Changes

:::::::Okay, now ''that'' is a total non sequitur.  Again, instead of making blanket assertions, perhaps you should learn why, given that they believe dark matter permeates the universe ''and'' that it is flat on large scales, cosmologists still think GR works.  Let me enlighten you.  If the universe were evenly filled with a uniformly dense substance, the curvature would be flat.  Yet there were would be matter in it!  And that's it.  On large enough scales, that's how the universe appears.  Hence there is no contradiction. [[User:Yill|Yill]] 00:19, 9 April 2010 (EDT)

:::::::Okay, now ''that'' is a total non sequitur.  Again, instead of making blanket assertions, perhaps you should learn why, given that they believe dark matter permeates the universe ''and'' that it is flat on large scales, cosmologists still think GR works.  Let me enlighten you.  If the universe were evenly filled with a uniformly dense substance, the curvature would be flat.  Yet there were would be matter in it!  And that's it.  On large enough scales, that's how the universe appears.  Hence there is no contradiction. [[User:Yill|Yill]] 00:19, 9 April 2010 (EDT)

:::::::: An additional clarification to the previous discussions: According to Einsteins equations (neglecting the cosmological constant for now), <math> G_{\mu}_{\nu} = R_{\mu}_{\nu} - \frac{1}{2} g_{\mu}_{\nu} R = 8 \pi G T_{\mu}_{\nu} <\math> in which <math> R_{\mu}_{\nu} </math> is representative of the curvature of spacetime (Ricci tensor) and <math> T_{\mu}_{\nu} </math> is representative of the matter/energy content of the given model (Stress-Energy tensor). So Einsteins equations state that the presence of matter gives rise to curvature effects in spacetime. In FLRW cosmology the existence of a spatially flat solution is possible if the total density ~ critical density required for a flat Universe. The fact that the Universe is non-static and we currently include a dark energy component does not mean that a Universe that is currently observed to be spatially flat is in conflict with predictions of General Relativity. The flatness problem is more of an initial value problem/fine tuning problem than that of a breakdown in GR.

:::::::: An additional clarification to the previous discussions: According to Einsteins equations (neglecting the cosmological constant for now), <math> G_{\mu \nu} = R_{\mu \nu} - \frac{1}{2} g_{\mu \nu} R = 8 \pi G T_{\mu \nu} <\math> in which <math> R_{\mu}_{\nu} </math> is representative of the curvature of spacetime (Ricci tensor) and <math> T_{\mu}_{\nu} </math> is representative of the matter/energy content of the given model (Stress-Energy tensor). So Einsteins equations state that the presence of matter gives rise to curvature effects in spacetime. In FLRW cosmology the existence of a spatially flat solution is possible if the total density ~ critical density required for a flat Universe. The fact that the Universe is non-static and we currently include a dark energy component does not mean that a Universe that is currently observed to be spatially flat is in conflict with predictions of General Relativity. The flatness problem is more of an initial value problem/fine tuning problem than that of a breakdown in GR.

== Proposed page move ==

== Proposed page move ==