30 December 1924 December 29, 2012 Author: Staff Edwin Hubble announces that other galaxies exist. Famous Words of Inspiration..."I don't always know what I'm talking about but I know I'm right." Muhammad Ali — Click here for more from Muhammad Ali Related posts: 19 December 1924 27 November 1924 30 December 1066 16 December 1972 Categories: History Tags: 1924, 30 December