Momentum in a non-isolated system

[Royston]

I've been thinking a lot recently about the creation of energy through gravitational collapse. Is it possible for energy to be created if momentum increases in a non-isolated system where the conservation law (1st law of thermal dynamics) is not applicable.

 

A simple scenario would be someone rolling down a hill...no energy is actually being used (so is conserved) but distance is covered (due to gravity taking hold). If the system doesn't follow the first law (non-isolated) is it possible for energy to be created ?

 

I've vaguely covered this idea when considering dark energy in another thread, but I was wondering if there was anything substantial that could back this up...a simple no will suffice, then I can move on and reject the premise.

[swansont]

If a system didn't follow the first law of thermodynamics, then energy would not be conserved, by definition. The problem is that you shouldn't be able to find a system that violates the first law.

[Royston]

If a system didn't follow the first law of thermodynamics, then energy would not be conserved, by definition. The problem is that you shouldn't be able to find a system that violates the first law.

 

This is what I don't understand about the Guth inflation period (so stepping away from classical mechanics) it seems more logical that energy creation happens in the collapsing period, before space-time begins to inflate again. I wasn't sure a black hole could be considered a truly isolated system ?

[Royston]

Maybe I should put it another way, why are the current cosmological models based on isolated sytems if the universe is expanding at an accelerated rate. I realise this has nothing to do with classical mechanics now.

 

Could it be possible that something like the Higgs field or maybe dark energy is non-isolated, and creates an asymmetric model where if 2 systems would normally achieve a thermal equilibrium with each other, this possibility would mean a creation of energy and volume. It just makes no sense to me that the big bang can acquire the energy to start if there isn't something happening before the inflation process for it to expand and increase in volume ? This is why there must be something happening when gravity takes over...maybe.

 

Apologies if this seems like a daft question, but I'm actually loosing sleep over it...and everything I've read so far seems to contradict isolated to non-isolated et.c