All Questions
Tagged with universe thermodynamics
70
questions
-2
votes
4
answers
98
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In a universe with no photons, will everything necessarily be at absolute zero temperature?
Imagine a universe governed by the same physical laws as ours, i.e., the same fundamental forces, with the only caveat that there are no photons, hence no electromagnetic radiation in this universe. ...
- 127
-1
votes
1
answer
138
views
Is there an upper limit to temperature in the universe?
The Sun's core temperature has been modelled to be $\approx 1.57 \times 10^7$ K
In supernovae:
"In lower mass cores the collapse is stopped and the newly formed neutron core has an initial ...
- 1,307
0
votes
1
answer
82
views
Spontaneous increase of vacuum energy?
If the vacuum energy of the universe is not at its minimum, that is, the universe is at a false/metastable vacuum state, then it could decay into the true vacuum state.
However, if our universe is ...
- 2,462
0
votes
1
answer
276
views
Is heat death absolutely and really inevitable? [duplicate]
As the second law of thermodynamics indicates, entropy would continue to grow in the universe until it reaches a maximal value (in an expanding universe with a cosmological constant, like ours) or ...
- 2,462
0
votes
0
answers
109
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Could entropy ever be reversed in the universe with infinite time?
In the far future there will be most likely a point where a maximal state of entropy will be reached in the universe where no more useful work could be done and no structures would form, reaching a ...
- 2,462
1
vote
1
answer
232
views
Could any new structures be formed after the heat death of the universe?
When the universe would reach a maximal state of entropy, heat death would presumably be reached and no structures would be left after the last black hole would evaporate.
However, is this really true?...
- 2,462
0
votes
1
answer
70
views
Is the universe getting hotter? Brighter?
Due to their fusion processes every star is radiating massive amounts of photons and (to a lesser extent) neutrinos. Are all of these getting absorbed in matter over time, warming it, or is the total ...
- 57
0
votes
0
answers
56
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Thermodynamical argument in cosmology
I'm interested in the following question: What could we say about the thermodynamical properties of the Universe, using thermodynamics alone (without using general relativity), assuming that the ...
- 7,592
0
votes
1
answer
53
views
What have been the biggest factors for the increase in entropy in the universe?
Entropy has been increasing since the Big Bang. But how? It seems relatively intuitive, but the universe is cooling down. Often when things cool down, entropy decreases. So why, in the case of the ...
- 1
1
vote
2
answers
262
views
Assuming that heat death or Big Freeze would be the final outcome for the universe, what would happen with energy?
According to Big Freeze, the universe will expand forever and it will reach a state of thermodynamical equilibrium. It is said that the temperature of the universe will reach an asymptotically ...
- 2,462
2
votes
1
answer
76
views
Reversal of the psychological arrow of time on the contraction of the universe [closed]
In Brief History of Time, it says that the people living in a contracting phase (although unsuitable for living or even existence itself, but lets assume) would remember the future but not the past. ...
- 472
-2
votes
1
answer
260
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IF heat was the absence of cold, how would that change physics [closed]
Back in high school, I had an argument with my physical science teacher. She said cold is the absence of heat. I asked why it couldn't be the other way around. She simply stated that was not possible. ...
0
votes
3
answers
175
views
What state of matter is the entire known universe?
What state of matter is the entire known universe? I know it contains all forms, but as it expands into the infinite nothingness, what state of matter does it act as? I know little about physics, but ...
4
votes
4
answers
267
views
Does an expanding universe cool down?
I want to know if and why the temperature of an expanding universe decreases with time.
Universe setup. My universe is modeled as the manifold $]0,\infty[\times\mathbb T^3$, where $$\mathbb T^3 = (\...
2
votes
1
answer
160
views
Can the universe be considered an isolated system?
Is it allowed to consider the physical universe as a thermodynamic isolated system obeying the general second law since the total entropy in a comoving volume does not decrease with time despite ...
- 928