Energy and the end of the universe.

In summary: So there is still some uncertainty about this. In summary, the concept of a "heat death" or any sort of death to the universe is based on the assumption that free energy is the only kind that can do physical things. However, this assumption is no longer held to be true, as entropy can also cause physical change on a larger scale.
  • #1
mee
213
1
If energy can neither be created or destroyed, why is there supposedly a "heat death" or any sort of death to the universe.
 
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  • #2
Energy can be free or not. If it's free it can do things, if it's not the only thing it can do is make heat. If the heat is the same temperature everywhere, nothing physical can happen on the larger scale. Entropy is the conversion of free energy into heat energy. The energy is not destroyed but its ability to effect change is no more.

This is now seen as a statistical effect, of the more probable states succeeding the less probable ones. And there could always be a quantum fluctuation, so the heat death is not the ultimate last thing the nineteenth century physicists envisioned.
 
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  • #3
heat and energy

selfAdjoint said:
Energy can be free or not. If it's free it can do things, if it's not the only thing it can do is make heat. If the heat is the same temperature everywhere, nothing physical can happen on the larger scale. Entropy is the conversion of free energy into heat energy. The energy is not destroyed but its ability to effect change is no more.

This is now seen as a statistical effect, of the more probable states succeeding the less probable ones. And there could always be a quantum fluctuation, so the heat death is not the ultimate last thing the nineteenth century physicists envisioned.

I assume by non free energy you mean matter and by heat you mean fusion or like in the Earth's core perhaps. Does heat not mean like in the cores of stars? Would this heat not effect change like fusion? Will there perhaps be a universe which is full of higher elements with new types of structures we currently don't understand coming into being? Are you basically telling me that "heat death" of the universe is an outdated concept?
 
  • #4
No, by not free I mean energy confined to jiggling, with no temperature differential anywhere. Matter is unstable on the longest scale (protons eventually decay even in the standard model), so that eventually we are talking about a bath of photons at equilibrium.
 
  • #5
Thank you.

selfAdjoint said:
No, by not free I mean energy confined to jiggling, with no temperature differential anywhere. Matter is unstable on the longest scale (protons eventually decay even in the standard model), so that eventually we are talking about a bath of photons at equilibrium.

But we have never actually detected a proton decay right?
 

What is the concept of "energy" in relation to the end of the universe?

Energy is a fundamental property of the universe that is required for all physical processes. It can be defined as the ability to do work and is present in all forms of matter and radiation. In relation to the end of the universe, energy plays a crucial role in determining the fate of the universe.

What is the role of energy in the expansion of the universe?

Energy is responsible for the expansion of the universe. According to the theory of general relativity, the distribution of matter and energy in the universe determines the curvature of spacetime, which in turn affects the rate of expansion. In the early universe, when the energy density was very high, it caused the universe to expand rapidly. As the universe continues to expand, the energy density decreases and the rate of expansion slows down.

Will the universe eventually run out of energy?

According to current theories, the universe will not run out of energy. Energy can neither be created nor destroyed, it can only be converted from one form to another. As the universe continues to expand, the energy density will decrease, but it will never reach zero. However, the universe may eventually reach a state of maximum entropy, where all energy is evenly distributed and no work can be done.

What is the relationship between energy and the "heat death" of the universe?

The concept of "heat death" of the universe is based on the idea that as the universe expands and the energy density decreases, all matter and energy will eventually become evenly distributed and reach a state of maximum entropy. This means that there will be no energy available for any processes to occur, resulting in a state of equilibrium and no further changes in the universe.

How does the concept of dark energy play a role in the end of the universe?

Dark energy is a theoretical form of energy that is believed to be responsible for the current accelerated expansion of the universe. It is thought to make up about 68% of the total energy in the universe. As the universe continues to expand, dark energy will become more dominant and could potentially lead to a "big rip" scenario where the universe expands at an increasing rate, tearing apart all structures and ultimately resulting in the end of the universe.

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