"Until Leonard Hayflick came along, everyone thought cells were immortal. That they’d divide over and over again, forever. Hayflick torpedoes that theory and proved that there is limit. A very predictable limit: a magic number. To thank him, science textbooks everywhere now refer to that as ‘the Hayflick limit.’ "
From http://www.wnyc.org/shows/radiolab/episodes/2007/06/15/segments/71875
(Thematically tied to my previous posted show from SciFri.)