This chapter chronicles how Einstein’s theories changed what we know about the universe. Bryson states that by the end of the nineteenth century, scientists assumed that they “had pinned down most of the mysteries of the physical world: electricity, magnetism, gases, optics, acoustics, kinetics, and statistical mechanics, to name just a few, all had fallen into order before them” (115). Scientists believed there wasn’t much left that science had to do.

Before Einstein, there was J. Willard Gibbs, a scientist who knew that science still had a lot more to offer. From 1875-78, Gibbs produced a collection of papers that showed how thermodynamics “didn’t apply simply to heat and energy at the sort of large and noisy scale of the steam engine, but was also present and influential at the atomic level of chemical reactions” (117).

There were also Albert Michelson and Edward Morley, who disproved the longstanding belief that luminiferous ether, an imaginary substance that was thought to permeate the universe, was real. Michelson invented a device known as the interferometer, which measured the Earth’s travel time around the Sun. After years of measurements, Michelson found that the “speed of light turned out to be the same in all directions and at all seasons” (119).