If you have any questions, please ask. I love yapping.

yapLet's say we have some periodic function f. The goal is to represent it as a bunch of sine waves. This is called a Fourier series (FS).

The FS coefficients are given by

            ⌠2⋅π
         1  ⎮         -i⋅k⋅x
f̂(k) =  ─── ⎮   f(x)⋅e       dx
        2⋅π ⌡0

for whole numbers k. We can then approximate the original function with

  n
 ___
 ╲          -i⋅k⋅x
 ╱    f̂(k)⋅e
 ‾‾‾
k = -n             

and make the approximation better by making n larger.

For non-periodic functions, we can still get an approximation! The Fourier Transform (FT) uses a continuous range of frequencies instead of whole numbers, and the sum is replaced by an integral (the inverse FT).

FT's are used everywhere, for example in signal processing and spectroscopy. If a recording contains an annoying high-pitched noise, we can apply the FT and filter the unwanted frequencies. Spectroscopy separates light into its different wavelengths. By comparing the resulting spectral lines with known measurements, we can determine which elements and molecules are present in stars and planets, for example.

idk what more to add ._.


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[–] 5 points 4 days ago (1 child)

Climate change is a brutal doom. Probably the worst thing you can doom about tbh. I mean, the realistic end of the world, how could you not. The more you know the worse it is.

Tragically there are so many negative things for me to focus on, big picture and personal life :catgirl-flop: maybe I'll get better at the skill. It'd be nice.

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  • [–] 6 points 4 days ago (1 child)

    exactly, the more you learn, the worse you feel, and it has exactly 0 impact on the course of events so i just sorta wallowed in the helplessness. brutal doom indeed.

    focusing on negative things in your personal life can be good and helpful; analysis can help find solutions. but after a certain point or with things outside of our immediate control, i felt an interminable cycle of depressy. you got this Eggnog, one step at a time!

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