Chapter Five
STAR JELLY AND TIME CONES: THE SPEED OF TIME
Time is nature’s way to keep everything from happening at once.
—John Wheeler
Last night the angels bent down to earth. There are nights when the heavens seem closer, when gravity holds you just a little less firmly. Last night was one of them. Yesterday afternoon a prairie high blew in from the west, and after a few hours I was sure I could smell yucca and sagebrush. In my garden the peonies bobbed in the gusts. Their ruffled petals fluttered like the organza of debutante dresses as they scattered their perfume on the wind. Above them the trees were restless. I could see the muscled shape of wind gusts moving through the leafy branches. Something in the air elevated my mood. I felt lighter, freer. At dusk a low bank of stratus clouds hovering just above the sunset turned neon pink against a pale turquoise sky, like a Tiepolo fresco. Then, almost as if it had been switched off, the wind died down.
Later, when darkness was firmly established, I went out into the yard again to take a look at the night sky. I was shocked. The night was stuffed with stars. I felt like the only person in an enchanted planetarium, bewitched by the demiurge of night. It was as if another order of darkness had been revealed, as if a layer had been peeled away to reveal a truer darkness, a deeper night, that filled me with dizzy awe. I wondered if the owl I’d seen in March was nearby, sitting on a branch in the secret reaches of night, its eyes sparkling with mystery. The sky was so clear and transparent it seemed that space was somehow closer to the surface of the earth. And everywhere stars. Clusters of stars, necklaces of stars. They sang like destiny in silver notes, and I could see them for what they were—distant, atomic fires of unthinkable immensity, inconceivably remote in time.
Starlight is pure history. Perhaps our earthly time-mosaic, created by the media and architecture, is the natural state of time, like a reflection of the heavens. Perhaps all time—past, present and future—exists at once, everywhere. But the stars take the prize. The night sky contains starlight that started its journey to earth during the Roman era, during the age of dinosaurs, and even from before the earth existed. In the vastness of space, light seems to slow to a crawl, and the vacuum becomes a crystal jelly.
Above my house, Polaris, the pole star, glittered like a fire opal. The luminous gleam from Polaris—the “Pillar of Heaven,” as the Greeks called it—took three hundred and sixty years to get here. It appeared to me as it was when the Puritans had just established their first colony in North America. Looking southwest I saw a high, bright star, the fourth-brightest in the sky, Arcturus, only thirty-six light years away. Its light began its interstellar trek to earth during the late 1960s, when NASA manned lunar bases and Woodstock marked the summit of a cultural revolution.
I walked around to the front of my house so that I could see the constellation of Andromeda, below Polaris, where Andromeda’s long V just touched the northeastern horizon. Floating just above the constellation was a faint smudge, though its smallness was deceiving. This was the largest single celestial object visible to the naked eye, the galaxy Andromeda, named after the constellation next to it. Its light began its earthbound journey more than two million years ago, when the first humans, Homo erectus, entered Europe from Africa. But there were stars even farther away—stars I could have seen only with the most powerful telescopes on earth—whose glow dates from the beginning of the universe itself. A time wind blows through the heavens.
The strange thing about time and the night sky is that the farther you see into it, the closer you are to the beginning of the universe itself. Because the universe is expanding, wherever we look into the night sky, we look towards a smaller universe. Right now the Hubble Space Telescope can see almost thirteen billion light years back, into a time when the universe was less than a tenth the size it is now. But there is no particular place the telescope has to point to see that far back. No matter where it is aimed, it will see back to the beginning of time. We are surrounded by our beginning—the small has swallowed the huge.
TIME CONES
Henceforth, space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality.
—Hermann Minkowski
The present is the past’s future. The past, as Herman Melville wrote, is the “Future’s slave,” but the past also shapes the present. No matter how deeply an event is embedded in the past, it opens only towards the future. The fact of its one-time existence, or of its having occurred, gives it a line of history that unfurls before it. Like the cornerstone of a building, each event in the past has a date of appearance, of completion, and then a long tunnel to the present. What did not happen has no tunnel. But there is another dimension of time, one that includes space. All that has happened—the single leaf that fell from a tree two hundred million years ago, the momentary satisfaction of a medieval glazier after installing a pane of glass in Chartres Cathedral—has a special shape in time that was envisaged by two great mathematicians of the early twentieth century.
Whether or not the idea of time as the fourth dimension originated in H. G. Wells’ novel The Time Machine, it was the Russian mathematician Hermann Minkowski who first put the concept into practice, at the beginning of the twentieth century. He developed a geometry that included time as the fourth dimension, and he was the first person to use the term “space-time,” referring to the unified continuum of all four dimensions. We take space-time for granted now, but when it first occurred to Minkowski it was a revolutionary idea. Minkowski realized that everything is moving through time. All things, even things that seem to be unmoving—a pebble sitting on the shore of a lake, an apartment building—are nevertheless in motion. He referred to the line that an object traces through time as a “world line.” When two world lines overlap, a meeting in space-time takes place, as when your world line overlaps that of the pebble, should you pick it up from the beach. You plucked it from its unseen path. Seen from this perspective, all things, including ourselves, trail invisible world lines.
A pebble and an apartment building create relatively straight world lines on a four-dimensional graph, but anything moving leaves wiggly lines. What is the shape of a coincidence? In Minkowski’s view of space-time, a coincidence would mark a statistically unlikely convergence of world lines—lines crossing great distances of space-time to meet each other. But an uncanny event would be represented by an entirely improbable, extraordinary convergence of world lines. An example of an uncanny event is the case of the Second World War paratrooper whose parachute failed to deploy over enemy territory. He was saved when he miraculously hit the top of a spruce tree at exactly the right point to ensure that each successively larger branch decelerated and cushioned his fall. By the time he hit the bottom branch, he merely slid off it and landed upright, with barely a bruise, in deep snow. That moment changed his life. And he was beyond lucky, as the convergence of world lines that brought about his miracle could statistically never happen again.
Minkowski’s theories proved critical for Albert Einstein, whose general theory of relativity hinged on Minkowski’s concept of four-dimensional space. Using Minkowskian world lines as a starting point, Einstein came up with an elegant, graphic way to visualize the relationship between time and the speed of light. He knew that light spreads out in a circle from its source, like the ripples from a pebble dropped in a pond. The surface of the pond is the present moment, and each successive moment is a plane just above the first, like a stack of glass sheets. In that stack, the expanding rings, moving upwards with time, create an inverted cone through the vertical time axis. Light in the universe behaves the same way. When a supernova explodes it takes time, even at the speed of light, for the resulting flash to reach other stars and galaxies. Einstein called these expanding world lines “light cones.”
The metaphor of the light cone was a tremendous way of unifying the concept of space-time with the way light spreads through the un
iverse. Before the light cone of a distant event arrives, we have no way of knowing what has happened within it, because, in fact, for us it hasn’t happened. It will only “happen” in earth time when the light reaches us. The edge of a light cone is an expanding “now,” trailing the history of the event—the exploding star, the solar flare—behind it. So you could also call them “time cones.”
Yet a star doesn’t have to explode to create a time cone; anything that happens—a flower opening, a cheque being cashed—produces a virtual time cone, even if the fact isn’t relayed at the speed of light. This is because all events and objects affect the things around them. So every world line is nested inside a time cone, and the two of them are tethered together at their beginning. We go on our way through time, creating our world lines, but information about us also spreads over the same period, creating time cones.
All these cones and world lines are oriented in one direction: towards the future. It seems that there is a grain, a direction, to time. Time combs through everything, all the world lines, and aligns them towards the future. In that sense history is like hair or fur: it is composed of many individual strands or world lines, and it stands up on end, the way cat fur does when you put a comb charged with static electricity near it, only in this case the static charge is the future. Everything that happened in the past aims towards a future from whose perspective all those things were inevitable, no matter how random or coincidental they were at the time they occurred. Once they happened, they became part of the absolute past, they did happen, and the future contains them all. But this knowledge is not like ours, unique and partial; it is the sum total of all that came before. All that has ever happened was necessary to make the present what it is. Our present is the past’s future, and the future will eventually contain all presents as pasts when all the time cones finally merge at the end of the universe.
I’d like to think there is a second fur, a second series of time lines that point in the same direction as that of history (as they must), extending not from history towards the present, but from the present towards the future. Because the future isn’t real yet, these lines must be virtual. And they are virtual even if, as in the case of repetitive or cyclic phenomena such as sunrises and seasons, the future is almost 100 percent certain. There will always be an element of unpredictability to the future; if the sun is destroyed by a cosmic cataclysm, it may not rise tomorrow. The predictable future, from the vantage of the past, exists solely in the imagination, not in an absolute, universal sense. Yet there it is, nevertheless. Life, consciousness, could be said to be the exception to the present limit of the one-way world lines, for anticipation also seems to create long, thin world lines that extend out of an event in the future towards an individual in the past.
Right now I’m constructing my own future world line. I’m planning an excursion, a writing retreat to Cayo Largo, in July. I’ve been looking at travel brochures and scouting resorts online. Cayo Largo seems to have everything I need: a small, oceanfront hotel complex on an otherwise deserted island, lots of nature, coral reefs and an all-inclusive plan. I’ve contacted an online travel agency and arranged a fantastic discount. I’ll be able to fly down and then work and snorkel for eight days for almost the same amount of money I’d spend during a week at home.
Anticipating a departure date, or any deadline, is a measure of how we experience the passage of time. Right now, my departure is a couple of weeks in the future. It seems distant, almost abstract. Yet I know how quickly the day will come up. Five days before, I will still be calm, unhurried, but four days before, I’ll begin to pack and buy the small items I’ll need. Anticipation is about waiting. Diane Ackerman described it in A Natural History of Love: “The essence of waiting is wishing the future to be in the present. For a slender moment or strings of moments, time does a shadow dance, and the future is roped by the imagination and dragged into the present as if it really were here and now.” But then, abruptly, it will be the day before my departure, and all sorts of last-minute errands and untied loose ends will arise: notes to leave for my son, light timers and alarms to set. My anti-time cone will become a bullhorn, barking orders from the future.
Today I bought a small handbook of Spanish phrases. I looked up the Spanish word for “time,” tiempo. It rang a bell. I’ve seen it somewhere else recently. On a hunch I went online and revisited a map of Cayo Largo. I scanned the names of beaches and points, and there it was, on the island’s southwest tip: Punta mal Tiempo, “Point of Bad Times.” The English translation sounded more ominous than the Spanish, which had a more rhythmic, romantic assonance. I wondered what Punta mal Tiempo would look like.
SPEAKING OF TIME
Whoever said we have “all the time in the world” wasn’t doing last-minute packing while an airport limousine waited outside. What had been “only a matter of time”—my departure date—had arrived “in no time at all.” There is no confusing a timeline for one of Minkowski’s world lines. My personal timetable was now reduced, I hoped, to being “in the nick of time.” As I was throwing a few last items into my suitcase, I realized that these different metaphorical ways of characterizing time represented time’s complex and intricate effect on every aspect of our lives.
We often refer to time as if it were a substance, and almost always as a quantity. When we have more than enough, we say that we have “time to spare” or that we have “oodles” of time. For slightly smaller durations we refer to “chunks” of time, as if it were a solid. But we also look at time as having length. If we have a “stretch of time” before us, or a “span,” then we can “take our time.” Strangely, our relationship to a surplus of time becomes almost predatory. We “kill time” or “waste” it or simply “while it away” But when time begins to “slip away,” to “run out” like a fluid, we refer to it as a resource: “time is scarce,” there’s only a “bit of time,” it is “limited.” Finally, when we are really “pressed” for time, like grapes in a wine press, or when our time is “up,” then it seems that time rises. We say how “time flies” like a bird or an arrow, while an approaching deadline indicates it is “high time.”
Everyone knows that time is valuable. You can “buy time” or you can live on “borrowed time.” Time can be hoarded or embezzled—you can do things “on your own time” or on “company time”; you can even “spend time”—but, according to folk wisdom, you’ll never get “lost time” back again, even if you try to “gain time” elsewhere. “Time hath, my lord, a wallet at his back,” said Shakespeare, “wherein he puts alms for oblivion.” The old adage has it that “time is money,” but even when not exchanged for cash it is “precious,” like a jewel. Time is sometimes characterized as an object—you can “find it,” and you can “shave off” a little. You can also “make up” some time, as airline pilots are fond of doing.
Romantic time is different. Love will last until “the end of time” or, in the case of stolen love, there will be “time for me and you.” The adulterer is said to be “two-timing,” and at the beginning of a romance, lovers claim they are having “the time of their lives.” Later, when they get older, they recall the “golden times.”
For English speakers the progress of time is sometimes militaristic—the “march of time”—while on other occasions it is compared to a fabric or bud that “unfolds.” The fabric of time can be sewn: “a stitch in time saves nine.” People who look young for their age are said to have kept Father Time “at bay,” like an intruder that was fought off. Success against time as an adversary means we have “stood the test of time,” while something that outlives many generations, like the “timeless” pyramids, has not only stood the test of time but “stands for all time.” Time can be a patron: old customs and institutions we admire are “time-honoured.” But as events move deeper into history, things get fuzzy. In the distant past, time becomes granular and semi-opaque. We look back through the “mists of time” to the “dim past,” where the “sands of time” lie deep.
; Time has many names; in German it is zeit—hence zeitgeist, the spirit of the times. In Dutch it is tijd, reminiscent of “tide,” as in “time and tide wait for no man.” In reality, the English word time does come from the same root as tide, at least in Old Norse. In Latin, time was called tempus, which in turn was derived from a Greek term that meant “to cut.” The Romans, like us, thought of time as something continuous that was apportioned, or “cut,” into hours, days, months and years.
Around the world there are not only differences in what time is called, there are profound differences in how it is perceived. According to Rafael Núñez, a cognitive scientist from the University of California, San Diego, the Aymara people of the South American Andes, unlike any other language group on earth, think of the past as being in front of them, with the future behind them.
Núñez films his subjects in the field because hand gestures often reveal the underlying way in which the speakers of a particular language metaphorize their world. Núñez noticed that when an Aymara talks about his great-grandparents, he will extend his arm all the way in front of him as he describes them. When he talks about his grandparents he will move his hand a little closer. And when he talks about his parents, he will bring his palm close to his chest. But when asked to talk about future generations he will casually point his thumb over his shoulder.
Soul of the World Page 9
