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 the most important observational cosmologists of the 20th century. Hubble is generally mistakenly known for Lemaître's law or "Hubble's law" which was discovered by Georges Lemaître. He is also mistakenly credited with the discovery of the existence of galaxies other than the Milky Way and his 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". These findings fundamentally changed the scientific view of the universe. 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 (a former mule-driver and janitor), Hubble and Humason found a direct relationship between a galaxy's distance and its relative speed away from the solar system.
1.) Gale E. Christianson (1996). Edwin Hubble: Mariner of the Nebulae. University of Chicago Press. p. 183. ISBN 9780226105215. "One morning, while driving north with Grace after the failed eclipse expedition of 1923, he broached Whitehead's idea of a God who might have chosen from a great many possibilities to make a different universe, but He made this one. By contemplating the universe, one might approximate some idea of its Creator. As time passed, however, he seemed even less certain: "We do not know why we are born into the world, but we can try to find out what sort of a world it is — at least in its physical aspects." His life was dedicated to science and the objective world of phenomena. The world of pure values is one which science cannot enter, and science is unconcerned with the transcendent, however compelling a private revelation or individual moment of ecstasy. He pulled no punches when a deeply depressed friend asked him about his belief: "The whole thing is so much bigger than I am, and I can't understand it, so I just trust myself to it; and forget about it.""
2.) Tom Bezzi (2000). Hubble Time. iUniverse. p. 93. ISBN 9780595142477. "John terribly depressed, and asked Edwin about his belief. Edwin said, "The whole thing is so much bigger than I am, and I can't understand it, so I just trust myself to it, and forget about it." It was not his nature to speculate. Theories, in his opinion, were appropriate cocktail conversation. He was essentially an observer, and as he said in The Realm (J the Nebulae: “Not until the empirical resources are exhausted, need we pass on to the dreamy realms of speculation.” Edwin never exhausted those empirical resources. “I am an observer, not a theoretical man,” he attested, and a lightly spoken word in a lecture or in a letter showed that observation was his choice."