Back when I was studying Physics at New Mexico Institute of Mining and Technology (they have since simplified the name), I took more than one class led by Albert Petschek. The school’s physics program was well-respected back then, in part because more than one McCarthy refugee found their way to the faculty.
Albert, it seemed to me, spent most of his time in his barren little office with the lights turned off, just thinking. Then he would publish a paper. That is obviously an oversimplification, but there is no denying that Albert was a really smart guy.
Early on I noticed that during his lectures, he would pause sometimes, maybe after describing the math of heat flux, and scan the class while holding an inscrutable face.
Then one time, perhaps in my junior year, he paused and I laughed. I was the only one, and Albert beamed at me. I had got his joke. This whole time the dude had been doing stand-up, but you needed to understand thermodynamics or quantum electrodynamics to get the joke.
Later I heard him say, “My brother is the smart one, but I am the witty one.” He said it with a smile, like that itself was a joke.
