Friday, July 16, 2010

#Astrophysicist Verifies #Einstein's Cosmic Lens Theory

Einstein predicted that massive objects could act as a lens by bending light around them using gravity, but astronomical observations could not verify his theory until now. Look for a series of new astronomical observations over the next five years now that an example of Einstein's predictions has been found. R.C.J.

Here is what the Le Laboratoire d’astrophysique says about its own work: The EPFL’s Laboratory of Astrophysics has for the first time observed a quasar that is located between the earth and a more distant galaxy and acts as a gravitational lens, a phenomenon that illustrates Albert Einstein’s theory of general relativity and will make entirely new kinds of observations possible. A quasar acting as a gravitational lens has now been observed for the first time. This discovery, made by the EPFL’s Laboratory of Astrophysics in cooperation with Caltech, represents an advance in the field, since it will allow scientists to weigh and measure a galaxy that contains a quasar. Gravitational lenses are common throughout the universe. They are caused by massive objects such as stars or galaxies that bend rays of light passing nearby. If these objects are between the earth and a more distant light source, the light will therefore be brighter and easier to observe, but also very distorted. If the alignment of the various stellar bodies is almost perfect, the image of the source will be multiplied. The lens phenomenon is not only an interesting result of Einstein’s theory of general relativity; it has also been a valuable astrophysical tool with important applications in the search for extrasolar planets and the study of stars, galaxies, clusters of galaxies and quasars. For example, the nature of the distortion, the number of images of the most distant objects and their position in the sky provide essential information about the distribution of matter in the lens galaxy and allow a measurement of its total matter, including dark matter, to be made...
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