I dont know anything about these things. No shame. Question that popped into my head:

Energy is aways converted, always lost from whatever is using it. There is no system that can put out more energy than can come in, right? So every star in the universe is burning fuel. Does that mean that eventually, be it trillions of years from now, all that energy will just run out? I know the universe is constantly expanding, but wont there eventually be not enough juice to keep it expanding? What happens then? This is probably a stupid question and I'm missing a big piece here. I know technically no energy is lost, it just goes somewhere. I dunno... Also, how does that expansion happen? Matter can't be created, so is it really just spreading out indefinitely until gravity kicks in lumping it back together?

Im not that great when it comes to physics and the laws of thermodynamics. But it is true that energy cannot be created or destroyed. Also, energy must be conserved. So all perpetual motion devices are not functional. Also, all the energy in the universe will go away, in at least one theory of the end of the universe. I believe its called Heat Death or the Big Freeze...Im not sure which

http://www.exitmundi.nl/eternity.htm

From one of my all time favorite sites.

http://www.exitmundi.nl/exitmundi.htm for all of them.

wow reading that just blew me away

energy cannot be created or destroyed

Incorrect.

Energy is aways converted, always lost from whatever is using it. There is no system that can put out more energy than can come in, right?

I'm no expert on this, but. . . if you're talking about perpetual motion, like for a motor or something, you could probably do that with magnetism. It wouldn't put out more energy than you put in, but it could convert the unlimited magnetic energy into a physical process that in effect creates a perpetual motor. If you make a circular magnetic field and put something like a top in the center of the vortex, as long as the source of the vortex is not solidly mounted, if it was put on springs for example, then the top should just keep on spinning.
But again, I'm no expert. . .

So every star in the universe is burning fuel. Does that mean that eventually, be it trillions of years from now, all that energy will just run out?
http://www.enchantedlearning.com/subjects/astronomy/stars/lifecycle/stardeath.shtml
"Stars expand as they grow old. As their core runs out of hydrogen and then helium, the core contacts and the outer layers expand, cool, and become less bright. This is a red giant or a red super giant (depending on the initial mass of the star). It will eventually collapse and explode. A star's life span and eventual fate are determined by the original mass of the star."


I know the universe is constantly expanding, but wont there eventually be not enough juice to keep it expanding?
The general idea of the mainstream cosmology mixed with Chinese mysticism will probably aid in understanding this.

In the beginning Yin (contraction) and Yang (expansion) were in perfect balance until Yang overpowered Yin creating what we call the universe in an instant, imediatly after, Yin slammed on the breaks. But since the expansion already had the momentum, no matter how hard contraction contracted it would continue to expand. Over time the breaks wear down, slowly at first, as it grows on the information before it the expansion expands faster and faster and faster and faster until all atoms are ripped apart. Or something like that, that is the general idea of the mainstream cosmological explanation.

The general idea of the mainstream cosmology mixed with Chinese mysticism will probably aid in understanding this.

In the beginning Yin (contraction) and Yang (expansion) were in perfect balance until Yang overpowered Yin creating what we call the universe in an instant, imediatly after, Yin slammed on the breaks. But since the expansion already had the momentum, no matter how hard contraction contracted it would continue to expand. Over time the breaks wear down, slowly at first, as it grows on the information before it the expansion expands faster and faster and faster and faster until all atoms are ripped apart. Or something like that, that is the general idea of the mainstream cosmological explanation.

It's nice to see that while your head is still deep in there, it is slowly coming out of your ass.

Energy and mass will reach equilibrium.... right?

Zay: http://en.wikipedia.org/wiki/Heat_death_of_the_universe



I'm no expert on this, but. . . if you're talking about perpetual motion, like for a motor or something, you could probably do that with magnetism. It wouldn't put out more energy than you put in, but it could convert the unlimited magnetic energy into a physical process that in effect creates a perpetual motor. If you make a circular magnetic field and put something like a top in the center of the vortex, as long as the source of the vortex is not solidly mounted, if it was put on springs for example, then the top should just keep on spinning.
But again, I'm no expert. . .


Nope. Magnets lose their charge over time, especially when interacting with other magnets.

Theoretically, perpetual motion is possible, but you wont be able to draw energy from it like a generator. These theoretic involve perfectly frictionless bearings or what have you. So far, the only thing like this that we have would be superconductors. They have zero resistance, so if you were to make an energized loop, you could have the electrons flowing for eternity, providing that it is kept cold enough to superconduct.

A big crunch just seems to make more sense to me then heat death. Damn Hawking radiation. It's only a theory remember

Incorrect.

Incorrect.

Incorrect.

Correct

Energy cannot be created or destroyed.
In short, the law of conservation of energy states that energy can not be created or destroyed, it can only be changed from one form to another or transferred from one body to another, but the total amount of energy remains constant (the same).

http://en.wikipedia.org/wiki/Conservation_of_energy


EDIT: Although energy can be created from matter, then you have to remember that matter itself is energy, in fact everything is energy. Except when there's nothing there, not even an empty space. Am I right here?

Incorrect.

No, U!!!! That's science 101 I'm afraid. Look up the law of thermodynamics, my friend.

No, U!!!! That's science 101 I'm afraid. Look up the law of thermodynamics, my friend.

Don't forget to look up Conservation of Energy

Don't forget to look up Conservation of Energy

That, too, But the law of thermodynamics gets the point across.

Energy can be created from matter, as has been said, but I guess the counterargument to that is that matter is energy - that's beyond my realm of knowledge so I can't comment.

Here's something fun - the first law of thermodynamics that is usually used to disprove perpetual motion, can't actually be proven, it's just an assumption we make from observation, we put a lot of faith in it because we are yet to disprove it.

So basically, the basis of the first law is 'we have yet to see perpetual motion', and the argument many people use against perpetual motion machines is 'first law of thermodynamics', so in effect we are saying 'there cannot be perpetual motion because we have yet to see perpetual motion'. Pretty crappy logic, eh?

Personally I think the first law is correct and perpetual motion is BS, but I still think it's fun to throw that at people.

Energy can be created from matter, as has been said, but I guess the counterargument to that is that matter is energy - that's beyond my realm of knowledge so I can't comment.

I already said that.

I already said that.

I know, I was reiterating since people didn't seem to catch it the first time.

Energy can be created from matter, as has been said, but I guess the counterargument to that is that matter is energy - that's beyond my realm of knowledge so I can't comment.

Ye'see? It's ok, you can have credit for being the first to figure it out.

that matter is energy - that's beyond my realm of knowledge so I can't comment.

E=mc² is the ridiculously famous equation for mass-energy equivalence. E = energy, m = mass, c = celeritas, (the speed of light in a vacuum).

E=mc² is the ridiculously famous equation for mass-energy equivalence. E = energy, m = mass, c = celeritas, (the speed of light in a vacuum).

I know, but my point is, are you converting mass to energy, or are you releasing the energy that is already there?

I don't know the answer to that question.

I know, I was reiterating since people didn't seem to catch it the first time.



Ye'see? It's ok, you can have credit for being the first to figure it out.

Yay :3

So, could a perpetual motion machine potentially exist in space?

Would they be able to create a perpetual motion machine that orbits the earth and uses the earth's gravitational pull to generate power?

So, could a perpetual motion machine potentially exist in space?

Would they be able to create a perpetual motion machine that orbits the earth and uses the earth's gravitational pull to generate power?

1) you would think so, but no*

2) No you couldn't

*If you could define a 'machine' as a bar of metal freely spinning around in space and doing nothing at all, then you would think it would keep going perpetually... but space isn't a perfect vacuum, so even then there is damping :(

Law of thermodynamics is as ironclad as a chastity belt. It is a fact. I always thought that the universe would eventually become heat, as suns produce tonnes of it, not to mention it has the lowest entropy level.

A big crunch just seems to make more sense to me then heat death. Damn Hawking radiation. It's only a theory remember

well shit gravity is only a theory too, looks like I am flying to work from now on!