Planck's Quantum Action (seq3 Common Sense Quantum Physics)

[eruse]

Nevermind - I misinterpreted your phrase as stating that action was at the origin of quantum mechanics. You are correct - action is the origin of QM.

Forgive me!

[ArjenDijksman]

Never mind. I should put better audio on this vid;-) And you're right, the concept action predates quantum mechanics. I think even it was Maupertuis that described it first as mvr.

[eruse]

To clarify:

[E=T-V] ; Energy = Kinetic - Potential

[S=∫(E)dt] ; Action = Integrate E with respect to time.

Euler/Lagrange suggested the principle of least action where variance δS is 0 to suggest objects take the shortest path.

Introducing "h", Planck showed that measurements of the energy of any system could not be done to arbitrary precision due to the "grainy" nature of the action.

This was the transition between Classical to Quantum, beginning with blackbody radiation.

Good vids btw!

[eruse]

Dear Arjen,

A quick correction if I may:

At 4:00, you said (if I heard correctly),

"So the concept 'action', is at the origin of quantum mechanics."

The origin of action predates Planck. Euler and Lagrange had already forwarded the idea of action as S=∫(E)dt where E=T-V. What Planck introduced, however, was the idea of a quantum of action (quantum meaning "how much" representing the smallest magnitude of a quantity.) (running out of characters, so I shall post another)