Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: chimera on 28/05/2005 11:05:41

Title: Expanding space and energy
Post by: chimera on 28/05/2005 11:05:41
Question: does the expansion of space mean that the original amount of energy available (I take it it's a fixed amount) is distributed over an increasing amount of space, and therefore there is less and less, or does this somehow remains the same. Cannot find anything on it, strangely.
Title: Re: Expanding space and energy
Post by: DoctorBeaver on 28/05/2005 16:52:58
If you take a given quantity of energy & distribute it over a larger volume, the amount of energy doesn't alter, it just becomes more diluted (if that's the right word)
Think of it thus - Orange cordial. Take 50cc and add water. It doesn't matter how much water you add there will always be 50cc of orange juice. All that happens is that the mixture becomes less concentrated.
Title: Re: Expanding space and energy
Post by: chimera on 28/05/2005 20:13:00
I was not speaking in absolute terms, but in relative terms. Would it become less and less while space expands, per given volume.

The living are the dead on holiday.  -- Maurice de Maeterlinck (1862-1949)
Title: Re: Expanding space and energy
Post by: DoctorBeaver on 28/05/2005 20:36:50
yes. There... could I be any more succinct? heh
Title: Re: Expanding space and energy
Post by: chimera on 28/05/2005 21:02:02
And I take it there is no new energy being created, by this vacuum expansion for instance? Or new particles popping out of the woodwork at times? They are matter c.q. energetic quanta, aren't they? Or is that not 'new' energy, but a redistribution or some other mechanism I cannot fathom at this point in time?

The living are the dead on holiday.  -- Maurice de Maeterlinck (1862-1949)
Title: Re: Expanding space and energy
Post by: DoctorBeaver on 28/05/2005 22:21:09
Virtual particles are being created but they annihalate each other. There is also some leakage from black holes in the form of Hawking radiation & various interactions between particles but I don't think it's enough to compensate for expansion & keep the overall density at a constant level