Edwin Powell Hubble — American Scientist born on November 20, 1889, died on September 28, 1953
Edwin Powell Hubble 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 known for showing that the recessional velocity of a galaxy increases with its distance from the earth, implying the universe is expanding, known as "Hubble's law" although this relation had been discovered previously by Georges Lemaître, who published his work in a less visible journal... (wikipedia)