One large Milky Way galaxy or many galaxies? 100 years ago, a young Edwin Hubble settled astronomy’s ‘Great Debate’
- Written by Chris Impey, University Distinguished Professor of Astronomy, University of Arizona
The Andromeda galaxy helped Edwin Hubble settle a great debate in astronomy. Stocktrek Images via Getty ImagesA hundred years ago, astronomer Edwin Hubble dramatically expanded the size of the known universe. At a meeting of the American Astronomical Society in January 1925, a paper read by one of his colleagues on his behalf reported that the...