devrimci_kürt Posted February 28, 2009 Posted February 28, 2009 is Dark Energy effect on the curvature of space time ? how?
iNow Posted February 28, 2009 Posted February 28, 2009 I am not sure if dark energy causes spacetime curvature. I do know, however, that dark matter does. The whole reason we think there is dark matter is because we see the spacetime curvature (from gravity) despite the absence of visible mass. Like I said, though, I am not sure if the same (or similar) can be said of dark energy. 1
Klaynos Posted February 28, 2009 Posted February 28, 2009 Dark energies effects can only be seen (as far as we know) on the increasing expansion rate of the universe. Whether this can be described as a curvature change or not I'm unsure. As for "How?" we don't know.
jamey2k9 Posted February 28, 2009 Posted February 28, 2009 (edited) the only effect of dark energy im aware of is that it's responable for the increasing rate of the universes expansion wikipedia has some detailed explanations of dark energy http://en.wikipedia.org/wiki/Dark_energy I meant to put energy Edited February 28, 2009 by jamey2k9
Klaynos Posted February 28, 2009 Posted February 28, 2009 the only effect of dark matter im aware of is the increasing rate of the universes expansion wikipedia has some detailed explanations of dark energy http://en.wikipedia.org/wiki/Dark_energy I think you meant dark energy not matter.
Martin Posted February 28, 2009 Posted February 28, 2009 is Dark Energy effect on the curvature of space time ?how? Dark energy (if it exists) must have an effect on the curvature of spacetime. Spacetime curvature is a more general idea than purely spatial curvature. The expansion of distances is an expression of spacetime curvature---a curvature which we cannot see just looking at space at the present moment. You could have a universe that was spatially flat and yet because of expansion or contraction it could have the more general spacetime type of curvature. A universe that is totally flat with no spacetime curvature can't even expand or contract. ====================== So if expansion accelerates, that means curvature is being affected. It is a fact about geometry. Dark energy is something people made up to explain the observed geometry. It has to effect curvature because that is what it was made up to do I tentatively believe it is real. But what I'm trying to say is that the curvature effect is realer. The acceleration, ie the curvature effect, is what we observe, so it is primary. The dark energy is secondary---it is what we infer or deduce from observing and reconstructing the expansion-history. I think that's right. I don't claim a particularly deep understanding of this stuff. iNow and Klaynos already gave you most of the story. Maybe we will hear from other knowledgeable people as well.
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