In his 1959 history of early astronomy, The Sleepwalkers, Arthur Koestler notoriously labeled Copernicus's De revolutionibus "the book nobody read." The Polish astronomer's landmark 16th-century work, which proposed that the earth revolves around the sun, was so difficult, argued Koestler, that it was ignored in its day, even by astronomers. But when Harvard historian of science Owen Gingerich came across a heavily annotated copy of the tome in Edinburgh's Royal Observatory, he decided to challenge Koestler's view and embarked on a 30-year quest to track down and personally examine each of the nearly 600 known extant first and second editions of the rare work. The result of his odyssey, The Book Nobody Read (Walker & Company), is as much memoir as science. An astrophysicist and rare book collector himself, Gingerich was definitely the man for the job. With rigorous sleuthing and a rarefied list of contacts, he discovers copies owned--and annotated--by the likes of Galileo, Kepler, and Tycho Brahe, and determines to his satisfaction that Koestler was "dead wrong." Still, a Greek epigram on the title page of De revolutionibus translates as "Let no one untutored in geometry enter here," and a similar caveat applies to The Book Nobody Read--it'll appeal mainly to history buffs, astronomy fans, and bibliophiles. If you're not a member of those clans, there's some tough sledding ahead. Gingerich will discuss his work at 6 PM on Thursday, April 8, at the Newberry Library, 60 W. Walton, 312-255-3700.