Cosmic Microwave Background
Parenting in the aftermath of the Big Bang.
It’s been a busy month; I’m sorry for my delinquency. I decided to publish this today, in celebration of Graham’s first birthday, rather than to continue editing or proofreading it. I hope I caught most of the worst mistakes, but I’m sure some remain. Anyway, enjoy.
It’s the last day of my weekend. I slept in, a luxury much depreciated but nevertheless infrequently afforded since my son, Graham, was born. Still, a quarter past seven feels a lot nicer than my usual 4:50 AM alarm. As a result, though, I’m behind, running out of time, so I’m multitasking—brushing my teeth on the toilet—when I see that my mom’s calling. I almost answer it, but think better. I’ll call her back once I’m dressed and there’s no toothpaste in my mouth.
The call ends; I get up and spit into the sink. While I rinse off my toothbrush my phone vibrates once against the countertop. I pick it up, ready to listen to my mom’s voicemail. There isn’t one. Instead, a short text:
Just wanted to let you know that Grandma died last night.
During those initial moments after my brain processes the message, I’m unsure how I feel. My face reddens and I take the rush of hot blood to be guilt, maybe shame, remorse seeking its proper object. She never met Graham, I realize. It would have taken, what? Half a day, a day at most.
In a few days, Graham will have his first birthday. He will have been around the sun exactly once, a circuit that most of us will complete around seventy times before we die, give or take. Although the last year of her life overlapped with Graham’s first, my grandmother never met Graham; she wouldn’t have comprehended his relation to her if she had. Ida was on her eighty-seventh lap across the solar system when she died, but the last seven or eight were rote at best, joyless and confusing, her memory and cognition abandoning her long before her body began to fail. There’s a real sense in which—even if I had organized a physical rendevous—they wouldn’t have truly met one another. Toward the end, she was a vacant husk. An introduction that ought to have been fraught with numinous significance would have been disorienting and upsetting for all parties. It was for the best.
Maybe, on some level, she’d have understood, I tell myself. Even if she didn’t, what if it would have made her happy? It would have been one day.
The earth rotates on its axis once every 24 hours; it has an orbital period of 365 days. Like the swinging of a pendulum or the ricochet of a billiard ball, orbital mechanics—though not exactly simple—are derived according to just a few fundamental physical laws. Furthermore, in classical mechanics, these laws are time-reversal invariant, meaning that the equations that describe the system’s evolution forward in time also describe it in reverse. The future is the mirror image of the past, and vice versa. At this level, everything is still reversible, undoable.
Directionality—in time as in space—is determined by an observer, defined in relation to a particular frame of reference. This was Galileo’s relativistic insight, inspired by a swaying chandelier, centuries ago in the cathedral. Perhaps it is cold comfort, but entropy and its concomitants—aging, senescence, death—emerge relativistically, macroscopically, from the fabric of being. They are contingent and perspective-bound.
One day.
I call my mom back; I mention none of this.
For a handful of childhood summers, my father’s extended family attempted to forge a tradition: an annual reunion at the coast, in Neskowin, one of the many essentially fungible wet and foggy beach towns that stud the Oregon Pacific like a bracelet. Every year, a new catastrophe struck, each worse than the last—a fire, a broken ankle, a stroke—until the tradition smothered quietly in its cradle. During its brief instantiation, however, we witnessed the unearthing of Neskowin’s Ghost Forest, an ancient grove of Sitka spruce that appeared, seemingly overnight, after a particularly tempestuous winter.
The mist-shrouded coastal clime was rendered downright mysterious by the sudden appearance of these millennia-dead trees. Jutting out of the sand and mist, they seemed the ancient, petrified fingers of some long-buried giant, black and stark against the endless expanse of gray ocean. One morning, my father and I explored them together. I wonder now if he was, unbeknownst to me, freshly incensed by a late-night argument with his atheistic father that I had not been privy to. I know they were prone to bitter disputes over matters metaphysical and theological, and the odd specificity of our conversation that day makes more sense in this light. Or, perhaps not. Maybe it was just the exhumed forest’s somber majesty, spurring questions of existential import.
One way or another, the subject turned to God, to Christianity and its constant assault from secular science. We discussed the culture’s obsession with Darwin’s theory of natural selection: “You know, Darwin himself said that evolution was wrong before he died,” Dad told me. “He was saved on his deathbed.” I didn’t doubt it for a second. My exposure to evolution was limited to the criticisms of its least charitable opponents; at ten years old, I already saw the theory for the ludicrously ad hoc explanation it was, an embarrassing attempt to deny Creation its Creator. Dad brought up Christian scientists and explained the methodological rigor with which they—by tallying the concentric circles circumscribing the innards of very old trees—demonstrated the veracity of Biblical history. He even tried to explain a few of the theoretical flaws of carbon dating—something about volcanoes—but this went over my head.
The conversation turned to that least-satisfying cosmological posit of all, the so-called Big Bang, the secularists’ theoretical catalyst for all creation. The patent absurdity of it was plain to see. “What came before the Big Bang, though?” I asked, hoping to impress with my incipient apologetics. “What caused that?”
We gazed out across the mist-shrouded half-forest, the silhouettes of its dead trunks contrasting sharply against a backdrop of barely-differentiated gray. These little islands of novelty—pockets of order within the incoherent ombre of sand, sea, and sky—seemed answer enough. I shivered in the brisk coastal air, as if together we had discovered irrefutable evidence of creation, a timepiece bearing the watchmaker’s inscription.
“Exactly,” my father replied.
That night, after I had gone to sleep, a blood clot lodged itself in my grandfather’s brain. It was bound to happen. The tenuous equilibrium of any ordered system—orbital, terrestrial, circulatory—has but a small set of similarly-ordered states into which it can evolve; there will always be, by many orders of magnitude, more states of disorder into which its parts can arrange. So if not this malfunction, some or another was, given enough time, inevitable. This is entropy, the second law of thermodynamics, the order of time. The reason why past and future are not symmetrical, emerging de facto out of de jure reversal-invariant physical law.
This I reflect on only with the benefit of a lifetime’s hindsight. Back then, I could not articulate my vague unease. I suppose it had the shape of my rhetorical question from the day prior: what caused that?
“Richard Of York Gave Battle In Vain” is a mnemonic that never really caught on. Who knows why? Perhaps it’s because the acronym “ROYGBIV” is uniquely memorable all on its own. Roy-gee-biv. Or, maybe we don’t need a mnemonic to recall the color spectrum of visible light. We see it—red, orange, yellow, green, blue, indigo, violet—every day. We’re more than intimately familiar with it; consciousness consists of it. Sure—with eyes shut—auditory experience can take center stage, but color still spills in through closed lids.
Homo sapiens have perceived a technicolor world for hundreds of thousands of years; for just as long, we sensed that there was more to it as well, lurking unseen just beyond the threshold of perception. Religion institutionalized our nascent suspicion, proposing other dimensions, heavens and hells, but this demarcation is a comparatively recent distinction. For most of our tenure as a species, the primal weltanschauung understood the relationship between the spiritual and material realms as one of simple identity.
Only a few centuries ago—a span too brief to register on a cosmic scale—did humankind discover that we had been right all along, that the visible light we see is merely the minute, observable portion of a spectrum that extends into asymmetrical infinity. Our perception captures only a fraction of the universe’s light, a sliver selected for by evolution because seeing it provided our ape forbears with some reproductive advantage. The shortest wavelength that our eyes discern, we see as the color violet; the longest, red. But we’ve developed methods to detect the infinitesimal gamma ray, and—on the other end—radio waves arbitrarily long, spanning the breadth of the universe.
The mantle of Galilean relativity was taken up by Albert Einstein at the beginning of the 20th century. Einstein expanded the applicability of the theory, first with Special Relativity—which added caveats for velocities approaching the speed of light—and later with General Relativity, which incorporated gravitational effects. A postulate of Einstein’s is that the speed of electromagnetic radiation—the speed of light—is constant in a vacuum, for all observers, regardless of their frame of reference.
Although the speed of light is a universal constant, its wavelength—due to the Doppler effect—can be perceived differently by different observers. In the same way that a car passing on the freeway increases in pitch as it approaches and descends into a low rumble as it departs, the wavelength of approaching light shifts blue, while receding light—moving, relative to us, away—shifts toward the red end of the spectrum in a phenomenon known as redshift.
My father was right; religion is under a sort of attack by science. Science and its methods have, systematically and for centuries, broken the tenuous logic of religious faith, peeling mystery off the cosmos in clumsy, fleshlike strips. One such blow came in 1929, with the discovery of the Hubble expansion.
While examining the electromagnetic spectra of distant galaxies, Edwin Hubble observed something astonishing: anywhere he pointed his telescope, anywhere he looked and in every direction, the spectra of these far-off worlds shifted always red, never blue. In every case, their light appeared to be receding, farther and farther away from us; the more distant the galaxy, the more pronounced the phenomenon. In the aftermath of the Big Bang, space itself was expanding too quickly for even light to keep up.
The coup de grâce came in the 1960s, delivered by the radio astronomers Arno Penzias and Robert Wilson, who inadvertently discovered the cosmic microwave background—literally the afterglow of the Big Bang. They stumbled upon it by accident, thinking it at first to be a malfunction of their radio telescope. As anticipated, it detected the radiation of the distant stars it pointed to—but, oddly, it registered too a low-level radioactive hum no matter where they directed it. Rather than mere icy vacuum, all of space was suffused with a cool-but-detectable warmth, radiation about three degrees above absolute zero.
A brief explanation: for 370,000 years after the big bang, the universe was too hot and energetic for stable atoms to form; thus, despite being full of photons—full of light—the universe was an opaque plasma of elementary particles and energy. Imagine it like a salad dressing: oil, slowly blended into vinegar. What Penzias and Wilson discovered with their radio telescope was the moment the emulsification broke: as space expanded, the temperature of the universe dropped and a phase transition occurred during which the universe became transparent. Matter condensed out of hot plasma; hydrogen atoms formed and released photons. Traveling for fourteen billion years, the photons had cooled off significantly by the time they reached Penzias and Wilson, but were still easily detectable with the proper tools.
The homogeneous glow of the microwave background betrays the remarkable uniformity of the early universe, a state in which any configuration looked, more or less, like any other. But—after the phase transition and the emergence of stable matter—gravity became the dominant universal force. As the cosmos evolved, atoms fused into stars, then galaxies. Suddenly, there were infinitely more possible disordered states in which to evolve than uniform, equilibrium states. Thus loosed the arrow of time from its crooked bow.
In a few trillion years, the expanding universe will have outpaced us entirely. In every galaxy across the universe, the speed of light will be outstripped by exponentially expanding vacuum, infinite distance, and the night sky will grow dark. The microwave background radiation will dissipate, and there will be no telltale evidence of the Big Bang, nothing at all to suggest that there is more to the world than what we can see. Any sentient life will be left with nothing more than the vague premonition of our early ancestors.
Suddenly, I realize how I feel—about the death of my grandmother, about the single day that I could not spare for her, about Graham turning one. I feel unsure of what to do: should I cringe away from the entropic aftermath of miraculous, impossible creation? Or bask in its cold light, omnipresent and all-illuminating, before it is gone forever? I feel that understanding—the meaning of love, God, consciousness—has come to me too late. My remorse finds its object: that the infinite mystery only just dawned on me and already passes through me like a sieve, light racing, receding, violet shifting blue, growing redder and redder. Any minute now it will disappear, first from the spectrum of my comprehension, then vanishing altogether.
I bathe Graham nightly; the first thing he does is pull the rubber stopper from the drain. He is too eager. He is endlessly fascinated by the spiraling bathwater, by the way his rubber ducks and plastic orbs inexorably circle the drain. When the bath is empty, he is nonplussed; he knows I will refill it, and the game will go on. The rigid order of time is observer-dependent, and from his perspective, there is still only the present in its infinitely interchangeable potential configurations. At this level, everything is still reversible, undoable.
Delay, delay, a little longer. Give me a little more time! A minute more, an hour—one day! A single day to count them for myself: the rings, the recursive history of the universe, nested and repeating, circumscribing petrified hearts of spruce! All I want: to arrest the heavens in orbit and send the planets spinning back to the beginning. It is all I wish to accomplish: to gather the prodigal galaxies, star by errant star, and wrap them in my embrace, hold them close forever. Is it too much to ask? To stop time? Freeze light in a vacuum, halt the universe in its tracks?
As always, thanks for reading. You can reach me at benjimahaffey@substack.com. Happy St. Patrick’s Day. Thanks to my brother, Joseph Mahaffey, for the illustration of the Ghost Forest.
Always look forward to these, and they’re always a joy.
Beautifully written.