How they 'split the atom' - Prof Philip Walton

Thanks very much, Brian, and can I, on behalf of the family, thank Brian and Porek for organizing this event. It's very nice to be commemorating not only your father, but a very famous Irishman. I would also like to congratulate Brian on the excellent book. I really enjoyed it and would recommend it strongly to you. What I am going to do in my short time is, I thought, having seen the still pictures of the man, you might like to see some movie, live pictures. For this, Ian copied onto PowerPoint for me various clips from a programme done by BBC Northern Ireland Television called The Heart of Matter. The commentator on that programme was Al Byrne, who died a few years ago, Gaye Byrne's brother. So we'll start with the first clip. This is just by way of introduction, it takes a little second to get going. This was about 25 years ago. That's, as I said, about 25 years ago, so he would have been in his mid-eighties then. Next one shows him approaching the physics department in Trinity, about writing to Lord Rutherford to try and get into the Cavendish. What he didn't actually mention there, I think he was helped in his ambition to get there by a Professor John Jolie from Geology in Trinity. He had done work on little halos in rocks which were created by alpha particles and had collaborated with our known Lord Rutherford personally, so I think he probably put a good word in for him. The next clip is about him explaining the experiment to Al Byrne. In the interest of brevity, I omitted some of the early part of this in which he explains what a proton is, and for those of you who don't know, if you take an atom of hydrogen and you remove the orbiting electron, you're left with a proton. This is in the main lecture theatre, the Fitzgerald lecture theatre in the physics department. Here we see the protons coming down, and they speed it up as a result of climate change. They come down, lift them here, produce two helium nuclei going in opposite directions. And this one coming out here strikes a fluorescent screen, and where it hits it, a tiny flash of light, which you can see by looking through this microscope, and here is the observer's apparatus. Here is the actual apparatus which we have, and right at the top is where the protons were produced. By the way, that is the only original bit of his apparatus there. The big stack beside it is a voltage doubling circuit, but it's not the original one. This is in the Science Museum in London. By the way, they were really working on a shoestring in the Cavendish Laboratory. They were very short of money and materials and whatnot, and all sorts of pieces of wood and rusty screws were all saved and used again and again. In fact, there's a story about Lord Rutherford one day. He had some very VIP visitor in his office, and there was a knock on the door, and it was the chief technician. And Rutherford said, what is it? Oh, sir, it's the bucket. And Rutherford, yes, well, what's about the bucket? It's got a hole in it. Well, said Rutherford, can't you mend it? Oh, he said, it's been mended about three times already. So I think he got the go-ahead to buy a new bucket, but that was the sort of thing that was going on. The next clip is himself describing the events of the 14th of April. The next thing I did was to get on to him. Doing some work was keeping some of the time, and he came over, satisfied himself that these were genuine scintillations, and carrying out some experiments, which I had carried out for myself previously before getting on to him. And we both agreed that this was a genuine event. So he got on to Rutherford, and Rutherford came very quickly. He was always quickly on the spot if people were getting up. We moved him into the little hut. He was a big man. And look at these scintillations. He didn't say anything at the time. And he came out of the little hut and sat down. Rutherford stood as his costume was when he wanted to talk. So he said something like this, those scintillations look mighty like alpha particle scintillations. And he went on to say that the opinion of the birth of the Alpha Party had been following him ever since, and that he ought to know what he saw. This was very cheerful news to both of us, to hear the word expert on alpha particles, to vouch for the genuineness of these scintillations which we had seen. Just one thing I'd like to correct there. The pictures of the tracks, that came later. What they actually saw were little flashes of light on a screen looking at it through a microscope. Those were tracks that were recorded in what's called a Wilson cloud chamber sometime afterwards. I'd just like to point out that practically all the work in constructing the apparatus, my father was excellent with his hands and he did most of the work of assembling the apparatus. Now, of course, as Brian has already mentioned, there was huge publicity at the time. And Brian already mentioned, Dad used to say that he thought one of the reasons for the big publicity was that play that was on in London, where this mad scientist had split the atom and he was holding the world to ransom. So, this clip just shows you some of the publicity that followed. Alchemist's dream has come true. You notice there the energy without limit. Well, just to mention that, of course, the splitting of the atom was only one step towards nuclear power and the other steps that had to take place. First of all, of course, the neutron had to be discovered and that was done in the same year, 1932. And then you had to have nuclear fission where a uranium atom can be split into two by bombarding it with a neutron and then those neutrons go on and split others. So, you could get a chain reaction going. And then the first demonstration of a chain reaction in the pile by Fermi in the University of Chicago. Now, the actual award of the Nobel Prize is the next clip. Before I show it, I just mention that, of course, when the announcement was made, it was very much fated and there was a special luncheon dinner in the President's dinner. And when they got to the boat going to Sweden, they were shown the Royal Suite instead of what they had booked. We, the three of us, the three elder children were at their old school. My mother and father were head boy and head girl at the same time in the Methodist College Belfast. And anyway, when the award was announced, the three, Alan, Marion and myself were boarders at the Methodist College Belfast. And I got a phone call from my mother and I was 11 years old at the time. She said, your father is to receive a very prestigious award, the Nobel Prize. And I said, what's that? At 11, you wouldn't have heard of a Nobel Prize. But anyway, it was duly announced next day in the school assembly. And of course, it was announced by the headmaster. And to celebrate, we were given a half day off school. So I was rather proud, at least that was important for me. My dad got you a half day off school. But there was a little boy went home and his mother said to him, what are you doing home again today? You seem to be always getting half days in that school. What is it this time? I'm not sure. Somebody split something. This is one of the press pictures too at the time. My younger sister, Jean, who is six years younger than I am, she was at home. The rest of us were away at school. So she got in all the newspapers, the photographs. These are the Nobel laureates proceeding down. What do you want this information for? Oh, he says he's been mentioning connections from abroad. This is the oration, I think. And that's Cockcroft recite BTS. The Swedish Academy would decide on a certain Thursday to whom they would make these awards. So the next Thursday, BBC News, 6 o'clock News. And the last clip I have, and it's not from this program, it's a clip of Einstein talking about relativity. And if you listen, this is not a very clear recording, and his accent, of course, is pretty heavy. But if you listen carefully, you'll hear towards the end his mention of their experiment. In which energy is equal to mass multiplied by the square of the velocity of light. True, this very small amount of mass may be converted into a very large amount of energy. And we figured, the mass is energy where in fact it is. And that's the end of the clips. And I want to just thank Ian, my son, for putting this together for me and being there in case it went wrong. Thank you very much.