nerve-wracking talk

I spent a ride down to Baltimore preparing a talk for mathematicians. That's outside my comfort zone. I gave the talk with the MINDS institute at Johns Hopkins at lunchtime. It was about passive symmetries, active symmetries, classical physics, and machine learning. There was no math. They only asked me, in the end, a few questions I couldn't answer. I hypothesized that the differences between passive and active symmetries is that the latter are statements about interventions.