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Cake day: February 28th, 2024

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  • I dug up the actual paper (Cook, 2004) and it turns out the bicycle was symmetrical… and, in fact, entirely virtual.

    The virtual bicycle used for simulation

    It’s a plot of a computer simulation, rather than records from a real-world physical experiment.

    A bicycle is composed of four rigid bodies: the two wheels, the frame, the front fork (the steering column). Each adjacent pair of parts is connected with a joint that allows rotation along a defined axis, and the wheels are connected to the ground by requiring that their lowest point must have zero height and no horizontal motion (no sliding).

    So the simulation has a lot of simplifications from reality, and the picture tells us more about the simulation model than it tells us about the real world. It is a pretty picture, though.

    Here’s the paper reference:

    Cook, M. 2004. It takes two neurons to ride a bicycle.

    (I couldn’t get it from the Cook’s Caltech site, but I found a copy elsewhere.)









  • shiny_idea@aussie.zoneto196@lemmy.worldSwiss Rule
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    4 months ago

    At a basic level… yes? I think all those words are important enough in English to be short words. They’re important in a way that “theatrical” and “equally” are not as important.

    And none of those words are as important in English as “a” or “I”.



  • shiny_idea@aussie.zonetoComicsDress (SMBC)
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    4 months ago

    Hmm. Your comment gave me something to think about. Now I’ve thought about it and done some research… I still think the comic is right, because it specifies a 4-holed sphere.

    Here’s my thinking:

    A sphere with two holes can be stretched into the shape of a drinking straw (or a donut, or a coffee cup). That same shape can be stretched into a disc with a single hole: one hole in the sphere becomes the outer boundary of the disc.

    Likewise, a disc with three holes has the same topology as a sphere with four holes. (Or a dress, or a T-shirt.)

    So yeah, you can say that a straw has one hole and a dress has three … but only when you’re counting holes in a disc.

    This page shows the sphere/disc thing visually, and uses clothes as examples:

    https://seattlemathmuseum.org/math-in-real-life/clothes-holes


  • shiny_idea@aussie.zonetoComicsDress (SMBC)
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    4 months ago

    Is it? Like the person in the comic, I count four… one for the head, one for the legs, and one for each arm. Am I missing something?

    (I don’t know if I’m not enough of a topologist to understand your joke … or too much of a topologist to understand your confusion.)