WHY DON'T WE START, GO THROUGH SOME OF YOUR EXPERIENCES CHRONOLOGICALLY. WHERE WERE YOU WORKING WHEN YOU FIRST HEARD ABOUT THE DISCOVERY OF FISSION? AND WHAT WAS YOUR REACTION TO THE IDEA THAT A BOMB COULD BE BUILT WHEN YOU FIRST THOUGHT ABOUT THAT?

The news about the discovery of fission reached me when I was in Warsaw early in 1939. I happened at that time to do some experiments on neutrons using uranium and therefore it didn't take me long to set up an experiment to test whether more neutrons are emitted in the process of fission than go in. And very soon I found that indeed there were more neutrons coming out. Now, this was an experiment which took me a little while to confirm because I had a very small source of neutrons. But in the course of time while I was doing the experiment, it occurred to me that if more neutrons come out than go in, this opens for the first time the possibility of a chain reaction propagated by the neutrons. Which means that a very large number of these fissions will occur. And if these fissions all these occur in a very short time, with all their energies released in an extremely short time, this will result in a mighty powerful explosion. In other words, this could be a device to make a weapon of much greater destructive power than Man ever thought before. So this is how I came onto the idea of the possibility of the atom bomb. My reaction pers--

JUST ONE SECOND. LET'S GO TO A CLOSER... WOULD YOU LIKE A GLASS OF WATER OR ANYTHING, JUST TO HAVE IT HANDY?

It's all right.

WHAT DID YOU THINK WHEN YOU REALIZED THAT WAS POSSIBLE?

Well, my first reaction was not to think about it. Because I was a scientist, interested only in doing pure research and not in its application. And certainly the possibility of using science for the production of a weapon of such destruction was completely outside my frames of reference, so to speak. I was brought up on principles that science should serve mankind. And the idea that science could be used to destroy many people was completely abhorrent to me. Therefore, in fact it didn't even enter into my mind that I should in any way be connected with such a application.

LET'S GO TIGHTER. SO IN THOSE DAYS, YOU TOLD US THAT LATER YOU DEVELOPED MORE OF A SOCIAL CONSCIENCE IN THE REALM OF WHERE YOUR WORK SHOULD TAKE YOU. BUT IN THOSE DAYS, MAYBE YOU CAN TELL ME HOW, AGAIN, YOU WERE INTERESTED IN PURE SCIENCE AND THE IDEA OF USING SCIENCE FOR MAKING WEAPONS WAS ABHORRENT TO YOU. WE'RE JUST GETTING IT A LITTLE DIFFERENT WAY.

You want me to repeat what I said?

PRETTY MUCH, YEAH. IF YOU DON'T MIND.

Well, I don't know, unless... My first reaction to this imaginary application of science to make a bomb was to try to put it out of my mind. For the simple reason that having been brought up that science should serve any application on principles mankind, I felt that which can act [in the] opposite direction is just opposed to the traditions of science, and it should certainly not be my concern. Therefore, the whole idea of my research work could be applied to produce a bomb of this magnitude was completely abhorrent to me. Therefore, I did not want to think about it. I thought by pushing it out of my mind maybe the thing would go away. Of course it didn't. And what began to worry me in the course of the next few weeks was the worry that -- the thought that other scientists may also got -- get onto the same idea, they may not have the same approach to science as I had. And they may feel that perhaps one should follow this possible outcome of the discovery. And I had in-particularly in mind German scientists. Because although by that time, many of the physicists in Germany were-- they had to go because of racial theories of Hitler. Nevertheless, enough first rate physicists would be left in Germany who could have produced this sort of bomb if it was at all possible to do. And I was afraid that -- we knew that war was going to come -- that in such a case, Hitler would not hesitate to make his scientists do it -- carry out this work, and use the bomb against us, and then win the war. If this idea at all was feasible. And so I found myself in this terrible dilemma. On the one hand, I felt it was something which I must not do, it's against all my principles. On the other hand, on practical grounds, I felt this may be threat to our civilization if the Nazis will win the war. And therefore, gradually sort of, in the course of the next few months -- it wasn't immediate -- that I began to prepare sort -- to work out a rationalization for my participating in this sort of work. Namely, I thought that the only way which-in which may stop Hitler from using the bomb against us would be if we, too, had it and threatened with retaliation. In other words, at that stage already I developed the idea of the nuclear deterrent. And we may say the bomb perhaps should be there but in order not to be used. And this made it necessary for us first to find out whether it is possible to make it, and then to make it actually, so it would be ready as a deterrent.

OK, GOOD. LET'S GO TO THE MEDIUM. YOU MENTIONED IN YOUR ARTICLE THAT YOU SAW AN ARTICLE PUBLISHED BY FLÜGGE, AND THAT WAS ONE OF THE THINGS THAT MADE YOU CONCERNED THAT THE GERMANS WERE WORKING ON THAT. CAN YOU TELL ME ABOUT THAT?

Well I was, during the summer of 1939, I came to England and I worked in Liverpool. I didn't talk much to many -- to people there, because of my knowledge of English was rather poor at the time. And so I had mostly to keep it the thought to myself. Nevertheless I pondered over this threat, the possible threat, of such a nuclear atomic weapon. And then I came across in, I think it was in June of 1939, when I came across an article in a German journal called the Naturwissenschaften. And there was Flügge, who was one of the German physicists, who wrote an article about the general uses of atomic energy for peaceful purposes. But he also intimated at the end of the article the possibility of its using as a weapon. And this made me even more worried; this means that other people actually had the idea. And if so, then they may actually be working on it.

SO THAT WAS IN SPRING OR SUMMER OF 1939. YOU WERE IN ENGLAND AT THAT TIME, BUT YOU MUST HAVE HAD SOME FIRST-HAND KNOWLEDGE OF WHAT WAS GOING ON IN POLAND.

Well, living in Poland so next to, Germany, of course we were very well... aware of the danger; we all knew that sooner or later, Hitler was going to invade Poland, particularly after the... invasion of Czechoslovakia, we knew that it our country would be the next, on his list. And we gradually got used to the idea -- we couldn't do anything about it, of course; the fight had to go on. But we were all the time aware, that we were living on the edge of a volcano that, at any moment, it may erupt. But, at that time, of course, I was in England, where life was very serene, you know, but we talked about the possibility of a war, I tried to, as much as I could, with my poor English, to warn my British friends -- nobody would listen to me, about it, so I had all sorts of time left on my own. But I could see the thing gradually happen, and indeed on the first of September, when Hitler did invade Poland, it didn't take more than a few weeks, to override the whole country, and then I realized that all our perhaps wishful thinking that the German might isn't as great as has been thought and described was not true, that in fact ... the German might ace it, in the end, and therefore the danger to other countries, to the west, was certainly very great, and then the whole danger of civilization, to civilization, was real. And this was the final point, which made me convinced, that I ought to start work on it. I had to finally overcome my scruples. I felt that one can no longer... sort.... believe that this is not going to come. And this is the reason why as soon as I realized this, that I went to Chadwick, who is the head of the department, the physics department at Liverpool, and put in the idea which I had, about research to work on the feasibility of the atom bomb.

AND AT THAT TIME, YOU STILL HAD FAMILY BEHIND IN POLAND -- YOU WERE ABLE TO BRING THEM TO ENGLAND?

Well, at that time, I did not think of bringing them to England, my family, because my idea was to go back to Poland -- I only came to England for one year -- to do the research work -- and then I intended to go back. And I, and of course, did worry about war there all the time, but one could not, sort, live with this and... we had to plan life as normal. The only point was that I thought that I might be able to bring my wife to England to be with me as soon as I received a, an additional fellowship from Liverpool. And unfortunately, it didn't come off. So I was I left the family behind and I was by myself.

NOW AFTER YOU STARTED WORKING ON THE BOMB PROJECT IN ENGLAND, WAS THE PHYSICS COMMUNITY IN ENGLAND COMMITTED TO THE DEVELOPMENT OF THE ATOMIC BOMB THE WAY THE MANHATTAN PROJECT WAS IN THE UNITED STATES?

In Britain scientists, most of the physicists who might have been interested in... atom bomb project, were actually taken away to do other work. I remember distinctly, in September, '39, all of a sudden all my, the senior colleagues in the physics department, disappeared. And, because they were called out to do work on radar, which was considered to be the immediate necessity, in order to, in able to, prevent a possible defeat of Britain invasion to aircraft. And therefore the only people left in my Department, apart from the head of the department, Chadwick, was to work, probably to go on the sort of duty, were the younger people. And of course myself, who was a foreigner, an alien, although a friendly alien but nevertheless barred from doing direct... war work. Therefore at the beginning there was nobody there, apart from Chadwick, with whom I could talk about this. And, and of course, the same happens... turned out at other places that...there too, the British bomb physicists were called away, and only the people who were foreign-born, the aliens, were left to carry the work in fact, the early, stages, there was mainly the people from Germany, Austria, and other countries, who were involved on this project.

SO, AS THE WAR PROGRESSED INTO 1940, 1941, WHAT WAS THE MAIN CONTRIBUTION THE BRITISH PHYSICS COMMUNITY MADE TOWARD THE ATOM BOMB RESEARCH?

Well, we, of course, did not know at that time what was going on in the United States or other countries. We are so isolated, particularly people like myself considered aliens, with all sorts of restrictions... of movement, therefore we, more or less each of us, had to work on its, on one's own. I had... I was given a few, initially only two, assistants, to carry out some experiments, and my main purpose was to see whether by doing some -- straightforward, perhaps -- experiments, to establish whether a bomb was feasible, or not. The main idea was to see whether, by... of the fast neutrons, will have... enough, probability, to produce fission, and... to propagate a chain reaction. Because if you were going to make a bomb, it's important to have, to be propagating fast neutrons; otherwise, the bomb will not differ in any way from an ordinary chemical explosion. And this was therefore the main point, which not every-, which not all scientists realized at the beginning -- I have a feeling that the German scientists never got on to this idea, but I may be wrong. Anyhow, this was therefore, the main purpose is to see what happens with the fast neutrons, and when they are produced in fission what is their energy, so... to know whether they can produce further fissions, how fast are they scattered, how fast do they lose energy, can uranium break up spontaneously -- otherwise it will break up the fall -- and a big enough assembly, can they produce to make a bomb: this is the sort of experiment which leads on, to the, em, answer whether the bomb is feasible on scientific grounds only, and this the type of, sort of experiment, which I'd been carrying out with my team, which I had in Liverpool using the cyclotron there, and later, of course Robert Frisch... joined us, and he carried out some of the crucial experiments on the cross-section... the probability of fission by fast neutrons. And so by 1941, we have established, I believe, that the, on the scientific grounds, an atom bomb was feasible.

AND THEN HOW DID THE UNITED STATES START COLLABORATING WITH THE U.K.? MAYBE YOU COULD MENTION THE MAUD REPORT. YOU ALSO MENTIONED THAT IN 1941 THE U.S. WAS KIND OF ON THE WRONG TRACK, AND UREY AND PEGRAM TALKED TO YOUR PEOPLE. COULD YOU TELL ME THAT STORY?

We had very little -- at that time we had very little information on what was going on in the United States, but some information did come through, of course, with some of the leaders of the project, like Chadwick, who was the head of the Liverpool Project; Oliphant, who was the head of the Birmingham Project. Oliphant used to go to the United States and, perhaps not necessarily on this project, but more on the problems of radar -- nevertheless, he maintained the contact. At the beginning, of course, was only the British Committee, which was called the MAUD Committee initially and later became the Tube Alloys, when it was decided to try to develop it; and but then we learned that in the United States, where the work has perhaps been going mainly on a different track; so they're mainly concerned with building reactors, propagated by slow neutrons. That the actual work on the atom bomb project, so almost grinded to a halt; it, because it appeared at that time that it would take a, the difficulties of establishing whether the bomb is feasible or not are greater than they thought. Of course, I didn't know at the time about this, but then in 1941 I was told by my chief, Chadwick, that two Americans, Pegram and Urey, are going to come, and... we have to tell them what we've done, although we are generally bound by, of course, by the Secrecy Act but, we are given this... order, that we've got to tell them. And so I had a visit from these two physicists, who were well known to me, of course, from the literature, and I just explained to them what we have achieved -- so did Robert Frisch -- and I understand, as a result of this -- they were greatly impressed, actually -- as a result of this they went back, and the whole project started... with renewed vigor in the United States, and soon afterwards, of course, it went off and they began to build Los Alamos and the other places, and later on, about two years later in 1943, the agreement came, between Roosevelt and Churchill, to collaborate on this bomb project.

SO THE BRITISH CONTRIBUTION TO DEVELOPING THE ATOMIC BOMB WAS VERY SIGNIFICANT?

Oh yes, in my opinion, it was definitely, I mean prob...ah make it clear that in course of time, the Americans would have gone... on to this with, even without help, British help, but when time is an important factor, as it was then, I believe that this, our results in Britain, it played a very important role in the developing of the American project.

SO, EVENTUALLY YOU DID COME TO THE UNITED STATES TO JOIN THE MANHATTAN PROJECT. WHAT WERE YOUR FIRST IMPRESSIONS?

Well I didn't have... before leaving England, I didn't know...

YOU WERE STARTING TO TELL ME ABOUT HOW YOU GAINED POLITICAL ASYLUM.

Before -- Is it all right now? Before leaving England, I had no idea at all where we are going. We are not informed. It could be anywhere in the States. And also what will be decisive to laboratory which we'll be working in, it's nature and so on. And so only after I arrived in the United States, and after I talked to General Groves in Washington when he told me about "Site Y" as it is called in Los Alamos. And of course, when I came there, I found everything was quite different from what I imagined. The location of course was entirely different from a laboratory in a big city. It was...used to be a ranch and it's location was beautiful in that place with all the mountains around it. Really can't you can't imagine the beauty of the place itself. And, but of course, most of all was the actual setting up of the laboratory. It was somewhat primitive from the point of view of the buildings. They were huts so wooden huts and so on. Not proper buildings. But the equipment was really fantastic. Everything, anything which was required to do experiments was provided there. No questions asked. All you had do was to write out a chit and the following day or so, soon after, the stuff arrived. Whether it was, if you like, a chain for a bicycle, or a whole cyclotron. I'm slightly exaggerating, of course, but this gives you the idea of the sort of things which is going on. So the point of view from an experimental physicist as I was, the facilities to do experiments, after my experiences before were really unbelievable. I would say it was a scientist's paradise, as I refer to it. The second very important point about Los Alamos was that they managed to get together so many of the great scientists of the world. And you could sit down for lunch, for example, or dinner at a table and find yourself with about half a dozen of Nobel Prize winners. And the people to whom all of us used to look up and always knew about them and think about -all there with us and talking to them and sharing their views and giving advice. So from this point of view I think it was really marvelous ...But I was very unhappy. I don't know if I should go on to this or not...

GO AHEAD WITH THAT THOUGHT THAT YOU WERE UNHAPPY.

But despite all the great opportunities for research in Los Alamos, I was very unhappy during my whole stay there. And the reason for my unhappiness was the gradual realization that the purpose for which I decided to start in England and then to continue to work on the atom bomb, seemed to be more and more invalid -- becoming invalid. Because, I...being in Los Alamos I realized the magnitude of the effort required to make the weapon. There's one thing to do an experiment in the laboratory, to say yes, theoretically it is possible. It is quite a different story to make the actual bomb. And I could see that with all the enormous expenditure, the enormous effort put in the United States, even so it will take quite a long time. And it looked -- at that time, 1944 -- quite likely, very likely that the war in Europe would be over before the project is most completed. This made me feel that the whole... my whole being there is quite unnecessary. And all my moral scruples which I started with initially came back to me. And so I felt that, "What am I doing here? What is the purpose of this work?" And this became worse. This worry became worse after a casual remark which was made in my presence by the head of the Manhattan Project, General Leslie Groves. And he said -- this was I think in March, 1944 -- he said, "Of course you realize..." -- he said this to Chadwick -- "...you realize, of course, that the whole purpose of this project is to subdue our main enemy, the Russians." In other words, it turned out -- and of course, he knew what he was talking about, I believed -- that it turned out that what we are working on is not to try to prevent the Germans from using the bomb against us, but actually to help the Americans to build a weapon which they then could use, if need be, against the Russians. And this was certainly not something which I wanted to work on, particularly at the time when the Russians were our allies. And I ...we relied upon them, to their enormous sacrifices to prepare the ground for a victory on our side against the Germans.

I'D LIKE YOU TO TELL ME ABOUT WHAT GROVES SAID AGAIN, BECAUSE THE WAY YOU SAID IT THAT TIME IT WAS LINKED TO YOUR STORY ABOUT BEING SAD -- IT WOULD BE HARD TO USE ONE WITHOUT THE OTHER. IF YOU DON"T MIND COULD YOU JUST DESCRIBE LIKE YOU DID THE OTHER DAY.

I see. All right. I'll do it again. In March, 1944, I received a very nasty shock. I-- at that time I was staying with the Chadwicks in their house, and General Leslie Groves when he came from time to time to Los Alamos used to visit the Chadwicks and stay for dinner. On one such occasion, he -- when we were discussing the progress of the project informally -- he suddenly turned to Chadwick and he said, "You, of course you realize that the main purpose of this project is to subdue the Russians, our chief enemy." Now this was a shock to me, because I always thought that the main idea of the project it was to develop the bomb, if need be to prevent a Nazi victory. And now I found that this was not. That the main aim...the main aim was that after the war was over -- by that time it looked as if it will be over even before the project is finished -- then I guess, we'll then be able to use this...the atom bomb, as a means of political pressure or whatever else or maybe even military pressure against the Russians.

HOW DID THIS STRIKE YOU COMING FROM HIM. HAD YOU HEARD THAT KIND OF SENTIMENT FROM ANYBODY ELSE?

No, I never heard this sort of statement made by anybody any of the scientists with whom we talked in Los Alamos. Certainly not before I left England. Not in England. But there... when we talked often talked about this political situation, about the progress of the war and so on and what the future, the post-war period would look like. But nobody ever suggested that the Russians should be our enemy. Or are enemies. Of course, all of us, including myself, intensely disliked the Communist regime particularly under Stalin. In my particular case, I felt that it was Stalin who betrayed us by making a pact with Hitler which enabled Hitler to...almost [with] impunity to invade Poland. Therefore I had no illusions about the Russian regime, but nevertheless, we were afraid of war. We're fighting for our lives. And the Russians were our allies. And we had to go on treating them as such and not preparing to fight them.

ON THE OTHER EXTREME OF PEOPLE YOU TALKED [TO] THERE WAS NIELS BOHR... WHAT WERE THE CONVERSATIONS WITH HIM ABOUT?

I should describe how I talked to him? Well I used to have frequent conversations with Niels Bohr. It arose from a very strange reason, namely I had a radio set in which I could receive the BBC world service. Having got used during the war years in England to the BBC and I trusted the BBC, I found it very difficult to follow the American communiques where every few seconds almost were interrupted with some sort of trivial advertisement. And I couldn't stand how they couldn't, in such serious situations, break up this continuative to news. That's the reason why I always listened to the BBC bulletins. Now Niels Bohr had similar ideas about how a news bulletin should be given, and I...and he therefore used to come in every morning at 8 o'clock to my room, and we used to listen to the news bulletins. And very often, after the end of the bulletin we would comment on them and discuss them. And then often he would give his comment not only about the news itself, but also continuing, extrapolating from there, what is the likelihood going to be of the development of atomic energy. What influence it will have on the political situation and the whole world. And his...and his concern that unless we can very early...at a very early stage, come to some agreement with the Russians to share this new discovery that we were into a period of great danger to the whole of mankind.

NOW COULD YOU TELL ME ABOUT YOUR DECISION TO LEAVE LOS ALAMOS?

As a result of my conversations with Niels Bohr, but mainly by observing the effort required to make the bomb, I came gradually to the conclusions that the Germans are very much unlikely to have developed the bomb if it took the Americans such an effort. And I could imagine, knowing what's going on in Germany, that they were far behind. And then I...it was the end of 1944, from discussions with Chadwick when he came to Los Alamos, I could deduce from this and the information which he -- intelligence information which he used to receive, that the... it appeared to have been quite clear that the Germans are not working on the atom bomb project. If so, the whole purpose -- my...all my fears about the Germans had vanished. The whole purpose of my being in Los Alamos was no longer there. Therefore I decided that I could see no reason why I should go on. I felt-I only started for one reason. This reason is no longer there. To be able to be consistent with my views I would no longer to work on the project. And therefore, I told Chadwick that I wanted to leave. He was not very happy about this. Although he understood very well reasons given him, but he was a bit worried what effect this may have of the view of the American British team. But nevertheless, he accepted my position. He said yes. And then I transmitted my request to the authorities. For me to leave...

HE WAS CONCERNED HOW YOUR LEAVING MIGHT BE VIEWED BY THE AMERICAN AUTHORITIES?

Well, I believe and this -- so it's going back looking with hindsight rather than at the time, I understood at the time -- that probably there might have been other people, other scientists too who had begun to have doubts whether it was worthwhile continuing with the project. And I think the Americans were probably worried that once a person leaves for this reason this may spread. It may demoralize the whole project. Therefore they are not at all keen for me to go. Quite apart from other fears which they had that maybe if I go back, somehow I may give away the secrets and in fact cause direct damage to the project. So therefore they were not at all happy. In fact they almost prevented me from going back by a sort of a I think a fictional report which they had of me which almost stopped me from going back. But as it turned out it was easy to show this was very wrong and I was allowed to got back. However, in order to avoid the fear which they had about the demoralizing effect which my departure might have, we've agreed that... the sensible reason for my leaving would not be the one which I explained to Chadwick, but rather put it down to a personal worry about my wife whom I had left in Poland. I thought by being in England I'll be a bit nearer to her and be able to find out what's happening. So this was the reason which was given at the time to the world. And I was told definitely by the Americans that I must not talk to anybody about my -- after my decision to leave, I was told specifically that I must not discuss this... my position on this matter with anybody in Los Alamos.

WHO TOLD YOU THAT YOU SHOULDN'T DISCUSS IT WITH ANYBODY?

Well I was told directly by Captain DeSilva, as he was then, who was the head of intelligence. After the trouble which I had...which I had with him about some of the problems which I thought a story was cooked up about me and after this was shown to be completely false. He had to agree. He couldn't have any reasons for not allowing me to go. But at least he made the stipulation that I must not talk to any of the scientist about the reasons for my leaving.

MAYBE YOU COULD TELL ME, VERY BRIEFLY SINCE YOU MENTIONED IT A LITTLE THIS SORT OF SPY STORY THAT WAS PUT FORTH?

Well as I....

SORT OF A SYNOPSIS OF IT.

I told you the other day it would be a bit of a problem.

WITHOUT GOING INTO THAT DEGREE OF DETAIL. MENTION THAT UH... YOU MIGHT...

Yes. When after I asked Chadwick, after I told Chadwick that I would like to leave, and he said he was going to inform the authorities in Los Alamos, he came back to me and he told me a very sad story. He said that there is a very thick dossier on me in the head of intelligence people there. And according to this dossier that I -- the apparent reason why I wanted to go...to leave Los Alamos is first to go back to England. From there to go be flown to the part of Poland at that time occupied by the Russians. Be parachuted down. And the main purpose was to give away all the secrets of the atom bomb to the Russians. Now, the basis for this allegation was that I used to go from time to time to Santa Fe. This is the only city which we are allowed to visit, and to help those persons who I wanted to help in certain difficulties there. And this person was deaf and therefore I had to speak fairly loudly. And I imagine that the Hispanic janitor used to listen in and he would then tell the stories. And what he couldn't understand he would add on from his own imagination. So in this fashion this spy story was built up. But of course, since it was built based on the imagination it was bound to contain facts which one could prove or disprove. And I very easily disproved them. That's the reason why they had no choice but to withdraw the whole -- they said they will destroy this dossier. And having got this embarrassment, they said well of course. And they couldn't stop me from going back. Yes, better?

ONE THING YOU MENTIONED THE OTHER DAY -- YOU SAID THAT WAR CHANGES THE WAY THAT PEOPLE THINK.

Yes.

DO YOU RECALL THE CONTEXT. I THINK YOU WERE TALKING ABOUT SOCIAL CONSCIENCE OR LACK OF IT DUE TO THE IMMEDIATE PROBLEMS OF WARTIME.

I often pondered over the years since Los Alamos what would be my reaction if a similar situation arose now. After all that I have learned during these years, and the mistakes which I have made -- which I believe to have made -- And even now, I still am not sure what my reaction would be. I mean, if I were an absolute pacifist, as some of my colleagues were who refused at that time to work on the project. And I know what my reaction would be. But since I'm not, since at one time I found a reason why I should work on this, therefore I'm not sure what my reaction would be. And this worries me. Because during war time it seemed that all our thought, ingrained moral principles which you have, seemed to be thrown overboard and you...we are in quite a different mentality. And only recently did this come to the fore to me that I -- somebody sent me a letter from, a copy of a letter, from Robert Oppenheimer to Fermi, written in 1943. It only came out through the Freedom of Information Act. And in this letter, Oppenheimer speaks about the use of radioactive material to poison the food in Germany. And he asked Fermi who had a reactor whether he could produce enough strontium-90 to do this. And he said, "Of course. We should only do it if we can poison at least half a million people." Now, for a scientist in normal times to think about using this method of poisoning people, I think it's unbelievable. It's a barbaric approach nobody would think about. And yet, during the war, this was entertained as a feasible, and in fact looking to this, the only reason I can image why it was not followed up is because -- as I knew for another reason -- it was infeasible. It couldn't be done. But this is one example how our values change during the war years. In a sense you worry what would happen in a war and they still go back and built the hydrogen bombs and anything else and use them even, if need be.

HOW DID YOU FEEL ABOUT THE NEWS OF HIROSHIMA? WHERE WERE YOU?

After leaving Los Alamos, I went back to Liverpool. Of course I knew what was going on. Something was going to happen. I didn't know in which form it will appear, but I was bound by the Secrecy Act, and therefore I was not allowed to talk to anybody about this over there. And therefore, the first time I learned about what's happened to the project was when I heard on the BBC on the 7th of August that atom bomb was dropped on Hiroshima. And then of course, the papers were full about this. Now the first reaction was of deep shock. Of course, I still hoped, all the time, that the bomb would not be used. That since it was meant to be used against the Germans there was, nobody had any thoughts that the Japanese may develop an atom bomb. Therefore, the same fear didn't apply to them. Therefore I thought, of course, that the Americans would insist that the project continues to find out whether the bomb works or not, they may test it, and this will be the end. And when I find out it was used against a city with this terrible devastation, I was of course shocked. And all my worst fears about -- which were told to me by Niels Bohr -- came really to vivid to me. That this is now a new world: a world full of danger. Shall we survive, now, with these new weapons now that they have been used? And so I began to think, "How can we prevent a possible nuclear war?" And I had this crazy idea that...let's have a moratorium on science. Because I knew at the time that the atom bomb is only the first step in the development of nuclear weapons. I already knew at that time about the hydrogen bomb, which would be a thousand times more powerful. And which we could really destroy most of our cities and possibly civilization. And so I thought to...at least to prevent this, let us put a moratorium on further research, and see whether doom is -- for three years as I suggested -- we could see whether we could arrange our world affairs in a better way so that we can live with each other. Of course, this was a crazy idea because we cannot stop research, and when I spoke to this to my scientific scientist colleagues they all came out against me. So I had to abandon this. But it had one good effect. Namely, that at least it awakened them, to the people who were not on the project, to the new dangers. And it was decided that scientists should have a certain role to play in warning and informing the public about these new dangers. This is where we set up in this country, the Atomic Scientists Association, who had this aim in mind. And ever since, I've been... concerned with this. Later on we enlarged this to the international arena by setting up the Pugwash Conferences on Science and World Affairs, where international scientists meet to discuss these problems and see how they can help politicians and statesmen to prevent this danger.

SO DO YOU FEEL THAT SCIENTISTS HAVE A RESPONSIBILITY TO SOCIETY? ... WHEN YOU WERE YOUNG AND WERE INTERESTED IN DOING PURE RESEARCH -- IS THERE ANY SUCH THING, IS IT VALID TO DO PURE RESEARCH WITHOUT BEING CONCERNED ABOUT HOW IT'S GOING TO AFFECT PEOPLE?

Are you on? Without the lights? ...I see. Beg your pardon. Shouldn't make that sort of comment. There used to be a time when scientists believed that what they are doing has nothing to do with the effect that their work may have on society. A scientist is only concerned with studying the laws of nature. And since the laws of nature are independent on emotions, for example, or other attributes of societal life, therefore it has nothing to do with science. But I think this illusion has disappeared. This is the sort of effort for scientists to live in an ivory tower I think, has gradually been disappearing and I believe, that for the final blow to this tower came with the Hiroshima bomb. Nowadays, no scientist can really go on believing that what he's doing -- the result of his work is not...is not his concern; it's the concern of politicians and other people. Because what he's doing has a direct bearing on the life and destiny of people. And therefore, if people are informed properly! If they want what may be the consequences for a certain piece of research, it gives them the chance to take measures to prevent any possible so dangerous untoward effects. And for this reason alone, I feel that the scientist has this responsibility, this social responsibility to be aware of the implications of the work he's doing and if need be to inform the public and politicians and warn them about possible dangers. And I believe that this has become particularly strong and...as the war...since the war. ..since the war years as the threat of science and technology -- not only science -- is be...becoming more and more imminent.

I MEANT TO ASK YOU THIS BEFORE, BUT WHEN YOU LEFT LOS ALAMOS, WHY DIDN'T A LOT OF OTHER PEOPLE DO THE SAME THING? WHAT WERE THEIR REASONS?

After even before leaving Los Alamos I could not talk to the scientists there what would be their reaction when the project comes...when the war is over. But before that, I talked to some of them and also subsequently I talked to scientists to know what their views were. Well, as it turned out, I was the only one to have left the project. I didn't know at the time this, there's only one. And you may wonder why there was only one person who should do this and not more because we are so many involved. But first of all, I want to make clear that there were a number of scientists who for either religious or other reasons refused to take part in the project. I was almost on the verge of being this myself. I just decided to do it at the last minute, and then the first minute to leave it. But therefore the people who came there already did not have this sort of reservations that other people who refused to do this. Secondly, there are a number of younger scientists who came on there mainly because they'd been told that some of the very famous scientists are going to be involved. And this was enough for them to work there. And therefore, I could say there was only a small number of scientists who originated the project who therefore...whose motives...main motivation was the same as mine: the fear of the Germans having the bomb, whom I would have expected to follow in the same way. If it was only a small number then one...only one being is not so surprising. And my own feeling is that there were several reason why other scientists did not follow. I mean, those people who thought about this. One was purely -- which I call go back to the purity of science. Namely, you do an experiment because you are curious about it. You do a piece a research work because you do something new and if on paper you predict something, you would like to see whether it's going to come true or not. And therefore, these scientists felt having gone so far with this idea you want to see whether it will work. And therefore they decided to put off any such thought about possible uses until the test at Alamogordo. Of course, to make sure that it does really work. So this is one group of scientists that decided that they will continue until the end of the project in this sense, until the test was carried out successfully. Another group of scientist were persuaded at the time that if one could use this weapon in Japan it will save a million American lives. It will bring the war in the Far East to a very speedy conclusion. And they, for patriotic reasons, they felt that for that, they should participate in this. Of course, they only thought one bomb. In fact, indeed, many scientists felt it shouldn't even be used directly against cities but have a trial somewhere on test grounds and so on. So this is the reason why they agreed. Although I find hardly any of my colleagues there who would agree to the second bomb. They felt the first one was enough. And if we waited another few days the Japanese would have surrendered in any case. So very few people are in favor of use of the second bomb. But this is were the reasons why I find these people felt that they would go on with the project. And of course, most importantly this, that each of us has got certain convictions, but our decisions are dictated by a number, a very large number of very small events which all act together and this reason why each of us...under same circumstances behave a different way. In my case it were under the circumstances -- that's because I was very much on the edge of it that I decided to take this step.

YOU TOUCHED ON SOMETHING THAT I THINK OPPENHEIMER CALLED THE "TECHNOLOGICAL SWEETNESS OF PURSUIT," IS THAT SOMETHING THAT DRIVES PEOPLE TODAY TO BUILD MORE AND MORE WEAPONS?

No doubt, it drives them today. I believe very strongly that the nuclear arms race at the present time is to a large extent dictated by technological advance. I mean, the impetus of the arms race is due to the new ideas which come out from scientists working in the weapons laboratories. They just had certain ideas, like we had about the bomb 40 years ago, 45 years ago and then they do experiments in the lab and then they are satisfied and they are successful. But by that time, the military hear about them and therefore they are eager to buy the ideas and go on developing. Therefore this is certainly is the motive, a very important motive for people at this time. But here I want to come back to my own attitude about these matters. Even in those days, the bomb itself was not a pure scientific project. The way in which we did in Liverpool was purely scientific. It was to establish the scientific elements required for making a bomb. But once this was established, classified as technology -- and I make this distinction between scientists and technologists. Although the scientist has to be concerned about the implications of his work, this does not mean that he should go into technology. There are other people who do it. They in turn should be concerned. Therefore, I would say that nowadays I see no excuse for scientists as such to work on development of weapons.

ARE YOU SURPRISED THAT ATOMIC BOMBS HAVE NOT BEEN USED IN WARFARE SINCE 1945?

Surprise is the wrong word for it. I'm... greatly relieved it has not been used. I mean, because I'm afraid had it been used probably I wouldn't be able to answer your question and of course it wouldn't have been here. We've managed to avoid its use. On several occasions there was the threat of its use. But so far we've managed to avoid this. Unfortunately, the possibilities of avoiding it are getting smaller and smaller. And this really is the worrying thing.

I was asked to write this article in the Bulletin. And this is for...almost for the first time when I brought this out into the open about my part of originating the work in Liverpool. I mean, of course Peierls and Frisch, they started in Birmingham, you see, but quite independently I worked out this in Liverpool. And of course, I was I said, not very proud of that period of my life, and I didn't want to so to talk about this. And so very little is known about this, my early part in this. I just want to explain to you that this is not something which is which is well known. But then I began to write history. And you know, when I was asked to write this article, I felt that one cannot sort of falsify history; therefore I had to state this and make this into the open. Also, I felt a certain of course a loyalty to Chadwick for all these years, because so the credit, if one can speak about credit in these matters, so it went to him as the leader. But I said, the reason why I raise this now, because curiously enough I found in some letters which if you...if you, in other programs you are doing -- maybe just of interest to you, I mentioned the other day Oliphant's worries that the ICI might, is only coming on in order to have an interest, take an interest in the future. Well I came across two letters from... one from Chadwick to Oliphant, and one from Oliphant to Chadwick in which they actually deal with these issues. And also at one stage, as a result of this which Chadwick says, he does -- he took umbrage on one statement by Oliphant who claimed the credit that it was only in his boys, Peierls and Frisch, who were responsible. Just want to read the last -- this paragraph on this letter. You can take the last part of this page and the following page. I don't know whether this business of a...