His semipopular books on physics are uniquely interesting and successful in presenting his philosophy and the human side of the story. He was always and still is immensely concerned with the problems of man and world affairs. As a person he is affable and kind, gets along with everybody, and he loves to tell stories, and sometimes our exchanges of Jewish jokes can last an hour.
During his tenure at CERN where he still visits every summer and consults, the Weisskopfs built a modest summer house on the French side of the border in a small Jura village overlooking the Lake of Geneva. It is twenty minutes' drive from CERN and they spend most of the summer there. On our own European trips of the last several years we have almost always included a brief stay with the Weisskopfs in their house in Vesancy. This village is just a few kilometers away from another one known as Ferney-Voltaire because Voltaire lived there for many years. In like manner I have dubbed Vesancy, Vesancy-Weisskopf. Viki likes that and it fits for he has become quite a personage in the village. He is known as Monsieur le Directeur, and the farmers tip their hats when they see his tall, lanky silhouette walking carefully across their fields.
In 1960 my book, Unsolved Problems of Mathematics, was published. Many years ago Françoise asked Steinhaus what it was that made me what people seemed to consider a fairly good mathematician. According to her, Steinhaus replied: ''C'est l'homme du monde qui pose le mieux les problèmes." Apparently my reputation, such as it is, is founded on my ability to pose problems and to ask the right kind of questions. This book presents my own unsolved problems. As a young man I liked the motto in front of George Cantor's thesis which is a Latin quotation: "In re mathematica ars proponendi quaestionem pluris facienda est quam solvendi."
Shortly after 1960 the book was translated into Russian. There is no copyright agreement between Russia and the West, and the Russians pay no royalties, but some Western authors discovered when they were in the Soviet Union that they could obtain some payment for the translations of their work. Hans Bethe and Bob Richtmyer successfully received compensation. So when I attended an International Mathematics Congress in Moscow in 1966 I remember that I could try too. The Russian language being close to Polish, I went to the publishing house to talk about this matter in my imitation of Russian. At the publishing house, which looked the same as everywhere else — girls typing and masses of files and papers — an elderly gentleman seemed to understand my request and asked me how I knew to come and see them. I gave him the names of my friends. He went to a back room, then returned. The reader should know that Russians do not pronounce H as in English. They say G. For instance Hitler is pronounced Gitler, Hamlet Gamlet, Hilbert Gilbert. The gentleman said to me in Russian with an engaging smile: "Come back tomorrow please with your passport, and we will give you" — I seemed to hear—"your gonorrhea." Of course he had really said "gonorar'' for "honorar" (honorarium or royalties). I wanted to say, "No, thank you," but I understood what he meant. The next day when I returned he handed me an envelope which contained three hundred rubles in cash. One is not allowed to export rubles from Russia, so after I had bought some souvenirs, amber, fur hats, books and the like, I still had one hundred rubles left. I had to put them in a postal savings account which in Russia pays one or two percent interest. This makes me a Soviet Union capitalist.
Sometime in the early 1960s I met Gian-Carlo Rota, a mathematician who is almost a quarter-century younger than I and definitely representative of the next generation. Or maybe even several generations later, for academically in mathematics the generation gap may exist already between lecturers and their students where chronologically the difference is only a few years. Our relationship is not built on our age difference. Rota claims that he is greatly influenced by me. So I coined the expression "influencer and influencee." Rota is one of my best influencees. Banach, for example, I consider as an influencer.
From the start I was impressed by Rota's feeling for several different mathematical fields and his opinions in many areas of research where he exhibits both erudition and common sense. It is increasingly rare now — in fact, it has been for the last twenty years or more in this era of increasing specialization — to find a person with knowledge of the historical lines of mathematical development.
Rota impressed me by his knowledge of some half-forgotten fields, the work of Sylvester, Cayley and others on classical invariant theory, and by the way he managed to connect the work of Italian geometers to Grassmanian geometry and modernize much of this research which dates to the last century. His main field of work was in combinatorial analysis, where again he managed to update some classical ideas and adapt them to geometry.
I suggested that Rota be invited to Los Alamos for a visit as a consultant. He has been doing this periodically ever since and proved very useful in several ways, including numerical analysis which is important in many of the large computational problems worked on the electronic computers.
Rota's personality is compatible with mine. His general education, active interest in philosophy (he is an expert on the work of Edmund Husserl and Martin Heidegger), and, above all, his knowledge of classical Latin and ancient history, have made him fill the gap left by the loss of von Neumann. Indeed we often vie in quoting from Horace, Ovid, and other authors in a good-humored display of boasting erudition. Rota is also a true bon vivant, exceedingly fond of good wines and foods, especially those from Italy. He is incredibly adept in the preparation of a great variety of pasta dishes. Italian born, he was brought to South America right after World War II, and at the age of eighteen he came to the United States. His college education took place here, but he has retained many European mannerisms in dress, tastes and habits. He is a Princeton graduate and now a professor at MIT.
Chapter 14. Professor Again
During the Los Alamos years I frequently took time off to return to academic life, and around 1965 I started visiting the University of Colorado on a more regular basis, so it was not a discontinuous change when in 1967 I decided to retire from Los Alamos and accept a professorship in Boulder. Nor was I going to a strange, new place; on the contrary, I was joining several of my good old friends who had also selected the Colorado Rockies as a place to live, David Hawkins, Bob Richtmyer and George Gamow. Hawkins had been a professor of philosophy in Boulder since he had left Los Alamos after the war; Richtmyer, the post-war leader of the theoretical division before Carson Mark, had given up the Courant Institute in New York for the cleaner air of Boulder; Gamow had become a professor in the physics department several years earlier. The University of Colorado was flourishing and expanding, especially in the sciences, and the mathematics department experienced an explosive growth in size and in quality. Besides, Boulder was sufficiently close to Los Alamos, an easy day's drive through spectacular scenery, so I could continue as a consultant and visit frequently. The focus of my involvement, however, shifted from Los Alamos to Boulder.