In the 1500s, there was scant cooperation among scholars of different countries: Books and papers were slow to travel, and great discoveries sometimes remained unrecognized for decades. Computer scientist Fauber focuses on four founding fathers of modern astronomy who sought each other out and advanced some central ideas in what was then an act of heresy. Copernicus was the forerunner in a time when “there was no place named ‘America,’ no light bulbs, no vaccines, no nationalism, no cheap steel, no secular state, no accurate clocks…and almost no books.” Working with such tools as he had, he advanced a thesis that boldly stated that Earth is not the center of the universe and that “all the spheres revolve around the Sun,” a heliocentric notion that put him at odds with the Catholic Church in a time of schism. Figuring in the story in roughly equal measure are three other scientists who pushed the “Copernican heresy” further: Johannes Kepler, Tycho Brahe, and Galileo Galilei. The story of their discoveries, aided by primitive telescopes, mathematical intuitions, and long letters back and forth, is well known; what Fauber does well is humanize these four residents of the pantheon of science. An overweening letter from Brahe to Kepler, for instance, opened the door to a personal visit, although Kepler scrawled in the margin, “Everyone loves themself!” Brahe was a strange man, though, as Fauber shows, not without reason: He had been kidnapped as a baby and raised “in splendid isolation by a boorish uncle and his coy wife”; Galileo’s mother “stole from him, spied on him, and fought with Marina, mother of his children.” The writing is sometimes a touch too casual—Galileo, writes the author, was born “too early to see the lax republican model of Venetian government spread over Europe like jam on toast”—but the story is seldom less than fascinating.A readable, enjoyable contribution to the history of science.