Zoom: From Atoms and Galaxies to Blizzards and Bees: How Everything Moves (2 page)

It was there that Hubble, haughty and unpleasant but one of the century’s best observational astronomers, photographed a special type of variable star and concluded that a famous bright elliptical blob in the constellation Andromeda is not merely a nearby nebula but a separate “island universe”—a remote empire of billions of suns. All the other spiral nebulae, he reasoned, must likewise be independent starry kingdoms stretching off into the distance. Instantly the cosmos became a million times larger.1

When I phoned Carnegie Observatories’ current director, Wendy Freedman, she told me that the discovery “ranked with the Copernican revolution.”

“Yes, Edwin Hubble may have been arrogant,” she conceded. “But there are only a few times in history when you change the very nature of the universe. You can’t take that away from him.”

Nor could you take credit away from the young Carnegie Institution for Science, which conjured milestone after milestone as though they were cards from a magician’s sleeve. Director Hale personally created the National Academy of Sciences. His astronomers announced that elliptical galaxies have only old stars, whereas spirals are still making new ones. These were bombshells. But the biggest of all was the discovery that is relevant to our pursuit: the 1929 announcement that the universe is expanding.

This had never been suspected. No holy book of any religion, no Renaissance scientist, no philosopher had ever written that the entire cosmos is growing larger. Indeed the early Greeks, superb logicians that they were, would have no doubt dismissed that notion as meaningless. If everything expands at the same time, how could anyone possibly know it was happening?2

The first hint that the cosmos is squirmy had arrived in Einstein’s brain in 1915, when he crafted his theory of general relativity because his math just would not work in a static universe. Yet the universe was assumed to be stationary—it was a “given,” a truism, and Einstein had no reason to doubt it, so he famously added a fudge-factor number that he called the cosmological constant. Thereafter, his equations worked just fine. But when Hubble found that virtually every galaxy displays a redshift, indicating its rapid recession from us, the conclusion was inescapable: the universe is blowing up. Galaxy clusters are separating from their neighbors. Einstein had predicted it within his mind without peering through a single telescope, and he would have announced it if only he had more confidence in himself. “The worst blunder of my life,” he famously muttered to anyone who would listen.

Here was motion on a scale of which no one had dreamed. Even nearby galaxies, those that live within the closest one thousandth of one percent of the cosmic inventory, which are the slowest moving of them all, rush away from us at a speed of 1,400 miles per second. Those dwelling at a “mere” one billion light-years from Earth zoom away at 14,000 miles per second. That’s 28,000 times faster than a high-speed bullet.

The visible stars that fill the night sky can’t move faster than 600 miles per second or they would escape the gravitational clutches of the Milky Way, never to return. Speeds like 1,400 miles per second—meaning you could go from Coney Island to Hollywood in the time it takes to say, “Got your seat belt on, honey?”—were bewildering in 1929. Yet such motion was couch-potato leisurely compared to what the next-gen postwar telescopes would reveal soon enough.

The newly observed speeds were breathtaking and also dispiriting. It became obvious—and remains so today—that no matter what system of propulsion is invented in the future, we will never visit the vast majority of galaxies: they are fleeing faster than we can ever hope to approach them.

The Sombrero galaxy, containing two hundred billion stars, rushes away from us at 562 miles a second. (Matt Francis)

Hale, still not finished despite suffering years of serious health problems (to which he finally succumbed in 1938), raised money for the next colossus, the two-hundred-inch telescope on Palomar Mountain in Southern California. It opened in 1949 and had a light-gathering mirror as wide as a living room. Palomar remained the world’s largest telescope for the next quarter century.

Still, Carnegie astronomers had long wanted an observing station in the Southern Hemisphere so they could access the many mysterious objects hidden over California’s horizon. In the 1980s they reluctantly abandoned their custody of Mount Wilson, from which stars now appeared dimmer than those in nearby Hollywood, thanks to runaway development and a yearly 10 percent growth in the number of streetlights.3 Instead, they looked to another site—a mountain in the Andes that the Carnegie Institution had acquired in 1969, when the peso exchange rate was so low that you could buy a genuine sugar-filled Coke for three cents. Named Las Campanas—“the bells”—the observatory soon became the institution’s main facility, on which it constructed two of the world’s largest telescopes.

The twin 250-inch giants were completed in 2002. Collectively called the Magellan Telescopes, they boast reflectors that are remarkable for their picture-window half-degree fields of view that can take in the entire moon in a single photograph. The exquisite images come courtesy of unique computer-driven pistons that deform the mirrors twice a minute to maintain their perfect parabolic shapes. Equally renowned is the site’s rock-steady image quality, unsurpassed in the world. It might as well be outer space.4

Such a top-tier research center allows no casual visitors, but I knew I could use my astronomy press credentials to spend a few nights up there. It’s the ideal place from which to probe the fastest speeds in the universe. After I chatted with Wendy Freedman, whom I called at her office in Pasadena, arrangements were made. I headed for South America.

The seemingly endless flight to Santiago was followed by good fortune. Las Campanas’s director was in town, and thus I met Dr. Miguel Roth for dinner at an outdoor table in one of the many beautiful neighborhoods of that fascinating city. Director for seventeen years, Roth is obviously very proud of the facility: “We’re up at eighty-five hundred feet, and it’s really dark. The site is incomparable. We get three hundred clear nights a year. The Atacama Desert stretches all around. The nearest corner store is one hundred miles away.”

Two days later, after an unnerving flight that skimmed past the Andes’ jagged snowy peaks, and after glancing around the cabin to appraise the potential tastiness of my fellow passengers, I arrived in the lovely seaside resort town of La Serena, home of the Las Campanas headquarters. That year, the staff was spending much of its time seeking supernovas, whose reliable “standard candle” brightnesses help determine exact galactic distances, which in turn lets scientists understand how the universe’s expansion changes with time. This, then, is the Carnegie Observatories’ main current quest—to decipher the fate of the universe!

And thus we reach the meat of this matter. It is nothing less than the greatest conundrum in all of science, and it revolves around speed. Happily, it can be simply stated. The Hubble constant—the speed at which galaxies rush away from us—mysteriously changed six billion years ago, when the universe was half its current age. Galaxy clusters started increasing their flyaway speeds, as if they all had rocket engines that suddenly ignited. The cause is often called dark energy, but that term is no more than a label affixed to an enigma first uncovered in 1998. As Wendy Freedman said with a sigh, “It’s very difficult to explain. It’s a perplexing mystery.”

With a quick revision reminiscent of the hastily airbrushed deletions in Soviet encyclopedias, cosmologists abruptly rewrote their “basics of the universe” handbook. Three-quarters of the cosmos was now exclusively reserved for some kind of weird antigravity entity whose existence was utterly unsuspected a year earlier. Probing its powerful effects became a sudden, urgent focus for astronomers. I suspected that this quest, above all, was what occupied those who awaited me atop that Chilean mountain.

The next day I left La Serena in a rented car heading northbound on a sparsely traveled section of the Pan-American Highway. The road immediately entered the southern edge of the vast Atacama Desert, the driest place on earth. Two desolate hours later I turned onto a relentlessly climbing dirt trail, passing wild burros and an animal called a viscacha, which looks like a cross between a squirrel and a rabbit and which seemed like a hallucination. The broad, bone-dry summit of Las Campanas was dotted with white domes. The high altitude and low humidity created a cloudless azure sky.

I had arrived at noon. Perfect timing. This is when everyone has just awakened. All freshly showered and hungry, they file into the spacious dining hall like some religious cult. Their language resembles English, but the dialect is peppered with esoteric astrophysical terms.

Astronomers Dan Kelson and Barry Madore, Wendy Freedman’s husband, sat with me. It was a precious opportunity, and I wasted no time plunging into profound issues involving cosmic velocity and what it might imply for the future of the universe. “I’m here for the ride,” Madore said with a modest laugh. “I’m not here for ultimate answers.”

But later, under the stars, he turned serious. “We’re living with uncertainty with the universe’s expansion,” he said after I’d joined him in an enormous dome whose humming computer fans and drive motors formed the sound track to our conversation. The uncertainty involved not just when the cosmos went from slowing down to speeding up but also whether the acceleration would continue or even ultimately reverse itself. Still, I thought, if a little uncertainty was the worst he had to deal with, he shouldn’t complain. Wasn’t it enough that humans dared scratch the surface of these fastest of all velocities? Entire cities of suns that speed fifty thousand miles farther away from us each second?

I was happy that such a major facility devoted its resources—a legacy of generous endowments that started with Andrew Carnegie’s fortune—to such a seemingly intractable quest, and I said so.

When asked to compare Las Campanas to publicly funded instutions, Madore said, “This Magellan telescope costs forty thousand dollars a night to operate. But we can still be playful and innovative and take some risks. That’s one big difference. The national observatories, like Kitt Peak—they’re all risk-averse. Here it’s a thrill a day.”

Night had brought a nourishing darkness to the Andes and the unseen black desert below us. The Milky Way—whose name had probably not taxed the astronomy muse—was astoundingly brilliant, with richly mottled detail, as in a pointillist painting. It dominated the Chilean night.

Now, on the catwalk outside one of the 6.5-meter giant telescopes, Miguel Roth joined me, and we gazed up like the Mesoamericans of old, who regarded the Milky Way as the center of all existence.

Miguel had given me carte blanche to roam, so I drove as instructed, with just my fog lights on, along the curvy mountain road that has no guardrails, violating every rule in the driver’s ed handbook. I went from one dome to another and visited the researchers in each. At one of the 6.5-meter instruments, I found exactly what I’d been seeking. Here the faint light from distant galaxies, amplified and enhanced one million times by the huge, twenty-foot-wide telescope mirrors, had been accumulating for hours but still had nine hours more to go; astronomers had nothing to do but wait and chat.

My lunch companion, Dan Kelson, was gathering the light from galaxies eight billion light-years away. He noticed my reporters’ notebook and started explaining: “This instrument is measuring four thousand galaxies at once. It’s an all-you-can-eat type of data collection.”

He was used to this endless cycle of data harvesting followed by intense analysis. A brilliant and articulate thirty-eight-year-old from Illinois, he had helped pioneer the new technique of cutting thousands of precisely positioned slits into a metal plate so that a particular group of galaxies can be analyzed simultaneously. If there was anything noteworthy about one city of suns floating in a field of thousands, like a single sunflower in a van Gogh painting, it would immediately pop out to be flagged for further study.

“When I was seven or eight my grandparents got me a refracting telescope from Sears,” he later told me. “I studied the lore of each constellation. I read every astronomy book in my elementary school’s library.”

He was hooked. Kelson earned his doctorate at the University of California, where he simultaneously met his future wife and pursued his parallel obsession with making ice cream: he consumed hundreds of quarts annually.

But all those kilos of saturated fat didn’t slow Kelson’s passion. His dissertation research involved many nights on the new telescopes at the Keck Observatory, atop Hawaii’s Mauna Kea, as well as analyzing Hubble Space Telescope data.

He was exactly the kind of person to whom Hubble would have wanted to pass the torch—exactly the right man to clarify Hubble’s bombshell of an exploding universe. His ability to merge cutting-edge spectral techniques with digital analysis formed the ideal skill set with which to follow the galactic footsteps of the legendary long-gone Carnegie astronomers.

By the first light of dawn, Kelson would be detecting objects rushing away from us at the astounding speed of 112,000 miles per second. That is more than half the speed of light. Kelson had in fact, some years earlier, discovered the farthest and fastest galaxy ever known. And his team did it again in 2013, making headlines around the world.

Some of that night’s dimmest smudges might lie at the very edges of the observable universe and be the fastest objects humans can ever see. This is the outer boundary of velocity—the motion envelope within which everything else dwells.5

And yet, astonishingly, these galaxy clusters aren’t really moving at all. Rather, the space between us and them is inflating. The galaxies are just sitting inertly, like Scrabble players waiting for a vowel. Each is gravitationally jostled by its companion galaxies, but the truly ultrafast speeds we see are an expanding-space phenomenon.

Of course, one might wonder how, if space is mere emptiness, it can expand on its own. How can nothingness do anything? Even with a mandate to explore all manner of motion, it’s still odd to discuss the animation of nothingness.