Edwin Hubble, (1889-1953)

Edwin Hubble was an American astronomer and cosmologist, whose discovery of galaxies other than the Milky Way changed our understanding of the universe.

Hubble was born in 1889 in Marshfield, Missouri. He studied mathematics and astronomy at the University of Chicago, and in 1910 he accepted a Rhodes scholarship to study in England at Oxford University. On his return to America he studied at Yerkes Observatory, University of Chicago, and was awarded a PhD in 1917. He took up an appointment at the Mount Wilson Observatory, California in 1919.

Hubble’s early work involved the study of faint nebulae. Using a 100-inch telescope at Mount Wilson he resolved the outer region of the Andromeda nebula. Between 1925 and 1929 he wrote three papers that showed the existence of isolated systems of stars called galaxies, which were too distant to be part of our Milky Way galaxy. This challenged the accepted view among astronomers that the whole universe consisted of the Milky Way.

Hubble also devised a method for classifying galaxies, and coined the terms ‘ellipticals’, ‘spirals’ and ‘barred spirals’ still used to describe galaxies today.

In 1929 he announced what became known as Hubble’s law, that the degree of redshift of a galaxy - and thus its velocity - increases with distance. This helped convince the scientific community that the universe is expanding uniformly.

Hubble served in the US Army at the Aberdeen Proving Ground during the Second World War. After the war, he continued his astronomical work, contributing to the construction of the 5.1-metre Hale reflecting telescope at Mount Palomar.

He died at San Marino, California in 1953.