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What Is the Fourier Transform?

(www.quantamagazine.org)
474 points rbanffy | 1 comments | | HN request time: 0s | source
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stackbutterflow ◴[] No.45136199[source]
> Fourier argued that the distribution of heat through the rod could be written as a sum of simple waves.

How do you even begin to think of such things? Some people are wired differently.

replies(3): >>45136302 #>>45139983 #>>45144713 #
1. AIPedant ◴[] No.45139983[source]
It didn't come completely out of nowhere, Euler and Bernoulli had looked at trigonometric series for studying the elastic motion of a deformed beam or rod. In that case, physical intuition about adding together sine waves is much more obvious. https://en.wikipedia.org/wiki/Euler%E2%80%93Bernoulli_beam_t...

Other mathematicians before Fourier had used trigonometric series to study waves, and physicists already understood harmonic superposition on eg a vibrating string. I don't have the source but I believe Gauss even noted that trigonometric series were a solution to the heat equation. Fourier's contribution was discovering that almost any function, including the general solution to the heat equation, could be modelled this way, and he provided machinery that let mathematicians apply the idea to an enormous range of problems.