Rubin , Vera Cooper


Rubin , Vera Cooper
(1928–) American astronomer
Born in Philadelphia, Pennsylvania, Rubin was educated at Vassar, at Cornell, and at Georgetown University, Washington DC, where she obtained her PhD in 1954. Since 1965 she has worked at the Carnegie Institution, Washington DC, while also being an adjunct staff member of the Mount Wilson and Las Campanas observatories.
Rubin's main work has long been concerned with galactic rotation measurements and it has led to one of the more persistent problems of modern astronomy. She has concentrated on spiral galaxies and has measured the rotational velocities of the arms of the galaxy as their distance from the center increases. The velocities of the spiral arms are measured by determining their doppler shifts. That is light emitted from a body moving away from an observer will show a red shift, and a blue shift when emitted from a body moving toward the observer. The degree of spectral shift is proportional to the velocity of the source.
The initial assumption, based upon Kepler's laws, was that rotational velocity would decrease with distance. Thus the theoretical expectation was that: v2 = GM/r2 where G is the gravitational constant, M the attracting mass, and r the orbital radius. It is clear from the equation that as r increases, v will decrease. Rubin, however, found that the rotational velocity of spiral galaxies either remains constant with increasing distance from the center or rises slightly. The only possible conclusion, assuming the laws of motion, was that the figure for M was too low. But as all visible matter had been taken into account in assessing the mass of the galaxy, the missing mass must be present in the form of ‘dark matter’. Rubin found similar results as she extended her survey. It seemed to her in 1983 that as much as 90% of the universe is not radiating sufficiently strongly on any wavelength detectable on Earth.
Rubin's work has presented modern astronomy with two major problems. Firstly to calculate the amount of dark matter in the universe and describe its distribution, and secondly to identify particles that make up the dark matter.
Earlier in her career, in collaboration with Kent Ford, Rubin made the extraordinary discovery that the Milky Way had a peculiar velocity of 500 kilometers per second quite independently of the expansion of the universe. When their results were published in 1975 they were met with considerable skepticism and it was assumed they had miscalculated the distances of the measured galaxies. However, later work by John Huchra and others in 1982 seems to have confirmed their measurements.

Scientists. . 2011.

Look at other dictionaries:

  • Vera Cooper Rubin — Vera Rubin Pour les articles homonymes, voir Rubin. Vera Cooper Rubin est une astronome américaine née le 23 juillet 1928 à Philadelphie (Pennsylvanie, États Unis). Elle est principalement connue pour son étude sur les vitesses de rotation des… …   Wikipédia en Français

  • Vera Cooper Rudin — Vera Rubin Pour les articles homonymes, voir Rubin. Vera Cooper Rubin est une astronome américaine née le 23 juillet 1928 à Philadelphie (Pennsylvanie, États Unis). Elle est principalement connue pour son étude sur les vitesses de rotation des… …   Wikipédia en Français

  • Vera Cooper Rubin — (* 23. Juli 1928 in Philadelphia, Pennsylvania) ist eine US amerikanische Astronomin, die sich vorwiegend mit der Erfassung der Verteilung der dunklen Materie beschäftigt. Vera Rubin wurde in Philadelphia geboren und wuchs in Washington, D.C. auf …   Deutsch Wikipedia

  • Vera Rubin — Pour les articles homonymes, voir Rubin. Vera Cooper Rubin (23 juillet 1928 à Philadelphie, Pennsylvanie, États Unis) est une astronome américaine. Elle est principalement connue pour son étude sur les vitesses de rotation des étoiles dans les… …   Wikipédia en Français

  • Vera Rubin — Vera (Cooper) Rubin (born 23 July 1928) is an astronomer who has done pioneering work on galaxy rotation rates. Her opus magnus was the uncovering of the discrepancy between the predicted angular motion of galaxies and the observed motion, by… …   Wikipedia

  • Vera Rubin — Vera Cooper Rubin (nacida el 23 de julio de 1928 en Filadelfia, Pensilvania) es una astrónoma estadounidense, pionera en el estudio de las tasas de rotación galácticas. Su descubrimiento de la denomianda curvas planas de rotación es la evidencia… …   Wikipedia Español

  • Vera Rubin — Vera Cooper Rubin (* 23. Juli 1928 in Philadelphia, Pennsylvania) ist eine US amerikanische Astronomin, die sich vorwiegend mit der Erfassung der Verteilung der dunklen Materie beschäftigt. Vera Rubin wurde in Philadelphia geboren und wuchs in… …   Deutsch Wikipedia

  • Liste der Biografien/Ru — Biografien: A B C D E F G H I J K L M N O P Q …   Deutsch Wikipedia

  • Рубин, Вера — Вера Рубин (урождённая Купер) (р. 23 июля 1928 г.) (анг. Vera Cooper Rubin) американский астроном, один из пионеров развития концепции вращения галактик. Она известна выявлением расхождений между предсказанным угловым движением галактик и… …   Википедия

  • Cornell University — Cornell redirects here. For other uses, see Cornell (disambiguation). Cornell University Emblem of Cornell University Motto I would found an institution where any person can find instruction in any study …   Wikipedia


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.