Then I thought, how about smell? Smell is something we sense; it is not related to any sound or picture. We do not know how to call it. It has no visual impact either. Does this contradict my guesses about simultaneous storage and connections? Then I remembered the famous incident related by Proust of the smell and taste of the "madeleine" (little cake). There are many descriptions in the literature of cases where a smell previously experienced and felt suddenly brings back a long-forgotten occasion when it was first associated with a place, or a person, many years before. So, perhaps on the contrary, this is another indication.
This feeling of analogy or association is necessary to place the set of impressions correctly on the suitable end points of a sequence of branches of a tree. And perhaps this is how people differ from each other in their memories. In some, more of these analogies are felt, stored, and better connected. Such analogies can be of an extremely abstract nature. I can conceive that a concrete picture, a visual sequence of dots and dashes, may bring back an abstract thought, which apparently in a mysterious coding had something in common with it. Some part of what is called mathematical talent may depend on the ability to see such analogies.
It is said that seventy-five percent of us have a dominant visual memory, twenty-five percent an auditory one. As for me, mine is quite visual. When I think about mathematical ideas, I see the abstract notions in symbolic pictures. They are visual assemblages, for example, a schematized picture of actual sets of points on a plane. In reading a statement like "an infinity of spheres or an infinity of sets," I imagine a picture with such almost real objects, getting smaller, vanishing on some horizon.
It is possible that human thought codes things not in terms of words or syllogisms or signs, for most people think pictorially, not verbally. There is a way of writing abstract ideas in a kind of shorthand which is almost orthogonal to the usual ways in which we communicate with each other by means of the spoken or written word. One may call this a "visual algorithm."
The process of logic itself working internally in the brain may be more analogous to a succession of operations with symbolic pictures, a sort of abstract analogue of the Chinese alphabet or some Mayan description of events — except that the elements are not merely words but more like sentences or whole stories with linkages between them forming a sort of meta- or super-logic with its own rules.
For me, some of the most interesting passages about the connections between the problem of time, as involved in the memory, and the physical or even mathematical meaning of it, whether it is classical or relativistic, were written, not by a physicist or a neurologist or a professional psychologist, but by Vladimir Nabokov in his book Ada. Some utterances by Einstein himself, as quoted in his biographies, show the great physicist's wonder at what living in time means, since we experience only the present. But, in reality, we consist of permanent and immutable world lines in four dimensions.
With such thoughts and worries about the thinking process, I was recovering my physical strength during this period of convalescence. What comforted me the most was the receipt of an invitation to attend a secret conference in Los Alamos in late April. This became for me a true sign of confidence in my mental recovery. I could not be told on the telephone or by letter what the conference was about. Secrecy was most intense at that time, but I guessed correctly that it would be devoted to the problems of thermonuclear bombs.
The conference lasted several days. Many friends were present. Some had been directly involved, like Frankel, Metropolis, Teller, and myself; others were consultants, like von Neumann. Fermi was absent. The discussions were active and inquisitive. They began with a presentation by Fraenkel of some calculations on the work initiated by Teller during the war. They were not detailed or complete enough and required work on computers (not the MANIACs but other machines in operation at the Aberdeen Proving Grounds). These were the first problems attacked that way.
The promising features of the plan were noticed and to some extent confirmed, but there remained great questions about the initiation of the process and, once initiated, about its successful continuation.
(All this was to have great importance in a later lawsuit between Sperry Rand and Honeywell over the validity of patents involving computers. The claim was that computers were already in the public domain then because the government of the United States used them and therefore the patents granted later were invalid. I was one of many who were called to testify on this in 1971.)
I participated in all the Los Alamos meetings. They lasted for hours, mornings and afternoons, and I noticed with pleasure that I was not unduly tired.
I remember telling Johnny about my illness. "I was given up for dead," I said, "and thought myself that I was already dead, except for a set of measure zero." This purely mathematical joke amused him, he laughed and asked, ''What measure?"
Edward Teller and Johnny were often together, and I joined them in private talks.
In one conversation they discussed the possibility of influencing the weather. They had in mind global changes, while I proposed more local interventions. For example, I remember asking Johnny whether hurricanes could not be diverted, attenuated, or dispersed with nuclear explosions. I wasn't thinking of a point source, which is symmetrical, but several explosions in a line. I reasoned that the violence and enormous energy of a hurricane lies on top of a mass of air (the weather) which itself moves gently and slowly. I wondered if one could not, even ever so slightly, change its course in time and in trajectory on the slowmoving overall weather, thus making it avoid populated areas. There are, of course, many questions and objections about such an undertaking. One of the necessary conditions would be to make detailed computations on the course of the motion of the air masses, calculations which do not exist even now. Through the years Johnny and I occasionally talked about this with experts in hydrodynamics and meteorology.
The conference over, I returned to Los Angeles. Upon alighting from the plane, two FBI agents approached me, showed their identification and asked for permission to search my luggage. A copy of the very secret Metropolis and Frankel report was missing, and they wondered if I might have taken it by mistake. We searched, but I did not have it. Later I learned that everybody who had attended the conference had been contacted. The authorities were very nervous, for this was potentially of grave consequence. The missing document reappeared much later among some of Teller's papers in a Los Alamos safe.
The time was rapidly approaching when I could resume teaching, but I was developing strongly negative feelings about Los Angeles. Rides through the streets where I had been driven in an ambulance reminded me of my recent illness. My feelings toward the University were colored by this, as well, and I was dissatisfied. I felt impatiently that it was not changing quickly enough from a glorified high school into a genuine institution of higher learning. I had disagreements with a dean about building up the academic level and increasing the staff. I was told he joked that he almost had a heart attack every time he saw me, even from a distance, so afraid was he that I was bringing him new proposals for expansion!
The best part of the University was the Hancock Library. It had an impressive building and some good books — but the building was better than the collection inside. The University had just acquired an old municipal library from Boston, and when I learned what it contained, I compared it to a priceless collection of hundredyearold Sears Roebuck catalogues. This sarcastic remark probably did not enhance my popularity.