John C. Mather, Ph.D., is a Senior Astrophysicist in the Observational Cosmology Laboratory at NASA's Goddard Space Flight Center. He won the Nobel Prize in 2006. He is a member of the Astrophysics Subcommittee of the NASA Advisory Committee and of the Standing Review Board for the Kepler project. He lives in Maryland.

John Boslough received honors in the history of science from Princeton University and has written widely on science for National Geographic and other publications. His previous books include Stephen Hawking's Universe and Masters of Time, co-authored by Wendy W. Cortesi. He lives in Princeton, New Jersey.