Physics Explained Ultraviolet Catastrophe: https://youtu.be/rCfPQLVzus4
This Veritassium Video goes back further in time and talks about Action, and the Genesis of this idea. https://youtu.be/qJZ1Ez28C-A
Chemistorian, The history of Atomic Theory. https://youtu.be/SqYPrA7upiE