From: Anders Sandberg (asa@nada.kth.se)
Date: Sun Nov 30 1997 - 05:45:15 MST
Twink <neptune@mars.superlink.net> writes:
> At 11:24 AM 11/28/97 +0100, Anders Sandberg <asa@nada.kth.se> wrote:
> >I think it sounds reasonable. Divide the universe into two sides, and
> >use one as an entropy dump. If it gets too "hot", wait for a while
> >until it has expanded, and then fump more entropy into it. Of course,
> >I suppose this would run into the NIMBY (Not In My Back Yard) effect
> >on a cosmic scale.... :-)
>
> No. This is not what I meant, though this too is possible. The dissipative
> structure analogy still means that total order plus total entropy is a fixed
> sum. Eventually, too, the system would run down.
Hmm, as far as I know there is no conservation of order plus entropy;
order is simply the negative of entropy, and the sum must according to
the laws of thermodynamics always go in the entropy direction. But
regions can achieve as much order as they want if they have energy and
can pump away the entropy. So the main questions are if there is
enough energy in an open universe, and if there are enough entropy
sinks.
> To picture what I am talking about imagine a bunch of molecules in a
> box. Let's say that at first they are all in one part of the box. After a
> certain amount of time, ceterus paribus, they will be spread out -- in
> the sense one would be likely to find them anywhere within the box.
> This would be an equilibrium state -- or more, accurately, collection of
> states. Now imagine that the box can expand faster than the
> molecules move. The molecules will never be able to fill the whole
> box, in the sense of the first example. One will always be able to
> give a rough estimate of where they are.
>
> Now if the universe as a whole behaved like that...
Yes, that would be nice. Unfortunately this is the
ball-of-galaxies-expanding-from-a-center-somewhere-in-a-big-void-model,
and not compatible with what we know or believe. The universe seems to
be expanding more like a big balloon with galaxies on its surface,
being slowly blown up. That means we do not get any low-entropy
regions for free, even when the spacetime expands. A pity.
-- ----------------------------------------------------------------------- Anders Sandberg Towards Ascension! asa@nada.kth.se http://www.nada.kth.se/~asa/ GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y
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