Sunday, November 20, 2011
Edwin Powell Hubble
After finishing his bachelors Hubble went to England, where he studied law, at the insistence of his dying father, at Queens College, Oxford on a Rhodes Scholarship. He remained in England for three years. Upon returning to the United States Hubble taught high school mathematics, physics and Spanish, also coaching basketball, for a year. After a year teaching he returned to his passion, astronomy, and began studying at the Yerkes Observatory at the University of Chicago, finishing his Ph.D. in 1917. His dissertation was titled "Photographic Investigations of Faint Nebulae" Hubble served in the United States Army during World War I, rising to the rank of major. In 1919 Hubble accepted a position at the Mt. Wilson Observatory, in Pasadena, California, where he remained on staff until his death. During World War II Hubble worked for the Army at the Aberdeen Proving Ground, in Aberdeen, Maryland, where he worked on ballistics and for which he was awarded the Legion of Merit.
Hubble's arrival at the Mt. Wilson Observatory coincided with the instillation of the Hooker Telescope, a 2.5 meter telescope, which at the time was the largest in the world. At the time most astronomers believed that the Milky Way Galaxy was the extent of the universe and that the fuzzy objects called nebulae were contained within it. Using the Hooker Telescope, Hubble was able to show that some of these fuzzy objects contained stars and were much too distant to be inside of the Milky Way. Hubble showed that some of these objects were in fact galaxies and he devised a method of categorizing them based on their shape, called the Hubble Sequence, which is still used today classify galaxies. Hubble's most astonishing discovery came from studying the spectra of 46 galaxies in which he showed that the further galaxies were from each other the faster that they were moving away from each other. Based on this observation Hubble concluded that the universe was expanding at a constant rate (it later was determined that the rate of expansion is actually increasing). With his colleague Milton Humason, he estimated that the rate of expansion is 500 Km per second per megaparsec. So a galaxy one megaparsec away is receding from the Milky Way at a rate of 500Km/second (a mega parsec is one million parsecs, each 3.3 light years or about 3.08x1022meters). This is called the Hubble Constant and astronomers have been refining the measurement ever since.
Honors won by Hubble include the Bruce Medal, awarded by the Astronomical Society of the Pacific, the Franklin Medal, awarded by the Franklin Institute, and Gold Medal, the highest honor of the Royal Astronomical Society of Great Britain. He was never awarded the Nobel Prize because it was not till after his death that astronomy was considered a subject for which the Nobel Prize in physics could be awarded and the Nobel Prize is not awarded posthumously. In addition to the Hubble Space Telescope, a telescope orbiting the earth, an asteroid and a crater on the moon are also named after Hubble. In 2008 the United States Postal Service issued a stamp honoring Hubble.
Hubble died on September 23, 1953.
Christianson, Gale E.; Edwin Hubble: Mariner of the Nebulae; University of Chicago Press; 1996
Anonymous; Edwin Hubble Biography at edwinhubble.com
Anonymous: Edwin P. Hubble at Hubble Space Telescope Website (hubble.nasa.gov)
Edwin Hubble Wikipedia Entry