Thanks! I never knew there was so much math in sound diffusers. Just spent a few bewildering minutes reading about quadratic residues on wikipedia, and then quadratic residue diffusers. Just mind-blowing what folks can use math for.

I especially like this:

Originally an abstract mathematical concept from the branch of number theory known as modular arithmetic, quadratic residues are now used in applications ranging from acoustical engineering to cryptography and the factoring of large numbers.

A lot of research – science as well as math – works to understand some rather abstract concepts that have no apparent value. And then, 300 years later, it solves a problem. Maybe the solution is just how to best diffuse noise, or maybe the solution saves millions of lives.

Coincidentally, another project going on right now is sound damping in what we call the DaVinci room, a very cool room with a vaulted ceiling. The noise is bad - I taught two days of courses to high school kids in there and it was too much. I'd been pushing for us to just carpet the ceiling but my partners didn't agree. We're putting up sound-absorbing panels right now. I thought it would look bad, but now I think it will look great! Here's the start: