I’ve been reading a bit lately about the history of the development of the first atomic bomb: the Manhattan Project. The topic is extremely fascinating for many reasons. It was not only a huge technological and scientific effort that required the direct implementation of theoretical ideas that emerged at most only 40 years before the construction of the bomb, but also a breaking point in world history. The human species had now been given the terrible and terrifying ability to annihilate itself.
Many books have been written about the subject (a particularly good one is “The Making of the Atomic Bomb”, by Richard Rhodes) and you can find a lot of information everywhere, but what has always interested me is what the physicists that were involved in the project thought at the moment. Especially since these were academic people who went from giving lectures and preparing homework assignments while working on basic research to developing the most terrible weapons of mass destruction known to date (without forgetting, of course, the historical context in which this happened)
A good window into the thoughts of some of these physicits is given in the 1981 documentary “The Day After Trinity“, which is centered on the figure of Robert Oppenheimer, the “father of the bomb”. Among the people interviewed for the documentary was Stan Ulam, a mathematician who helped in the development of the working concept for the first H-bomb (the Teller-Ulam design) and that on a brighter note contributed to the creation of a technique cherished by all physicists today: the Monte Carlo method. Ulam was working here in Madison at the time (1940) as an assistant professor when he volunteered for war work. He says that he received a letter from Hans Bethe, inviting him to join “an unidentified project that was doing important work, the physics having something to do with the interior of stars.” When he found out that he was going to New Mexico (where the development and ulterior testing of the bomb happened), he went to the library to borrow a tourist guide about the state. In an interview in 1987 for Los Alamos Science he says about the book:
At the back of the book, on the slip of paper on which borrowers signed their names, I read the names of Joan Hinton, David Frisch, Joseph McKibben, and all the other people who had been mysteriously disappearing [from Madison] to hush-hush war jobs without saying where. I had uncovered their destination in a simple and unexpected fashion. It is next to impossible to maintain absolute secrecy and security in war time.
So, I went to the library to see if the book was still available, and it was! Unfortunately, the slip is gone, probably due to the rebinding that it went through at some point when the library management system was switched to computers. A map of the state, showing a much smaller Los Alamos before the war, is included.
Tiny Los Alamos, before the US started the development of the bomb that later would give birth to the Los Alamos National Laboratory.
The Federal Writers' Project Guide to New Mexico from 1940.
On the topic of how hard it was to keep the location of the project secret, Richard Feynman mentions something similar in his book “Surely you’re joking, Mr Feynman!“, using his traditional sense of humor:
We were told to be very careful – not to buy our train ticket in Princeton, for example, because Princeton was a very small station, and if everybody bought train tickets to Albuquerque, New Mexico, in Princeton, there would be some suspicions that something was up. And so everybody bought their tickets somewhere else, except me, because I figured if everybody bought their tickets somewhere else…
So when I went to the train station and said, “I want to go to Albuquerque, New Mexico,” the man says, “Oh, so all this stuff is for you!” We had been shipping out crates full of counters for weeks and expecting that they didn’t notice the address was Albuquerque.
The whole enterprise raised many moral issues inside the physics community itself. It is particularly interesting to hear the testimony of Robert Wilson in the documentary. Feynman in his book recalls how everybody was excited in Los Alamos after the first successful test of the atomic bomb (the Trinity test). Everybody, except for Wilson, who he saw moping having realized about the impact of what they had accomplished and its terrible consequences. In the words of Oppenheimer himself: “Physicists have known sin, and this is a knowledge which they cannot lose.”
