Before he became “the architect of the nuclear age,” Italian physicist Enrico Fermi (1901-1954) was known to his colleagues as The Pope of Physics (Holt, $30) for his infallible accuracy. One of the rare physicists equally adept as a theorist and an experimentalist, Fermi was also one of the few to be self-taught; a math prodigy, in 1915 he discovered a book on mathematical physics written in Latin in the 1830s and was hooked. As Gino Segrè and Bettina Hoerlin recount in their masterful history of Fermi’s life, times, and work, the Nobel laureate was “seemingly impervious to fatigue, frustration, or dissatisfaction,” where science was concerned. Yet the authors, both related to people who knew Fermi, draw out the unfailingly thoughtful, complex man behind the world-changing discoveries. Claiming to be apolitical, Fermi was eager to make Italy a center for scientific research. Later, he was more attuned to the anti-Semitism of Mussolini’s Italy than his Jewish wife was, and it was he who persuaded her to emigrate to the U.S. With World War II, physics grew ever more inextricably linked to politics, and Fermi, who won the Nobel in 1938 for induced radioactivity (picking up the award on his way to Columbia University), could no longer practice “science for the sake of science.” In the U.S., though his Italian citizenship made him suspect, he was integral to the Manhattan Project and built the world’s first atomic-fission pile. Without getting too technical, the authors give readers enough science to appreciate Fermi’s achievements; while he was absorbed in the question of “could” nuclear physics be done, the world still wrestles with the “should“ of it.