←back to thread

What Is the Fourier Transform?

(www.quantamagazine.org)
474 points rbanffy | 1 comments | 04 Sep 25 22:11 UTC | HN request time: 0s | source
Show context
Salgat ◴[04 Sep 25 22:35 UTC] No.45133006[source]▶
Always blew my mind that every signal can be recreated simply by adding different sine waves together.
replies(5): >>45133032 #>>45133064 #>>45133091 #>>45133402 #>>45133641 #
esafak ◴[04 Sep 25 22:42 UTC] No.45133064[source]▶
Only if it is band-limited.
replies(3): >>45133146 #>>45133266 #>>45133418 #
1. ajross ◴[04 Sep 25 22:51 UTC] No.45133146[source]▶
No, even functions with non-finite frequency representation. You just need a non-finite number of sines. Nyquist speaks only to a finite number of samples.