Hero of Alexandria invented the aeolipile, a primitive steam engine, in the first century. A hollow sphere with elbow-shaped tubes mounted on an axle and suspended over a cauldron of boiling water, the engine likely could not have powered anything. “It should probably be remembered,” wrote historian William Rosen, “as the first in a line of engineering dead ends.”

Archaeologists in France discovered in 1865 a Stone Age human skull with a hole sawed in it. They believed it had served as a drinking vessel; one wrote the hole was “expressly made for the application of the lips.” But later study by an anatomist proved this to be incorrect: the skull was actually evidence of ancient brain surgery.

Before Sally Ride spent a week aboard the Challenger shuttle in 1983 and became the first American woman in space, NASA engineers asked her if she wanted a hundred tampons in her flight kit. “No,” she later recalled responding, “that would not be the right number.” They said they wanted to be safe. “Well,” she assured them, “you can cut that in half with no problem at all.”

In 1965 Stanley Kubrick and Arthur C. Clarke discussed a film project, then called Journey Beyond the Stars. “Science-fiction films have always meant monsters or sex, so we have tried to find another term,” said Clarke. “The best we’ve been able to come up with is a space odyssey,” added Kubrick. “The far-flung islands Homer’s wonderful characters visited were no less remote to them than the planets our spacemen will soon be landing on are to us.”