ForumsWEPRSphere Eversion

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steevo15
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steevo15
1,562 posts
Peasant

So, my friend was showing me this really cool video involving spheres, and turning them inside out. I thought that I'd share it with the AG community.

This is a special kind of sphere, it is made out of a special kind of elastic material that can pass through itself. But if you puncture the material or if it folds or comes to a sharp bend, the whole sphere will disintegrate.

So basically, the question is, how would you turn a sphere like this inside out?

Here are the two youtube videos showing how you would turn the sphere inside out and the math behind it.

Sphere inside out part - 1

Sphere inside out - part 2

The rules of the "game" are in the first video, in the first minute or so. The solution starts at around 1:32. The rest is the math behind it.

The videos explain it in a very elementary way, but it is a very complex subject.

So my challenge to the AG community: watch the first 1 minute of the first video to understand "the rules", then try to turn the sphere inside out by yourself. Or, you can just watch all of both videos and be amazed by the craziness of geometry.

I wasn't quite sure where to put this thread, so move it if need be.

  • 18 Replies
TSL3_needed
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TSL3_needed
5,579 posts
Nomad

That's really interesting. Theoretical math is the only interesting math for me. Although they could've used real people and not computers.

Strop
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Strop
10,816 posts
Bard

Oh I see, I didn't listen to the rules, that intersections are allowed. That makes it possible to do in 3-D after all.

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