Suddenly the Universe Got a Whole Lot Bigger (Conceptually Speaking)

Did You Know? Originally it was thought that the stars of our galaxy filled the whole universe. But after discoveries in the early 1900s (that recently!) some astronomers began to hold that the Andromeda Nebula (now the Andromeda Galaxy) and other “spiral nebulae” were, in fact, distant galaxies in their own right (not smaller parts of our own galaxy) and that the universe was much larger and emptier than previously thought. The subject was disputed by Harlow Shapley and Heber Curtis on April 26, 1920, in what is known in astronomical circles as “The Great Debate.” Turns out Curtis (the advocate of the big, empty universe position) was right, as Edwin Hubble showed by 1925. LEARN MORE.