- In mathematical logic, Russell’s paradox (also known as Russell’s antinomy) is a set-theoretic paradox published by the British philosopher and mathematician Bertrand Russell in 1901. Russell’s paradox shows that every set theory that contains an unrestricted comprehension principle leads to contradictions. The paradox had already been discovered independently in 1899 by the German mathematician Ernst Zermelo. However, Zermelo did not publish the idea, which remained known only to David Hilbert, Edmund Husserl, and other academics at the University of Göttingen. At the end of the 1890s, Georg Cantor – considered the founder of modern set theory – had already realized that his theory would lead to a contradiction, as he told Hilbert and Richard Dedekind by letter.
- Billiards is a good game (mag.uchicago.edu)
Michelson’s wonder was what his head did with his hands, and a few boxes and rotating mirrors. He measured things, especially things that were regarded as unmeasurable, ineffable, and precious as life itself. Among other things, he had measured light and a star. I watched him play billiards nearly every noon for several months before he retired from the University, and, in introducing myself, I could further say with equal truth, “Shake the hand that shook the hand of John L. Sullivan.” If I get the right opening, though, I prefer saying, “When young, I watched Michelson play billiards.”