Total eclipses of the Sun are rare and dramatic—and on April 8, 2024, one will cross the US. But when exactly will it happen? In this short but richly illustrated book, prominent scientist and computation pioneer Stephen Wolfram tells the triumphant and hard-won story—spanning more than two thousand years—of how science, mathematics and computation have brought us to the point where we can now predict the time of the eclipse to within one second. Learn how the problem of eclipses brought us some of the earliest exact science, the first known computer, contributions from many of the all-time greats of mathematics and physics, and critical technology for the space program. See how all this provides a clear, modern understanding of a phenomenon that has surprised and amazed throughout human history.