Friedmann–Einstein universe: Difference between revisions
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The Friedmann-Einstein universe is a model of the universe published by [[Albert Einstein]] in 1931. <ref>{{cite journal|last1=Einstein|first1=Albert|title=Zum kosmologischen Problem der allgemeinen Relativitätstheorie|journal=Sitzungs. König. Preuss. Akad.|date=1931|pages=235-237}}</ref>Interpreting [[Edwin Hubble]]'s discovery of a linear relation between the redshifts of the galaxies and their radial distance as evidence for an expanding universe, Einstein abandoned his earlier static model of the universe and embraced the dynamic cosmology of [[Alexander Friedmann]]. Removing the [[cosmological constant]] term from the [[Friedmann equations]] on the grounds that it was |
The Friedmann-Einstein universe is a model of the universe published by [[Albert Einstein]] in 1931. <ref>{{cite journal|last1=Einstein|first1=Albert|title=Zum kosmologischen Problem der allgemeinen Relativitätstheorie|journal=Sitzungs. König. Preuss. Akad.|date=1931|pages=235-237}}</ref>Interpreting [[Edwin Hubble]]'s discovery of a linear relation between the redshifts of the galaxies and their radial distance as evidence for an expanding universe, Einstein abandoned his earlier static model of the universe and embraced the dynamic cosmology of [[Alexander Friedmann]]. Removing the [[cosmological constant]] term from the [[Friedmann equations]] on the grounds that it was both unsatisfactory and unnecessary, Einstein arrived at a model of the universe that expands and then contracts. |
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<ref>{{cite book|last1=Nussbaumer and Bieri|title=Discovering the Expanding Universe|date=2009|publisher=Cambridge University Press|location=Cambridge|pages=147-148}}</ref> |
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In the model, Einstein derived simple expressions relating the density of matter, the radius of the universe and the timespan of the expansion to the [[Hubble constant]]. With the use of the contemporaneous value of 500 km/s/Mpc for the Hubble constant, he calculated values of 10^-26 cm^-3, 10^8 light-years and 10^10 years for the density of matter, the radius of the universe and the timespan of the expansion. It has recently been discovered that these calculations contain a systematic error.<ref>{{cite journal|last1=O'Raifeartaigh and McCann|title=Einstein's cosmic model of 1931 revisited: an analysis and translation of a forgotten model of the universe|journal=Eur. Phys. J. (H)|date=2014|volume=39|issue=1|pages=37-62|url=https://arxiv.org/abs/1312.2192}}</ref> |
In the model, Einstein derived simple expressions relating the density of matter, the radius of the universe and the timespan of the expansion to the [[Hubble constant]]. With the use of the contemporaneous value of 500 km/s/Mpc for the Hubble constant, he calculated values of 10^-26 cm^-3, 10^8 light-years and 10^10 years for the density of matter, the radius of the universe and the timespan of the expansion. It has recently been discovered that these calculations contain a systematic error.<ref>{{cite journal|last1=O'Raifeartaigh and McCann|title=Einstein's cosmic model of 1931 revisited: an analysis and translation of a forgotten model of the universe|journal=Eur. Phys. J. (H)|date=2014|volume=39|issue=1|pages=37-62|url=https://arxiv.org/abs/1312.2192}}</ref> |
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Revision as of 18:20, 13 October 2016
The Friedmann-Einstein universe is a model of the universe published by Albert Einstein in 1931. [1]Interpreting Edwin Hubble's discovery of a linear relation between the redshifts of the galaxies and their radial distance as evidence for an expanding universe, Einstein abandoned his earlier static model of the universe and embraced the dynamic cosmology of Alexander Friedmann. Removing the cosmological constant term from the Friedmann equations on the grounds that it was both unsatisfactory and unnecessary, Einstein arrived at a model of the universe that expands and then contracts. [2] In the model, Einstein derived simple expressions relating the density of matter, the radius of the universe and the timespan of the expansion to the Hubble constant. With the use of the contemporaneous value of 500 km/s/Mpc for the Hubble constant, he calculated values of 10^-26 cm^-3, 10^8 light-years and 10^10 years for the density of matter, the radius of the universe and the timespan of the expansion. It has recently been discovered that these calculations contain a systematic error.[3]
- ^ Einstein, Albert (1931). "Zum kosmologischen Problem der allgemeinen Relativitätstheorie". Sitzungs. König. Preuss. Akad.: 235–237.
- ^ Nussbaumer and Bieri (2009). Discovering the Expanding Universe. Cambridge: Cambridge University Press. pp. 147–148.
- ^ O'Raifeartaigh and McCann (2014). "Einstein's cosmic model of 1931 revisited: an analysis and translation of a forgotten model of the universe". Eur. Phys. J. (H). 39 (1): 37–62.