From: <complex-science@necsi.org> (Sungchul Ji)
Sender: <y3list1@necsi.org> (Yaneer Bar-Yam)
To: complex-science
Date: Mon, 18 Aug 2008 01:32:40 -0400
Message-ID: <redirect-22676592@necsi.org>
In-Reply-To: <list-22520613@necsi.org>
References: <list-22520613@necsi.org>
Subject: Re: Isolated Universe? [was Re: How to avoid mis-interpreting ...]
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Tony,

Thanks for your thought-provoking comments.
Can it be that there are many universes, depending on how one defines
them?  For example, the universe defined on the basis of the Big Bang
theory, and the one defined based on the first law of thermodynamics
(i.e., the universe wherein the statement, "The energy and matter of the
Universe remains constant", holds).  For convenience, we may refer to the
former as the Big Bang universe (BBU) and the latter as the first-law
universe (FLU).  If the boundary of BBU is either undefinable or porous
(due to the Heisenberg uncertainty principle?), we can still have FLU if
BBU happens to contain FLU, i.e., BBU > FLU.

I would not be surprised at all if such a possibility has already been
discussed among cosmologists, logicians, and/or philosophers?

Sung


> On 06/08/2008, at 2:02 PM, (Sungchul Ji) wrote:
>
>> *The Universe by definition doesn't even have any boundary and hence
>> cannot exchange any matter or energy with it.
>
> I'm starting to see that reflexive acceptance of the assumption that
> such a definition is in any way related to the world we find ourselves
> in might be contributing significantly to lack of progress in
> understanding the bigger picture.
>
> At any moment, our cosmos can be seen as bound by various event
> horizons: the Big Bang at the Hubble radius and many black holes
> within. Those event horizons are all very porous, but each in one
> direction, the CMB flux entering from (near) the Big Bang horizon and
> anything that strays too close exiting through the black hole horizons.
>
> In 'Three Roads to Quantum Gravity', Lee Smolin argues that we can't
> know anything beyond these event horizons, then goes on to propose an
> evolutionary scenario connecting the two (a scenario I have some
> sympathy for but which I still doubt is yet sufficient to give us a
> full explanation for conservative physics by natural means). But the
> inference relevant here from Smolin's first point is that we should
> not use fact of the Big Bang to jump to a conclusion that even the
> complete "Universe" (for want of a better word) produced by the Big
> Bang is even bound, let alone Closed or Isolated in the sense Sung
> uses for clearly confined systems.
>
> I don't want to take this any further for now. It is just that I have
> developed an allergy to the reflexive assumption that local truths can
> be safely applied to global considerations. There is not even a way to
> get evidence as to whether they can or cannot.
>
>
>
>
> Tony Smith
> Complex Systems Researcher
> Meme Media
> Melbourne, Australia
> http://www.meme.com.au/
>
>