What has changed in 60 years, I wonder? If you are teaching this material, what do you have to update and/or contextualize?

This is a good question and my initial thought would be Atomic Physics and Cosmology.

A book like Modern Atomic Physics by Vasant Natarajan (2015) would be a good place to look - https://www.routledge.com/Modern-Atomic-Physics/Natarajan/p/...

The recent book (free) Atomic Physics for Everyone: An Introduction to Atomic Physics, Quantum Mechanics, and Precision Spectroscopy with No College-Level Prerequisites (2025) should also be good for an initial understanding of atomic physics - https://news.ycombinator.com/item?id=46961595

Also Wikipedia has a helpful Timeline of fundamental physics discoveries page to browse - https://en.wikipedia.org/wiki/Timeline_of_fundamental_physic...

Finally, asking Google something like "what is new in physics since feynman lectures", Gemini gave me a helpful summary in its "AI Overview" which you can also try out.

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