Veritasium
5 HN recommenders · recommended in 6 months, 2022–2024
26:33 · 11M views · Nov 3, 2022
Veritasium tells the story of the Fast Fourier Transform, from its use in detecting nuclear tests to Cold War politics, and how it could have changed the arms race. It includes a short, intuitive explanation of what the Fourier transform does.
HN points people to it as the explanation that finally made Fourier transforms and the FFT click, with a good historical story.
9 comments from Hacker News
That video did the same for me. I also like the reducible video for Fast Fourier Transforms as well as the Veratasium piece that shares some fun history. Reducible - FFTs the most ingenious algorithm ever [LINK] Veritasium - The Most Important Algorithm of All Time this video
The 2-minute brute-force explanation of Fourier transforms in a recent Veritasium video was my "aha!" moment. this video
If you have 26 minutes spare, Veritaserum's video [0] on the history of FTs and FFTs is quite good. Effectively, a Fourier Transform can turn a signal into its underlying frequencies using a neat property of maths. For a piece of music, say, you could produce a spectrogram [1] – Foobar2000 [2] has a nice one built in – to visualise the frequency of music with time. In general, this is all sorts of useful applications any time you have a signal – electronics, climate physics, astrophysics, detecting nuclear explosion testing underground, and so on. It's essential to modern medical imaging, and a whole bunch of differential equations can be solved a lot faster by using this. The FFT takes the naive O(N^2) algorithm and makes it O(n log n) by bunching together repeated calculations, so if you have a million samples, that's some 70,000 times faster. At the time of its discovery it was critical for Fourier analysis to actually be reasonable to do on a computer, taking days instead of years. [0] this video [1] [LINK] [2] [LINK]
Veritasium has an explainer of the Fast Fourier Transform on youtube. From how it's used and an interest history. this video
You might also like this recent Veritasium video on the link between the Nuclear test ban treaty and FFT. this video