ATOP MAUNA KEA, ON HAWAII’S BIG ISLAND — On a clear day, you can see almost forever. With the help of adaptive optics, almost back to the beginning of this universe. And it is usually clear here at 13,796 feet above sea level, and above half of the atmosphere’s oxygen. That is why the W.M. Keck Observatory’s two telescopes, primarily operated by the University of California and the California Institute of Technology, are here, far from urban lights and above much of the atmosphere which, although it makes the stars twinkle prettily, does so by distorting light.
Hence the need for adaptive optics. This technology became available for civilian science when the end of the Cold War led to the declassification of some devices developed for the Strategic Defense Initiative (SDI).
The Keck telescopes — the world’s largest — are gathering light produced shortly (as these things are reckoned; about 800 million years) after the Big Bang, just under 14 billion years ago. Analysis of the light, which can be done by astronomers working anywhere, yields information about the life cycle of stars. (Grim news: our star, the sun, is doomed, so we are too, in less than 2 billion years.) The Keck telescopes have detected more than 60 planets orbiting other stars. Ten years ago, the only planets we knew of were those orbiting our own sun.
It is axiomatic that not only is the universe stranger than we know, it is stranger than we can know. But one reason the Keck telescopes are significantly augmenting our store of knowledge is the application to astronomy of adaptive optics developed for SDI. SDI’s challenge is to target, from space, ballistic missiles launched on Earth. This requires making ultraprecise measurements from space, through the distortions of the Earth’s atmosphere. Astronomy’s challenge involves looking outward — analyzing light that is distorted by the atmosphere before it reaches telescopes on Earth.
The Keck telescopes each weigh 300 tons, stand eight stories tall and involve operations of more precision than those of the finest wristwatch. They can gather 13-billion-year-old light that is 500 million times fainter than the naked eye can see. They gather the light using a primary mirror 10 meters (33 feet) in diameter, composed of 36 hexagonal segments, each engineered to conform to within a millionth of an inch of single continuous surface.
But the really remarkable device is a mirror about the size of a man’s hand. Distortions in the gathered light are removed by bouncing the light off this mirror, which has 400 pistons operated by tiny, computer-driven motors that make adjustments in the mirror’s surface 642 times a second.
From 1609 when Galileo built a refracting telescope (a lens assisting the naked eye) until the Hubble space-based telescope was launched in 1990, the atmosphere complicated astronomy. However, Hubble, which cost more than all other telescopes in history combined, does not make Earth-based telescopes anachronistic.
Hubble and its successors — next comes the Next Generation Space Telescope — operate in the cold vacuum that is space. But a multinational consortium has proposed an Overwhelmingly Large Telescope that would gather light on Earth with 2,000 panels of mirrors in an apparatus the size of a football field. Ever-better land- and space-based telescopes will find tantalizing hints about how the expansion of the universe (actually, this universe; there may be many others) began — a Big Bang? — and whether it will continue to expand or will collapse back on itself in a Big Crunch.
In any case, Earth’s fate is not going to be pretty, so what’s the use in wondering? Because wondering is what we are for.
Mauna Kea is a dormant volcano. About 40 miles southeast of here, lava from the Kilauea volcano, boiling with heat left over from Earth’s formation 4.35 billion years ago, has recently been spilling across a highway and into the ocean. To stand a few hundred feet from the stream of lava plunging into the Pacific, amid the searing heat and sulfurous fumes, is to sense what the Keck Observatory, in its very different setting, explores — the violent impermanence that permeates the entire universe.
"We are curious people," says Keck Observatory director Frederic Chaffee matter-of-factly. "And the universe is an amazing place." The most amazing things in it are the curious creatures. They have evolved literally from stardust, becoming conscious beings capable of building — indeed, their glory is that they are, in a sense, incapable of not building — mountaintop telescopes, silhouetted against the edge of the atmosphere, searching for clues as to how all this started and how it will end.
George Will can be reached at The Washington Post Writers Group, 1150 15th St. NW, Washington, DC 20071-9200.
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