Comment on Baldur's Gayte

iAvicenna@lemmy.world ⁨1⁩ ⁨month⁩ ago

• ytg@sopuli.xyz ⁨1⁩ ⁨month⁩ ago

  Wouldn’t a straw be the product of a circle and a line?

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  • iAvicenna@lemmy.world ⁨1⁩ ⁨month⁩ ago

    What you said is stronger than being homotopic. homotopic is weaker, for instance a line is homotopic to a point, By taking the straw (even if it has thickness) and just shrinking it along its longer axis you eventually arrive at a circle. If it has thickness you will arrive at a band and then you can also retract radially to arrive at a circle.

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• stevedice@sh.itjust.works ⁨1⁩ ⁨month⁩ ago

  I think people don’t know a torus is hollow.

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• Semjaza@lemmynsfw.com ⁨1⁩ ⁨month⁩ ago

  A CD is clearly homotopic to a torus, though…

  And the walls of a straw do have thickness…
  A straw goes:

  Gas - solid - gas - solid - gas

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  • iAvicenna@lemmy.world ⁨1⁩ ⁨month⁩ ago

    If solid torus yes, if just the regular torus (surface of the solid torus) no. CD is homotopic to a circle and so is a solid torus.

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