The end of all?

[bob000555]

This may sound stupid but if a perpetual energy machine is imposable(due to the laws of thermodynamics) does that not mean that the universe will eventually run out of energy?

[Rocket Man]

the only difference i can see, is that there are no surroundings for the universe to lose energy to. however, it may lose energy to radiated heat into the empty blackness

 

this is my understanding and does not incorporate other phenomena like dark energy or vacuum energy

[sabbath]

Entropy I guess?

 

Isaac Asimov had a short story on this, forgot which. That the energy produced by stars (where we get our energy i.e. the sun) will eventually die out, even the stars that are man made (that's some future technology!) and that may be the "end of all" then. But if it is so, that would be billions and billions of years from now.

[apologia]

The universe will run out of available energy. The universe at one time will only consist of unavailable energy, making the system stop.

[bascule]

Isaac Asimov had a short story on this, forgot which.

 

The Last Question

[sabbath]

It is a curious fact that innumerable readers have asked me if I wrote this story. They seem never to remember the title of the story or (for sure) the author, except for the vague thought it might be me. But, of course, they never forget the story itself especially the ending. The idea seems to drown out everything -- and I'm satisfied that it should.

-Asimov

 

Couldn't be truer.

 

Thanks for the link bascule.

[Rocket Man]

The universe will run out of available energy. The universe at one time will only consist of unavailable energy, making the system stop.

 

if the system runs out of available energy, that means that there is no heat to produce IR radiataion ie the system reaches 0 kelvin and the matter might begin to disintegrate/form a bose condensate.

mass energy seems unavailable at the moment, but low temperatures might say otherwise.

merits research.

[Klaynos]

I recall reading in another thread there isn't really enough bosons in the universe to make bose-condensates a seriouse issue...

 

A couple points I'd like to add is one idea is that the universe will just end up as a big empty equally distrobuted mass patter. There are other threads abut this around....

 

the only difference i can see, is that there are no surroundings for the universe to lose energy to. however, it may lose energy to radiated heat into the empty blackness

 

The first part is right, the energy does not change, but the avaliable energy does. The second part is rubbish, I'm afraid, there is nothing outside the universe, no blackness, it doesn't exist. Anything the radiation moves into is part of the universe...

[bob000555]

So if the energy cant leave the universe we will never run out of it, unless it turns into mass via the reverse of e=mc2?

[SkepticLance]

Since the universe, no matter how big it gets from expansion, will always be finite, and since energy cannot be destroyed, there will always be some energy. However, the energy density will inevitably drop till it is too low to support life, of any kind.

 

There was an article in Scientific American about this a few years back. The authors concluded that it would take about a trillion years to get to this point.

[H2SO4]

well if the universe is expanding, but slowing down, then that means that the whole things gonna come back together and probaly create anpther big bang so it probaly wont stay cold forever. If this is indeed what happens, i wonder how many times this has happened. It hurts my head

[SkepticLance]

Actually, H2SO4, the fact that the universe's expansion is accelerating makes contraction unlikely. Still, who the hell knows for sure.

[bascule]

Since the universe, no matter how big it gets from expansion, will always be finite

 

We don't know if the universe is finite or not. I'd like to think it is, but it certainly isn't scientific knowledge...

[SkepticLance]

bascule.

Whether the universe is finite depends on your definition of 'the universe'. If current ideas are correct (Big Bang followed by expansion) then the universe is indeed finite.

 

On the other hand, some physicists accept the possibility that our piece of reality may be just one of many in a 'multiverse'. if so, then we are in speculation-land about finite vs infinite.

[Klaynos]

It's always possible that it could expand and the expansion eventually slows and it could just reach an equilibrium position...

[lethalfang]

This really is quite simple as far as classical thermodynamics is concerned. According to the laws of thermodynamics, anything (including the universe) will one day reach equilibrium. Anything at equilbrium will have a statistically uniform (random) distribution of all matter and all energy. Nothing interesting will occur in equilbrium, and anything at equilbrium cannot do work of any kind.

The system at equilbrium still has internal energy. The product of entropy and temperature is a form of energy, but it cannot do work of any sort.

[macrocosmos]

If you subscribe to bang theory it is possible to run out of energy, this is why that particular theory is so flawed, however if you look at this universe as a small area of infinite space that is currently in a state of expansion with a singularity at the heart of each galaxy eventualy gravity will cause each singularity to combine as one singularity which will produce sufficient gravity to cause this universe to collapse back in on itself and you will achieve a state in which time which is motion dependant will have stopped and matter and energy are seperated, matter as a singular mass and energy as a unified force surrounding the mass, unfortunately to fully understand this you have to understand the function of space.

[bob000555]

But if the universe is expanding and mass can be changed to energy via E=MC2 then there will be energy, unless it is radiated faster then it can be made from mass. Is this right?

[lethalfang]

But if the universe is expanding and mass can be changed to energy via E=MC2 then there will be energy, unless it is radiated faster then it can be made from mass. Is this right?

 

According to current understanding, matter can only convert to energy when matter meets anti-matter.

There isn't enough anti-matter around to conver all matter to energy.

Even there is, matter will eventually run out as well.

[olifhar]

Entropy I guess?

 

Isaac Asimov had a short story on this' date=' forgot which. That the energy produced by stars (where we get our energy i.e. the sun) will eventually die out, even the stars that are man made (that's some future technology!) and that may be the "end of all" then. But if it is so, that would be billions and billions of years from now.[/quote']

 

That would be kind of interesting. Too bad that even if I were still around by then (or *almost* then, considering my brain and sensory apparatus is still functioning) that nothing would be observable, except for heat radiation...

 

Addendum: @macrocosmos-- I just remembered that our good friend Professor Hawking has something on the beginning and end of time, and touches upon the possible recollapse of the universe, what you are talking about.

[bob000555]

According to current understanding' date=' matter can only convert to energy when matter meets anti-matter.

There isn't enough anti-matter around to conver all matter to energy.

Even there is, matter will eventually run out as well.[/quote']

No, E=MC2 mens that one unit of mass is converted to energy at the rate of mass(m) times the speed of light squared(C2). This is how nuclear bombs have such grate amounts of energy.

[lethalfang]

No, E=MC2 mens that one unit of mass is converted to energy at the rate of mass(m) times the speed of light squared(C2). This is how nuclear bombs have such grate amounts of energy.

 

Anti-matter of subatomic particles are created in nuclear fission and nuclear fusion, and that's how mass is lost in nuclear explosion.

The total quantum number in the universe is conserved according to our understanding, thus, to convert the matter into energy, one must have equal amount of anti-matter.

[Klaynos]

Binding energy in nucleuses, is derived from the mass change and E=mc², IIRC this is the important aspect in nuclear energy... hence it's name...

 

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

 

Graph of the nucleus binding energies:

http://en.wikipedia.org/wiki/Image:AvgBindingEnergyPerNucleon.jpg