• Captain Aggravated@sh.itjust.works
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    4 days ago

    “Such a thing is possible” It kind of isn’t though? It’s a sphere that can pass through itself but not be sharply creased…how are these rules not just made up?

    • Kogasa
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      4 days ago

      Specifically, the thing that exists is a regular homotopy of immersions from the standard embedding to its opposite. The “rules” aren’t supposed to be self evident, they’re part of a broader context in topology

          • someacnt_@lemmy.world
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            3 days ago

            Welp, my head cannot comprehend how that is possible. How is it deforming the shape around?

            Maybe I am confusing homotopy and isotopy again.

        • Kogasa
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          4 days ago

          Yeah, basic graduate level math is a lot more useful than whatever you do with your life to warrant such an attitude.