Oddbean new post about login | logout 100 years ago tonight, Edwin Hubble made the astronomical observation that definitively established the existence of the #universe beyond our own Milky Way galaxy. His discovery of a Cepheid variable #star in the Andromeda Galaxy — famously labeled "VAR!" with red ink in Hubble's own hand on the plate — demonstrated beyond a doubt that Andromeda was a separate #galaxy from our own. Read more on the Carnegie Observatories site: https://obs.carnegiescience.edu/PAST/m31var #Astronomy #History https://cdn.masto.host/astrodonsocial/media_attachments/files/111/185/187/872/979/773/original/fdf3e0d66b1194ef.png
