Numberphile
ASTOUNDING: 1 + 2 + 3 + 4 + 5 + ... = -1/12
About this video
A Numberphile video in which physicists Tony Padilla and Ed Copeland show a seemingly astounding result that 1+2+3+4+... equals -1/12. The argument is informal and has drawn criticism for glossing over what the result actually means.

