Read an Excerpt
chapter 1
What Came Before the Big Bang?
Though time and space had started to curve like a sagging clothesline, there wasn’t wholesale panic in physics, because the chance that the line might snap apart didn’t quite exist yet (black holes, which snap space and time, were brought into the picture later on). Brilliant equations are devised to keep reality intact, so the very fact that the mathematics was so arcane kept some very disturbing ideas away from the general public. But this all changed with the advent of the big bang theory. In one stroke, time snapped in two. There was time as we know it, which arrived on the scene with the big bang, and there was something else—weird time, pre-time, no time?—that existed outside our universe.
Following Einstein’s lead, let’s see if we can visualize reality outside our universe. For the sake of convenience, we’ll put the riddle this way: “What came before the big bang?” There’s no better way to visualize the problem than stepping into an imaginary time machine that’s whisking us back some 13.7 billion years. As we get close to the unimaginable explosion that began this universe’s creation, our time machine is exposed to extreme danger. It took thousands of years for the infant universe, which was superheated, to cool down enough for the first atoms to coalesce. But since our time machine is imaginary to begin with, we can imagine it coasting through superheated space without melting or flying apart into subatomic particles.
Getting within a few seconds of the big bang, we feel we’re nearing the goal. “Seconds” means that time exists, and now the only challenge is to shave seconds down to millionths, billionths, and trillionths of a second. The human brain doesn’t operate at such fine scales, but let’s assume we have an onboard computer that can translate trillionths of a second into human terms. Eventually we arrive at the smallest unit of time (and space) that it is possible to imagine. William Blake’s famous lines of verse, “Hold Infinity in the palm of your hand / And Eternity in an hour,” is coming true, although an hour is much, much too long. At this point, when the scale of the cosmos was infinitesimally tiny, our onboard computer goes haywire and unexpectedly, nothing can compute.
Our whole frame of reference has dissolved. There is no matter or energy, just a swirling chaos, and within this chaos there are no rules of the kind we call the laws of nature. Without rules, time itself falls apart. The captain of our time machine turns to the passengers to tell them how bad the situation is, but unfortunately, he can’t, for several reasons. As time collapses, so do concepts like “before” and “after.” To the captain, we no longer left earth at a certain time and arrived later at the big bang. Events are all gummed together in an unimaginable way. The passengers can’t cry, “Let me out of here,” either, because space has also dissolved, rendering “in” and “out” useless concepts.
This breakdown at the very threshold of creation is real, even if our time machine isn’t. No matter how hard you work at it, regardless of how fine the slivers of time you shave, the threshold cannot be crossed—not by ordinary means, because, you see, the big bang “occurred everywhere,” so it was not somewhere to where we could travel.
We are left with two options. Either “What came before the big bang?” is an impossible question to answer, or else extraordinary means must be discovered that could possibly reveal an answer. One thing is certain, however: the origin of time and space didn’t happen in time and space. It happened somewhere extraordinary, which, luckily for us, means that extraordinary answers aren’t out of place—they are demanded. With that in mind, let the cosmic riddling begin.
Grasping the mystery
“Before” and “after” are concepts that make sense only within the framework of space-time. You were born before you could walk; you will reach old age after middle age. The same isn’t true of the birth of the universe. It has been widely theorized that time and space emerged with the big bang. If that’s true—and it’s only one possibility, not a fixed assumption—then the real question is “What came before time began?” Is that any better than the first way of putting it?
No. “Before time began” is a self-contradiction, like saying “when sugar wasn’t sweet.” We are squarely in the realm of impossible questions, but that’s no reason to give up in advance. Quantum physics took to heart a conversation between Alice and the Red Queen in Lewis Carroll’s Through the Looking-Glass. After Alice announces that she is seven and a half years old, the Queen retorts that she is a hundred and one, five months, and a day.
“I can’t believe that!” said Alice.
“Can’t you?” the Queen said in a pitying tone. “Try again: draw a long breath, and shut your eyes.”
Alice laughed. “There’s no use trying,” she said. “One can’t believe impossible things.”
“I dare say you haven’t had much practice,” said the Queen. “When I was your age, I always did it for half an hour a day. Why, sometimes I’ve believed as many as six impossible things before breakfast.”
Quantum behavior forces us to be even more tolerant of impossible things. There is nothing ordinary about the conditions at the time of the big bang. To grasp them, some cherished beliefs must be challenged and then cast aside. First, one must realize that the big bang wasn’t the beginning of the universe but of the current universe. Ignoring for now whether the current universe was created from another universe, physics can’t actually trace the cosmos back to the absolute beginning. Taking measurements only works when you have something to measure, and in the very beginning there was an infinitesimal sliver of something, without order of any kind: no objects, no space-time continuum, no laws of nature. In other words, pure chaos. In this unimaginable state, all the matter and energy harnessed in hundreds of billions of galaxies was compressed. Within a fraction of a second, expansion accelerated with inconceivable speed. Inflation lasted between 10-36 (1/1 followed by 36 zeros) to about 10-32 seconds. By the time inflation ended, the universe had increased its size by a staggering factor of 1026, while it cooled down by a factor of 100,000 times or so. A commonly accepted (but by no means definitive) scenario maps the birthing process as follows:
•10-43 seconds—The big bang.
•10-36 seconds—The universe undergoes a rapid expansion (known as cosmic inflation), under superheated conditions, enlarging from the size of an atom to the size of a grapefruit. There are no atoms in existence, however, or any light. In a state of near chaos, the constants and the laws of nature are thought to be in flux.
•10-32 seconds—Still unimaginably hot, the universe boils with electrons, quarks, and other particles. The previous rapid inflation decreases, or takes a pause, for reasons not fully understood.
•10-6 seconds—Having cooled dramatically, the infant universe now gives rise to protons and neutrons that are formed from groups of quarks.
•3 minutes—Charged particles exist but no atoms yet, and light cannot escape the dark fog that the universe has become.
•300,000 years—The cooling process has reached a state where atoms of hydrogen and helium begin to form out of electrons, protons, and neutrons. Light can now escape, and how far it travels will determine from this point onward the outer edge (the event horizon) of the visible universe.
•1 billion years—Through the attraction of gravity, hydrogen and helium coalesce into clouds that will give rise to stars and galaxies.
This time line follows the momentum produced by the big bang, which was sufficient, even when the universe was the size of a single atom, to produce the billions of galaxies visible today. They continue to be driven apart by the force of the initial unimaginable expansion. Many complex events have occurred since the beginning (whole books are devoted to describing just the first three minutes of creation), but for our purposes, it’s enough to view the rough outline.
Because we can all envision how a stick of dynamite or a volcano explodes, the big bang seems to fit our commonsense view of reality. But our grasp of what happened is fragile. In fact, the first seconds of creation call into question almost everything we perceive about time, space, matter, and energy. The great mystery about the emergence of our universe is how something was created out of nothing, and no one can truly comprehend how this occurred. On the one hand, “the nothing” is unreachable by any form of observation. On the other hand, the initial chaos of the infant universe is a totally alien state, being devoid of atoms, light, and perhaps even the four basic forces of nature.
This whole mystery can’t be avoided, because the same birthing process continues, right this minute and all the time, at the subatomic level. Genesis is now. The subatomic particles that the cosmos is built upon wink in and out of existence continually. Like a cosmic on/off switch, there is a mechanism that turns nothing (the so-called vacuum state) into a teeming ocean of physical objects. Our commonsense view of reality sees the stars floating in a cold, empty void. In actuality, however, the void is rich with creative possibilities, which we see playing out all around us.
Already the argument feels like it’s getting abstract, ready to float away like a helium balloon. We don’t want that to happen. Every cosmic mystery has a human face. Imagine that you are sitting outside in a lawn chair on a summer day. A warm breeze makes you drowsy, and your mind is filled with half-seen images and half-realized thoughts. Suddenly someone asks, “What do you want for dinner?” You open your eyes and answer, “Lasagna.” In this little scenario the mystery of the big bang is encapsulated. Your mind is capable of being empty, a blank. Chaotic images and thoughts roam across it. But when you are asked a question and make a reply, this emptiness comes to life. Out of infinite possibilities, you pick a single thought, and it forms in your mind of its own accord.
This last part is crucial. When you say “lasagna”—or any other word—you don’t build it up from something smaller. You don’t construct it at all; it just comes to you. For example, words can be broken down into letters, the way matter can be broken down into atoms. But of course, this isn’t a true description of the creative process. All creation brings something out of nothing. It’s humbling to realize that even as we feel comfortable being creators, immersed in infinite words and thoughts, we have no idea where they come from. Do you know your next thought? Even Einstein looked upon his most brilliant thoughts as happy accidents. The point is that creating something out of nothing is a human process, not a faraway cosmic event.
The transition of nothing into something always achieves the same result: a possibility becomes actual. Physics dehumanizes the process and does so with incredible precision. In unimaginably small scales of time, vibrations of quanta come out of emptiness and quickly merge back into emptiness, but this quantum on/off cycle is totally invisible to us. The rules governing physical creation must be deduced. You can’t apply a stethoscope to the outside of the Superdome in order to discover the rules of football, and that’s essentially what cosmology is doing, in attempting to explain the origin of the universe. Logical deduction is a great tool, but this may be a case in which it creates as many problems as it solves.
A baffling beginning
There’s little doubt that the objects in space didn’t exist before the big bang. But did space and time (technically, the space-time continuum) also emerge with them? The standard reply is yes. If there were once no objects, there was no space or time, either. So what was the pre-created state like? It didn’t have an inside or outside, which are properties of space. As the infant universe expanded, it wasn’t expanding with anything around it, and now, while billions of galaxies operate in outer space, the universe isn’t like a balloon with a skin. Here again, the concepts of before and after, inside and outside simply don’t apply.
Are we left with anything to hold on to? Barely. “To exist” suggests the possibility that even without time and space, things might happen. Here’s a useful analogy. Imagine that you are sitting in a room where you notice that objects are moving slightly: the milk in your cereal bowl is jiggling, and you can feel a vibration coming up through the floor.
As it happens, you are deaf, so you have no way of knowing if something is pounding on the walls of the room from the outside. (Some people might be sensitive enough to feel a vibration in their bodies—let’s leave this aside.) But you can measure the waves in your cereal bowl and the vibrations of other objects, including the floor, ceiling, and walls. This is roughly how cosmologists confront the big bang. The universe is full of vibrations and waves emitted billions of years ago. These can be measured and inferences drawn from them. But uneasiness appears if we ask a simple question: Can someone who is deaf from birth actually know what sound is? Though there are measurable vibrations associated with sound, feeling them is not the same experience as hearing a solo violin, the voice of Ella Fitzgerald, or a dynamite explosion.
In the same way, measuring the light from racing galaxies and the background microwave radiation in the current universe (this radiation is a residue of the big bang) doesn’t tell us what the beginning of the universe was like—we are working from inferences, just like a deaf person observing waves in his cereal bowl, and this limitation could be a fatal flaw in any explanation of where the universe came from.
We can still try, from our standpoint here in our space-time, to explore laws of nature that operate outside space and time. In particular, physics can resort to the language of mathematics in the hopes that its existence doesn’t depend on which universe you happen to live in. Most of the speculation that follows keeps faith with mathematics as something eternally valid. Even in an alien universe, where time goes backward and people walk on the ceiling, if you add one apple to another apple, the sum is two apples, right?
However, no one has ever proved that this faith is actually valid. The mathematics that’s applicable to black holes, for example, is locked in speculation, because a black hole is totally impenetrable. Mathematics could be the product of the human brain. Take the number zero. It hasn’t always been around. By 1747 BCE, the ancient Egyptians and Babylonians had a written symbol for zero as a concept, but it wasn’t used as a number for calculating purposes until around AD 800, in India, long past the heyday of Greek and Roman culture.
