Hans Bethe was a giant in the field of nuclear physics. He rubbed shoulders with Einstein, Bohr, and Pauli, was head of the Theoretical Division of the US atomic bomb project, and was awarded a Nobel Prize. In 1999, at the age of 93, Bethe gave a series of three lectures to the residents of his retirement community near Cornell University, where he had taught since 1935. Video of the lectures is available on the Cornell website.

In the first lecture, Bethe covers the development of the “old quantum theory”, covering the work of Max Planck and Niels Bohr. In the second and third lectures, he relates how modern quantum mechanics was developed, with a healthy amount of personal recollection along the way:

Professor Bethe offers personal anecdotes about many of the famous names commonly associated with quantum physics, including Bohr, Heisenberg, Born, Pauli, de Broglie, Schrödinger, and Dirac.

Without a doubt, this is the most high-power presentation ever made at a retirement home. (via @stevenstrogatz)