using this to learn about convolution and FFT in general
Cooley and Tukey's paper
3blue1brown's video
Reducible's Video Part1
Reducible's Video Part2
https://fse.studenttheses.ub.rug.nl/25184/1/bCS_2021_GhidirimschiN.pdf.pdf
https://www.algorithm-archive.org/contents/cooley_tukey/cooley_tukey.html