Physics
Renormalization
Quick fact
The renormalization procedure, developed in the late 1940s by Feynman, Schwinger, and Tomonaga, turned quantum electrodynamics from a theory plagued by unmanageable infinities into one whose predictions match experiments to better than one part in a trillion (e.g., the electron's magnetic moment).
Why this is interesting
When physicists calculate the properties of an electron—like its mass or charge—using equations of quantum electrodynamics, they often get infinity as the answer. How can a theory that seems 'broken' by infinities actually make the most precise predictions in science?