|Interviewer: Robin Hughes
Recorded: January 20, 1992
This is a transcript of the complete original interview conducted for the Australian Biography project. Each transcript page covers one videotape (approximately 35 minutes). There is also QuickTime video of the full interview available. To play the video, click on the icon in the right hand column. In addition, each question in the transcript is linked to the video. Clicking on a question will play the video from that point. (Help with this feature.) Optionally, you can download the video file for offline viewing (approx. 10MB).
The interview has been left it in its original state so that you can get a sense of how the conversation developed. The repetition of some questions, or a question followed by another question, is often due to the end of a particular tape or some other interruption, and has been indicated at the appropriate place in the text. There has been minimal tidying up of the text so that the flavour of the encounter has been kept.
So when you checked it in the laboratory the next day, had his water been right?
Yes exactly right. I put the particles through crossed electric and magnetic fields, that measures their velocity, and then from the velocity knowing one can calculate the mass, knowing their energy that they possess from their range in air. So he was quite right.
Was Rutherford's intuition always so bang on?
No not always, he had some very funny ideas at times, but he was so often right, for instance, in 1921 in London, he gave a lecture in which he said that he thought that there must be inside the nucleus of the atom, one of the particles that make up the nucleus must be - have zero electric charge. Must be a very close union of a proton which has a positive charge and an electron which has a negative charge, so close that it apparently has no charge, and he talked about the properties of such a particle, if it existed, that it should be able to pass through matter without making many collisions and so on, and described it in an incredible way. Now he and Chadwick looked for this particle very carefully by every means that they could think of for ten years. But then - eleven years later in 1932, there was a report from Paris that Joliot-Curie, the husband of Madame Curie's daughter, had discovered that particles that were ... that a radiation rather that was produced from bombardment of beryllium metal with alpha particles from radium knocked out protons from a piece of paraffin wax that they were knocked out, and he thought it was due to some peculiar property of this very high energy radiation which apparently was there, but Ruther ... but Chadwick knew at once that this must be neutrons, because they were billiard balls as it were hitting a billiard ball although it had zero electric charge on it, it would knock the proton out. So he set to work to do experiments to prove that this was so. Within a week he had the answer. He'd discovered the neutron, and there it was - Rutherford said that the neutron must exist, in order to explain some of the properties of the nucleus of the atom, and eleven years later, Chadwick discovered the neutron. Although they'd been looking all that time for this elusive particle, which they felt in their water must exist, you see. So it's obvious, you see, that this sort of intuitive approach by Rutherford covered almost everything you see, it ...
Has intuition played an important part in your own work?
Well I'm not a Rutherford, nor a Born or an Einstein but I have had glimmers at times of intuitive approach to things which have worked out.
Your own star was evolving at this time and your reputation, as you were given opportunities, some people who get to assist a great man like Rutherford, some young men, find that their work is not always given due credence, that the great man sometimes takes ...
(interrupting) Oh but that was one point about Rutherford, that he always ... See the paper describing this work is by Oliphant, Marsdorp and Rutherford. His name was last.
So you were given ...
(interrupting) He never took any credit for anything that other people had done.
So you were given due credit, and so your ...
... reputation was growing ...
How were you feeling at this stage? About your future?
Oh well I was beginning to feel my oats as it were, and beginning to feel that I'd love to have a Cavendish laboratory of my own.
So ambition had been awakened.
... have a show of my own instead of being a junior in the laboratory. And so I, when an offer came to me to become Professor of Physics in Birmingham, in central England, I went and had a look around and talked to people, and it was rough, and it put Moss the ... the Chairman of the Faculty that was looking for a new Professor on to me, and when I - but when I went and told Rutherford that I was thinking of going to Birmingham, he was terribly angry. He was ... he said, 'Chadwick's gone and let me down, he's gone to Liverpool, now you're leaving me in the lurch and going to Birmingham', and he was very angry with me. Really, really nasty to me. The next day I had a letter from him, saying he was sorry that he'd lost his temper. Wishing me all luck in oh, what I was intending to do, and said he'd love to talk over with me what I'd ... sort of program I had in mind and so on, offering me every assistance. Unfortunately that was the year that he died.
And that was a major loss to you.
Yes, he died at the very young age really of sixty-seven. Of a messed-up simple operation for a strangulated hernia in the umbilicus.
And what do you think was the main thing that you had learned from him? If you had to try and put into perspective what you'd got out of your time with him, what would you say was the single thing that stood you in good stead for the rest of your life?
Well I got as interested in the nucleus in this internal part of the atom of matter as he was, and I thought I'd like to go on and do this but do this at higher energies. Now in Berkeley in California. the discovery had been made by a great friend of mine, Ernest Lawrence, of a thing that he called the cyclotron. Whereby you accelerated particles in a magnetic field where they performed circular paths and gave them a little flip each time they went past a certain point, so that you increased their energy till they got to the edge, and you could get very high energies in that way. So I went off in 1938 and spent some time in Berkeley with Lawrence, learning how the cyclotron was made and worked, and he was terrifically helpful and became one of my closest friends. I went back to Birmingham, built the largest cyclotron in Europe at that time ... still is one of the largest in Europe, and is still working. That was done in 1937-8. [It was] begun in '37, it was not finished in '38 when we were dragged unfortunately into war work. It was quite apparent that Hitler was on the rage and a lot of us were taken and initiated into the very sec[ret], deadly secrets of radar, because they realised that this sort of thing was going to play a big part in any future, and each of us was then given experience of radar, and then when the war broke out the cyclotron still wasn't finished. I was given the job of trying to produce electromagnetic waves of very much shorter wavelength than were available at that time. At that time the shortest wavelength available was about a metre and a half, and that was produced with a little, tiny little valve called a micro-pup, which didn't give much energy. But it was used in the chain stations, radar stations around the country, where the aerial system, because the wavelength was so long, had to be very big. It was about as big as a tennis court sticking up in the air you see, this great array of dipoles and it was thought that it would be much simpler to do things if one had much shorter wavelengths. And I agreed with this very strongly, particularly for airborne radar which was almost impossible with that wavelength of one and a half metres. So we set to work. I got together - carefully got together a small team of people who were ... had no real experience in radio at all, of radio, and I, I didn't know much about it, except that I'd used amplifiers for my - detecting my particles and for working the cyclotron. But I'd determined to get a group of people who would think fundamentally about it, because having visited the various establishments that were dealing with radio for the services, and the laboratories and works where radio valves and radio receivers and transmitters were developed, I knew that they'd never reach the short wavelengths by the techniques that they were using. That one had to have the resident circuit as we called it, inside the tube itself, it was no good having it outside the generator of the waves. So we set to work to try and devise various devices which would do this, thinking in fundamental terms, rather than just following practice, radio practice. And two of the boys, Boot and ah, and ah ... oh, dear me, old man's memory, and ah ...
It doesn't matter.
... a more senior man whose name I'll remember in a moment, discovered that they could make resonators which were like a revolver with holes in a ring, and slots that pointed towards a cathode inside. The whole thing made out of metal with just a glass to bring the power out, and this worked like magic. This was the magnetron. And of course I'd like to have a dollar for every magnetron that's in the kitchens of the world nowadays, but it proved to be extremely good and reliable. It's frequency stability was improved by a man named Sayers, and within eighteen months or so we'd shot our bolt. We'd got these things flying. We'd got radar working in the air. We'd got it working at pointing searchlights at aircraft at night. We'd got it working on ships. We'd got it detecting ships at sea, and all in eighteen months or two years. And then I thought, I wouldn't ... ah, bugger it all. Ah, this is not a really interesting work, this is work for engineers now. So I went back to the work on nuclear physics. Now the interesting thing is that working with me in the laboratory at that time were two German refugees from Hitler's Germany. One was named Peierls, the other one's name Frisch. Professor Peierls was ... I'd invited to become Professor of Applied Physics and Applied Mathematics and, rather, Theoretical Physics - and Frisch had come from Copenhagen where he'd been working with Niels Bohr and his aunt. And it was these two people together of course, they were enemy aliens, they weren't allowed to know anything about this secret weapon of radar you see, so they had to be kept out of that. So not being allowed to do that, they set to work to do some calculations about nuclear energy, about the possibility of getting nuclear energy. And they, lo and behold - they came through with a paper [in] which they said that if one could separate the uranium - the rare isotope of uranium which was only present to the extent in normal uranium of less than 1% - if one could separate it and use uranium 235, which was mucked up by the 238 which was mixed with it, if one could separate it then one could make a bomb of enormous power. And they calculated the amount of uranium 235 that was required, and also the explosive force that might be produced. And this was absolutely hair-raising. Here were these two chaps, not allowed to have anything to do with the secrets of radar, producing this paper on this possibility of making a nuclear weapon. So this paper was sent to the United States to inform them - they were not in the war at that time of course, and - because we - but we had very close relationship with them on the scientific side, and they had a committee in America that was supposed to be looking at the possibility of getting nuclear energy, since the German, Hahn, had discovered nuclear fission in 1937, in - yes '37. And so everybody was on the - looked - thought here was the possibility of a chain reaction and nobody had found it, but here were Frisch and Peierls, had worked out exactly what to do. And we sent it to America, and then didn't have any reply. So I had to dash across to America in connection with the magnetron, which was being developed in America, American version of it by the Bell Telephone Laboratories in New York. And, but while I was there, I was asked to see what had happened to our report: the Peierls-Frisch Report. So I went to the to Washington to the Chairman of the American Committee, who was the head of their department that was responsible for standards, their Standards Laboratory, and he was a real stick in the mud and he'd taken this report, thought it was a bit interesting, but had stuck it in his safe and hadn't circulated it to the other members of the committee. So I went straight away to see Bush and Conant who were the President's scientific and technical advisers, and both of them took the point of view, well this is very interesting, but this is for the next war not for this war. So still dissatisfied I got on an aeroplane, in those days of course there were DC2s, and flew across to - the eighteen hour flight - to Berkeley and to Oakland next door to Berkeley in California, and went to see Lawrence, whom I'd worked with, you see, and knew to be a live wire, and a member of the committee. So I told him about this, and he was so upset that he got on a plane with me and we went back to Washington. Then within a few days the Manhattan District [sic] was formed as a result of this, and the the enormous Russian, ah, rather American project well on its way.
That was strange wasn't it? As it all happened as a result of Frisch and Peierls, who were not allowed to be associated with the secret work, setting to work to do calculations about the possibility of chain reactions with uranium.
And had you not gone across there, and stirred the whole thing up, the project, the Manhattan Project that finally led to the atomic bomb may never have happened.
It may never have happened, but I can't imagine that somebody wouldn't have woken up to the facts of the matter. They had a lot of very experienced people in America. A number of them like Bater and so on who were refugees from Germany, and other people like Robert Oppenheimer who were theoreticians of great experience, and who had worked in Europe, and were not ignorant of our ways.
Why were you so anxious that this should get moving?
Because we had information from the Secret Service that the Germans were trying to produce a nuclear weapon, and that the man in charge was a very famous scientist, who [was] a theoretician, but unfortunately they didn't - or fortunately perhaps for us, they, they took the wrong path. They went for the nuclear reactor, whereas ... not the separation of the isotopes of the uranium. And this was remarkable on the part of a man with the intuition of the German scientists of that time, who were very good indeed.
So what was your own part then in this Operation Manhattan that then followed?
Oh then, after that there were negotiations with the Americans, and finally the Americans relented and we were - we moved to America. Whole of the British team moved to America en masse, because there they had the productive facilities that in Britain were used entirely for making aeroplanes. British industry was all out whereas there was spare industry still in America.
So what was your contribution to it?
Well, mine was a very minor one, I joined with Chadwick [who] was the leader of our team, and I was his Deputy, so while I was ah officially attached to a group that was run by Lawrence, separating the isotopes of uranium, ah in fact I was ah Chadwick's deputy, and ah I visited ah and took part in all the discussions, and every ah month or so I was - I went to England to report to Sir John Anderson who at that time was Lord President to the Council. The grand name that was given to the man who was ah the Junior Minister but was responsible for all the technical and scientific things. And ah ah then back again to America and flying across the Atlantic in bombers on nine occasions. The reason it wasn't ten was because once I went across in the Queen Mary (laughs) which was fast enough to avoid the submarines.
[end of tape]