Most people will probably remember the times tables from primary school quizzes. There might be patterns in some of them (the simple doubling of the 2 times table) but others you just learnt by rote. And it was never quite clear just why it was necessary to know what 7 x 9 is off the top of your head.
This is the Fourier Transform. You can thank it for providing the music you stream every day, squeezing down the images you see on the Internet into tiny little JPG files, and even powering your noise-canceling headphones. Here’s how it works.
Everyone who has played poker or even Go Fish knows the basics of shuffling cards. There’s the riffle shuffle (combining two halves of a decks and making a bridge), overhand shuffling (quickly splicing cards from the deck back into the deck) and regular ol’ mixing all the cards up on a table. Which way is the best?