Scholar and science writer Ainissa Ramirez examines eight inventions—clocks, steel rails, copper communication cables, photographic film, the light bulb, the hard drive, laboratory glassware, and silicon chips—and shows how they shaped human experience. Ramirez tells the story of a woman who 'sold time,' an inventor who inspired Edison, and an enthusiastic entrepreneur whose discovery paved the way for the computer. Among other things, she describes how the pursuit of precision shaped our sleep patterns, how railroads commercialized Christmas, how the forced brevity of telegrams influenced Hemingway's literary style, and how a young chemist exposed the use of Polaroid cameras for passports and racial segregation under apartheid in South Africa.