An Entertainment for Angels, rather than for Men, one observer called electricity, and it proved to be the most significant scientific discovery of the Enlightenment. Lecturers attracted huge audiences who marveled at sparkling fountains, flaming drinks, pirouetting dancers, and electrified boys. Flamboyant experimenters made chains of soldiers leap into the air, while wealthy women titillated their admirers with a sensational electric kiss. Optimists predicted that this strange power of nature would cure illnesses, improve crop production, even bring the dead back to life. An...

From the time of Hippocrates to that of Louis Pasteur, the medical profession relied on plausible but almost wholly mistaken ideas about the causes of and best treatments for infectious illness. Bleeding, purging, and mysterious nostrums remained staple remedies, and surgeons, often wearing filthy butcher's aprons, blithely spread infection from patient to patient. Then between 1879 and 1900 came the germ revolution. After two decades of scientific virtuosity, outstanding feats of intellectual courage, bitter personal rivalries, and a large dose of good fortune, doctors came to realize...

As the inventor of the separate-condenser steam engine--that Promethean symbol of technological innovation and industrial progress--James Watt has become synonymous with the spirit of invention, while his last name has long been immortalized as the very measurement of power. But contrary to popular belief, Watt did not single-handedly bring about the steam revolution. His "perfect engine" was as much a product of late-nineteenth-century Britain as it was of the inventor's imagination.

As one of the greatest technological developments in human history, the steam engine was a major...

How is it possible that Earth's atmospheric temperature has remained perfectly suited to supporting life for billions of years? Why do oxygen levels in the atmosphere remain relatively stable when only a minuscule increase would cause everything on Earth to spontaneously combust? Why are the oceans salty, but not salty enough to make them uninhabitable? In the 1960s, an English scientist names James Lovelock formulated a groundbreaking and highly controversial explanation: Earth is alive.

Naming his theory after the ancient Greek earth goddess, Lovelock's "Gaia hypothesis" argued that...

Launched in 1942, the Manhattan Project was a well-funded, secret effort by the United States, the United Kingdom, and Canada to develop an atomic bomb before the Nazis. The results--the bombs named "Little Boy" and "Fat Man"--were dropped on Hiroshima and Nagasaki in August of 1945.

A vast state within a state, the Manhattan Project employed 130,000 people and cost the United States and its allies 2 billion dollars, but its contribution to science as a prestigious investment was invaluable. After the bombs were dropped, states began allocating unprecedented funds for scientific research,...