Reposted by flooo
100 years ago today, #OTD in 1925, Edwin Hubble announced that Andromeda and other spiral nebulae were definitely separate galaxies outside the Milky Way, in a paper read to an AAS meeting by H.N. Russell.
There was no doubt that the Universe was more than just our little island of stars. 🧪 🔭 ⚛️
