Quote:
Originally Posted by Shnoz
If I may post yet another brain-bending question. Given that nothing in the Universe can exceed the speed of light, would it be possible to calculate an absolute size to our entire Universe?
I would imagine that very simply put it would require a multiplication by the age of the Universe and the speed of light. Of course, things such as the Hubble Constant would have to be taken into account; but to find the biggest size our Universe could possibly be, would such an equation work?
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Sophie,
Nothing can exceed the speed of light
through space, but the expansion of space-time
can exceed the speed of light. This doesn't contradict special relativity as distance and time in space time expansion is not the same as our customary definition of these terms.
Getting back to your question, multiplying the speed of light by the age of the universe will only give a very rough value of the size of the observable universe. For example during the flight of a 13 billion year old photon, the Universe would have expanded by a certain amount and this needs to be factored in. Unfortunately since the expansion of the Universe is accelerating we only have a snapshot of the Hubble "constant" as it is now, not over the 13 billion year history.
Hence the size of the Universe will always be at best an estimate.
Steven