Albert Einstein's General Theory of Relativity, published in , predicted that massive objects, such as stars, could bend light rays passing nearby. This prediction was verified by the observation of such bending of starlight near the Sun in That same year, an English physicist, Sir Oliver Lodge, suggested that this phenomenon could produce a gravitational lens.
In , Einstein himself showed that, if a brightly-emitting object were exactly behind a massive body capable of making a gravitational lens, the result would be an image of a ring around the massive lensing object. However, he dismissed the possibility of ever discovering such a lens, because of the small chance that the precise coincidence required would ever arise. Gravitational Lensing View All Articles. Looking Through a Giant Magnifying Glass.
What Is Gravitational Lensing? Galaxy cluster Abell , located about 4 billion light-years away, contains an astounding assortment of several hundred galaxies tied together by the mutual pull of gravity.
Entangled among the galaxies are mysterious-looking arcs of blue light. These are actually distorted images of remote galaxies behind the cluster. These far-flung galaxies are too faint for Hubble to see directly. Instead, the gravity from the cluster acts as a huge lens in space that magnifies and stretches images of background galaxies like a funhouse mirror. Nearly distant galaxies have multiple images caused by the lensing effect. The most stunning example is "the Dragon," an extended feature that is probably several duplicated images of a single background spiral galaxy stretched along an arc.
More information Privacy policy. This site uses cookies to assist with navigation, analyse your use of our services, collect data for ads personalisation and provide content from third parties. By using our site, you acknowledge that you have read and understand our Privacy Policy and Terms of Use.
July 25, The four images of the quasar are marked A-D. The lensing galaxy is very faint and it was discovered only after careful analysis of the image, its position is marked with an x. This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission.
The content is provided for information purposes only. Global consensus needed to develop climate risk disclosures for companies 14 hours ago. Relevant PhysicsForums posts Level of details in prime focus vs eyepiece images 5 hours ago. Question about Kuiper belt 17 hours ago. Our Beautiful Universe - Photos and Videos 21 hours ago. Temperature of gas in a cluster Nov 12, Maximum mass of a neutron star Nov 09, Related Stories.
New Type Ia supernova discovered using gravitational lensing Jul 24, Massive objects therefore create their gravitational fields by warping the spacetime continuum.
Light rays travel through the Universe on paths called geodesics, which are in essence the shortest distance between two points in a curved space.
In a flat plane, such as the almost constant gravitational field near the Earth's surface, the geodesics are essentially straight. In the wider Universe, however, this is not the case. On curved surfaces, such as the warped spacetime of the large-scale Universe, the geodesics are curved. Because of this, it is most likely that every ray of light we detect has been deflected to some small degree as it travels through space.
This is caused by the gravity of the various galaxies and clusters of galaxies that a light ray passes on its journey. Known as gravitational lensing, this extraordinary property of nature was predicted to exist by Albert Einstein's General Theory of Relativity in the early 20th century. The mathematics showed that any massive celestial object can bend passing light rays in the same way that a glass lens bends light in a telescope or microscope.
However, the amount of deflection was tiny and would need special conditions to be met in order for telescopes to detect it. Left Illustrations of the effect of a lensing mass on a circularly symmetric image.
Right In galaxy cluster Abell , strongly lensed arcs can be seen around the cluster. Every background galaxy is weakly lensed.
0コメント