Accelerating expansion of universe is an illusion

In summary, some scientists have put forth a new theory suggesting that the accelerating expansion of the universe may be an illusion caused by our relative motion through space. This theory could potentially eliminate the need for dark energy, a concept that has puzzled scientists for years. However, there is still ongoing debate and research on this topic, and more observational evidence is needed to confirm or refute this theory. The Nobel Prize was awarded for the discovery of the accelerating expansion of the universe, but some argue that the citation should have been more specific to the observational techniques used rather than the conclusion about the expansion.
  • #36
netdragon said:
I also can see why they picked to honor it now because of the threat of evidence mounting against universal acceleration of expansion.
There is no evidence mounting against universal acceleration. A cosmological-constant driven accelerated expansion remains the best fit to all current data.

netdragon said:
I agree more with your Edit better than your first statement but complexity of the computer is irrelevant when no computer is powerful enough to solve a problem. You seemed to have taken a "hidden variable" interpretation and believe there is actually a deterministic state versus a probabilistic one and that we can fully "know" the state if we crunch hard enough and have a complex enough computer.
I'm only assuming unitary quantum mechanics. And there's no such thing as wave function collapse, by the way.
 
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  • #37
Chalnoth said:
And there's no such thing as wave function collapse, by the way.
Isn't that a matter of interpretation?
 
  • #38
bapowell said:
Isn't that a matter of interpretation?
Only if you think making up dynamics counts as "interpretation".
 
  • #40
RUTA said:
As time went on you would see all the redshifts diminish, passing from redshifts to blueshifts.

Thanks for the answer RUTA.

(I’m getting more and more convinced that spacetime is nothing but a sheet of rubber... :smile:)
 
  • #41
Chalnoth said:
Why not? If you have the current configuration of our universe exactly, then in running the clock backward it will necessarily reach an identical state.

Chalnoth said:
Well, we'd be running back in time too, so we wouldn't see anything at all out of the ordinary :)

DevilsAvocado said:
Agreed! :smile:

): yranidro eht fo tuo lla ta gnihtyna ees t'ndluow ew os ,oot emit ni kcab gninnur eb d'ew ,lleW


Could I change my mind...? :rolleyes:

Thinking a little bit more about this, it (maybe) doesn’t work, because:
  • AFAICT it’s more or less impossible to refute BB and the expansion of the universe, due to the red-shift in the CMB.

  • This means that at some point in history, intelligent observers would have to go thru the horrific experience of living their lives backwards, when the arrow of time change direction. I will not get into the disgusting details in the everyday process of getting food thru the body... in the wrong direction... Please note that we are talking about observers that only 'yesterday' did this in normal manners. I don’t think a civilization could cope and survive this kind of madness.

  • It also means that at some point in history, our laws of nature have to change, e.g. the second law of thermodynamics. You could hardly call it an "exact copy" of the early universe, if you have different/reversed laws of nature...

  • Personally, I don’t think that the human brain could function in a world with a reversed arrow of time. We need to have memories of yesterday and plans and expectations for tomorrow. My guess is that this is 'hardwired' in the brain, and we stop being humans without this functionality. This video about Clive Wearing shows a man with just 30 sec memory:


    https://www.youtube.com/watch?v=wDNDRDJy-vo

  • And then of course you have the problem with a supercomputer, bigger than the universe, calculating "the universal wavefunction"... :smile:
 
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  • #42
netdragon said:
... Doesn't the "no cloning" theorem prevent that? Or is it allowed as long as the "exact copy" doesn't exist simultaneously as the original?

Edit: No, in both Copenhagen and revised Everett interpretations, ways around "no cloning" exist for this discussion as long as no exact copy is made but instead separate measurements are made on the same quantum wave function. Instead, quantum decoherence is the issue. QC is reversible but wave function collapse isn't. See later.

We are not talking about "copying" the universe, "just" a very hypothetical change of expansion to contraction. The "main problem" would then be; the arrow of time, the second law of thermodynamics, and the entropy of the universe, i.e. if you’re looking for an "exact copy", meaning exactly the same state and entropy that was at BB.
 
  • #43
Chalnoth said:
Only if you think making up dynamics counts as "interpretation".
Actually, after staring at this sentence for the past 2 hours, I have absolutely no idea what it means. But, seriously, only attempt a clarification if you intend to actually explain something, rather than giving another vague and sarcastic response that is manifestly unhelpful.
 
  • #44
DevilsAvocado said:
We are not talking about "copying" the universe, "just" a very hypothetical change of expansion to contraction. The "main problem" would then be; the arrow of time, the second law of thermodynamics, and the entropy of the universe, i.e. if you’re looking for an "exact copy", meaning exactly the same state and entropy that was at BB.
Actually, I think the main problem would be that so far, by all indications, dark energy is truly a cosmological constant. As our experimental accuracy increases further, it only looks more and more constant.
 
  • #45
Chalnoth said:
Actually, I think the main problem would be that so far, by all indications, dark energy is truly a cosmological constant. As our experimental accuracy increases further, it only looks more and more constant.

Absolutely agree. (and this put another very solid point on "my list" ;)
 

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