# Where does energy go

1. Aug 26, 2008

### nottheone

A friend of mine thinks he is a physicist (he's not). He told me he thinks dark energy is nothing more than the regular energy of the universe being dissipated in space. Is that possible? Where DOES energy go? For every force there must be a reaction so it almost seems reasonable, energy has to go somewhere. Give me some ammo to tell him he is wrong.

2. Aug 26, 2008

### robertm

Since he is the one making the claim, the burden of proof falls not to you. Let him try and develop his theory; his inevitable failure will save you a lot of grief.

Also, suggest that he should learn the basic principles of physics before beginning to theorize on the fundamental nature of "Dark Energy".

3. Aug 26, 2008

### Coin

Energy is never created or destroyed, only converted into different forms (although one of the forms it can be converted into is matter).

If you're trying to figure out where energy "goes" once it is "used", it is converted into forms which are not reusable. The canonical answer for where the energy "goes" that I usually hear is that it becomes "heat". Probably a better answer is that the energy doesn't "go" anywhere, it is just continually converted from lower-entropy to higher-entropy forms ("higher-entropy" effectively meaning "less useful").

Dark Energy is, by definition, the expansion above and beyond what would be caused by the actual "regular energy of the universe being dissipated in space". If it were regular energy dissipated in space it wouldn't be Dark Energy, it would just be Energy. Right? You don't even have to explain what Dark Energy is to say that much, it's just the semantics of the thing.

If you can explain what dark energy is they'll probably give you a nobel prize.

4. Aug 27, 2008

### nottheone

Sorry to be thick but I am not clear on how your answers refute his theory or what basic principles you are talking about. First, it is only 'dark' energy because that's what we call it. Second, if energy goes to higher entropy forms why couldn't the highest entropy be that space absorbs the energy and expands.

Would it be reasonable to say that the universe's rate of energy conversion to higher entropy is getting faster? That would fit the theory that the expansion is accelerating and if it isn't that would refute him.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook