Edwin Hubble

Edwin Hubble (1889–1953) was an American astronomer who did something that sounds impossible: he made the universe bigger. A trained lawyer and amateur boxer who liked to smoke a pipe and drop the occasional fake British accent, he ended up settling one of the oldest questions humans have ever asked — how big is everything, and is it holding still?

The stroke of genius

Working at the giant Mount Wilson telescope, Hubble proved that the fuzzy "spiral nebulae" in the sky were entire other galaxies, unimaginably far away — the founding discovery of modern cosmology. Then he noticed something even bigger: the farther a galaxy is, the faster it's rushing away from us, its light stretched to redder wavelengths by red shift. The universe wasn't static at all. It was expanding. The Hubble Space Telescope is named in his honour.

Before Hubble, most astronomers thought our Milky Way was the whole universe. In 1923 he found a special pulsing star inside the Andromeda "nebula" and used it as a cosmic ruler. The answer came back: Andromeda was hundreds of thousands of times too far away to be part of our galaxy. In one measurement the cosmos went from a single island to an ocean of billions of galaxies. He scrawled the word "VAR!" on the photographic plate — and quietly rewrote our address in the universe.