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Talk:Counterexamples to Relativity (view source)
Revision as of 12:19, August 13, 2010
, 12:19, August 13, 2010→Curvature of Space
:I actually think the edit has merit, as long as the word "initial" is inserted before curvature, since the problem is that any initial curvature should be vastly amplified over time as the universe undergoes its usual expansion. And it is in fact the global curvature that is the issue here; ''any'' manifold we use to model the universe is by definition locally flat (since this is a fundamental property of manifolds). The ship and horizon observation is not a local observation, since it is fundamentally predicated on the global curvature of the Earth. "Local" means that it can be done at arbitrarily small distance scales, which that observation cannot. [[User:Yill|Yill]] 17:06, 4 April 2010 (EDT)
:I actually think the edit has merit, as long as the word "initial" is inserted before curvature, since the problem is that any initial curvature should be vastly amplified over time as the universe undergoes its usual expansion. And it is in fact the global curvature that is the issue here; ''any'' manifold we use to model the universe is by definition locally flat (since this is a fundamental property of manifolds). The ship and horizon observation is not a local observation, since it is fundamentally predicated on the global curvature of the Earth. "Local" means that it can be done at arbitrarily small distance scales, which that observation cannot. [[User:Yill|Yill]] 17:06, 4 April 2010 (EDT)
General relativity predicts that space-''time'' should be curved and not just spatial sections of the 4D spacetime manifold. And space-time is indeed observed to be curved (because the universe is expanding and is hence described by a curved FRW metric). This is true even if space alone is flat, as it is observed to be. That space is observed to be flat doesn't contradict relativity - it is a question of initial conditions of the universe and has a neat solution in inflationary cosmology. So Point no. 6 is absolutely unnecessary. Of course, most of the other points are too. But I just want to see how Andy will respond to this and edit the article so that it indeed can be said to belong to a "trustworthy encyclopedia".
[[User:Saywhat|Saywhat]] 08:19, 13 August 2010 (EDT)
== Reversion explained ==
== Reversion explained ==