here's the first proof, that derives the pythagorean theorem from the impossibility of perpetual motion (and, implicitly, that the concept of torque is meaningful and behaves nicely wrt rotations). i cannot claim to really understand what is going on here pic.twitter.com/CuA0OdAiPq

— QC (@QiaochuYuan) October 9, 2020

Conceputally, I find that really easy to understand. How could it be any other way? That seems absurdly basic to me. But then again, I never have any problem with concepts.