
The Hidden Twist to Making a Möbius Strip - tokenadult
https://www.quantamagazine.org/20170209-mobius-strip-symplectic-geometry/
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colanderman
Speaking of cutting Möbius strips, I used to love making Möbius bagels [1].
Fair warning: your significant other will likely be unimpressed to discover
that a gnarled bagel is the "special surprise" you promised for breakfast.

[1]
[http://www.georgehart.com/bagel/bagel.html](http://www.georgehart.com/bagel/bagel.html)

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trjordan
I feel like I'm missing something. This feels like all set-up, with no reveal.

Is there more to the article, beyond the "Mobius Rip" section?

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yohoho22
It's seems to be meant as a supplement to the author's much longer piece "A
Fight to Fix Geometry’s Foundations"[1] that was published the same day.

That article links to this one in a sidebar.

1: [https://www.quantamagazine.org/20170209-the-fight-to-fix-
sym...](https://www.quantamagazine.org/20170209-the-fight-to-fix-symplectic-
geometry/)

~~~
acqq
That article is a very interesting read, thanks!

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baldfat
If anyone is talking about Mobius Strips then Cliff Stoll MUST be mentioned.
This guys passion for Mobius Strips is infectious.

[https://www.youtube.com/watch?v=AAsICMPwGPY](https://www.youtube.com/watch?v=AAsICMPwGPY)

Also he was one of the first system admins to actually catch a hacker who was
using his server in Germany in 1989.
[https://www.c-span.org/video/?10122-1/cuckoos-
egg](https://www.c-span.org/video/?10122-1/cuckoos-egg)

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yvgctdffffff
If you glue those two pieces back together you get a single unbroken loop, not
two circles. So, no, its not "easy to draw the circle segments so they don't
intersect" because the lines won't form two circles

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SomeStupidPoint
...That's the point?

You can't create a global situation where there are no intersections (and two
circles), because of the twist in the gluing process. But you can create the
appearance of it by constructing pieces in the deconstructed space, and not
properly analyzing the results when gluing.

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yvgctdffffff
Ah. So "it's easy to draw what appear to be the circle segments, but aren't".

You see when he said "the circle segments" I thought he meant "the circle
segments" instead of "straight lines that do not belong to the circles we were
discussing earlier".

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SomeStupidPoint
Well, perhaps this is reading too much in to the language, but you actually
draw the circle _segments_ without them crossing, but the gluing to
reconstruct the space doesn't permit the _segments_ to be glued back in to the
_circles_ they were decomposed from.

So you _can_ draw a decomposition of the shapes in the decomposed space which
apparently satisfies the properties, but you run in to trouble when you try to
glue those partial solutions back together -- in this case, you can't
simultaneously reconstruct the space _and_ the shapes.

