Does hot water freeze faster than cold water? On its face this idea seems like it should be ridiculously simple to test, and even easier to intuit, but this question has in fact had physicists arguing for decades.
Erasto Mpemba’s observations initiated decades of research into the Mpemba effect: whether a liquid (typically water) which is initially hot can freeze faster than the same liquid which begins cold.
There’s a name for the phenomenon of something hot freezing faster than something cold: the Mpemba effect, named for Erasto Mpemba (pictured above) who as a teenager in Tanzania witnessed something strange in high school in the 1960s. His class was making ice cream, and in a rush to secure…