Science/physics question,,,,

[maxmaximus]

That's pure supposition.

 

---------- Post added 25-12-2012 at 09:35 ----------

 

 

I haven't seen that particular theory, but I'm not sure what your point is, galaxies aren't popping out of nothing if they are still being created, star birth certainly still happens, in massive regions of hydrogen (and a bit of dust) where a pertubation causes an imbalance in density, which gradually collapses into a star.

I don't think anything can pop out of nothing, I don't even think nothing is possible, it is believed though that vacuum fluctuation can create matter.

[Cyclone]

I don't think anything can pop out of nothing, I don't even think nothing is possible, it is believed though that vacuum fluctuation can create matter.

 

But basically only when the pair of particles that form, do so across the event horizon of a black hole (that's what Hawking radiation is).

 

And what that really creates is a matter, anti-matter pair, one of which is trapped.

If matter and anti-matter are created equally, then overall nothing has been created or lost.

 

I'm still not sure what point you're trying to make though.

 

The best supported hypothesis at the moment is still heat death, not big crunch, although the margin of error is large enough that it could still be the big crunch in reality.

[maxmaximus]

But basically only when the pair of particles that form, do so across the event horizon of a black hole (that's what Hawking radiation is).

 

And what that really creates is a matter, anti-matter pair, one of which is trapped.

If matter and anti-matter are created equally, then overall nothing has been created or lost.

 

 

I already said that in post 16, and if it’s the matter as opposed to the antimatter that is push away from the black hole we now have some new matter that could eventually form new stars.

 

I'm still not sure what point you're trying to make though.

 

The best supported hypothesis at the moment is still heat death, not big crunch, although the margin of error is large enough that it could still be the big crunch in reality.

 

Or it could be both, take our sun, for now it exerts enough force to counter gravity but at some point it is expected that its outward force will be greater than gravity so it will expand, but this expansion will use much of its energy and gravity will once again be dominant and the sun along with the rest of our solar system will have a big crunch. At this point the energy and mass isn’t lost it's compressed into a small size and may one day be part of a new solar system.

 

Alternatively the sun will just explode and create a gaseous clown that will be subject the same gradational forces that created solar systems and galaxies.

[Norbert]

Alternatively the sun will just explode and create a gaseous clown that will be subject the same gradational forces that created solar systems and galaxies.

 

Oh my god,

[Obelix]

I already said that in post 16, and if it’s the matter as opposed to the antimatter that is push away from the black hole we now have some new matter that could eventually form new stars.

 

You don't have new matter - if you did that violates the first Law.

 

Hawking radiation is a means by which black holes can lose mass and radiate that mass as energy. You create a particle and antiparticle -one falls into the hole and the other escapes. That would create a net energy imbalance, however the problem is resolved as the black hole is close enough to allow quantum tunelling and that means that the energy increase is balanced by a decrease in the mass of the black hole.

[PeteMorris]

You don't have new matter - if you did that violates the first Law.

 

Hawking radiation is a means by which black holes can lose mass and radiate that mass as energy. You create a particle and antiparticle -one falls into the hole and the other escapes. That would create a net energy imbalance, however the problem is resolved as the black hole is close enough to allow quantum tunelling and that means that the energy increase is balanced by a decrease in the mass of the black hole.

 

Is this something to do with perpetual motion? :hihi:

 

Ok I'm off to hide now!...Sorry!...

[maxmaximus]

You don't have new matter - if you did that violates the first Law.

 

Hawking radiation is a means by which black holes can lose mass and radiate that mass as energy. You create a particle and antiparticle -one falls into the hole and the other escapes. That would create a net energy imbalance, however the problem is resolved as the black hole is close enough to allow quantum tunelling and that means that the energy increase is balanced by a decrease in the mass of the black hole.

 

In a zero-energy universe the total amount of energy is zero and quantum vacuum fluctuation causes expansion which would generates matter as a side-effect, and the new matter is cancelled out by negative energy in the form of gravity, so it doesn't violate uncertainty principle, nor the first law of thermodynamics.

[Cyclone]

I already said that in post 16, and if it’s the matter as opposed to the antimatter that is push away from the black hole we now have some new matter that could eventually form new stars.

 

 

 

Or it could be both, take our sun, for now it exerts enough force to counter gravity but at some point it is expected that its outward force will be greater than gravity so it will expand, but this expansion will use much of its energy and gravity will once again be dominant and the sun along with the rest of our solar system will have a big crunch. At this point the energy and mass isn’t lost it's compressed into a small size and may one day be part of a new solar system.

 

Alternatively the sun will just explode and create a gaseous clown that will be subject the same gradational forces that created solar systems and galaxies.

 

We aren't talking about the small cycles within the universe, I'm sure a lot of the material from failed/exploded/burned out stars is used again (although not for fusion obviously as the final part of the fusion cycle is to form iron and that can't be fused to release any more energy).

Overall though, the current best prediction is heat death, with nothing afterwards, ultimate entropy.

[maxmaximus]

We aren't talking about the small cycles within the universe, I'm sure a lot of the material from failed/exploded/burned out stars is used again (although not for fusion obviously as the final part of the fusion cycle is to form iron and that can't be fused to release any more energy).

Overall though, the current best prediction is heat death, with nothing afterwards, ultimate entropy.

 

Doesn’t quantum mechanics state that if a reaction is possible then the opposite reaction is also possible?

 

---------- Post added 26-12-2012 at 15:31 ----------

 

In short, if the unverse is expanding as we are led to beleive, then surely at some point it will gain, or have gained enough mass to reverse the expansion and have enough gravity to suck it all back in..

 

Maybe that theory is flawed, i dont know.

 

But if that is correct, then at what point would the retraction, reversal of expansion stop, or would it just continue and eat up everything?

 

Maybe that process would happen, and once it had reversed so far it would then start expanding again, then be pulled back etc for infinity?

 

I'm guessing though that it could never expand once it had been pulled back in, as the mass pulling it back would be infinitely increasing....

 

My head hurts just thinking of this stuff!

 

Scientists say anti matter exists, they claim quantum fluctuation give rise to virtual particle-antiparticle pairs, they believe dark matter must exist but have no idea what it is, supposing when these particle-antiparticle pairs pop into existence they don’t annihilate each other, but instead repel each other with all the matter collecting together to form galaxies and all the anti matter collecting together to fill the void, this would give rise to expansion as the antimatter filled void is pushing away from the matter filled galaxies.

[Cyclone]

I don't think quantum mechanics does state that. But the opposite is true, if you put enough energy into Iron you can unfuse it (I don't think there's a technical word for the process, or I don't know it) and push it back up the fusion chain.

But no matter what, it cannot release any more energy by undergoing fusion, it's at the bottom of the chain, the most fused, stable (lowest energy) atom that exists.

Thinking about it, it must undergo further fusion (otherwise there would be no heavier atoms around at all), but this is a process that absorbs energy within a star, not releases it.

 

Anti matter doesn't repel matter... That's why to study it we have to capture it using magnetism.