Or would it?
What we see when we look up into the darkness of a summer night isn’t just a pattern of pinpoint lights. We’re also looking up at the state of our knowledge and the contents of our imagination. Does our own galaxy encompass the whole observable universe? Or is it only one among a huge number of galaxies in a vastly larger universe? The difference is enormous. Both are theories. One was plausible before 1925. The other is true. The revolution in imagining who we are and where we are is Copernican.
In the years since, there have been many discoveries more astonishing, including Hubble’s discovery, several years later, that the universe is expanding. But measuring that Cepheid variable in Andromeda fascinates me. It’s tempting to construe its effect solely in human terms, to say, with a vainglorious sniff, that it diminishes the place of humans in the universe. Ah, well. There’s no end to that. One of the central problems of cosmology all along has been getting a true sense of scale. The age of the universe, its size, its origin, whether it’s static or expanding or contracting—these things are all interrelated, and they all depend on being able to measure distance accurately out to the far reaches of the universe. The more we know, the smaller we humans seem to loom against the universal backdrop. Luckily, what matters isn’t how big or important we are. It’s how interesting the universe is.
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My maternal grandfather was born in the 1880s. He used to marvel that in his lifetime humans had gone from horse-drawn carriages to the moon. I like to think of it a different way. He was born about the time astronomers finally proved that the ether—the peculiar light-carrying substance through which all celestial bodies were supposed to move—doesn’t exist. He was married around the publication of Einstein’s theory of general relativity. He died a few years after Arno Penzias and Robert Wilson found the lingering echo of the Big Bang with a radio telescope in New Jersey. I don’t imagine my grandfather was aware of any of these discoveries. And yet within his lifetime, the dimensions of the universe increased by a factor I’m not mathematician enough to work out. Call it ten to the plenty.
In 1931, Edwin Hubble concluded that the universe was 1.8 billion years old, a nonsensical number since geologists had already shown that the rocks on Earth are nearly twice that age. (Recent knowledge in itself!) In 1952, the scale of distance was recalculated with greater accuracy, and suddenly the age of the universe doubled to 3.6 billion years, much older but still a problematic figure. In 1955, the universe aged another 1.9 billion years overnight, again thanks to a clearer understanding of the things that shine in the dark. In the past eighty years the universe has expanded faster and aged faster—in the minds of humans—than it’s doing in actuality. The current age of the universe, as measured in 2003, is now 13.7 billion years, give or take 200 million. That’s another way of saying that the distance to the edge of the observable universe is 13.7 billion light-years.
What astronomers are seeing when they look at a galaxy like Abell 1835 IR1916—13.2 billion light-years away—is light (or radiation) that was emitted 13.2 billion years ago, light that’s about three times older than the planet we live on. Imagine a galaxy just a little farther away, at the extreme edge of what astronomers can observe. Suppose it emits light even as you’re reading this sentence. How far away will the edge of the observable universe be when that light reaches us? The answer is somewhere between 78 and 90 billion light-years. In fact, cosmologists have no idea how much of our universe lies beyond the threshold of observability. There’s even sober speculation that we live in a multiverse, that our universe is merely one of a possibly infinite series of universes. One of the best arguments for the multiverse is the simple fact that we exist.
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Science is mostly a tale of continuity. Scientists today are working within the same professional framework—the same idea about how they do what they do, what hypotheses are, what evidence is—as scientists did a century ago. That’s the strength of the endeavor. The change from one picture of the universe to another is incremental, based on work that obeys the self-regulating, international standards of the scientific enterprise. But I find myself marveling at its discontinuity, too.
In 1920 there was one galaxy and now there are 100 billion.
In 1955 the universe was 5.5 billion years old. Now it’s believed to be two and a half times older—an estimate with a much higher degree of precision.
For many years, the Big Bang was a conceptual possibility, the logical implication of an expanding universe. (What happens when you run the film of an expanding universe backwards?) But in 1965, Penzias and Wilson found an evenly diffused radiation permeating the sky, with a temperature of 2.7 degrees Kelvin. They had discovered the cosmic microwave background—residual radiation from the Big Bang.
The cosmic microwave background has been measured again and again, with greater and greater precision. Recent measurements support a theory of inflation first proposed by Alan Guth in 1979 and since refined. It says that at an unimaginably short time after the Big Bang, the universe experienced an abrupt inflation, doubling in size over and over again until inflation stopped an unimaginably short instant later. The result is the relatively smooth and geometrically flat universe we find ourselves living in.
Research suggests that the universe is made of 4 percent atoms (now called baryonic matter), 22 percent dark matter, and 74 percent dark energy. As an idea, dark matter first popped up in the 1930s. Dark energy is the thought of the past few years. No one knows what either of them is, except that without them the behavior of the universe makes no sense. It’s worth remembering, too, that the modern idea of the atom—that is, the old-fashioned modern idea, well before quarks—only came together in 1932, when the neutron was discovered.
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Someone, somewhere, is likely to be shouting, “Aha!” about now.
“You’re saying that our so-called scientific knowledge is only a projection of sorts and that there’s no scientific truth, only relativistic assumptions—culturally created ideas—about the universe around us. Isn’t that what you’re saying?”
Thanks for asking. The answer is no. Science is a cultural enterprise, like everything humans do, and it sometimes suffers from characteristically human flaws. But the evolution of what we know about the universe doesn’t reveal the indeterminacy of science. It reveals the extraordinary intellectual and imaginative yields that a self-critical, self-evaluating, self-testing, experimental search for understanding can generate over time.
We know the universe to be a very different and in every way more amazing place than we did even a generation ago. We have no idea how much more surprising it will turn out to be, should we manage to survive as a species that’s able to do science. If what you want from life is a constant, fixed, unchanging truth, then fresh news from science can only seem bewildering. But the unchanging truths that people cling to in this inconstant world tend to rest on unexamined and untestable assumptions. At their best they may be permanent ethical truths, which can’t be contradicted by the open-ended possibilities of scientific exploration. At their worst, they’re dogma.
The open-endedness of science isn’t its failing. It is its very beauty. Each answer is merely the prelude to the next question, and you never know when you’ll come upon an answer that forces you to rethink almost everything. This is as true in biology—itself overwhelmed by recent knowledge—as it is in cosmology. Yet many people can’t help hoping for a final set of answers. “So how old is it really—and how big is it really?” they ask about the universe, with an emphasis on “really.” The fact that the answer depends on when you happen to ask it—1931, 1955, 2003, today—seems to many people to imply that science has no answers worth giving.
But this is simply the bias inherent in living in the “now.” Stated as a sentence, that bias goes like this: “We’re here now, so we expect some answers.” Think about the analogies meant to convey the imm
ensity of time. They always end in the present. If the history of the universe is a clock, mankind emerges at eleven seconds to midnight, and then what? The clock stops at the current time, as if the game is over. But there’s no time limit on the questions science asks, and there’s little likelihood of a final set of answers. Humanity emerges, looks up at the stars, and soon there’s a probe in space telling us that most of what exists is stuff we can’t identify. Who would want it any other way?
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Thinking about the recentness of what we know means thinking simultaneously about the strangeness of the past and the strangeness of the present—the reciprocal strangenesses that time brings about. I have a hard time trying to imagine the universe as it might have been in 1920—the whole of it packed into the Milky Way. But I have an equally hard time imagining what it was like being a hired hand on my grandfather’s farm in 1920. The changes in the way we live loom far larger in our minds than changes in the theoretical model of a universe that most of us think about—if we think about it at all—only on dark, clear nights. But the changes go together.
At best, I’m the kind of cosmological reader who has to skip the math. As a result, my grasp on most of what astronomers have learned in my lifetime is largely aesthetic. I admire the finished painting, but I have no real conception of what it means to apply the paint. And for me, the old forms of knowledge are hard enough. Not the ones rooted in dogma, but the ones rooted in a practical application of what astronomers have learned over the years. Understanding the motion of the moon through the sky is far more complicated than it sounds, as I’ve discovered from trying to sort it out.
Knowing how and why the universe is expanding doesn’t change the rules of celestial navigation any more than it changes the stories people tell about the figures in the constellations. The recentness of what we know doesn’t annul the old knowledge; it transfigures it. Suddenly, what we used to know is now part of the story of how we go about knowing things and no longer a description of the universe around us. But go out on a deep summer night and there overhead are all the skies we’ve ever seen.
Appendix
Ocotber 28
On April 18, 1818, William Cobbett—a fifty-five-year-old Englishman living on a farm in North Hempstead, Long Island—wrote in his journal, “We have sprouts from the cabbage stems preserved under cover; the Swedish turnip is giving me greens from bulbs planted out in March; and I have some broccoli too, just coming on for use. How I have got this broccoli I must explain in my Gardener’s Guide; for write one I must. I can never leave this country without an attempt to make every farmer a gardener.”
As always, Cobbett was making a point. He did write a gardener’s guide, called The American Gardener, first published in London in 1821. If you look up “Dandelion,” you’ll find this apparently peripheral note: “In the spring (June) 1817, when I came to Long Island, and when nothing in the shape of greens was to be had for love or money, Dandelions were our resource; and I have always, since that time, looked at this weed with a more friendly eye.” Cobbett’s point is this: once settled, he managed to have greens by April. The rest of Long Island could grow none by June. The secret? Hotbeds.
This is Cobbett all over: two parts practical knowledge, two parts rural economy—and one part self-satisfaction, a pleasure it’s hard to begrudge him. A quick sketch of who and what Cobbett was when he decided “to make every farmer a gardener” will allow you to enjoy his self-satisfaction too. Cobbett came to America in 1817 in what he called “self-banishment,” fleeing the wrath of an English government that suspended habeas corpus in order to imprison its enemies more easily. Cobbett was the most important of them. By 1817, he had been writing Cobbett’s Weekly Political Register, the only politically independent newspaper in England, for fifteen years, and he would continue to write it until a week before his death in 1835. That paper, published every Saturday, was the voice of political reform, and “among the great mass of people it became the most powerful journal in England,” according to one of Cobbett’s biographers.
Cobbett had lived in the New World before 1817. He came to New Brunswick in 1785 as a soldier. After his discharge and marriage in England, he returned with his wife, Nancy, to Philadelphia in 1792, “passing,” as he says, “eight years there, becoming bookseller and author, and taking a prominent part in all the important discussions of the interesting period from 1793 to 1799, during which there was, in that country, a continual struggle carried on between the English and the French parties.” Those vitriolic “discussions” were in ink. Cobbett’s American pseudonym was Peter Porcupine. His vehicle was Porcupine’s Gazette—in nearly all respects, but one, a precursor to Cobbett’s Weekly Political Register. That one respect was the side he took.
Before 1800, Cobbett was an archconservative, a member of the English party trying to bring about closer ties between America and its parent country, a relationship still in tatters after the American revolution and made far worse by the French revolution and its consequences. But at home in England Cobbett found a corrupt government, a failing monetary policy, a venal Parliament, and a collapsing agriculture. He made a volte-face of stunning proportions and passed it off as consistency. He began to view the “weed” America, like the dandelion, with a friendlier eye. He began to clamor for reform of Parliament, to campaign against a national debt and a paper money that was bankrupting farmers and destroying the lives of farm laborers. And when he faced the near certainty of being imprisoned by the English government—it would have been his second political incarceration—he boarded ship with two of his sons and made America his refuge until the end of 1819.
This is the person you must imagine writing The American Gardener—nearly as famous a man as there was at the time in England or America. He is already, as William Hazlitt said in 1821, “unquestionably the most powerful political writer of the present day,” and he’s on the cusp of becoming, as Hazlitt also put it, “one of the best writers in the language.” For the great period of Cobbett’s work is about to begin. If Cobbett ever lay fallow, it was in the grave.
While he was in America, living on Long Island, Cobbett kept up his political barrage in the pages of the Political Register. On December 6, 1817, he began writing A Grammar of the English Language, in a Series of Letters, which was published in New York the following year. It is, as Hazlitt affirms, “as entertaining as a story-book,” and it sold one hundred thousand copies by 1834 and remained in print at least until 1919, a fact that’s all the more amazing when you remember that Cobbett began life as an unlettered plowboy. He wrote and published A Year’s Residence in the United States of America and began work on The American Gardener. Still ahead lay some of his greatest books, published in quick succession in the early 1820s: Cottage Economy, a French grammar that was no less successful than his English grammar, and the first of the essays that became Rural Rides, a masterpiece of political and agricultural reporting.
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It sounds as though Cobbett was dipped in printer’s ink at birth and baptized with political ichor. But he was the child of a farm laborer and grew up in Hampshire during a period of agricultural prosperity. He had as many ideas as there were minutes in his day, which always began at four a.m. “He is like a young and lusty bridegroom,” Hazlitt wrote, “that divorces a favourite speculation every morning, and marries a new one every night. He is not wedded to his notions, not he. He has not one Mrs. Cobbett among all his opinions.” But there was a Mrs. Cobbett among his sentiments, and that was a love of the land, of farming, gardening, and the virtues of a prosperous rural life, no matter how poor in outward show.
Between 1793 and 1821 the small farmers and rural laborers of England forgot how to brew beer and bake bread and raise pigs, which are among the arts that Cobbett discusses in Cottage Economy. It seems incredible until you realize that we’ve lost similar kinds of knowledge just as quickly and completely in our own time. Knowledge of the land a
nd how to live wisely and thriftily on it doesn’t just lie there, dormant, like a crocus that renews itself in the first flush of spring. It must be cultivated, and it must be knotted, in practice, to the people who have cultivated it before us. In Cottage Economy, Cobbett tried to reconnect the rural men and women of 1821, defrauded of their agricultural birthright by England’s disastrous wartime economy, with their elders, who were wise almost beyond remembering in the ways of the land.
This is a hard idea to get across—the notion that once upon a time, perhaps only a little while ago, people knew a better way of doing things. The small amount of humility needed to believe it is beyond us. The result is that we always exaggerate the simplicity, the uncouthness of the past. We assume that what people knew then isn’t worth knowing now. Or, worse, we assume that those people, now in the grave, aren’t really up to the demands of what we know. This is the peculiar wonder of Cobbett. He doesn’t despise what his elders knew. Nor does he doubt the abilities of the present generation, unless they flee, as he writes in Rural Rides, “from the dirty work as cunning horses do from the bridle.”
Cobbett found that America in 1817 was “a country of farmers.” But it was also a country where the abundance of land overwhelmed the desire to garden on a single spot. “When large parcels of land are undertaken to be cultivated,” Cobbett writes, “small ones are held in contempt; and, though a good garden supplies so large a part of what’s consumed by a family, and keeps supplying it all the year round too, there are many farmers even in England, who grudge even a wheelbarrow full of manure that is bestowed on the garden.” Cobbett’s purpose in The American Gardener is nothing less than to teach the rudiments of gardening to American farmers and to inculcate the love of cottage gardens found among rural laborers in the England he grew up in.
More Scenes from the Rural Life Page 27