Palomar's big eye on the sky

First Light, the Search for the Edge of the Universe, by Richard Preston. New York: Atlantic Monthly Press. 263 pp. $18.95. Good science writing illuminates a technical subject for the layman without distorting or oversimplifying the facts. It's an art. ``First Light, the Search for the Edge of the Universe'' is a superior example.

Richard Preston's quietly dramatic tale of the 200-inch Hale telescope at Palomar Observatory and the people who use it to make cosmic discoveries is informative, lively, and always clear - no matter how complex the ideas.

At center stage is the marvelous machine. The big eye on the sky saw ``first light'' 40 years ago and is still the world's largest working telescope. Its vision is now enhanced by multiple cameras and sophisticated computer programs that enable scientists to study the universe in four dimensions - through time as well as space.

Preston explains:

``Astronomers refer to the depth of astronomical vision as lookback time. Seeing outward is equivalent to looking backward in time, because the telescope's mirror is capturing primeval light. The universe - as we see it - could be imagined as a series of concentric shells centered on the earth - shells of lookback time. The shells closest to the earth contain images of galaxies near us in time and space. Farther out are shells containing images of remote galaxies - galaxies as they existed before our time. Still farther out is the shell of the early uni-verse. Some of the photons [particles of light] reaching a telescope's mirror are nearly as old as the universe itself.''

As he explains the scientific facts and theories, Preston also explores the human dimension of the search for a more distant ``first light'' through profiles of the people involved in the project.

Maarten Schmidt, the principal investigator, has been studying quasars - luminous objects billions of light-years away and two or three times as old as the earth - for 25 years. He was the first to identify in quasars the redshift phenomenon that indicates the distance of an object from our solar system. Jim Gunn is the creator of the four-shooter camera and a gadgeteer supreme. Then there's Don Schneider, an astronomer whose Cassandra image-processing computer program sorts through the data captured by the cameras to pinpoint possible quasars. And not to be overlooked is Juan Carrasco, the senior night assistant whose understanding of the complicated mechanism he operates is critical to a successful night's shoot. He knows that ``nobody in his right mind would let an astronomer touch the controls of the most powerful telescope on earth.''

As counterpoint to the story of Schmidt and his colleagues reaching into lookback time, Preston presents a husband-and-wife team who are after stellar objects still capable of interacting with the earth. Gene Shoemaker is an astrogeologist. Carolyn Shoemaker is close to becoming the champion comet collector of all time. Together they use an 18-inch telescope at Palomar to track minor planets and comets. They spend their summers in Australia studying craters caused by meteors and asteroids that didn't miss the earth. Especially in his account of these ``mom and pop'' researchers, Preston humanizes astronomy - a nice twist on a science that so strongly challenges man-centered mentality.

Parts of ``First Light'' have appeared in The New Yorker magazine, and the book has won the 1988 American Institute of Physics Science Writing Award. No wonder. Preston's narrative - a blend of anecdote, history, scientific theory, and technical explanation - brings the heavens down to earth.

Ruth Johnstone Wales is on the Monitor staff.