The Tuning Fork Mystery: an unexpected update

Here is the original tuning fork mystery video.
https://www.youtube.com/watch?v=NVUCf8mB1Wg

But some people could not get the frequency doubling to work. Now we think we have the start of an explanation.

More updates to follow as Hugh and I investigate it further!

Here those folks who are not sponsoring this video but did sponsor the previous one:
https://brilliant.org/standupmaths

CORRECTIONS
- None yet. Let me know if you spot anything!

Thanks to my Patreon supporters who enable me to spend a day doing a lot of maths by hand. Here is a random subset:

Elaine Hewitson
John Lewis
Andrew Mohlmann
Cameron Ball
Erwin Herrsche

Support my channel and I can make more videos:
https://www.patreon.com/standupmaths

Music by Howard Carter
Filming and editing by Trunkman Productions
Design by Simon Wright
MATT PARKER: Stand-up Mathematician
Website: http://standupmaths.com/
Maths book: http://makeanddo4D.com/
Nerdy maths toys: http://mathsgear.co.uk/

Видео The Tuning Fork Mystery: an unexpected update канала Stand-up Maths