Since H. G. Wells' 1895 classic The Time Machine, readers of science fiction have puzzled over the paradoxes of time travel. What would happen if a time traveler tried to change history? Would some force or law of nature prevent him? Or would his action produce a "new" history, branching away from the original?In the last decade of the twentieth century a group of theoretical physicists at the California Institute of Technology undertook a serious investigation of the possibility of pastward time travel, inspiring a serious and sustained study that engaged more than thirty physicists working...
Since H. G. Wells' 1895 classic The Time Machine, readers of science fiction have puzzled over the paradoxes of time travel. What would happen if a ti...
In September 1955, Navy Lieutenant Commander Grover B. Windham and a crew of eight flew out of Guantanamo Bay into the eye of Hurricane Janet swirling in the Caribbean: a routine weather reconnaissance mission from which they never returned. In the wake of World War II, the Air Force and the Navy had discovered a new civilian arena where daring pilots could test their courage and skill. These Hurricane Hunters flew into raging storms to gauge their strength and predict their paths. Without computer, global positioning, or satellite support, they relied on rudimentary radar systems to locate...
In September 1955, Navy Lieutenant Commander Grover B. Windham and a crew of eight flew out of Guantanamo Bay into the eye of Hurricane Janet swirling...
In 1942, with war raging on two fronts and military pilots in short supply, the U.S. Army Air Force enlisted a handful of skilled female aviators to deliver military planes from factories to air bases--expanding the successful program to include more than one thousand women. These superb pilots flew every aircraft in the U.S. Army Air Force--including B-26s when men were afraid to--logging more than siz million miles in all kinds of weather. yet when World War II ended, their wartime heroism was left unheralded.
In 1961, with the dawn of the space age, a handful of top female pilots...
In 1942, with war raging on two fronts and military pilots in short supply, the U.S. Army Air Force enlisted a handful of skilled female aviators t...
In the 1980s and 1990s, in places where no one thought it possible, scientists found organisms they called extremophiles: lovers of extremes. There were bacteria in volcanic hydrothermal vents on the ocean floor, single-celled algae in Antarctic ice floes, and fungi in the cooling pools of nuclear reactors.
But might there be life stranger than the most extreme extremophile? Might there be, somewhere, another kind of life entirely? In fact, scientists have hypothesized life that uses ammonia instead of water, life based not in carbon but in silicon, life driven by nuclear chemistry, and...
In the 1980s and 1990s, in places where no one thought it possible, scientists found organisms they called extremophiles: lovers of extremes. There we...
