From: (Stanley Salthe) Sender: (Yaneer Bar-Yam) To: complex-science Date: Mon, 18 Aug 2008 01:32:40 -0400 Message-ID: X-Original-Return-Path: Received: from outbound2.mail.tds.net ([216.170.230.92] verified) by necsi.org (CommuniGate Pro SMTP 4.0.6) with ESMTP id 22521333 for complex-science@necsi.org; Thu, 07 Aug 2008 08:56:26 -0400 Received: from outaamta01.mail.tds.net (outaamta01.mail.tds.net [216.170.230.31]) by outbound2.mail.tds.net (8.13.6/8.13.4) with ESMTP id m77CuOCw004076 for ; Thu, 7 Aug 2008 07:56:25 -0500 Received: from [192.168.0.2] (really [69.21.86.140]) by outaamta01.mail.tds.net with ESMTP id <20080807125622.PWLM12265.outaamta01.mail.tds.net@[192.168.0.2]> for ; Thu, 7 Aug 2008 07:56:22 -0500 Mime-Version: 1.0 X-Original-Message-Id: In-Reply-To: References: X-Original-Date: Thu, 7 Aug 2008 08:56:17 -0400 X-Original-To: Subject: Re: Isolated Universe? [was Re: How to avoid mis-interpreting ...] Content-Type: multipart/alternative; boundary="============_-994008714==_ma============" --============_-994008714==_ma============ Content-Type: text/plain; charset="us-ascii" ; format="flowed" Commenting upon Tony's posting -- >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. S: As one works philosophically upon the 'Big Picture', I'm not sure what "lack of progress" there is. How can we assess such lack of progress? > >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. S: This refers to observer imitations rather than to universe boundaries. > >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. S: It would be difficult to understand the fact of the Second Law of thermodynamics if the universe were NOT thermodynamically isolated and far from equilibrium (a consequence of universal expansion). > >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. S: Basing one's thinking materially upon local truths rather than idealistically upon mathematical models is an optional choice. Why is one better than the other? STAN > > > > >Tony Smith > >Complex Systems Researcher > >Meme Media > >Melbourne, Australia > >http://www.meme.com.au/ --============_-994008714==_ma============ Content-Type: text/html; charset="us-ascii" Re: Isolated Universe? [was Re: How to avoid mis-interpret
Commenting upon Tony's posting --


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.

      S: As one works philosophically upon the 'Big Picture', I'm not sure what "lack of progress" there is.  How can we assess such lack of progress?


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.

       S: This refers to observer imitations rather than to universe boundaries.

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.

       S:  It would be difficult to understand the fact of the Second Law of thermodynamics if the universe were NOT thermodynamically isolated and far from equilibrium (a consequence of universal expansion).


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.

      S: Basing one's thinking materially upon local truths rather than idealistically upon mathematical models is an optional choice.  Why is one  better than the other?

STAN





Tony Smith
Complex Systems Researcher
Meme Media
Melbourne, Australia
http://www.meme.com.au/

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