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Topic: Arthur C. Clarke's "The Wall of Darkness" - what's the point?
Replies: 10   Last Post: Apr 2, 2013 3:31 PM

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 Robert Clark Posts: 68 Registered: 12/13/04
Re: Arthur C. Clarke's "The Wall of Darkness" - what's the point?
Posted: Apr 2, 2013 1:01 PM

On Apr 1, 3:02 pm, 1treePetrifiedForestLane <Space...@hotmail.com>
wrote:
> what is the difference between a M-strip and a K-bottle?

Here's a good description:

Klein bottle.
"In mathematics, the Klein bottle (pron.: /?kla?n/) is an example of a
non-orientable surface; informally, it is a surface (a two-dimensional
manifold) in which notions of left and right cannot be consistently
defined. Other related non-orientable objects include the Möbius strip
and the real projective plane. Whereas a Möbius strip is a surface
with boundary, a Klein bottle has no boundary (for comparison, a
sphere is an orientable surface with no boundary)."
http://en.wikipedia.org/wiki/Klein_bottle

Möbius strip.
http://en.wikipedia.org/wiki/M%C3%B6bius_strip

Another distinction is that the Möbius strip can be fully realized
in 3-dimensional space while the Klein bottle can not. The image
usually shown for the Klein bottle is just the projection of it into 3-
dimensional space.
It's like how the common picture of the tesseract is just the
projection of this 4-dimensional cube into 3-dimensional space:

http://en.wikipedia.org/wiki/Tesseract

Bob Clark

Date Subject Author
3/30/13 Robert Clark
3/30/13 HOPEINCHRIST
3/31/13 Brian Q. Hutchings
3/31/13 HOPEINCHRIST
4/1/13 Guest
4/1/13 Brian Q. Hutchings
4/2/13 Bill Taylor
4/2/13 Robert Clark
4/2/13 Brian Q. Hutchings