inside atoms.
There may be other species of energy. In the 1990s, new measures of the universe’s rate of expansion showed that the rate is increasing. Borrowing an idea first floated by Einstein, many physicists and astronomers now argue that there may be a form of antigravity that is present in all of space, so its power increases as the universe expands. Today, the mass of this energy may account for as much as 70 percent of the total mass of the universe. But even if it is beginning to dominate our universe, we don’t yet understand what this energy is or how it works, so physicists call it dark energy. The term is a placeholder. Watch this space, because understanding dark energy is one of the great challenges of contemporary science.
Matter appeared within the first second after the big bang. Matter is the stuff that energy pushes around. Until just over a century ago, scientists and philosophers assumed that matter and energy were distinct. We now know that matter is really a highly compressed form of energy. The young Albert Einstein demonstrated this in a famous paper in 1905. That formula—energy (E) is equal to mass (m) times the speed of light (c) squared, or E = mc2—tells us how much energy is compressed inside a given amount of matter. To figure out how much energy is locked up in a bit of matter, multiply the mass of the matter not by the speed of light (which is more than one billion kilometers per hour) but by the speed of light times itself. This is a colossal number, so if you uncompress a tiny bit of matter, you get a huge amount of energy. That’s what happens when an H-bomb explodes. In the early universe, the opposite process occurred. Huge amounts of energy were compressed into tiny amounts of matter, like motes of dust in a vast fog of energy. Remarkably, we humans have managed to re-create such energies briefly, in the Large Hadron Collider outside Geneva. And, yes, particles do start popping out of that boiling ocean of energy.
And we’re still in the first second…
The First Structures
Within the chaotic fog of energy just after the big bang, distinct forms and structures began to appear. Though the fog of energy is always there, the structures that emerged from it will give our origin story shape and a plotline. Some structures or patterns will last for billions of years, some for a split second, but none are conserved. They are evanescent, like waves on the ocean’s surface. The first law of thermodynamics tells us that the ocean of energy is always there; it’s conserved. The second law of thermodynamics tells us that all the forms that emerge will eventually dissolve back into the ocean of energy. The forms, like the movements of a dance, are not conserved.
Some distinct structures and forms emerged within a second of the big bang. Why? Why is the universe not just a random flux of energy? This is a fundamental question.
If our story had a creator god, explaining structure would be easy. We could just assume (as many origin stories do) that God preferred structure to chaos. But most versions of the modern origin story no longer accept the idea of a creator god because modern science can find no direct evidence for a god. Many people have experiences of gods, but those reported experiences are diverse and contradictory, and they cannot be reproduced. They are too malleable, too diffuse, and too subjective to provide objective, scientific evidence.
So the modern origin story has to find other ways of explaining the emergence of structures and forms. And that’s not easy, because the second law of thermodynamics tells us that sooner or later, all structures will eventually break down. As the Austrian physicist Erwin Schrödinger wrote: “We now recognize this fundamental law of physics to be just the natural tendency of things to approach the chaotic state (the same tendency that the books of a library or the piles of papers and manuscripts on a writing desk display) unless we obviate it.”11
If there is a bad guy in the modern origin story, it is surely entropy, the apparently universal tendency for structures to dissolve into randomness. Entropy is the loyal servant of the second law of thermodynamics. So, if we think of entropy as a character in our story, we should imagine it as dissolute, lurking, careless of others’ pain and suffering, not interested in looking you in the eye. Entropy is also very, very dangerous, and in the end it will get us all. Entropy stands at the finale of all origin stories. It will dissolve away all structures, all shapes, every star and every galaxy and every living cell. Joseph Campbell described entropy’s role poetically in a book on mythology: “The world, as we know it… yields but one ending: death, disintegration, dismemberment, and the crucifixion of our heart with the passing of the forms that we have loved.”12
Modern science explains entropy’s role in the cold-blooded language of statistics. Of all the myriad ways in which things can be arranged, the overwhelming majority are unstructured, random, disordered. Most change is like taking a pack of 1080 cards (that’s 10 followed by 80 zeros, or roughly the number of atoms in the universe) and shuffling it again and again in the hope of finding all the aces next to each other. That’s an inconceivably rare pattern, so rare that you are unlikely to see it even if you keep shuffling for many times the age of the universe. Most of the time you’re going to find little or no structure. If you throw a bomb into a construction site full of bricks, mortar, wires, and paint, what are the odds that when the dust clears, you’ll find an apartment building all wired up, decorated, and ready for buyers? The world of magic can ignore entropy, but our world can’t. That’s why most of the universe, particularly the vast empty spaces between galaxies, lacks shape and structure.
So powerful is entropy that it is not easy to understand how any structures appeared in the first place. But we know that they did. And they seem to have appeared with entropy’s permission. It’s as if, in return for letting things link up to form more complex structures, entropy demanded a complexity tax, to be paid in energy. In fact, we’ll see that entropy has demanded many different types of complexity taxes, a bit like the Russian emperor Peter the Great, who formed a special government office to dream up new taxes. Entropy likes this deal because the taxes paid by all complex entities will help entropy’s grim task of turning the entire universe into mush. The very act of paying entropy taxes creates more chaos and more waste, just as running a modern city generates huge amounts of garbage and heat. We all pay entropy’s taxes every second of our lives. We will stop paying on the day we die.
So how did the very first structures emerge? This is a problem for which science does not yet have complete answers, though there are many promising ideas.
In addition to energy and matter, some basic operating rules emerged from the big bang. Scientists did not begin to understand how fundamental these rules were until the scientific revolution in the seventeenth century. Today, we describe these rules as the fundamental laws of physics. They explain why the frantic and chaotic energies of the primeval atom were not completely directionless—the laws of physics steered change down particular pathways and blocked a nearly infinite range of other possibilities. The laws of physics filtered out those states of the universe that were not compatible with them, so at any given moment, the universe existed in only one of the many states that were compatible with the universe’s operating rules. These new states, in turn, generated more rules that steered change down new pathways.
This constant filtering out of impossible states guaranteed a minimum of structure. We don’t know why the rules emerged or why they took the forms they did. We don’t even know if these rules were inevitable. Perhaps other universes exist with slightly different rules. Perhaps in some universes, gravity is stronger or electromagnetism is weaker. If so, these universes’ inhabitants (if they have any) will tell different origin stories. Maybe some universes lasted for a millionth of a second, while others will exist much longer than ours. Perhaps some universes generate many exotic life-forms while others are biological graveyards. If indeed our universe exists in a multiverse, then we can imagine a grand throwing of the dice when our universe was created, followed by an announcement: “Okay, there will be gravity in this universe, and electromagnetism as well, and electromagnetism is going to be 1036 times as strong as gravity.” (That really is the ratio of the strength of gravity and electromagnetism, at least in our universe.) The existence of these rules ensured that our universe would never be totally chaotic. Something interesting was guaranteed to emerge somewhere.
There were structures and patterns as soon as energy emerged in distinct forms. When energy congealed into the first particles of matter, these, too, had rules. Neutrons, protons, and electrons, the basic constituents of atoms, appeared within seconds of the big bang, as did proton and electron antiparticles (that is, negatively charged protons and positively charged electrons), forming what physicists call matter and antimatter. As the universe plunged below the temperatures at which matter and antimatter could easily be created, there took place a violent, universe-wide demolition derby in which matter and antimatter annihilated each other, unlocking huge amounts of energy. Luckily for us, a tiny surplus of matter (perhaps one particle in a billion) survived the carnage. The leftover particles of matter got locked into place because temperatures were soon too low to turn them back into pure energy. And that leftover stuff is what our universe is made of.
As temperatures fell, matter diversified. Electrons and neutrinos were ruled by electromagnetism and the weak nuclear force. The protons and neutrons that form atomic nuclei were made from triplets of strange particles known as quarks, bound together by the strong nuclear force. Electrons, neutrons, quarks, protons, neutrinos… within just a few seconds of the big bang, our rapidly cooling universe had locked in some distinct structures, each with its own emergent properties. But as the hurricane of the big bang abated, the extreme energies needed to unlock these primordial structures vanished, and that’s why, to us, the different forms of energy and particles such as protons and electrons seem more or less immortal.
This is how chance and necessity combined to produce the first simple structures. The laws of physics had filtered out many possibilities—that was the necessity part. Chance then rearranged things randomly from the possibilities that remained. This is how it all works. As nanophysicist Peter Hoffmann writes: “Tempered by physical law, which adds a dash of necessity, chance becomes the creative force, the mover and shaker of our universe. All the beauty we see around us, from galaxies to sunflowers, is the result of this creative collaboration between chaos and necessity.”13
The First Atoms
Within a few minutes of the big bang, as protons and neutrons teamed up, more structures appeared. A single proton is the nucleus of a hydrogen atom; a pair of protons (with two neutrons) form the nucleus of a helium atom, so the universe was beginning to build the first atoms. But it takes a lot of energy to fuse protons because their positive charges repel each other, and temperatures were falling fast just after the big bang, so it was impossible to fuse more protons to form the nuclei of larger atoms. This explains a fundamental aspect of our universe: almost three-quarters of all the atoms in it are hydrogen, and most of the rest are helium.
