A history of gravity, and a study of its importance and relevance to our lives, as well as its influence on other areas of science.
Physicists will tell you that four forces control the universe. Of these, gravity may the most obvious, but it is also the most mysterious. Newton managed to predict the force of gravity but couldn't explain how it worked at a distance. Einstein picked up on the simple premise that gravity and acceleration are interchangeable to devise his mind-bending general relativity, showing how matter warps space and time. Not only did this explain how gravity worked – and how apparently simple gravitation has four separate components – but it predicted everything from black holes to gravity's effect on time. Whether it's the reality of anti-gravity or the unexpected discovery that a ball and a laser beam drop at the same rate, gravity is the force that fascinates.
As the most familiar physical force in the universe, gravity may not seem exciting, but British science writer Clegg (Armageddon Science) shows how this "omnipresent" force which strengthens bones and muscles and binds together planets, stars, and galaxies is anything but simple. The history of gravity theory begins with the ancient Greeks, who reasoned that "earthy" (as opposed to "airy") objects had a kind of "natural heaviness" that made them "want to be at the center of the universe." Centuries later, Galileo's experiments with pendulums and rolling spheres revealed gravity as a force that controlled motion everywhere, but even Isaac Newton's laws of motion failed to pierce the veil around this mysterious "action at a distance." It took Einstein's groundbreaking work on relativity theory to reveal how much gravity shapes the universe, warping space into an invisible world only revealed second-hand by the movement of masses and light. Clegg's accessible presentation offers insight into everything from Aristotelian science to black holes and string theory as it reveals the complexities and surprises of a familiar force that continues to surprise scientists.