Get 30% off ANY KiwiCo crate: https://kiwico.com/stevemould30

Penrose Unilluminable Room is a room with mirrored walls that can't be fully illuminated by a single point source of light. I thought I was the first person to build one but Action Lab beat me to it: https://youtu.be/inMihNPjevM

Here's Nils Berglund's channel: https://www.youtube.com/c/NilsBerglund

Alex Bellos's elliptical billiard table can be found here: https://youtu.be/4KHCuXN2F3I

You can buy my books here:
https://stevemould.com/books

You can support me on Patreon here:
https://www.patreon.com/stevemould

just like these amazing people:

Frank Hereford
Will Ackerly
Brendan Williams
Cameron Leigh Middleton
Matthew Cocke
Frederic Merizen
Jeremy Cole
Alan Wilderland
Joel Van der loo
Glenn Watson
Doug Peterson
Paul Warelis
John Zelinka
Alnitak
Grant Hay
Heather Liu
Marshall Fitzpatrik
Lukas Biewalk
JJ Masson
Ben McIntosh
Damien Szerszinski

Twitter: http://twitter.com/moulds
Instagram: https://www.instagram.com/stevemouldscience/
Facebook: https://www.facebook.com/stevemouldscience/
Buy nerdy maths things: http://mathsgear.co.uk