Similarly, as I pointed out in the next post, 1 + 2 + 4 + 8 + ... = -1, right?
Oh come on, you really left Ramanujan out?
Shame on you.
1+2+3+4+5+.....+ ∞ = -1/12
Actually, the original version of the joke I posted earlier is:
If you don't hit the switch, the train will run over 1 + 1 + 1 + ... = ∞
If yo do, it will run over 1 + 2 + 3 + .. which can be analytically continued to -1/12
The geometric series one is easier to understand, since the formula is taught in school (albeit with instructions that it's not valid in the case I mention without analytic continuation).