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<TITLE>RE: [extropy-chat] LIMBOIDS</TITLE>
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<P><FONT SIZE=2>Or as some people think, this is a conscious universe and even the non-living things have some</FONT>
<BR><FONT SIZE=2>consciousness in some way (waiting to be proved by scientific experiments if possible).</FONT>
</P>
<P><FONT SIZE=2>Thanks.</FONT>
<BR><FONT SIZE=2> </FONT>
<BR><FONT SIZE=2>Walter.</FONT>
<BR><FONT SIZE=2>---------</FONT>
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<BR>
<P><FONT SIZE=2>-----Original Message-----</FONT>
<BR><FONT SIZE=2>From: extropy-chat-bounces@lists.extropy.org [<A HREF="mailto:extropy-chat-bounces@lists.extropy.org">mailto:extropy-chat-bounces@lists.extropy.org</A>] On Behalf Of scerir</FONT>
<BR><FONT SIZE=2>Sent: Tuesday, November 02, 2004 4:26 AM</FONT>
<BR><FONT SIZE=2>To: ExI chat list</FONT>
<BR><FONT SIZE=2>Subject: Re: [extropy-chat] LIMBOIDS</FONT>
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<BR>
<P><FONT SIZE=2>> LIMBOIDS </FONT>
<BR><FONT SIZE=2>> What, if anything, separates life from nonlife?</FONT>
</P>
<P><FONT SIZE=2>[miscellanea]</FONT>
</P>
<P><FONT SIZE=2>At Caltech, Chris Adami is studying exactly that, imo.</FONT>
<BR><FONT SIZE=2><A HREF="http://dllab.caltech.edu/avida/" TARGET="_blank">http://dllab.caltech.edu/avida/</A></FONT>
<BR><FONT SIZE=2><A HREF="http://dllab.caltech.edu/research/" TARGET="_blank">http://dllab.caltech.edu/research/</A></FONT>
</P>
<P><FONT SIZE=2>"According to our approach living organisms </FONT>
<BR><FONT SIZE=2>and computer programs are beautiful structures </FONT>
<BR><FONT SIZE=2>and are pretty much the same thing." (?!)</FONT>
<BR><FONT SIZE=2><A HREF="http://physis.sourceforge.net/" TARGET="_blank">http://physis.sourceforge.net/</A> </FONT>
</P>
<P><FONT SIZE=2>John Baez wrote: 'Is life improbable?', </FONT>
<BR><FONT SIZE=2>in Found. Phys. 19 (1989), 91-95,</FONT>
<BR><FONT SIZE=2>and sometimes this paper appears here too</FONT>
<BR><FONT SIZE=2><A HREF="http://math.ucr.edu/home/baez/improbable.pdf" TARGET="_blank">http://math.ucr.edu/home/baez/improbable.pdf</A></FONT>
<BR><FONT SIZE=2>According to J.B. his paper explains the flaw </FONT>
<BR><FONT SIZE=2>in a famous proof by Wigner. What his [Wigner's] </FONT>
<BR><FONT SIZE=2>argument actually proves is something much </FONT>
<BR><FONT SIZE=2>weaker than what he wanted to prove. Roughly, </FONT>
<BR><FONT SIZE=2>he proves that if you first pick a specific </FONT>
<BR><FONT SIZE=2>design of a machine and then randomly choose </FONT>
<BR><FONT SIZE=2>the laws of physics, it's unlikely this machine </FONT>
<BR><FONT SIZE=2>will be able to reproduce itself in a specific </FONT>
<BR><FONT SIZE=2>amount of time. This should not be surprising: </FONT>
<BR><FONT SIZE=2>to design a machine that does a specified task, </FONT>
<BR><FONT SIZE=2>one usually needs to know a little about the laws </FONT>
<BR><FONT SIZE=2>of physics ahead of time. When I restated the problem </FONT>
<BR><FONT SIZE=2>- says J.B. - and redid Wigner's calculation,</FONT>
<BR><FONT SIZE=2>I got drastically different results.</FONT>
</P>
<P><FONT SIZE=2>See also: quant-ph/0303124</FONT>
<BR><FONT SIZE=2>'Quantum Mechanical Universal Constructor'</FONT>
<BR><FONT SIZE=2>by Arun K. Pati, and Samuel L. Braunstein</FONT>
<BR><FONT SIZE=2>" Arbitrary quantum states cannot be copied. </FONT>
<BR><FONT SIZE=2>In fact, to make a copy we must provide complete </FONT>
<BR><FONT SIZE=2>information about the system. However, can a quantum </FONT>
<BR><FONT SIZE=2>system self-replicate? This is not answered by the </FONT>
<BR><FONT SIZE=2>no-cloning theorem. In the classical context, Von Neumann </FONT>
<BR><FONT SIZE=2>showed that a 'universal constructor' can exist which </FONT>
<BR><FONT SIZE=2>can self-replicate an arbitrary system, provided that </FONT>
<BR><FONT SIZE=2>it had access to instructions for making copy of the </FONT>
<BR><FONT SIZE=2>system. We question the existence of a universal </FONT>
<BR><FONT SIZE=2>constructor that may allow for the self-replication</FONT>
<BR><FONT SIZE=2>of an arbitrary quantum system. We prove that there </FONT>
<BR><FONT SIZE=2>is no deterministic universal quantum constructor </FONT>
<BR><FONT SIZE=2>which can operate with finite resources.</FONT>
<BR><FONT SIZE=2>Further, we delineate conditions under which such </FONT>
<BR><FONT SIZE=2>a universal constructor can be designed to operate </FONT>
<BR><FONT SIZE=2>deterministically and probabilistically. "</FONT>
</P>
<P><FONT SIZE=2>For now, beautiful manmade boids are here</FONT>
<BR><FONT SIZE=2><A HREF="http://www.red3d.com/cwr/boids/" TARGET="_blank">http://www.red3d.com/cwr/boids/</A></FONT>
<BR><FONT SIZE=2>(no need of a universal quantum constructor!)</FONT>
</P>
<P><FONT SIZE=2> </FONT>
</P>
<BR>
<BR>
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