A connection between a classical puzzle about rational numbers and what makes music harmonious.
========== I have two seemingly unrelated challenges
for you. The first relates to music, and the second gives a foundational result in measure
theory, which is the formal underpinning for how mathematicians define integration and
probability. The second challenge, which I’ll get to about halfway through the video, has
to do with covering numbers with open sets, and is very counter-intuitive. Or at least,
when I first saw it I was confused for a while. Foremost, I’d like to explain what’s going
on, but I also plan to share a surprising connection it has with music.
Here’s the first challenge. I’m going to play a musical note with a given frequency,
let’s say 220 hertz, then I’m going to choose some number between 1 and 2, which
we’ll call r, and play a second musical note whose frequency is r times the frequency
of the first note, 220. For some val...