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Astronomy and Cosmology
Cosmology
Size of Universe: Exploring 13.7bn Years of Space
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[QUOTE="Chalnoth, post: 5469113, member: 162258"] The speed of light limit is only a [i]local[/i] limit. That is, nothing can outrun a light ray. There is no well-defined notion of velocity for far-away objects at all, so there can't really be any speed limit. With regard to the fact that we can see matter that is currently nearly 50 billion light years away, that matter was much closer when the light we see was emitted. For example, the furthest matter that we can see is the matter that emitted the CMB. The CMB was just a few hundred thousand years after the "Big Bang", and the part of the universe that emitted the CMB we observe today is about 46 billion light years away, but it was only about 42 million light years away when it emitted that light. It's taken 13 billion years for the light to cross that distance because the expansion was so fast back then. [/QUOTE]
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Astronomy and Cosmology
Cosmology
Size of Universe: Exploring 13.7bn Years of Space
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