From: dmd1@lehigh.edu (DON DAVIS)
Subject: responses re points on sphere
Date: Mon, 07 Aug 2000 08:25:19 EDT
Newsgroups: [missing]
To: Distribution.List@lehigh.edu (toplist)
Summary: [missing]

From: Dave Rusin <rusin@math.niu.edu>
Date: Sun, 6 Aug 2000 14:10:00 -0500 (CDT)
Subject: Re:  question from physicist

The question about distributing points evenly on spheres shows up
regularly on discussion groups like USENET's sci.math, so I wrote
up a FAQ to address this and a few related questions. You can direct
people to this page:  index/spheres.html

Of course there is no "even" way to distribute  N  points in general.
I don't even think it's true that there is a unique equilibrium
configuration of points moving under electrostatic repulsion.
Tables have been computed showing configurations of various numbers
of points.

dave
__________________________________________________
Date: Sun, 06 Aug 2000 19:34:24 -0400
From: Dan Christensen <jdc@jhu.edu>
Subject: Re: question from physicist

> It starts with a physical problem:  What is the minimum-energy
> configuration of n>1 identical particles of equal charge, constrained to
> move on the surface of a sphere?

This question is often asked in computer graphics newsgroups.  One FAQ
for this topic can be found by following the first link on

  index/spheres.html

which has other useful information.  The potential energy measure of
dispersion is called D3 there, and isn't treated in any detail, since
there is in general no simple answer to this question.  For even more
information, search on google for "points sphere":

  http://www.google.com/search?q=points+sphere+

For example, the page

  http://www.swin.edu.au/astronomy/pbourke/geometry/spherepoints/

(the first that comes up) gives C code for an approximate algorithm.

Dan