a MUCH better photo of the icosahedron

[Jonathan Post]

As whether the cosmos is Dodecahedral:

<a href="http://physicsweb.org/articles/world/18/9/3">A cosmic hall of
mirrors
Feature: September 2005

PhysicsWeb
Most astronomers think that the universe is infinite, but recent
measurements suggest that it could be finite and relatively small. Indeed,
as Jean-Pierre Luminet describes, we could be living in an exotic universe
shaped rather like a football</a>
"... Topologists have proved that in addition to the ordinary, simply
connected Euclidean, spherical and hyperbolic spaces, there are 17 other
Euclidean spaces and an infinite number of spherical and hyperbolic spaces -
all of which are multiply connected...."

On 12/16/06, Ralf Stephan <ralf at ark.in-berlin.de> wrote:
>
> Brendan McKay:
> > Now here is an interesting trivium: Even though Persian and Arabic
> > are written right to left, numbers are written left to right.
> > You are all about to jump up and tell me that the order of writing a
> > decimal positional system is arbitrary, so what I call left to right
> > might as well be called right to left starting at the high-order
> > digit. However, that is not correct and I reassert that numbers are
> > written left to right.  Can anyone guess what my proof is?
>
> The fact that our number system is derived from Arabic,
> and we use it left-to-right?
>
> (Not a hard proof but a good reason.)
>
>
> ralf
>
>
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