Science is based not only on observation and experiment, but on theory as well. As Einstein said, “Theory tells us what to measure.” And theories are often crystallized into succinct calculations, like those made using Einstein's famous E = mc2. This book looks at fifty such great calculations, exploring how and why they were developed and assessing their impact on the history of science. As the author shows, many significant scientific calculations are quite simple and fairly easy to understand, even for readers will little math background. But their implications can be surprising and profound. For example, what links a famous comet and the cost of an annuity? Why do scientists claim there is “dark matter” in the universe if it can’t be observed? How does carbon-based life on Earth depend on a quirk of nuclear physics? The answer to each question is an illuminating calculation. This accessible, engaging book will help you understand these breakthroughs and how they changed our view of life and the world.