Delightfully weird Banach-Tarski video will make you wish you were a…

An oversimplified explanation of the mind-numbingly paradoxical Banach-Tarski theorem states that a solid sphere can be cut into non-overlapping pieces (geometricians would say that such a ball has been "decomposed"), and reassembled in a new arrangement, such that the end result is two identical copies of the original… » 1/05/12 3:15pm 1/05/12 3:15pm

Why You Can’t Travel Back in Time and Kill Hitler

Click to view » 11/20/08 12:00pm 11/20/08 12:00pmNext month sees the release of , a film about Claus von Stauffenberg, the man who tried to assassinate Adolph Hitler. Plenty of time travelers have had the same idea, although their plan was to kill Hitler before he enacted mass genocide. Their intentions may be noble, but the plans always seem to go awry, …