The World of Enrico Fermi pt2 (1970)

September 1939 A Nazi Germany attacks Poland the start of World War II a month earlier Albert Einstein had met with Leo zard the Hungarian immigrant physicist zard and others drafted a letter to President Roosevelt which Einstein agreed to [Music] sign the letter informed the president of the work of zard and of another immigrant physicist Enrico fery confirmed the German discovery of uranium fishing and cited evidence that the Nazis were beginning research on a nuclear [Music] bomb Roosevelt recognized this danger and ordered support for research it seemed clear that the United States had no choice but to enter the Dreadful Atomic race [Music] [Applause] [Music] the key question to answer first was whether a chain reaction in uranium could really be set up fam and zard led the work in self-imposed secrecy because slow neutrons were more likely to produce fishing the uranium was to be embedded in a moderating substance that would slow the neutrons carbon in the form of graphite if it were pure enough was the most promising substance so a pile of uranium and graphite was built at Columbia University fairy explained later how graphite was tested what was happening is that in those days we were trying to learn something about the absur from properties of graphite because perhaps graphite was no good so we built Columns of graphite maybe 4T on the side or something like that maybe 10 ft high so physicist on the seventh floor of pine laboratory started looking like PA minus it was the first time when apparatus in physics was so big that you could climb on top of [Music] it in December 1941 it became became clear that a chain reaction was likely to occur with a bigger pile and purer graphite and if that were true a piece of pure uranium itself might well be made into a weapon it was decided to expand the research program ironically the very next day the Japanese attack on Pearl Harbor pushed America into the war all human resources now had to be mobilized including the scientists the pile project was moved from Columbia University in New York to Chicago Labs were established at the University of Chicago in a deserted squash court under the grandstand of a football field an odd location but it was Secure and now secrecy was more essential than ever the American physicist Arthur H Compton was in charge of the whole operation fairy was to direct the test of whether a large uranium carbon pile would really sustain a chain reaction this was no longer basic search but urgent war workor fmy was again the same effective leader he had been in his lab in Rome the young nuclear physicists on his team responded to his zest and warmth the other I think the main point of his attraction was the intimate way in which he did uh physics uh he dealt with it directly and he dealt with it with you he never left it to you he always talked about the work as in a sense as an adventure on which we were both on and that we would do together uh jointly that is we we had a those of us who worked with him had a sense of participation in the experiment there is no film or photograph of the pile they built only this painting and a model famy later described the pile it bricks of graphite piled up in this pile there is uh uranium spread throughout the interior some neutrons produced in the uranium Collide against the graphite be slowed down to the appropriate energy react again with uranium produce more neutrum and so on and so forth the final test began as long as the control rods were in place they absorbed enough neutrons to keep the pile from self-sustaining reaction on the morning of December 2nd 1942 fmy directed that the control rods be slowly pulled out until only one was left this was pulled out by hand step by step with each step The Meters showed that the activity of the pile increased then on the brink of History fmy called a lunch break after lunch we were zoomed and at 3:25 p.m. I remember the time because I wrote it on the rubber balloon that uh encased the the structure we resumed and uh by this time fam he was in full control and he knew precisely how far to pull the last Rod out he gave me my instructions and he announced to the uh attending those attending that we would now have a chain reaction and sure enough we did Arthur Compton could now make his report I picked up the phone and called Dr cornet at Cambridge the Italian Navigators just landed in the new world I told you the Italian Navigator had indeed landed in a new world a new kind of fire had been ignited that showed the possibility both of peaceful nuclear power and of the nuclear bomb as it turned out later the Germans too were constructing a uranium pile to produce the pure raw materials uranium 235 in plutonium a Monumental Enterprise sprang up across America the two largest plants being at Oak Ridge Tennessee and Hanford Washington the basic theory for the weapon was being developed at Los Alamos some 40 mi from Santa Fe in New Mexico in what had been a boy school now heavily secured the overall direction of the project rested with the Army who selected Robert Oppenheimer as Chief scientist the local people in town thought the site might be a concentration camp for enemy aliens it was true that along with American scientists Oppenheimer had many foreigners in his Camp fmy who came to Los Alamos to help where he could Edward Teller a Hungarian and Emilio SRA once fairy student and his friend and colleague from Rome among the many Americans involved were Lawrence and Robbie who came as consultants by the summer of 1945 the complicated design problems seemed solved the raw material atal was ready and the Army could make the arrangements to test whether an explosive reaction would occur the stretch of desert to the south at Alam magora was chosen as the test site in the early Dawn Of July 16th all was ready ironically the war with Germany had just ended in May some of the scientists were hoping that the awesome results predicted on paper would somehow turn out to be forbidden by nature's laws after all [Music] the enormous heat of the explosion turned the desert sand to Glass the scientists were ODed the war with Japan was clearly in its final phase and some of the scientists wrote petitions to the president to use Atomic weapons if at all on non- civilian targets President Truman decided otherwise at his orders in early August 1945 the Air Force dropped two bombs on Hiroshima and Nagasaki [Music] historians are still debating whether the Japanese generals would not have surrendered soon anyway but the long and terribly costly war was over two weeks after the end of the war a very different explosion occurred the scientists who had been working for the Army rebelled because the Army wanted to keep the same Security on Research as during wartime Samuel Allison spoke for we are determined to return to free research as before the war if the exchange of scientific information was prohibited by military regulation research workers in America would leave the field of atomic research and devote themselves to studying the color of butterfly wings fairby agreed wholeheartedly stating publicly that research must be freed from military supervision if nuclear science were to be developed for the benefit of all mankind as he explained later of course we knew that atomic energy was potentially capable also of peaceful applications one of them is the possibility of producing large scale amounts of energy with a fuel of very little weight this feature could make atomic energy useful in some situations in which ordinary fuels might not be practical also the reaction produc uses as byproducts huge amounts of radioactive substances they can be used for all sorts of purposes in physics chemistry and especially in medicine steps toward the attainment of these peaceful applications were taken even his Fey returned to the University of Chicago to begin the last great phase of his career looking as ever for interesting problems in new Fields he turned to the physics of subnuclear particles had a tremendous interest in any piece of apparatus and it didn't matter whether it was a complicated computer or whether it was I remember an example of a lawnmower he had never worked a power lawnmower and I had just gotten this power lawnmower and he was out at the house and he saw it wanted to see how it worked and wanted to do it whereupon he cut my lawn which I think was a tremendous honor to have a your professor cut your lawn his equipment would essentially disintegrate just when he finished getting all the relevant pertinent data that he needed he didn't waste his time which many businesses today do building very expensive uh sophisticated equipment he just designed his equipment to do the job that was necessary in order to get the results that he was trying to attain and after that he didn't have to worry anymore about the equipment he had a very high sense of economy economy of time and effort and he was used to quote a few verses that that he thought were due to mangelo when you have made enough that you believe that is sufficient don't touch it anymore because you will spoil [Music] it in the summer vacations he returned to the New Mexico mountains near Los Alamos again he organized hikes and trips with his colleagues and their families always combining friendship and talk about physics as he had done with his students in Rome a generation before one of his frequent companions was Norman no he rather enjoyed stirring uh a pot of beans and cooking bacon uh and perhaps he didn't do this at home that I don't know but he uh like to make breakfast in the morning on these camping trips and Rico would stop the car and get out his fishing pole and uh some of the younger ones of us uh took our diversion by panning for gold he didn't catch any fish and we didn't succeed in getting any gold was in the postwar period in Chicago he founded another school both in experiment and theory and some of the most significant younger exponents of physics both theoretical and experimental uh or directly his students and they remember fairy the teacher with pride and pleasure fairy uh loved to teach he he seemed to get almost a physical pleasure from it he loved to teach so much that he almost seemed to Delight in people who didn't understand what he was saying the first time one of the major purposes of his life was to make things clear and he made them clear to himself and he made them clear to other others his idea was well it helped him understand things in a way to to explain them and uh he always was able to single out those aspects of the problem which are the really essential one so that the once you grasp those points you have a superior view of what the whole problem is about I felt that the circumstances under which I could learn from him were just about ideal namely I worked on a problem for a matter of a few weeks and then came in contact uh with fairy to discuss it and he would show me how to make progress on a problem on which I had already worked each step as it unfolded to his mind he would put down and he would be led along until he came to the conclusion and when he finished if you took a picture of that Blackboard you would have the the basis of a well organized paper for a a scientific journal he liked to uh do a little one-upsmanship and some of this was the uh was this business of having only one piece of chalk it's very difficult to argue with somebody who has the only piece of chalk he would put himself questions or whenever it was an idol moment whenever he was strolling along he his mind was working on some feature of the world which he had which had caught his attention to see if he could put it into place he could take it apart see how it was working sometimes he put these questions in a rather surprising way just to make a kind of joke a kind of real puzzle they were not quite puzzles but they were almost puzzles he would look at you and say this famous one which is often told of him how many piano tuners do you think there are in Chicago oh you feel you have to look that up but of course you don't have to look that up you just have to ask yourself you can approach a problem many different ways about how many people have pianos how many houses are there what fraction what chances there have a piano how often does it have to be tuned how many pianos can a man tune in a day and pretty soon you have a rough answer oh you won't know exactly but you'll know it's not thousands or not ones but somewhere in between and of course the better you know the subject the more you'll be able to answer it questions of this sort Fair me questions there were other questions for which fairy felt there were no quick answers these were political and moral questions that agitated many other scientists after the war the scientists who were concerned about the spread of nuclear weapons got together and formed the Federation of American scientists a chief aim was to keep the development of atomic energy under civilian control in the US fmy tried to stay out of such debates but events soon forced him to take a public stand in the 1950s a senator Joseph McCarthy became more and more feared for his witch hunts the this Distortion of the Senate's Powers distressed fairy who had a deep rooted respect for government and institutions we had a good deal of trust that when the military said they had a requirement they must know what they were talking about and he had a tenden to suppose that those who in some vague sense were the government must be quite expert at that as he was expert at physics in the atmosphere generating by McCarthy a sensationalistic book appeared which caused fairy to call a press conference a rare thing for him he felt the book was unfair to many of his friends and colleagues and flatly said so then Oppenheimer himself was attacked the man who directed the vast secret research work at Los Alamos and served in his country's highest councils was accused of being a security risk fairy was outraged and testified on oppenheim's behalf at last he saw it was impossible for scientists to stay aloof when political decisions were being made that involved Science And scientists Oppenheimer interviewed in the last month of his life later recalled he realized that that some of the things that had come to him many of them things that had come to several of us together uh were pretty hard and that he no longer felt entirely content with the way in which she had dealt with them in that turbulent summer of 1954 Fair left a deeply troubled America for a visit to his native Italy as always science filled his days in the lecture room and in informal conversation with his friends and colleagues [Music] it was fairy's last trip he came home to discover that he had an incurable cancer the day after the operation uh Herbert Anderson and I went to see him in the hospital and when we went there he knew and he also knew that uh he had only a few months more to live when you meet a man at that time you really do not know what to say Fe turned to me and said well don't look so unhappy for a man after 50 nothing really new is likely to happen and it is probably more of the same thing and so there is not much loss to be anticipated and then he turned to me with a smile and said now you tell me as an Indian do you think I'll will be an elephant next time and sort of laughed and broke the whole Gloom of the first encounter on the 29th of November 1954 enrio FY died his impact during his lifetime very great is in the professional Community among physicists um he was deeply loved um imitated as far as it lay in people's power to do so by very many um he changed the style in which a whole set of problems were thought about and the language that was used he gave me the impression of a superb musician who when presented the piece of music for the first time is able to play it with extraordinary eloquence in the same way he was able to bring to be on any problem presented to him his enormous attending of physic fmy had a tremendous ability to bring out the Simplicity and the beauty in physics and to many of us and probably I suppose to most physicists it is the beauty of the subject which is the most characteristic and attractive feature during the 53 years of fam's life the course of physics and with it history itself had undergone a profound transformation and in good part as a result of his work but the search for Simplicity and Beauty through the ideas of physics is still as important as it was in Fair's world [Music] n