Re:Sphere Eversion
by Causality1 on Saturday July 04, 2020 @04:46AM
(#23731044)
This is a topic I read about every few years and I always end up having to just trust that they're right because I can't follow the math and they're clearly using definitions for "crease" and "smooth" that don't match my own.
[ Parent
| on HN ]
I think the part that turns me off to it is "Look we can flip a sphere inside out" followed shortly after by "You can't do this in real life".
So what's the point then? Who cares?
The point is that it's a solution to a difficult mathematical problem, and a particularly interesting one since it has a different result with one less dimension and naively there's no reason to expect any different in 3D.
A lot of math is like this, in the sense that you can't set it up in the real world and prove it's true with physical objects, but it's still interesting and often practically useful. I guess the difference here is that it's close to being physically possible, causing frustration here among HN readers? But it's odd to see so much disparagement of the result. This is a famous result in topology, with good reason.