Thirteenth-century professor Thaddeus of Bologna once claimed anyone who ate eggplant for nine days would go insane. A student decided to test the theory and after nine days returned to report he was not mad. Thaddeus asked him to turn around; on observing the student’s behind he announced, “All this about the eggplant has been proved.” It is said the student subsequently wrote a learned treatise on the subject.

Color film in the 1950s barely registered dark skin tones; Kodak had developed the product to measure images against the white skin of a model known as Shirley. The company eventually modified its film emulsion, responding to complaints from advertisers promoting wood furniture and chocolate.

A scholar in Peking contracted malaria in 1899 and was given medication with an ingredient labeled “dragon bones.” The bone chips, he found, were inscribed with writing dating back to China’s second dynasty. Thousands more were uncovered in the decades following; many of these “oracle bones” had inscriptions recording celestial events, which scientists have since used to calculate changes in the length of an earth day and in the rate of the earth’s rotation.

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.”