Second Part

0:09:07 I had a test for the little green men idea though I had to pinch myself to take it seriously;  I had to spend a week in my room at Churchill College marking a scholarship exam almost directly after the first pulse appeared on November 28th; I was having lunch there one day sitting next to Sir Edward Bullard, the geophysicist, and told him; he said that if they were narrow band they were probably intelligence; as he took it seriously I had to too; we were already measuring the band width and they were indeed narrow band but my argument was that if you have intelligent signals they are likely to be coming from a planet, and that would have to be in orbit around a star; working in the Old Cavendish and doing careful timing of the pulses I'd discovered they were keeping time to better that a millionth of a second per day and I realized that I could detect planetary orbital motion so set up measurements to do that; I timed the pulses accurately for about a month but decided that if I could detect this planetary orbital motion; you can detect that by the Doppler shift; ultimately discovered that the only orbital motion was the earth's and when subtracted from the data there was nothing left, or if there was then it would be so distant from the star that life would not have been possible; took from November 28th; I was doing Doppler shift measurements until January and it took me that time to prove that there wasn't any additional Doppler shift; that eased my mind as it is not physics any more if it is intelligence; at the same time Joscelyn had been analysing past data because it was likely that if we discovered one then there might be others on the charts; she came up with three others which eventually she checked and they turned out to be pulsars too; I had discussed with Martin Ryle before Christmas when I did not know the answer what on earth we were going to do with this data if it turned out that intelligent signals were a likely explanation; you can't just publish it or release it like a news flash; we thought we would inform the Royal Society and get it handled nationally as it was too big a thing to deal with ourselves; luckily that never happened so we started to hunt for conventional scientific explanations; I went to the library and looked up books on midget stars and discovered that white dwarfs and neutron stars were possible solutions; we had enough to write about without saying what they were but describing the work we had done was quite a lengthy job; hinted at the end that this could have been oscillations of a white dwarf or a neutron star; kept our mouths shut which the Americans criticized us for later but I don't repent for a second; revealed the results first in the Cavendish at a group seminar as I felt people there should know what we had been doing; gave it in the Maxwell Theatre

7:54:00 Fred Hoyle was at the seminar; my relations with him were quite reasonable in those days; I met him on committees; he was a wonderful lecturer and always had something interesting to say;  whenever the Observatory Club, as it was called, had meetings they were particularly full when Fred was speaking; he raised a very pertinent question at the seminar suggesting we wanted something between a neutron star and a white dwarf; a neutron star would have given rather more rapid flashes and the white dwarf rather too slow; after my lecture we told Jodrell Bank and they confirmed it instantly and could track it across the sky, which we couldn't do; we announced it jointly in 'Nature' in 1968, including Joscelyn Bell and the three others who had been involved in follow up work, Paul Scott, Robin Collins and John Pilkington; it appeared within about two weeks of the seminar

12:12:07 Got the Nobel Prize with Martin Ryle in 1974; Joscelyn was an excellent student, well organized and a hard worker; she had also put a lot of effort into constructing the telescope at Lord's Bridge; when it comes to the design of the experiment, what observations to make, and the follow up work, she was working under my instructions; another student would have done the same; she is on record as saying that she does not think she ought to have shared in the prize

15:56:05 After this, continued with solar wind measurements; one of the features that we discovered in the sky survey of scintillation on the nine hundred radio galaxies we were observing over twenty-four hours was that certain patches of the sky showed more scintillation than others; these changed from day to day; realized we were making maps of interplanetary weather in a certain sense; this is a very important aspect of space research nowadays because there is so much space technology that has orbiting satellites around the earth; disturbances on the sun can be immensely damaging and can put satellites out of operation or even expose astronauts to high levels of radiation; I decided that here was a radio astronomical technique which might allow you to predict when damaging conditions are going to occur in space close to the earth; it takes two or three days for a solar disturbance to propagate from the sun to the earth; the Americans using current techniques are not able to predict their arrival very easily; the telescope was working until 1994 studying space weather, even after we had completed our sky surveys; we worked on pulsars for a bit but returned to the work on space weather using radio astronomy technique, something I am still interested in; hoped that the Americans would take it up but they preferred to launch spacecraft but I still think there is useful work to be done

21:23:13 The discovery of pulsars opened up a completely new chapter of astronomy; pulsars are spinning neutron stars which act like a celestial lighthouse; neutron stars are tiny and weigh typically just over the mass of the sun but are only a few miles across; the stars are compressed by gravity until they are a tiny angular size; they are on the verge of becoming black holes; Stephen Hawking used to phone me saying how delighted he was that neutron stars had been detected; led to the study of dense matter; confirmed the Roger Penrose and Stephen Hawking concept; more recent work on neutron stars found they gave extremely accurate time measurement in space and in regions where you can actually check out theories of relativity with enormous precision; it had never been known whether some of Einstein's prediction, like gravitational radiation, were correct or not; pulsars demonstrate that these things must exist; Taylor and Hulse in the U.S. found a pulsar which was in orbit about another neutron star, probably a pulsar, and could measure the orbital period to two neutron stars approaching each other; this opens up gravitational relativistic physics and that is a big area that led to another Nobel Prize to Hulse and Taylor

27:15:07 Never worked with Hawking as he is a theoretician; Martin Rees, as a young graduate student, used to come around the old Cavendish talking about what radio galaxies might be; his sort of physics led to theories of how radio galaxies work, which turned out to be correct; he was very influential in understanding the radio maps that Martin Ryle was then making of high resolution showing exactly what was going on in these active galaxies; Rees is extremely clever and pretty wise; he used to think that astrophysics was an American practice rather than a British one but seems to have changed his mind; he is an extremely good President of the Royal Society

29:33:13 Never tempted to go to work in America though I have had offers and have spent a sabbatical at Yale; I have always enjoyed going there, but Cambridge was the centre of the universe; still is a wonderful place to be with so much going on and I think we are extremely lucky to be here; we attract the best young people and they are the stimulus, the pace-makers, that keep the place alive; I have always enjoyed our teaching methods here; have the one to one contact with young people which there is less of in the U.S.; think the combination of research and teaching is a wonderful mix; don't think I really understood physics until I taught it for two or three years; I enjoy lecturing; I had to do the introductory physics lectures in 1976 to anybody doing physics for the Natural Science tripos, about 450 students; had to not bore the brightest or baffle the dimmest, teaching them a lot of basic physics but introducing more difficult things they would meet later on; the supervision system is one of the secrets of Cambridge with close contact with students; the questions bright students ask you are very challenging; too busy to write books but love presenting ideas; gave the Faraday Christmas Lectures; feel it is a duty to explain science to the general public

34:24:16 Contact with religion at school somehow gets into your blood if you go to chapel once a day; I love the old music and the King James Bible; I married a clergyman's daughter which was pretty influential; while I have been a doubter all my life and still am, I do believe in God and believe in supporting the local parish church; having thought a lot about it I can't account for the world without God; to take the atheist view of Richard Dawkins seems to me to be total nonsense; I have read his book carefully and his arguments fall flat as far as I am concerned; sciences not anti-religion; being a scientist and facing up to scientific understanding makes you prepared to believe in another world; I can't see the point of the universe unless there is an intelligence behind it, so you might as well call it God; when you look at the evidence it seems pretty strong too

37:20:21 Advice to a young research student is don't follow the band wagon; try to get into some work that is on the boundaries; when I started in research I was late in applying to the Cavendish as I hadn't planned to be an academic; getting into radio astronomy was the best thing that could have happened to me because all the popular areas had no vacancies; I had the technology and could get into it and do something; my advice is not to get into a well-worn popular subject; try and choose an area which looks interesting and exciting, about which little is known; at the moment, neuroscience or something like that as we haven't a clue how the brain works; when you are starting research your first paper is about the most important you will write; starting research is a very tricky time and I nearly gave up as I didn't think it was getting anywhere; on work methods, I think ideas come to you when you are actually engaged in something; dream a little bit and see whether ideas come