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 "no longer necessary", Einstein arrived at a model of the universe that expands and then contracts. |
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 "no longer necessary", Einstein arrived at a model of the universe that expands and then contracts. |
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In the model, Einstein derived expressions for the density of matter, the radius of the universe and the timespan of the expansion in terms of the [[Hubble constant]]. With the use of the contemporaneous value of 500 km s-1 Mpc-1 for the Hubble constant, he calculated values of 10-26 cm-3, 108 light-years and 1010 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. |
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Using value of the Hubble constant to estimated values for each of theses parameters these parameters. |
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Revision as of 18:01, 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 "no longer necessary", Einstein arrived at a model of the universe that expands and then contracts.
In the model, Einstein derived expressions for the density of matter, the radius of the universe and the timespan of the expansion in terms of the Hubble constant. With the use of the contemporaneous value of 500 km s-1 Mpc-1 for the Hubble constant, he calculated values of 10-26 cm-3, 108 light-years and 1010 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. Using value of the Hubble constant to estimated values for each of theses parameters these parameters.
- ^ Einstein, Albert (1931). "Zum kosmologischen Problem der allgemeinen Relativitätstheorie". Sitzungs. König. Preuss. Akad.: 235–237.