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DougMerritt12/08/20242 repliesview on HN

That's not an unreasonable question, however the larger point is that this sort of thing cannot be done perfectly accurately.

This was established mathematically, answering an old 1966 question from famous mathematician Mark Kac: "You can't hear the shape of a drum" -- there isn't a unique answer even when allowed to use arbitrary test sounds.

Wikipedia: https://en.wikipedia.org/wiki/Hearing_the_shape_of_a_drum

Article in American Scientist 1996 Jan-Feb: https://www2.math.upenn.edu/~kazdan/425S11/Drum-Gordon-Webb....


Replies

gyrovagueGeist12/08/2024

I love this paper, but something I think is often missed when it comes up is that you CAN hear the shape of many drums if you restrict the shape space, for example with a prior of "what a drum should look like" Zelditch proved spectral uniqueness for convex, fully connected, drums with some symmetry.

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scarmig12/08/2024

If you add multiple hearing points, you massively constrain the space of possible drums. The question then becomes something like "can you see the shape of a drum?"

Proof of concept: echolocation.

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