Banach-Tarski paradox

English

Etymology

Named after Polish mathematicians Stefan Banach and Alfred Tarski.

Proper noun

Banach-Tarski paradox

1. (mathematics) A theorem in set-theoretic geometry, which states that given a solid ball in three‑dimensional space, there exists a decomposition of the ball into a finite number of disjoint subsets, which can then be put back together in a different way to yield two identical copies of the original ball.