On Tue, Aug 04, 2009 at 03:51:38PM -0600, Nicholas Thompson wrote:
> This is why I like to ask questions of PEOPLE: because when you get
> conflicting answers, you have somewhere to go to try and resolve the
> conflict.  
> 
> So I have three different definitions of a manifold: 
> 
> 1. A patchwork made of many patches
> 
> 2. The structure of a manifold is encoded by a collection of charts that
> form an atlas. 
> 
> 3. a "function" that violates the usual function rule that there can be
> only y value for each x value.  (or do I have that backwards).
> 
> I can map 1 or 2 on to one another, but not three.  i think 3. is the most
> like meaning that Holt has in mind because I think he thinks of
> consciousness as analogous to a mathematical formula that generates outputs
> (responses) from inputs(environments).  
> 

1 & 2 were different ways of saying the same thing - one does need a
definition of patch or chart, though. I think (although I could be
mistaken), each chart (or patch) must be a diffeomorphism (aka smooth
map), although it may be sufficient for them to be continuous. The
reason I say that, is that I don't believe one could consider the
Cantor set to be a manifold.

Most of my experience of manifolds have been smooth manifolds (every
point is surrounded by neighbourhood with a diffeomorphic
chart/patch), with the occasional nod to piecewise smooth manifolds
(has corners). The surface of a sphere is a smooth manifold. The
surface of a cube is not, but it is piecewise smooth.

No 3 above was just a way of saying that graphs of suitably smooth functions are
manifolds, but not all manifolds are graphs of functions.

> Thanks, everybody. 
> 
> Nick 
> 
> Nicholas S. Thompson
> Emeritus Professor of Psychology and Ethology, 
> Clark University (nthomp...@clarku.edu)
> http://home.earthlink.net/~nickthompson/naturaldesigns/
> 
> 
> 
> 
> > [Original Message]
> > From: Jochen Fromm <jfr...@t-online.de>
> > To: The Friday Morning Applied Complexity Coffee Group <friam@redfish.com>
> > Date: 8/4/2009 6:31:57 PM
> > Subject: Re: [FRIAM] "manifold" in mathematics
> >
> > A manifold can be described as a 
> > complex patchwork made of many patches.
> > If we try to describe self-consciousness 
> > as a manifold then we get
> >
> > - the patch of a strange loop 
> > associated with insight in confusion
> > (according to Douglas Hofstadter)
> >
> > - the patch of an imaginary 
> > "center of narrative gravity" 
> > (according to Daniel Dennett)
> >
> > - the patch of the theater of consciousness 
> > which represents the audience itself
> > (according to Bernard J. Baars)
> >
> > have I missed an important patch ?
> >
> > -J.
> >
> > ============================================================
> > FRIAM Applied Complexity Group listserv
> > Meets Fridays 9a-11:30 at cafe at St. John's College
> > lectures, archives, unsubscribe, maps at http://www.friam.org
> 
> 
> 
> ============================================================
> FRIAM Applied Complexity Group listserv
> Meets Fridays 9a-11:30 at cafe at St. John's College
> lectures, archives, unsubscribe, maps at http://www.friam.org

-- 

----------------------------------------------------------------------------
Prof Russell Standish                  Phone 0425 253119 (mobile)
Mathematics                              
UNSW SYDNEY 2052                         hpco...@hpcoders.com.au
Australia                                http://www.hpcoders.com.au
----------------------------------------------------------------------------

============================================================
FRIAM Applied Complexity Group listserv
Meets Fridays 9a-11:30 at cafe at St. John's College
lectures, archives, unsubscribe, maps at http://www.friam.org

Reply via email to