Quote:
Originally Posted by hugh
That's true if objects could travel faster than the speed of light. But you can't get 46 billion light years away in only 13 billion years without travelling ~3x faster than the speed of light.
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You do not quite have a grasp of the issue. The Universe is expanding while the light particles from (in this specific case) galaxy MACSO647-JD are in transit. In transit specifically to the James Webb telescope. Their arrival kicks the Webb telescope staff into high gear. The scientists determine with an incredible amount of precision the wavelength of these light particles. This is where the real science begins.
And wow, do things get tricky from here on in. Determining distance in an expanding Universe is a challenge. There is more than one moving part to deal with. Add to that the additional 'problem' that the Universe is expanding at an increasing rate. Cosmologists think about time on the intergalactic scale as the light-travel distance.
The cosmic speed limit is the speed of light. The size of the Universe is the size which can be observed and detected.
In the hypothetical realm the question can be asked: "At what distance away from us does the speed at which things are moving away reach the speed of light?” Then the answer is around 46.5 billion light years.
Finally, (at least in terms of my level of competency with respect to this subject) It is space which is expanding along with -- or carrying along with the objects in that space. You could think of it this way: With a magic marker dot up a balloon with smudges, etc. Blow the balloon up. What happens?
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