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[–] 3 points 1 year ago* (last edited 1 year ago) (6 children)

a torus is not homotopic to a straw though unless you take the straw and glue it at its ends. a straw is homotopic to a circle, a torus is homotopic to product of two circles, Baldur's gate is homotopic to a disk which is homotopic to a point unless we are talking about the game storage medium which used to be a CD which is also homotopic to a circle

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  • [–] 2 points 1 year ago (1 child)

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

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  • [–] 1 point 1 year 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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  • [–] 1 point 1 year ago (2 children)

    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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