The long-running mystery of the Feynman Sprinkler

Richard Feynman left the world many legacies, including multiple books on physics, the atomic bomb, and some stellar bongo solos. He also left the world the mystery of the Feynman Sprinkler — proving that science doesn't have to be impressive to be frustrating. » 1/09/14 8:00am 1/09/14 8:00am

What does Mach One (or Two or Three) mean?

We've heard blasé dialog about Mach numbers from fighter pilots in movies, but do you know what Mach numbers actually mean? Among other things, it means that two planes going at Mach 1 can actually be going at very different speeds. » 7/23/13 11:21am 7/23/13 11:21am