Quote:
Originally Posted by AnotherCat
That is the current belief for cases where special relativity applies i.e. locally over small distances where one can approximate spacetime to being flat. However, general relativity which applies over large distances, where the curvature of spacetime must be taken into account, does not prohibit speeds faster than that of light.
An example is, if the current model of the universe's expansion is correct, that galaxies sufficiently far away from us are traveling at speeds greater than that of light. Furthermore, despite their speed being faster than that of light, we can still see some of them.
Regardless, I think it is unlikely that current models/theories/laws will survive unchanged so I have an open mind. They are mathematically and observationally correct at this time, but history tells us that they are probably going to get modified with time.
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I've been arguing this in terms of the faster-than-light communication required in much of science fiction. If cosmic space is stretching to make galaxies speed apart at even greater speeds, I don't see how that makes faster-than-light communication any more possible.
I agree that we still have much to learn, but I still don't agree that anything we learn is going to make the basics we know completely wrong. It would also have to make everything we see completely wrong, as well. That's the part I have trouble coming to terms with. How do you who think we could be wrong explain how these mistakes don't manifest themselves in what we see of the universe? Does the speed of light hold in all cases except in some few that conveniently explain some macguffins used in some sci-fi novels?