One evening last October, a University of Texas at Austin astronomer named Gary Hill stood behind a lectern at Miss Hattie’s Café and Saloon, which occupies a restored nineteenth- century bank building in downtown San Angelo, and cheerfully proclaimed his ignorance. “We really don’t understand the universe,” he said. “We thought we did, but it turns out we only understand about four percent of it.”
A dozen or so people, among them businessmen, the editor of the local newspaper, a school librarian, and a couple of college professors, had assembled at Miss Hattie’s, where the lace curtains and rose-print wallpaper harked back to a time when the universe was no larger than our own galaxy and Newton’s laws seemed to explain it and a tunnel linked the building where we sat to a nearby bordello. There was something old-fashioned too about the fact that a bespectacled, British-born scientist had traveled from the state capital to give a talk to the curious and that the curious had turned out to hear what he had to say. His subject, on the other hand, was the very future of cosmology and physics and how they might be affected by one telescope in particular, located 212 miles farther west.
Galileo stuck lenses onto either end of an organ pipe; today’s research telescopes, while considerably more elaborate, still perform the same fundamental task of collecting and focusing light. It’s all astronomers have to go on: electromagnetic radiation from distant objects, whether it arrives in the form of X-rays or visible light or radio waves. “We’re detectives, but we can only use what light will give us,” Hill had said to me earlier that day. “So we get fairly ingenious in the ways we analyze light to look for clues.” They rely, for instance, on spectroscopy, the process of separating light emitted by an object in space into its component wavelengths, as a prism does, then analyzing those components. And they invent new tools to analyze the light. To probe deeper and deeper into space, scientists must design better and better detectors, sensitive to the faintest of emissions.
Such instruments don’t come cheaply, which is why Hill and his colleague Karl Gebhardt have periodically taken to the road over the past three and a half years: They’ve been promoting an ambitious $34 million overhaul of a telescope at UT’s McDonald Observatory, in the Davis Mountains of West Texas. Speaking to potential donors in Houston or a luncheon group in Abilene, they’ve been publicizing an endeavor called HETDEX, or the Hobby-Eberly Telescope Dark Energy Experiment, the aim of which is to help attack what some have labeled one of the most important problems in science.
Hill grew up in England but left to go to where the telescopes were, first as a graduate student in Hawaii, then as a postdoctoral researcher in West Texas, in 1988. Finding that certain instruments at the observatory weren’t sensitive enough, he designed and built a new spectrograph on the cheap, still in use today. He is now the observatory’s chief astronomer. At Miss Hattie’s he applied his knack for innovative thinking to the problem of business attire—he wore a striped green shirt and a pink tie—and as he spoke, he grinned and nodded infectiously. “We have a huge opportunity to lay the groundwork in Texas for understanding how the universe has changed through time,” he said. He outlined the goals of the experiment: to conduct the largest survey of other galaxies ever completed and to use that information to measure how the scale of the universe has evolved—and to reinvent the telescope in the process. By doing so, Hill, Gebhardt, and their collaborators hope to better understand what astronomers call dark energy, though no one really knows what the term means: “Dark energy” is a label for a mystery. “The thing is,” Hill told his audience, “it may not be dark and it may not be energy.”
After the presentation had ended and most of the audience had departed, Hill was subjected to a more rigorous interrogation at dinner from Ken Gunter, a tall, poker-faced San Angelo businessman and a member of the McDonald’s Board of Visitors, a statewide group of observatory supporters. This turned into a debate between the gruff West Texan and the polite but impassioned British scientist, while half a dozen others at the table looked on. Though he supports the experiment, Gunter was skeptical as to whether he could raise funds for it. “What is the pragmatic end product, except exciting a bunch of astronomy Ph.D.’s in Austin? Give me something I can identify with. If you want to raise some honest-to-God money, you better start raising some honest-to-God tie back to medical or energy.” That, said Hill, wasn’t the point. The most practical argument he could make for the telescope was that it might excite students in a country where science education was failing and draw better faculty to the university. Gunter seemed unconvinced. “My sense is that most people don’t give two hoots in hell whether the universe is expanding or contracting or moving sideways!” he said, and drew out a cigar.
Earlier that day I’d ridden in a rented suburban with Hill; David Lambert, the director of the observatory; and Joel Barna, its development director, from Midland to Abilene to San Angelo. The flat landscape was staked by the technology of energy production: Near Midland the pump jacks kowtowed to the brush, while farther south a line of soaring silver windmills receded toward the horizon. (One question often posed by lay audiences in Texas, Hill told me, is “How can we harness dark energy for human use?”) It was a warm, hazy morning, and as we’d all risen early to catch a seven o’clock flight from Austin to Midland, a soporific air had fallen over the car, leaving me in a state of sleepy wonderment at one of astronomy’s fundamental principles, that light can ripple for billions of years through the vast universe and