Heat death

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wolram

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i have been thinking how our universe could continue if it suffers
heat death, i can think of one possibility , that is that a
bose einstein condensate could form, is that a possibility?
if it is then interactions between BECs could rekindle our universe
 

Chi Meson

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Sorry.

Heat is, specifically, the flow of thermal energy. Heat death does not mean that there is no more "temperature." It simply means that there is no more transfer of energy between objects.

A transfer of energy is required to cause any sort of change in a system; therefore, if no energy can be transfered, then no work can be done. THis includes breathing.

Unfortunately again, the actual temperature of most of the universe will be about 4 degrees above absolute zero (or was that 0.4?), still too warm for the BEC.

ANd yet again unfortunately, the only interaction that might occur (up to the minute theoreticians out there: please correct me if I am wrong) is that some matter will "fall" into other matter. Not much of an interaction to do much work and no where near the "rekindleing of Universe" magnitude. I picture this analogy: all the mountains of the earth have crumbled into sand and the earth is now an ultra smooth ball. NOthing can fall anymore because nothing is higher than anything else (This is "heat death"). All of a sudden, the Pauli Exclusion Principle is recinded for, say 50% of the matter of the earth; the earth collapses into a smaller sphere.

Whoop-de-do. Now its even harder for anything else to be done.
 

marcus

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Originally posted by Chi Meson
Sorry....
Whoop-de-do. Now its even harder for anything else to be done.
Do you suppose that the universe might be closed
Ω0 > 1, spatially nearly flat but finite?
And yet because of positive cosmological constant, slated to
expand endlessly barring unforeseen events?

Ned Wright has been considering this model recently---fitting it to the supernova data. It is not totally out of the question.

In that case all a highly-evolved species would need to do is manipulate Λ (!) and they might reverse expansion and bring about a big crunch. I am not saying that OUR species would ever do such an outrageous thing to nature, but I suppose that some species might----one that didnt like the increasingly cold lonely enfeebled prospect of endless expansion.
 

Eh

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How would it be possible for a species to change the negative pressure of the cosmological constant? There appears to be the idea (from supergravity and quintessence) that the force driving the acceleration could become positive and thus cause a contraction, but it doesn't seem to be something anything intelligent could cause.

In the event of a big crunch, all life is screwed at any rate. Heat death would just be a more appealing fate for those who are claustrophobic.
 

marcus

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Originally posted by Eh
In the event of a big crunch, all life is screwed at any rate. Heat death would just be a more appealing fate for those who are claustrophobic.
but if the crunch was followed by another expansion stage---a kind of replay---life might re-evolve and have a second chance

anyway it is all too speculative to be much good for discussion
and we have no indication (as far as I know) that there is any life except on earth

Eh, have you read ned wright's "News of the Universe" for August?

I would like to know what you think about his fitting supernova data to a "closed", or spatially finite, case.
There is a graph there that looks interesting.
Do you know what I am talking about? Try this link

http://www.astro.ucla.edu/~wright/sne_cosmology.html
 
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Eh

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I took a look, but the graph seemed to indicate omega is actually hovering between being open and closed. In other words, it's a close call. But given that no one can find out where this missing mass is, I think cosmologists tend to lean towards a value of 1.

Still, assuming a big crunch is going to happen, there would seem to be a few problems. I will assume that some quantum theory of gravity is valid and that a bounce could happen.(both string theory and LQG seem to allow it) The question of entropy comes up, with the universe containing less and less useful energy with each cycle. So given a long past of contractions/expansions, the universe should be quite disordered and not suited for life. But I'm not sure about the details of this, or if SST or LQG could offer a solution for that.
 
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Chi Meson

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Marcus said:
"In that case all a highly-evolved species would need to do is manipulate Ë (!) and they might reverse expansion and bring about a big crunch. "

I suppose we should practice by manipulating pi?

Heh heh. THat's a joke.
 

marcus

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Originally posted by Chi Meson

I suppose we should practice by manipulating pi?
I would not want MY species to be involved in anything as
underhanded as manipulating pi.

Species who manipulate pi---the curvature of space---are very likely to end up creating a supermassive black hole at the center of their galaxy and disappearing down it.

Originally posted by Chi Meson


Heh heh. THat's a joke.
Heh heh
 

r637h

Manipulate pi? Hell, it's trancendental anyway.

How can one fiddle
With a transcendental?

Impiety, if not downright Blasphemy. Euclid might curse you from his grave, not to mention several Egyptians.

Planck's quantum may just come to our rescue. Possibly, it provides just enough uncertainty to balance us onto a flat universe.

But alter a quantum to provide "steady state?" I think that's "more or less" up to Fate (one of the many facets of God).

Me, you ask? I'm still fiddling around with micro-cosmic stuff: Why an individual isotopic atom is provoked to decay. Pithy stuff.

Oh, you didn't ask? Beg Pardon.

Thanks, Rudy

PS: I think Marcus' view is near-brilliant or at the least, very bright; and I think Ned Wright may be on a very productive track.

And... heh heh, heh.
 
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LURCH

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Originally posted by Eh


Still, assuming a big crunch is going to happen, there would seem to be a few problems. I will assume that some quantum theory of gravity is valid and that a bounce could happen.(both string theory and LQG seem to allow it) The question of entropy comes up, with the universe containing less and less useful energy with each cycle. So given a long past of contractions/expansions, the universe should be quite disordered and not suited for life. But I'm not sure about the details of this, or if SST or LQG could offer a solution for that.

I have heard of the problem of entropy in oscilating-universe cosmology, but I don't think it applies. Entropy is the distribution of energy throughout the universe, and doesn't apply to loss of energy from the universe as a whole. Indeed, if energy were to leave the universe, it would be a violation of the principle of conservation. Experimental evidence supports this principle very well, showing that energy can't just cease to exist (which is what would be happening if it somehow left the cosmos).
 

jammieg

Given the universe grows with the sophistication of our instruments for observing it, it's unlikely this is the only one big bang universe to ever occured or in existence.
 

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