A fun question about handedness

Here’s a very quick question, which I actually got from OK Cupid, of all places: if you turn a left-handed glove inside-out, does it (a) stay a left-handed glove, (b) turn into a right-handed glove, or (c) become neither? Think about it, and stay tuned for an answer and discussion of such issues very soon.

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One Response to A fun question about handedness

  1. Interesting question! says:

    At first, I would say that a right-handed glove, when flipped inside-out, stays right handed, since you can continuously deform the glove from one to the other.

    But perhaps not! Suppose that you had latex gloves (or vinyl gloves for those LaTeX averse like me) – that way there are no intrinsic differences due to thumbs, for now. If you put one on each hand, and dye the palms one color and the backs another color, you could tell the two apart. But suppose the dye bled through the gloves, so that the inside were colored as well. You could turn the right-handed glove into the left-handed one by flipping it inside out!

    Since the orientation is not about shape, but what is inside or outside, we can stick our glove on top of a Cartesian space, with the tip of the third finger on the z-axis. At the tip, the normal vector to the surface of the glove points upwards (so it is positive) – we can define this as right. But if we flip it through itself past the xy-plane, the new outward direction points in the negative z-directions – so it is left-handed.

    But what about thumbs. Topologically, it feels like thumbs make no difference. And if you put a glove on the right hand, put your fingertips together, and you could have someone flip the glove over to the left hand. The thumbs would stay in the right position, I think – it would be kind of weird if the thumb sheath suddenly jumped to the back of the left hand.

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