Linked Questions

0
votes
1answer
130 views

What is the proof of constant energy in the universe? [duplicate]

It might sound a bit naive but, How is it that conservation of energy is never broken, how is it that we know that always and for sure the energy in our universe is constant and we cannot create a ...
69
votes
6answers
19k views

Is the total energy of the universe zero?

In popular science books and articles, I keep running into the claim that the total energy of the Universe is zero, "because the positive energy of matter is cancelled out by the negative energy of ...
23
votes
5answers
7k views

Why do things cool down?

What I've heard from books and other materials is that heat is nothing but the sum of the movement of molecules. So, as you all know, one common myth breaker was "Unlike in movies, you don't get ...
13
votes
4answers
2k views

Does the fact that energy is not conserved in cosmology open the possibility of new matter/atoms being created in the universe?

Does it open the possibility of new baryonic matter/atoms being created in the universe and avoiding the Heat Death of the universe?
15
votes
5answers
3k views

Does the amount of gravitational potential energy in the universe increase as it expands?

It seems to me that extra gravitational potential energy is created as the universe expands and the distance between massive objects such as galaxy clusters increases; this implies that energy is not ...
12
votes
3answers
3k views

When they say that the universe cooled after the big bang, where did the heat go?

Layman here, Stumbling through some physics stack posts and started reading the Wikipedia for the chronology of the big bang. In it, it states The very earliest universe was so hot, or energetic, ...
1
vote
3answers
2k views

Experimental proof for Conservation of Total Energy

In physics, the law conservation of energy states that the total energy of an isolated system cannot change—it is said to be conserved over time. (Source : wikipedia(conservation of energy) And ...
3
votes
2answers
750 views

What is the total energy of the Universe? [duplicate]

The Law of Conservation of Energy states that: Energy can't be created nor can be destroyed. It only changes from one form to another. According to this the total energy in a closed system never ...
2
votes
1answer
1k views

Is the total enthalpy of the universe constant? [duplicate]

Is the total enthalpy of the universe constant? It would seem like the answer would have to be yes, since (1) enthalpy change represents the heat exchange between the system and the surroundings, and ...
0
votes
2answers
830 views

How can the total amount of energy in the universe be zero? [duplicate]

First of all, it is important to note that I'm not very savvy in neither general relativity nor any other area of expertise that answering this question may require. Therefore, I mean for the question ...
0
votes
2answers
826 views

When the Cosmic Microwave Background radiation cools, where does the energy go? [duplicate]

I understand how photons can change wavelength via gravitational redshifting, but that doesn't seem to be what's going on with the CMB radiation. I've heard it explained as happening because of the ...
2
votes
4answers
213 views

Where's all the light going in the universe?

According to my knowledge, matter can not go faster than light, and light is emitted constantly in the universe from many types of reactions. If this is so, then isn't light constantly getting past ...
1
vote
1answer
142 views

Time evolution of the universal wave function

Consider the energy conservation principle, than the total amount of energy in the universe is a fixed value $E$. Let us denote with $| \psi \rangle$ the wave function of the entire universe. Is it ...