Edwin Hubble
For the United States politician with a similar name, see Edwin N. Hubbell.Edwin Powell Hubble (
November 20,
1889 â€"
September 28,
1953) was an
American astronomer, noted for his discovery of
galaxies beyond the
Milky Way and the cosmological
redshift. Edwin Hubble was one of the first to argue that the red shift of distant galaxies is due to the
Doppler effect induced by the
expansion of the universe. He was one of the leading astronomers of modern times and laid down the foundation upon which
physical cosmology now rests.
Edwin Hubble was born to an insurance executive in
Marshfield, Missouri and moved to
Wheaton, Illinois in
1889. In his younger days, he was noted more for his athletic abilities rather than his intellectual genius, although he did earn good grades in every subject, except for spelling. He won seven first places
[For the record, these were discus, hammer throw, pole vault, standing and running high jump, shot put, mile-relay. The third-placing was for broad jump.] and a third placing in a single high school meet in
1906. That year he also set a state record for
high jump in
Illinois.
His studies at the
University of Chicago concentrated on mathematics and astronomy which led to a
BS degree in
1910. He spent the next three years as one of Oxford's first
Rhodes Scholars, where he studied in the field of law and received the
MA degree, after which he returned to the
United States as a
high school teacher and a
basketball coach in
New Albany, Indiana.
He served in
World War I and quickly became
Major. He returned to astronomy at the
Yerkes Observatory of the University of
Chicago, where he earned a
PhD in
1917 with a dissertation entitled "Photographic Investigations of Faint Nebulae". In
1919 Hubble was offered a staff position by
George Ellery Hale, the founder and director of Carnegie Institution's
Mount Wilson Observatory, near
Pasadena, California, where he remained until his death. He also served in the
US army during
World War II. Shortly before his death, Palomar's 200-inch
Hale Telescope was completed; Hubble was the first to use it.
He died of a
heart attack on
September 28,
1953, in
San Marino, California. His wife, Grace, did not have a
funeral for him and never revealed what was done with his body - it was apparently Hubble's wish to have no funeral service and be
buried in an unmarked grave, or that he wanted to be
cremated. As of
2006, the whereabouts of his remains are unknown.
Galaxies exist beyond the Milky Way
Hubble's arrival at Mount Wilson in
1919 coincided roughly with the completion of the 100-inch
Hooker Telescope, then the world's largest telescope. Hubble's observations in
1923â€"
1924 with the Hooker Telescope established beyond doubt that the fuzzy "
nebulae" seen earlier with less sensitive telescopes were not part of our
galaxy, as had been thought, but were galaxies themselves, outside the
Milky Way. He announced this discovery on
December 30,
1924.
Hubble also devised a
classification system for galaxies, grouping them according to their content, distance, shape, size and brightness.
The universe is expanding
Hubble was generally incorrectly credited with discovering
[This had actually been observed by Vesto Slipher in the 1910s, but the world was largely unaware. Ref: Slipher (1917): Proc. Amer. Phil. Soc., 56, 403.]The world is also largely unaware that Hubble never believed that his own model of the expanding universe model was the correct one:
… if redshift are not primarily due to velocity shift … the velocity-distance relation is linear, the distribution of the nebula is uniform, there is no evidence of expansion, no trace of curvature, no restriction of the time scale … and we find ourselves in the presence of one of the principle of nature that is still unknown to us today … whereas, if redshifts are velocity shifts which measure the rate of expansion, the expanding models are definitely inconsistent with the observations that have been made … expanding models are a forced interpretation of the observational results (E. Hubble, Ap. J., 84, 517, 1936.)
[If the redshifts are a Doppler shift] … the observations as they stand lead to the anomaly of a closed universe, curiously small and dense, and, it may be added, suspiciously young. On the other hand, if redshifts are not Doppler effects, these anomalies disappear and the region observed appears as a small, homogeneous, but insignificant portion of a universe extended indefinitely both in space and time. (Royal Astronomical Society Monthly Notices, 17, 506, 1937).
the
redshift of galaxies. These measurements and their significance were understood before 1917 by
James Edward Keeler (Lick & Allegheny),
Vesto Melvin Slipher (Lowell), and Professor
William Wallace Campbell (Lick) at other observatories. Combining his own measurements of galaxy distances with
Vesto Slipher's measurements of the redshifts associated with the galaxies, Hubble and
Milton L. Humason discovered a rough proportionality of the objects' distances with their redshifts. Though there was considerable scatter (now known to be due to peculiar velocities), Hubble and Humason were able to plot a trend line from the 46 galaxies they studied and obtained a value for the Hubble-Humason constant of 500 km/s/Mpc, which is much higher than the currently accepted value due to errors in their distance calibrations. Such errors in determining distance continue to plague modern astronomers. See the article on
cosmic distance ladder for more details. In
1929 Hubble and Humason formulated the empirical Redshift Distance Law of galaxies, nowadays termed simply
Hubble's law, which, if the redshift is interpreted as a measure of recession speed, is consistent with the solutions of
Einstein's
General Relativity Equations for an homogeneous, isotropic expanding space
de Sitter universe or
de Sitter space. Although concepts underlying an
expanding universe were well understood earlier, this statement by Hubble and Humeson lead to wider scale acceptance for this view. The law states that the greater the distance between any two galaxies, the greater their relative speed of separation.
This discovery later resulted in formulation of the
Big Bang theory by
George Gamow, a consequence of the observed velocities of distant galaxies that when taken together with the
cosmological principle imply that space is expanding according to the
Friedmann-Lemaître model of
general relativity.
Earlier, in
1917,
Albert Einstein had found that his newly developed General Theory of Relativity indicated that the universe must be either expanding or contracting. Unable to believe what his own equations were telling him, Einstein introduced a
cosmological constant (a "fudge factor") to the equations to avoid this "problem". When Einstein heard of Hubble's discovery, he said that changing his equations was "the biggest blunder of my life".
[http://www.pbs.org/wnet/hawking/strange/html/strange_cosmo.html]Other discoveries
Hubble discovered the
asteroid 1373 Cincinnati on
August 30,
1935. He also wrote
The Observational Approach to Cosmology and
The Realm of the Nebulae around this time.
Hubble spent much of the later part of his career attempting to have astronomy considered an area of physics, instead of being its own science. He did this largely so that astronomers - including himself - could be recognized by the
Nobel Prize Committee for their valuable contributions to astrophysics. This campaign was long unsuccessful and unfortunately Hubble's great achievements would remain unrewarded. The Nobel Prize Committee eventually decided that astronomical work would be eligible for the physics prize. Unfortunately for Hubble, this occurred in
1953 some months after Hubble's death. The Nobel Prize is never awarded posthumously.
Awards*
Bruce Medal in
1938.
*
Gold Medal of the Royal Astronomical Society in
1940.
*
Medal of Merit for outstanding contribution to
ballistics research in
1946--
ARPNamed after him*
Asteroid 2069 Hubble.
*
Hubble crater on the
Moon.
* Orbiting
Hubble Space Telescope.
*Hubble E.P.,
The Observational Approach to Cosmology (Oxford, 1937).
*Hubble E.P.,
The Realm of the Nebulae (New Haven, 1936).
*
Time 100 Profile*
Astronomy at the University of Louisville - Photographs of Edwin Hubble at
New Albany High School.
*
Edwin Hubble bio - Written by
Allan Sandage*
*
Galaxies**
Galaxy classification**
Gerard de Vaucouleurs**
De Vaucouleurs modified Hubble sequence**
Galaxy classification**
Spiral nebula*
Expansion of the universe**
Big bang**
Albert Einstein**
Relativity**
Hubble's law**
Hubble constant*
Hubble Space Telescope*
Cosmic distance ladder{{Persondata
NAME=Hubble, Edwin Powell | ALTERNATIVE NAMES= | SHORT DESCRIPTION=American astronomer | DATE OF BIRTH=20 November, 1889 | PLACE OF BIRTH=Marshfield, Missouri | DATE OF DEATH=28 September, 1953 | PLACE OF DEATH=San Marino, California
|
