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Gravitational lensing (view source)
Revision as of 15:36, October 25, 2012
, 15:36, October 25, 2012Section-> CMB
'''Gravitational lensing''' is a gravitational-optical effect whereby a background object like a distant [[quasar]] is magnified, distorted and brightened by a foreground [[galaxy|galaxies]]. An intervening concentration of [[matter]] is declared to bring 'focusing' effect attributed to [[general relativity]] so that even objects normally beyond [[Scientific observation|observational]] distance can bee seen by [[astronomer]]s at the [[Earth]]. It is alleged that, for example, the [[galaxy cluster]] Abell 2218, distorts and magnifies light from galaxies behind it.<ref>{{cite web
'''Gravitational lensing''' is a gravitational-optical effect whereby a background object like a distant [[quasar]] is magnified, distorted and brightened by a foreground [[galaxy|galaxies]]. An intervening concentration of [[matter]] is declared to bring 'focusing' effect attributed to [[general relativity]] so that even objects normally beyond [[Scientific observation|observational]] distance can bee seen by [[astronomer]]s at the [[Earth]]. It is alleged that, for example, the [[galaxy cluster]] Abell 2218, distorts and magnifies light from galaxies behind it.<ref name="Samec">{{cite web
|title=No sign of gravitational lensing in the cosmic microwave background
|title=No sign of gravitational lensing in the cosmic microwave background
|author=Ron Samec
|author=Ron Samec
|publisher=Creation Ministries International
|publisher=Creation Ministries International
|url=http://creation.com/no-sign-of-gravitational-lensing-in-the-cosmic-microwave-background
|url=http://creation.com/no-sign-of-gravitational-lensing-in-the-cosmic-microwave-background
|accessdate=2012-10-25}}</ref>
|accessdate=2012-10-25}}</ref>
==Gravitational lensing and Cosmic microwave background==
Galactic groups and clusters are the largest foreground concentration of matter in the universe that are accountable for the gravitational lensing. However, Lieu and Mitaz have shown that WMAP (Wilkinson Microwave Anisotropy Probe) high resolution observational data of the [[Cosmic microwave background]] (CMB) could reveal no evidence whatsoever for such effect.<ref name="LieuMitaz"/> Consequently, a conclusion was drawn by authors of the paper that important elements of physics are missing from the standard cosmological [[Big Bang]] model.<ref name="LieuMitaz">{{cite web
|author=Lieu, R. and Mitaz, J
|title=On the Absence of Gravitational Lensing of the Cosmic Microwave Background
|publisher=The Astrophysical Journal
|volume=628
|issue=2
|year=2005
|doi=10.1086/429793
|url=http://iopscience.iop.org/0004-637X/628/2/583/pdf/0004-637X_628_2_583.pdf}}</ref> Other suggested that this is a major blow to the Big Bang theory where the existence of CMB is regarded for being the main evidence for its occurrence and [[cosmic inflation]] as an ad-hoc idea to support it falls apart. If the CMB is not of cosmological origin (i.e. remnant of Big Bang) but rather local phenomenon, it has been suggested it could be a rather homogeneous expulsion of a nearby [[supernova]].<ref name="Samec"/>
==References==
==References==
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<references/>
[[Category:Astronomy]]
[[Category:Astronomy]]
[[Category:Cosmology]]
[[Category:Cosmology]]