Albert Einstein:

Blackholes are where God divided by zero.
I don’t believe in mathematics.

George Gamow (1904-1968) Russian-born American nuclear physicist
and cosmologist remarked that "it is well known to students of high school
algebra" that division by zero is not valid; and Einstein admitted it as
{\bf the biggest blunder of his life} [1]：
1. Gamow, G., My World Line (Viking, New York). p 44, 1970.