INT: Excellent answer. Can you talk me through what it was like in the setting up of the first tests of the hydrogen bomb?

HY: Well, I remember the first tests of the hydrogen bomb still very vividly. It was approximately November first 1952, just before the Presidential election, just before the election of President Eisenhower. I was the director of the Livermore Laboratory, which was then very new, we'd only been open for a few months, but and none of us from the laboratory were there. And by that time Teller had joined us at Livermore, he wasn't there either, that is when I say he wasn't there, I mean, he wasn't out at Eniwetok where the test of what was called the Mike Test was about to be held. But we were in touch with Los Alamos, we knew what was happening and we set up a wireless arrangement so that we could listen specifically to the special signals they were sending out from any Eniwetok which would announce that the zero hour had passed. And we arranged so that Edward Teller went to look at the seismograph in Berkeley and I was at my office in Livermore and when the signals changed to indicate that the button had been pushed, I phoned Teller to tell him that zero hour had passed and about the appropriate time later, about twenty five or thirty minutes later, he phoned me to tell me that he had seen a small signal on the seismograph in Berkeley. I then phoned the people at Los Alamos to tell them that it had been successful. There was so much political tension involved in this whole process that they were not allowing ordinary communications between the Los Alamos contingent and Eniwetok and the Los Alamos headquarters in New Mexico. So were in fact the link that provided them with the information that the hydrogen bomb had obviously worked. But I remember it still very vividly and it arises in my memory every now and then, because at that moment, I had this deep feeling, you know, we had passed another really major juncture in history.

INT: Why was that? What do you mean a major juncture?

HY: Well, I thought, as did many other people at the time that there was a big and important difference between the hydrogen bomb and the atomic bomb, that it would influence the course of events, that if war came it would be still more destructive and terrible and that mankind was faced with a new problem that was not entirely novel, but the magnitude, the quantitative side of this problem was indeed serious.

INT: So what did you feel like when you saw your first hydrogen bomb? Can you describe to me what it was like?

HY: Well, I saw a number of atomic explosions first, so I was prepared for the general picture. I had been in Nevada and seen a number of the explosions down there in the neighbourhood of twenty kilotons, that is roughly the size of the Hiroshima bomb. I didn't see the first hydrogen bomb. As I described earlier, I was at my desk in Livermore when it happened. But I was out there two years later and saw one of the very large hydrogen explosions then. In fact, I was at Eniwetok and the explosion was at Bikini, which is, I forget exactly, but more than a hundred miles away. And I saw this enormous flash, this great light, the cloud rising and so on and it was, of course, tremendously impressive.

INT: What... In '54, the Bravo Test could you explain to me what happened in that test that became so significant in terms of the public's understanding?

HY: The Bravo Test was only the second large nuclear explosion, the Mike Test in 1952 was the first and Bravo was the first of a series of tests planned for the early spring of 1954. The yield was about double what they expected, which is really not a surprise, the calculations are very difficult and uncertain. So the fact that it was twice what they expected... people had exaggerated the importance of that particular matter. But predicting the fall-out was always difficult and in this particular case it was even more difficult than usual, because the nuclear debris rose to something like a hundred and twenty thousand feet into the atmosphere, some of it, not all of it, some of it was lower and in between the ground and the top of the radioactive cloud, the wind direction actually changed, reversed twice and it was through these winds with all this sheer that the radioactive particles had to fall down in order to reach the ground and predicting exactly the path they would take was extremely difficult and we had really no experience. We had only just one explosion before. Well, what actually happened is the radioactive fell on inhabited islands, by extraordinarily good luck the natives on one of the large atolls werat the north end of the island and it was the south end of the island that got more than a lethal dose, but even as it was, tgot a very dangerous, very bad dose of radiation. There was a Japanese fishing boat and there were other islands in the vicinity that got lesser amounts of radioactivity. That created a tremendous stir. When the word finally got out, it took a while for the word to get out, some weeks, created a tremendous stir and concern over what was the meaning of this, what was happening and so that was beginning of a really big effort to do something about not only the building and stock piling of hydrogen bombs, but to do something about the testing of them, in order to prevent this sort of thing from happening even worse another time.

INT: OK, thank you. Roll number 10141, Herbert York continuation. Herb, can I ask you, in '53, '54 the AEC decided to investigate Robert Oppenheimer. Can you tell me a bit about the background to that and what your feelings were about?

HY: (Coughs) Well, the background to the investigation of Robert Oppenheimer, which took place very early in the Eisenhower administration, was really a string of events, going back to the wartime itself and even some events before the War, involving connections between Robert Oppenheimer and Communist or leftist organisations. He had been basically apolitical as a young man, devoting himself entirely to physics, but when the Spanish Civil War finally came along, he became sensitised to the general question of what was happening in Europe, to the Jews and as well as in Spain and began to support through financial donations and through membership in groups, the Republican side in the Spanish Civil War. He also married a woman whose first husband had been a member of the Communist Party and his younger brother, Frank, whom I knew very well at Berkeley, had also been a member of the Communist Party. Robert Oppenheimer himself hadn't, but many of his students had. There'd been a rather complicated matter involving an approach that originated apparently in the Russian Embassy in San Francisco in which they were trying to get some information about what was going on in Berkeley and somebody actually brought this up with Oppenheimer and he gave an equivocal answer when later the security people asked him. Then after the War, when questions of building the hydrogen bomb came up, when the question of building a nuclear airplane came up, Robert Oppenheimer advised negatively with respect to going ahead on these projects for genuine technical reasons. But the suspicions were there, the problem of the Cold War, the problem of McCarthyism and so on was already coming up and it was easy for some people to believe that the reason Oppenheimer made these negatives recommendations was because he was somehow secretly trying to help the Russians. So the suspicion he was somehow disloyal came up and there were people who believed and wrote that he was in fact more probably than not a Soviet agent. In addition to these political matters, he was a vain man and so was Lewis Strauss, who was then the head of the Atomic Energy Commission and the two of them clashed on a personal basis and Strauss felt that on a number of public occasions, Oppenheimer had humiliated him in giving testimony before the Congress. So there was personal tension between the two men and there were others also who had personal problems with Robert Oppenheimer. The then Secretary of the Air Force, for example had grave doubts about Oppenheimer and his loyalty. So, ultimately, to make a long story short, they decided to remove his clearances, they could have just let them lapse, but they weren't satisfied to do that, because he would still have been used as a consultant and they wanted him removed from the consulting room altogether. They didn't want him coming back in some kind of later version on some committee that might be formed a little later. They wanted him gone and by they, I mean his enemies within the Congress, the Pentagon and then Teller and some of the others at Berkeley, they wanted Robert Oppenheimer out of there and Strauss wanted him out of there permanently. So they decided to remove his clearance. He himself decided that he wanted to have a hearing, that he regarded this as improper and that he was innocent of any of the charges, even the moderate ones and so he wanted a hearing and so they had a hearing. And in a matter of a few weeks there's thousands of pages of testimony which had been studied by scholars and others. At the end of the hearing, he was found to be a security risk. Some of the key testimony was given by Edward Teller and some of the other people from Berkeley also testified against him. Many more people testified in his favour, including people who were know for their anti-Communism and were certainly not people who were soft on Russia, General Groves testified in his favour, John von Neumann testified