Martin Schwarzschild reminisces about Enrico Fermi and what it was like to work with him.

Schwarzschild:

And had agreed already, initially among themselves and then officially, to keep it secret. That meant that at the luncheons they couldn't talk about that work. And therefore, astrophysics came up rather more often than under normal conditions it would have been. So that in many ways, Fermi, particularly, was very ready to talk astrophysics. And a couple of times he helped me, just straight scientifically helped me, over key hurdles.

The impression that Fermi made on me was absolutely enormous, as a person. Scientifically that group was so phenomenal that it really didn't make any difference how phenomenal they were. The moment somebody is so much better than your own intelligence, it doesn't really make that much difference, isn't that right. But Fermi in addition was such an extraordinary person.

If you asked him a scientific question, he would put all his brain into transmitting what he understood into your brain — and making absolutely sure that you got it. He had a way of explaining something, and then looking at you and saying, "Have you understood it?" And then saying, "No!" And then automatically he'd work on you until you had it. Without any faking — I mean, there was no question that he knew that he was the brighter brain, and he would never flatter you, but he would just make it a job between you. So it was never embarrassing to ask Fermi a question. It became a common undertaking, to get into your head what he understood. It was unbelievably impressive.

He was a keen observer of people, and never could stay serious for more than half an hour at a time. It was a marvelous group, and he learned fast that I, by nature, am also towards the happy and gay side, that I didn't mind my leg being pulled. It became a really very enjoyable, but also very impressive, experience.