ForumsWEPRSphere Eversion

18 3877
steevo15
offline
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
DDX
offline
DDX
3,562 posts
Nomad

Oh, I have read about them, They are quite weird in my opinion, even after a classmate of mine gave his Calc C project on one I still didn't quite understand it. All I know is that due to the infinitesimal +'s and -'s allow the sphere to be an object to be turned inside out! I think they also sell a coffee mug like that somewhere.

Snakebite
offline
Snakebite
996 posts
Nomad

This thread belongs in the Tavern because it has nothing to do with politics, religion or world events.

But, this was awesome and thanks for sharing!

steevo15
offline
steevo15
1,562 posts
Peasant

This thread belongs in the Tavern because it has nothing to do with politics, religion or world events.


Notice the "etc." tacked on to the end of the forum name. I put this in here figuring it is something requiring intellect, and the tavern is seemingly not really a place for intellectual things, so I put it here hoping it wouldn't get buried.

I still didn't quite understand it.


Yeah, the great thing about these videos is that it explains them in such a simple way to understand, if you haven't watched I'd definetly suggest it.
DDX
offline
DDX
3,562 posts
Nomad

This thread belongs in the Tavern because it has nothing to do with politics, religion or world events.


calm down dude, It is too complex to dump it in the tavern. They were thinking about tacking on &quothilosophy" to the forum too.
Green12324
offline
Green12324
4,097 posts
Peasant

Well, I'm not a very mathematical person so I don't really see the point of this. I mean why would we want to know how to turn a sphere inside out, when it can't even be done in reality?

But I guess that it was fairly interesting, probably learned a few new things.

Strop
offline
Strop
10,816 posts
Bard

Simple guess without looking at the solution: dimensional transformation?

Trust me, stuff like that which may seem to have no application ends up being strangely applicable to seemingly completely unrelated problems. Fermat's Last Theorem being the most famous example.

Of course, I'm not sure what kind of real-world application Fermat's Last Theorem has, hence the differences in the branches of mathematics called "real" and "applied", lol.

Xcalibur45
offline
Xcalibur45
1,830 posts
Farmer

Wow that was wierd.

DDX
offline
DDX
3,562 posts
Nomad

It's not technically dimensional transformation because you can accomplish this the current dimensions. I like to think of a soap bubble that is colored on the outside and unbreakable to the extent that there are no creases.

samdawghomie
offline
samdawghomie
3,550 posts
Peasant

Wow. After watching this I want to take a nap. But it is quite interesting how you can do that to a sphere but not a circle, with following the rules.

DDX
offline
DDX
3,562 posts
Nomad

well you have to remember that a circle is a 2-D and the sphere is 3-D.

Lain
offline
Lain
176 posts
Nomad

Physics is so interesting. I wish more people would post awesome stuff like this.

Snakebite
offline
Snakebite
996 posts
Nomad

calm down dude, It is too complex to dump it in the tavern. They were thinking about tacking on &quothilosophy" to the forum too.


I'm curious, how many times will I be called "Dude" before people start figuring out I'm a girl...

Back on topic, I posted that before I watched the second video. I can see now how this could be posted here. Also, I wasn't criticizing, I was just making a statement.
Zophia
offline
Zophia
9,434 posts
Scribe

I'm curious, how many times will I be called "Dude" before people start figuring out I'm a girl...
Until you hit the first gender-hatted rank? Honestly, I thought you were a guy too. Name doesn't reveal it at all~ If it's any comfort, I think it happens to every girl online that isn't blatantly feminine all over the place.

As for on topic!:

AWESOME! No srsly, wickedly cool awesomeness. Actually quite interesting with the number of curves and all that. Somehow I could imagine a flash game being based on such math...
Snakebite
offline
Snakebite
996 posts
Nomad

Somehow I could imagine a flash game being based on such math...


I agree. I'll talk to my friend in The Netherlands and see what he can do.
steevo15
offline
steevo15
1,562 posts
Peasant

Somehow I could imagine a flash game being based on such math...


I could somehow imagine it too...boy, that'd be awesome.

So have any of you been able to think of ways to turn the sphere inside out? The answer is rather complex, I doubt any of you will get it. But it would be interesting to hear your theories.
Showing 1-15 of 18