Three of Hans Bethe's friends and colleagues relate fond memories

Hans Bethe was a collective mentor to Cornell's Department of Physics. Among his friends and colleagues in the department were David Mermin, the Horace White Professor of Physics; Saul Teukolsky, the Hans A. Bethe Professor of Physics and Astrophysics, and chair of the department; and Kurt Gottfried, professor of physics, emeritus, whose third-floor Newman Lab office was for many years just down the hall from Bethe's. Here they recount anecdotes about the humanity and humor for which Bethe is warmly remembered.

Hans Bethe rides a bike through the underground tunnel of the Cornell Electron Storage Ring, accompanied by Boyce McDaniel, then director of the Wilson Synchrotron. Cornell University photo by Sol Goldberg

A little over two years ago I received a phone call from Rose Bethe asking if I would be willing to interview Hans on the early history of solid state physics and his role in its development, with the resulting videotape to be shown at the March 2003 meeting of the American Physical Society. My field of physics for much of my career has been in solid state theory. Hans, though, said goodbye to the field in 1933, lured into nuclear physics by the discovery of the neutron.

Because Bethe and I worked in different fields, I had few direct scientific interactions with him during my 40 years at Cornell. Until he retired, 30 years ago, there were wonderful annual meetings of all the theorists in his office to decide who was teaching what courses for the coming academic year, which he presided over with great tact and efficiency, making everybody feel good about whatever they ended up with, whether or not they had thought that was what they wanted to be doing. And for decades, well into his retirement, he gave the first weekly physics colloquium of each new academic year, annually renewing our sense of his power, depth and scope, well on into his 90s. Twice he attended colloquia that I gave, asking a pertinent question after the first, and pronouncing a benediction after the second that I still treasure: "You must have had a lot of fun doing that."

I hadn't seen Hans for several years when I appeared at the Bethes' house for a planning session, and was delighted to find him, at 96, still surrounded by books and papers. We had a wonderful conversation about physics and about the growing perils an outspoken young physicist faced in Germany in the early 1930s.

What amazed me during the interview itself was the clarity and precision of Hans' memory of the scientific issues he was dealing with 75 years earlier, in a field of physics he had ceased to work in 70 years ago. Not only was he on top of his own contributions, but he was fully conversant with developments in the three quarters of a century since he had left the field. I -- like, I suspect, most ordinary and even quite good physicists -- have trouble remembering what I was up to 10 years ago, and completely lose track of a field when I move to a different area.

At the end of the videotape I thank Hans for the conversation, and he replies, "It was fun." Fun was important to him. In 1931 he managed, to the subsequent fury of the editor, to get into a reputable physics journal a paper that was pure parody. After he retired in the 1970s, the lecture rooms on the seventh floor of Clark Hall were renamed in his honor, and a beautiful bust of Hans was installed opposite the elevators. One year at the physics department holiday party, a video was shown. The elevator door opened. Hans, playing himself, stepped out, looked furtively around, verified that nobody was there, stepped quickly to the bust, removed a feather duster from behind his back and gave it a thorough going over. Then he rushed back to the elevator and disappeared. Some people might get quite worked up about discovering how the stars burn, but to Hans Bethe, it was mainly a lot of fun.

-- David Mermin

Hans Bethe was already an icon when I arrived at Cornell as a young assistant professor in 1974. He officially retired the following year, but continued working in his office down the hall as if nothing had changed. Every few weeks the tranquility of our floor would be interrupted by the invasion of a TV crew to interview him about important issues of the day. The combination of being one of the scientific leaders of the Manhattan Project and projecting an air of reasoned confidence carried great weight.

Around 1982 a colleague and I wrote a textbook on astrophysics. We sent a draft of each of the 20 chapters to 20 colleagues who had agreed to review them for us. Nineteen responded either briefly or not at all. Hans had agreed to review the chapter on nuclear astrophysics. He had us make a two-hour appointment in his office. He then proceeded to take us, line by line, through the corrections. "On line 3 of paragraph 2, you used a value of 200 for the nuclear compressibility. Didn't you see the new value that came out a few months ago in the Physical Review?" It was a wonderful experience for us.

Just two weeks before he died, I visited him. Although he was very frail, he wanted to talk science. We discussed the recently discovered double pulsar system, which may lead to new tests of general relativity theory and give insights into the properties of neutron stars. Hans' almost childlike delight in the prospect of our learning something new in this way was infectious. It reminded me that despite all the honors and awards he had received, physics still gave him the greatest joy. I came away from my visit inspired, as so many others have before me.

-- Saul Teukolsky

I collaborated a lot with Hans Bethe on arms control and related matters, especially in the 1980s, and was with him on many occasions in Washington. At that time, graduate students in our department organized a large teach-in in Bailey Hall at which Bethe was the lead speaker. A press conference was held for Hans before it started in the Newman Lab seminar room. The organizers (and I) were rather embarrassed when only three reporters appeared, one from the Cornell Daily Sun, one from the Cornell radio station and one from a local paper (not The Ithaca Journal). After waiting for some time, the conference began, and Hans, without a murmur, launched into his prepared remarks with the same gravity and thoroughness as if it was the National Press Club.

I also recall him recounting, on returning from Washington, where he had testified on nuclear arms control, that he had refused to have his appearance rescheduled for later in the hearing because he had a dinner appointment with a former student.

He was not in any sense a prima donna, despite all his astounding accomplishments, but he was aware of his powers. In his first public address opposing the anti-missile system, he told the audience, "I know you're opposed to the ABM system, and I'm going to tell you why." And in a talk at Victor Weisskopf's 80th birthday, he said, "When I was young, I was rather arrogant -- but I've learned how to hide it."

He loved the mountains, and was famous for having amazing endurance. Even in 1983, at the age of 77, I remember him descending from a high pass as much younger friends were climbing up, and at age 89, he used his walking stick like an ice axe on a narrow exposed trail on a Teton pass hike.

-- Kurt Gottfried