This nuclear blast went off in 1946 at Bikini Atoll in Micronesia. How did some of the radiation get back to the United States? Why, we imported it, of course!

It's not often you do a search on a scientific subject and come up with a journal from 1888, but people were puzzled by this mystery for a while: Female birds, usually once they've reached a sufficiently advanced age, can suddenly grow male plumage and take on male behaviors.

Ever since the invention of the telescope, people knew what the planets of the solar system looked like. By the turn of the 20th century, we even had excellent photos of many of them. But before the first satellites—-or even the first high-altitude photos from V2 rockets and stratosphere balloons—-no one had any idea…

The most famous debate of the 1900s was meant to determine what, exactly, was the center of the universe. The greatest lesson modern people can draw from it is that each of the debaters was both right and wrong.

One of the ways that we know when and where comets came crashing into Earth is by checking the ground for iridium. Although this platinum-colored metal is common in space, Earth's supply of iridium seems to have vanished. Why is it so common out there, but so very rare down here?

Scientific discovery may require reason, rationality, and a firm handle on the facts, but science history has its share of myths, urban legends, and tall tales. Thought experiments are misinterpreted as real experiments; the scientist with the most interesting story gets the credit for a discovery; misunderstandings…

Ever heard of The Demon Core? It was named by Los Alamos scientists — who are generally not a superstitious lot — after it claimed multiple lives, in a series of strange and horrible accidents. Discover a legend of science... that's worthy of a horror movie.

Scientists, by definition, investigate the unknown. And where there's the unknown, there's danger. (There's also a lot of immense tedium and fiddling around with trivial details.) Sometimes, an apparently run-of-the-mill scientific expedition can turn deadly, without any warning.

The first X-ray machines needed patients to sit still for well over an hour, they doused people with 1500 times the amount of radiation as today's machines, and the pictures were fuzzy at best. But they were still absolutely amazing.

Vikings did a lot of navigating in their line of work. Those who didn't know how to use the sun to get exactly where they wanted to go would end up razing only sandcastles, pillaging only bird's nests, and setting fire only to their own beards. So when cloudy, foggy, gray days caused these intrepid seamen to tear the…