Edwin Hubble

Edwin Hubble

Edwin Powell Hubble (November 20, 1889 – September 28, 1953) was an American astronomer who played a crucial role in establishing the field of extragalactic astronomy and is generally regarded as one of the most important observational cosmologists of the 20th century. Hubble is generally mistakenly known for "Lemaître's law", discovered by Georges Lemaître, which is known more extensively as "Hubble's law". Hubble is also mistakenly credited with the discovery of the existence of galaxies other than the Milky Way, and with the galactic red shift discovery that the loss in frequency—the redshift—observed in the spectra of light from other galaxies increased in proportion to a particular galaxy's distance from Earth. This relationship became known as "Lemaître's law" or "Hubble's law". The existence of other galaxies and red shift was actually first discovered by the American astronomer Vesto Slipher. Using the data collected by Vesto Slipher and his (Hubble's) assistant Milton Humason, Hubble and Humason found a direct relationship between a galaxy's distance and its relative speed away from the solar system.

Hubble supported the Doppler shift interpretation of the observed redshift that had been proposed earlier by Vesto Slipher, and that led to the theory of the metric expansion of space. He tended to believe the frequency of any beam of light could, by some so far unknown means, be diminished ever stronger, the longer the beam travels through space.