What is the connection between Olber's paradox and the age of the universe?

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Discussion Overview

The discussion revolves around the connection between Olber's paradox and the age of the universe, exploring whether the finite existence of the universe and the light from distant stars contribute to the paradox. Participants examine implications for both finite and infinite models of the universe.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants suggest that the finite existence of the universe and the light from distant stars not reaching us is a valid argument against an infinitely old universe.
  • Others argue that the darkness of the night sky is simply due to the sun being on the other side of the Earth, indicating a misunderstanding of the paradox.
  • One participant notes that the explanation provided in a referenced video aligns with the idea that a finite universe contradicts an infinite/eternal universe.
  • Another participant states that the assumption of a static universe is necessary for the particular answer to Olber's paradox, and that an expanding universe with redshifted light resolves the paradox.
  • It is mentioned that the expansion of the universe implies a finite age, as extrapolating back too far leads to a singularity, which is not expected to be real.

Areas of Agreement / Disagreement

Participants express differing views on the implications of Olber's paradox for the age of the universe, with no consensus reached on whether the paradox is resolved by a finite universe or if it remains a point of contention.

Contextual Notes

The discussion includes assumptions about the nature of the universe, such as whether it is static or expanding, and the implications of these assumptions on the understanding of Olber's paradox. There is also mention of a singularity, which remains an unresolved concept in the context of the discussion.

TheAlkemist
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I just watched this http://www.youtube.com/watch?v=TFwtJC9_dXs" that said it's because the universe has a finite existence and the light from most of the stars hasn't reached us yet and this would be an argument against an infinitely old universe. Is this correct?
 
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No. It's simply because the sun is on the other side of the Earth.
 
Pengwuino said:
No. It's simply because the sun is on the other side of the Earth.

Exactly. It wouldn't be so dark at all if your eyes could detect visible light better.

But seems like a misunderstanding, perhaps a rephrase and better explanation of your question is in order.
 
TheAlkemist said:
I just watched this http://www.youtube.com/watch?v=TFwtJC9_dXs" that said it's because the universe has a finite existence and the light from most of the stars hasn't reached us yet and this would be an argument against an infinitely old universe. Is this correct?

I haven't watched that clip, but I think that's essentially the correct answer to what was called Olber's paradox.
 
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Doc Al said:
I haven't watched that clip, but I think that's essentially the correct answer to what was called Olber's paradox.
Yes, that's what the explanation was in the clip. But is it in conflict with an infinite/eternal universe?
 
TheAlkemist said:
But is it in conflict with an infinite/eternal universe?
I'd say so. Perhaps a cosmologist will chime in with more details.
 
TheAlkemist said:
I just watched this http://www.youtube.com/watch?v=TFwtJC9_dXs" that said it's because the universe has a finite existence and the light from most of the stars hasn't reached us yet and this would be an argument against an infinitely old universe. Is this correct?

This particular answer to the paradox requires the assumption of a static universe. If we have an expanding universe, light from distant stars is redshifted, and Olber's paradox never occurs. It is the expansion, then, that solves the problem.

Now, for entirely different reasons, the expansion of the universe requires an expanding universe to have a finite age, because if you extrapolate back in time too far, you end up with a singularity. Nobody expects this singularity to be real, but somewhere between here and the singularity must be some sort of physical process (currently unknown) that generates a region of expanding space-time.
 
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