John Carver was born in Sydney in 1926. He received a BSc in 1947 and an MSc in 1948 from the University of Sydney. Carver then went to England (1949 to 1953) to study for his PhD at the Cavendish Laboratory, University of Cambridge. From 1953 to 1961 he was a research fellow, fellow and then senior fellow at the then Research School of Physical Sciences at the ANU. In 1961 Professor Carver was appointed elder professor and head of the department of physics at the University of Adelaide, a position he held until 1978. It was here that his involvement with space-related research began. Working collaboratively with the government facilities at Woomera, he developed scientific rocket payloads to study the absorption of radiation in the atmosphere and the evolution of the Earth's atmosphere more generally. In 1967 he provided the scientific payload for WRESAT, the first Australian satellite, launched from Woomera. Professor Carver returned to the ANU as professor of physics and director of the Research School of Physical Sciences in 1978, a position from which he retired in 1992. Upon his retirement he was appointed emeritus professor and served the ANU as deputy vice-chancellor and director of the Institute of Advanced Studies from 1993 to 1994. Professor Carver passed away on Christmas Day 2004.
In addition to his work within the academic world, Professor Carver contributed to a number of influential national and international bodies. From 1977 to 1982 he was chairman of the Radio Research Board of Australia and from 1983 to 1986 he was chairman of the Anglo-Australian Telescope Board.
Interviewed by Professor Bob Crompton in 1997.
Professor Carver's scientific work includes research in nuclear and atomic physics. His academic career spans 18 years as the Elder Professor of Physics at the University of Adelaide and 15 years as the Director of the Research School of Physical Sciences and Engineering at the Australian National University. In addition, he has served on a number of influential national and international committees. His work has been recognised by his being made a Member of the Order of Australia in 1986 and by fellowships of this Academy and the Academy of Technological Sciences and Engineering.
Forging early links with science
John, I wonder if you can identify any links in the chain of events – perhaps going back to your very early years – that drew you into a career in science, and particularly into physics. You were born and brought up in Sydney, I think.
I was. Looking back, of course, one can invent reasons for how things occurred, but I was always fascinated by science. As a boy I liked playing with mechanical things, particularly Meccano – a great thing in those days, although my grandchildren prefer rather inferior products such as Duplo. My father was very much a handy person round the house, and I learnt a lot of carpentry from him. My grandfather, Harry Heath, had an electrical shop in Rose Bay and as I grew up I spent quite a bit of time there, especially in the workshop at the back, where I learnt a bit about repairing various electrical things like toasters and irons. (Things used to be brought in for repair in those days; it rarely happens now.) And I also could repair some radio sets. Radio fascinated me, and the shortwave radio we listened in to avidly.
At Fort Street Boys' High School it had been customary for everybody to do law, but by my time a lot of the bright people were going into science. Some of our teachers were good, some bad. Our physics master was a very good teacher and a quite good soccer player who used to kick schoolbags from one end of the room to the other! He taught us to appreciate doing difficult things. In those couple of years we did a lot of laboratory work – complicated and brightening – during which he used to blow down your ear and say, ‘You’re better than Newton, son.’ I’ve never been sure whether or not he really meant such things.
My latter schooldays and my university days were during the war, when science – physics, in particular – was a very important and glamorous subject. A lot of us felt that if we couldn’t get into science, we might try engineering or medicine.
University physics and mathematics
Which university did you go on to?
The University of Sydney, which was then the only university in Sydney. It was a pretty good place, but only a small core of what it is now. Victor Bailey was the head of the Department of Physics during the interregnum between Professor von Willer, who had just retired but was still teaching, and Harry Messel’s appointment some years later. Dick Makinson was another important teacher and researcher there.
I was so pleased to be at university to do physics and mathematics. We had a pretty good teaching course, quite intensive. One had two streams each of mathematics and physics. Particularly in mathematics, if you took on the upper stream you got two to three lectures a day, every day, you got twice as much lecturing material as in the pass class, and you really had to work hard at it.
In first year I did maths, physics, chemistry and geology, but in second year I did physics, mathematics and a subject called subsidiary physics, which included useful things like workshop practice and engineering drawing design, some extra physics lectures and some extra physics laboratory work. (I always had a horror of doing any drawings after that year: we had to draw a spherometer, the most objectionable object I’d ever met.) The subsidiary physics course provided quite good training, in some ways an introduction to research, because we had to set up a Millikan’s experiment. We spent a full term, a third of the year, on getting it going – putting in as many hours as we could spare and using homemade bits and pieces which included a big electric arc light. We measured the energy change and got the charge nicely quantised. It was all very beautiful; I was certainly pleased with the experiment.
Third year was another important time. The group of people a few years ahead of us had been whipped off from their courses after two years of science, to be turned into radar officers – and then they had very responsible jobs, because Australia did most of the radar throughout the Pacific war. In our third year, at the end of the war, they all came back. They might have been only a few years older than we were, but in maturity they were a lifetime older. There was a certain degree of rivalry between the two groups, symbolised by this little incident. These other fellows wore their uniforms for the first few weeks until they got some civvy clothes, and a lieutenant left his Naval cap on the bench in the lecture room. But when my friend Ray Mitchell took the cap out and gave it him, his response was, ‘Oh, thank you, sonny.’ That didn’t do too much to improve relations for a while! (After some time, though, we all became friends and welded into one group.)
We benefited from a very intensive course of electronics in that year, using the equipment that had been built in the radar officers’ training course. The techniques were still fairly new, but the staff had taught the Sydney radar training courses – and physicists are adaptable people, as we soon learnt. There was never a thought that you couldn’t do anything, and the people who put together the radar training course actually put together all the small two-inch oscilloscopes which everyone used. Phil Guest, who was then a lecturer or senior lecturer, organised the practical course. The ex-radar officers, of course, were miles ahead of us in learning that technology and we had to work like blazes to get anywhere near their knowledge.
The fascinating entry into nuclear physics
We went on into honours year, where the pattern in Sydney was to join a research group and then spend a fair amount of time at lectures. We had very enjoyable courses in relativity and quantum mechanics, and spectroscopy and atomic physics, because Bailey was particularly interested in electricity in gases – so we had 3rd and 4th year courses in that subject. After the honours year you would do an MSc in the following year and write a thesis on it. (Then waited around for six months before going off to some other country, usually England, to do a PhD. There was no PhD in Sydney until just as I was leaving.)
I joined the nuclear physics research group, a pretty active, well-balanced group in which we were all working for an MSc. Dick Makinson looked after the whole thing, but Guy White was the Führer of the group. It was a Sydney tradition to have almost a do-it-yourself education system. There were always a few bright students who would be not so far ahead of you that you didn’t get to know them, and we’d all been teaching one or two years below us as we went through – I started teaching first-year class when I was in second year, in the labs. I enjoyed it and it brought money, which was badly needed in the pocket. Besides Guy White there were quite a few other very bright people. Peter Thoneman had come on a fellowship and had built a plasma ion source which turned out to be an extremely important device, because some years later the basic principles of it were taken over into almost every accelerator in the world. Peter Treacy was one year ahead of me, doing nuclear physics, and Paul Klemens and Clive Coogan had done well in solid state physics.
There are two ways you could have gone: instrumentation for nuclear physics, and actually doing nuclear physics experiments. What were the main experiments?
We were trying to get an accelerator going that would be a neutron source. (I suspect it didn’t ever get going properly, though.) One of the good things we did, which was extremely valuable to me, was to make loads and loads of different sorts of Geiger counters. Kurt Landecker taught us glassblowing and most of us became quite proficient amateur glassblowers, using a technique in which the glassware was always held in retort stands and clamps and we moved the flame. That’s very non-U; proper glassblowers like to have the flame fixed and move the glass. I never could do that, but building so many different sorts of Geiger counters stood me in good stead later.
Did any of Bailey’s electricity and gases stuff help you in your experiments?
Yes. A particular filling gas caused Guy a lot of trouble, in that the counter seemed to be very low efficiency, with methylene bromide in it. I worried about this, and after he left I built a number of counters filled with this obnoxious gas. I realised that there was something gobbling up the electrons: it was, in fact, an electron attaching gas. That fascinated me and I developed a little theory as to how it would go on. I made some devices that allowed one to measure electron attachment coefficients by coincidences between a chamber which had the attaching gas in it and one which didn’t. That was delightful, and I published it with Guy in Nature as our first paper. And that came about because Bailey had drummed into us all sorts of jolly things about electricity and gases. Bailey was a marvellous little man – an eccentric, with a tremendous opinion of his own abilities, enormous enthusiasm and strong hatreds. We laughed at him, but we enjoyed him. He certainly taught us that we could do anything and we should be very competent physicists.
Journeying on an ANU scholarship
That takes us on to the ANU scholarship you won. There wasn’t yet an Australian National University physically to go to so, like other ANU PhD scholars, you went across to England to do your DPhil course. How were you aware that such arrangements existed, and how did you select your university?
Well, in Sydney the pattern had been formed that every year people seemed to go off on scholarships to Britain. A lot of the staff had been there and come back. Mathematics was even worse than Physics in that sense, being entirely staffed by people who had done their maths in Sydney, had gone off to Cambridge and got a PhD and had then come back and joined the staff. Such good scholarships seemed to me to offer a wonderful opportunity.
I met Mark Oliphant for the first time when he visited Sydney while I was a student there. He’s always been impressive, but he looked very formidable to me – and about 110 years old. (He would have been about 45 or 48, I suppose.) He was strong but very likeable. He talked and listened to what you had to say, and that was nice.
He was at that stage still at Birmingham but looking at how to develop the school at ANU, so I talked with him about scholarships. I think they were advertised; certainly the staff – Makinson and Bailey – told me about them. Bailey, in his usual arrogant, extravagant way, asked where we wanted to go. I told him I thought of joining Oliphant, that there were a number of places like Birmingham and Glasgow as well as Oxford and Cambridge. Bailey said there wasn’t going to be any nonsense like that. No student of his was going to Manchester or Liverpool or Glasgow: ‘Go to Oxford or Cambridge, otherwise it will be just like going from Sydney to Sydney.’ You had to move up the line. Probably that was why there was a very tight ship out of the Sydney Physics Department, mainly to Cambridge and just a few to Oxford. But Cambridge was stronger than Oxford in nuclear physics.
Oliphant of course took a slightly different view. He was trying to place the students around with some of his mates at provincial English universities. He had himself recruited a very good team of Australians in Birmingham, but I heard enough on the grapevine to think that Birmingham might be mixing concrete for a while. Much as I admired Oliphant, I thought it would be better to go to Cambridge.
In 1949 the only way to get out of Sydney was by ship so, with several other graduate students, we sailed off on the Orontes for our great journey. We went the standard route through Suez to Britain. It didn’t strike me as strange at that time, although looking back on it I find it rather interesting that, at every port where we stopped, there was a Union Jack and British soldiers on the ground. But we didn’t stop at any ‘foreign’ places: Colombo and Aden were British.
Jim Roberts and I were travelling together on the Orontes. He was going to Cambridge on a studentship for the Council for Scientific and Industrial Research, to do theoretical work. There were several other students in the company of the ship. All of us who were potential research students in different subjects – going to do PhDs, first-class honours and all the rest of it – were in the tourist class. The ANU gave me £75 for my passage to Britain, which was adequate. (I paid £79, actually.) Quite a few of my other friends, mainly those who hadn’t perhaps done quite so well academically but were journeying to join the long-range weapons establishment, were in the first class, wearing bow ties every night.
At Colombo we were joined by a group of Ceylonese students, most of whom were also going off to Cambridge but a few to London and Oxford. We became very close, in some cases, lifelong friends with them, mainly because I and the other Australians had a good supply of 'Kwells', the anti-seasickness pills. They hadn’t heard of this magic, and they badly needed it for a little while!
Settling in for a Cambridge doctorate
After a happy journey we got to Cambridge, a beautiful place but confusing for a stranger. But Peter Treacy met us both there, which was rather comforting. He had gone to Cambridge just the year before me and seemed to be getting on all right. He had taken an ‘1851 Exhibition’, a very prestigious scholarship.
I then had to work out how to join some experimental group. They had there a sort of Dutch auction, quite a funny business: you spent the first couple of weeks wandering around the lab, talking to people, with supervisors trying to attract students, students trying to pick the best supervisor. There were some very good people doing a lot of physics, but the place was no longer Rutherford’s and had no really tight organisation. Eventually I discovered that the brightest young person in the department was Denys Wilkinson, only a few years older than I but already beginning to be a bit of a name. (Unfortunately, he had suffered a serious neutron cataract. He had taken leave from nuclear physics for a year or two, during which time he had become quite an expert birdwatcher. He was even thinking of making a career as an ornithologist.)
I went next to see the professor, Otto Frisch. He was a wonderful man but a complete eccentric, and as lazy as can be. He had great ideas but he didn’t like taking on too many responsibilities. There are lots of stories about him. His favourite trick was to keep a dirty old pair of trousers in the bottom drawer of his desk. If things got too difficult in an interview with a research student – in other words, if he was being pushed to actually do something – he used to reach down, pull the drawer open and take out these dirty trousers: ‘I’ve got to go to the cleaners.’
Frisch confirmed my views about Wilkinson, whom I went to see at home. He was in bed with the worst dose of flu I’d ever seen, but pale though he was, he talked wonderful sense and was very enthusiastic about the sort of things we would be able to do. My only worry was whether he’d last long enough to get me right through my PhD. Just for the record: Sir Denys, as he became, is still going strong and is likely to go on for decades.
A fiery incident: working on photodisintegration of the deuteron
So you teamed up with Wilkinson?
Yes, and that got me on a very good route. I became his proper, legal research student. We worked on photodisintegration of the deuteron and then of some other material. We had three working accelerators, two high-tension sets and a small cyclotron, and a Van de Graaff machine was being built. Nobody with any sense would go into building the Van de Graaff, so that was left to honours people who were making sacrifices, really. The cyclotron was a very small one, not particularly interesting, but the high-tension sets that we used – despite being the original old-style Cockcroft-Walton machines – were pretty good. Denys had the one called HT2, and we managed to work on that with a couple of technicians.
We had no delusions that this accelerator was going to last for ever. We only wanted to do some quick experiments with it over the next three or four years and get going. The pattern of things was that each of the research students would be doing some particular experiment on the accelerator, often involving the building of counters or a system like that. I was given a room and a desk down on the ground floor, but thanks to Denys I also had a room set up as a lab in the old part of the Cavendish. Knowing I needed to build some counters, I began by putting together a good vacuum system and a pumping system to build ion chambers of some sort.
Next I built a high-pressure proportional counter filled with deuterium. It was quite a fearsome device, with a side-arm in which you could circulate the deuterium. The deuterium was filled through palladium tubes at the back, I dropped a piece of sodium in the side-arm of the counter, and when everything was raring to go I would get hold of a Bunsen torch and heat up the side-arm to fire the sodium all over it, and then circulate the gas with a convection heater to take out the last bit of oxygen. It was extremely pure stuff. I had one accident with that, when the end blew off at one stage and I had a glorious fire of deuterium gas at high pressure and sodium. But apart from that it all went pretty well. That was my main system.
It was an unusual counter. As is common, it had a very fine wire down the centre. But it was quite novel – no other counters operated at this sort of pressure – and I wanted to have only one insulator, just in one end, and then a wire with a plumb-bob on the end of it. You had to set it up in the vertical. We had 100 yards to go from the attic of the old Cavendish, where I had built it, down to the ground floor, out in the rough corridor and then across the courtyard to where our accelerator was. But I always got it there eventually, and didn’t break the wire.
What was the experiment for which you built the counter?
It was photodisintegration of the deuteron. By having a high-pressure chamber and exposing it to gamma-rays from an accelerator, one could disintegrate the deuteron so the photo protons went off and were detected in the proportional counter.
I did a lot of that, and we measured it as a function of energy by looking at the gamma-rays of different energies. That was a very successful experiment. When the standard textbook of that time, Blatt and Weisskopf’s book, came out, I was pleased to see my points were in the diagrams. (In fact, I watched all the half a dozen points I provided; it’s a truly fundamental measurement.) When the points were first put into review papers, our papers with my name on them were always quoted. Gradually they got into reviews of reviews and textbooks – the quotation usually was the last review but you could still see the same points. I’d like to have them luminous or something.
I think there are about seven papers with your name and Wilkinson’s on them from that time.
It was a very productive period and all good fun. We had a happy time. I was there about three and a half years in all.
Moving back – and up – to an ANU accelerator
When you returned to Australia, in 1953, you were one of the very early staff members of the then Research School of Physical Sciences.
At Cambridge, Oliphant had called a few meetings of the various ANU research students, and we went to Birmingham – Stuart Butler and a few others were there. Oliphant talked about some of his ideas of what going to be built in Canberra, and I must say most of us actually believed that all this was going to happen: when we came to Canberra in two or three years’ time the accelerator would be built and we’d all discover the anti-proton, get Nobel Prizes and retire for the rest of our lives.
I met Ernie Titterton, the first appointed professor of nuclear physics, while I was in Cambridge. He had been at Birmingham before going away to Los Alamos, where he had done a lot of the electronic triggering for the first bombs. When he came back he ran a photo plate group at Harwell, and he used to come and irradiate some photo plates at our accelerator.
I came home on the Himalaya, the ANU paying more to get me back than the £75 they sent me over on because academic staff members were entitled to first-class passages. Consequently I learned to tie a bow tie – you do it with one hand – and had a grand time. And then I got to Canberra.
I had some vague memory of visiting Canberra as a lad, when we came up with my father by car. But when I made the long train journey from Sydney to Canberra and arrived at the little stop, I did wonder slightly whether this really was the national capital. I was then picked up by somebody from the administration of the university and put in Brassey House, where there was a lot of unmarried staff. (I met my wife in Canberra, but not until later when she came out from England.)
Ernest Titterton looked after me in nuclear physics. We had a small Philips set – quite nice, and more reliable than the Cockcroft-Walton set at Cambridge.
Was the so-called Oliphant Building there then?
No. The Cockcroft Building was there, more or less. We had the accelerator on a lower level, with a small building which was later encompassed by the tandem accelerator building. The Cockcroft-Walton sets were marvellous, rather beautiful machines like a cinematic scientist’s dream: tall towers and sparks and so on. Both in Cambridge and in Canberra I spent a lot of times crouched in the corner of the room, watching to see where the spark went as somebody wound up the Cockcroft-Walton set to its highest voltage – because they invariably break down. (They often broke down at 2 o’clock in the morning when you were trying to run them.)
Another great advantage of Canberra was that we had some decent ladders and devices for climbing up to the top, whereas in Cambridge we had the most ropy, broken ladders. In the best of times I hated going up them, but to go up in the middle of the night when you could not be sure that somebody had properly earthed the accelerator was pretty awful.
Using the detector which I had brought (along with a few other useful things in my pockets) back to Canberra, I went on with my photodisintegration work, continuing much of what I had done in Cambridge. I could do as good a job here and the facilities were literally as good as they had been. But I also did some different things, arising from my old interest in being able to make ion chambers and Geiger counters. I could make a Geiger counter, say, with a tantalum cathode, expose it to the radiation and produce photo-induced radioactivity in it. That was a very efficient way of actually detecting the reactions.
Using a little synchrotron to study a giant resonance
What work in that period were you proudest of?
Well, it would have been with our little 33 MeV synchrotron, in the basement of the Oliphant Building where the tunnel runs through, linking the two buildings. It had been at Harwell and was a gift. I would hardly call it a commercial machine – electron synchrotons – but people at Malvern designed and constructed several. We ended up with a 33 MeV machine which came to us in loads and loads of packages, and it was a fiendish job to get it together and working. Ronnie Edge was one of those who had helped to pack up the machine in Britain and reassemble it in Canberra.
We did a lot of good work with that machine. At that time most photodisintegration work had been with a number of 22 MeV betatrons around the world. Our work had been done in Cambridge and then at ANU using discrete gamma-ray sources, from about 4 MeV up to 18 MeV (we were about the only people to do that) but you could do only a limited number of things with that. With the 33 MeV machine we had a little window of 10 MeV or so above the limits that the betatrons could get to, in the middle of the tails of the giant resonances – which I should explain.
I have talked about photodisintegration work with the deuteron, but in the heavy nuclei there is a giant resonance which moves systematically through the periodic table: all the neutrons move against all the protons in the nucleus, so you get some very simple behaviours. It is relatively easy to interpret theoretically, and we did a lot of interpretation on it. As the neutrons move against all the protons, that gives you a dipole resonance, with this collective motion making it quite strong. It was good to be able to see it move systematically to lower and lower energies as you got to heavier and heavier nuclei.
In the tail above the giant resonance, you can get not just one neutron emitted but two, three, four or five, and so there are a lot of things one can measure, looking at the competition with the emission of neutrons and protons and so on.
Was the tandem accelerator in operation during that time?
No. It started just as my period there was ending and it got running soon afterwards. The synchrotron had a failure shortly after I left, and was dissembled and sent off to Perth to be put together again.
Did you work at all on the machine at the end of the Cockcroft, where my lab was?
No, not really, except for a little bit with Reg Mills and one or two other people there. It was a smaller high-tension set which was mainly used as a neutron source – a very powerful one. But it was burnt up in the fire which destroyed a fair amount of that building.
I was at the ANU in Canberra from 1953 to ’61, with a year’s study leave in 1958-59 during which I went off to Harwell and resumed contact with all the people I’d been with in the Cavendish. I had a very productive year there, mainly writing papers with Arnold Jones, and working with staff in Hangar 8, led by Dr Bretscher. We did a lot of the inverse of photodisintegration: instead of doing (gamma, n) we did (n or p, gamma) and (d, gamma).
Harwell was at that time a very nice place. Peter Thoneman had set up there and had a fusion reactor called ZETA going which was overblown in publicity, unfortunately. ZETA was supposed to have been the answer to all fusion problems – and John Cockcroft, who was then Director at Harwell, really believed then that it was. But unfortunately it wasn’t, and people in Hangar 8 showed that the companion neutrons were not thermal neutrons at all. ZETA was a highly classified object at that stage.
Your first period at ANU, John, ended when you were appointed to the Elder Chair of Physics, in Adelaide. That brought a great switch in your scientific interests, didn’t it?
I blame it all on Mark Oliphant, actually. He had been asked to find someone to fill the Chair in Adelaide, and he put my name forward and encouraged me to go. I had a number of long talks with him about it. He said, ‘You’re just the right age to do it’ – because I was just the age at which he’d gone to Birmingham.
In Canberra my vision of what could happen in nuclear physics really depended on the big successes we might have had in the particle physics area. The failure of the big accelerator project meant that most of these aspirations had to be abandoned. We were not to be the discoverers of the anti-proton. I soon realised that doing quantum mechanical problems in nuclei was no more interesting than doing them in atoms and molecules. I was interested in nuclei originally with my deuteron photo work because that was one of the fundamental forces, and the measurement was basic to new science. Although important nuclear physics work was to go on in laboratories such as ours had become – and we had to cut down to a lower energy group – it was not fundamentally opening up new insights on the structure of matter. That required you to be in a higher league.
There was no opportunity to do nuclear physics in Adelaide, and in my view it would have been very foolish to try to set it up. Moving the synchrotron there would have been possible but it would have occupied all our efforts to observe things. Anyway, I wasn’t unhappy about the idea of doing atomic and molecular physics, because I always thought a lot about it – I suppose partly because of my background in Sydney on some of those problems. So I felt that a change could be good. (It wasn’t as big a change as some people think, since I had nearly always worked on photo-effects in nuclei and I now worked on photo-effects in atoms and molecules, and I was always looking for things like the giant resonances.)
Adelaide had a great advantage which I did not think had been exploited enough: it was right next to one of the biggest physical laboratories in the country, the Weapons Research Establishment (as it was then), with the work at Woomera. So I had no difficulty in saying that if anyone was to do anything sensible in Adelaide, they had to have an advantage – and the advantage was this enormous defence establishment, which wanted some involvement with universities and by comparison with the university system had money pouring out of its ears. When I went to talk to people in Adelaide I put that sort of proposition to them and found many of them wanted to have a strong connection like that. I had a very good welcome from Bill Boswell, who was the director at Salisbury and Woomera and controlled vast sums of money and resources. Also, I made contact with John Knott, the Secretary to the Department of Supply, in Melbourne, and he was on side too.
We were then able to do experiments using half a dozen rockets a year from the establishment out at Salisbury, pretty good stuff. Some at least of the research students found it quite exciting work. We had to build a group of people in Adelaide, but that was a good time to go into trying something new because the universities were again in an expanding mood.
You were switching, too, from an institute which was training PhD students but primarily involved with research, to a more conventional university with both teaching and research.
Yes. Being appointed Elder Professor meant very much taking over the shop, in that the professor in those days controlled all the moneys. In Adelaide it was probably worse – or better – in that sense than almost anywhere else in the country. I was also chief examiner in physics at the schools, and sat on the Public Examinations Board of the University of Adelaide. So you not only controlled everything that was done in the Physics Department, but in principle you controlled the whole teaching of physics in the state. I took all those things seriously and spent a lot of time going round the schools, talking to students. We had a formal arrangement to examine their laboratory notebooks, and we used to do a lot of that.
There was a team of very good people around – people like David Sutton, Graham Elford and Stan Tomlin. I was just about the youngest member of staff when I was appointed to that job. And I must say I enjoyed every minute of it. The teaching I had not done before, but I had done a lot of tutorial work in Cambridge and I had always demonstrated in labs, so I didn’t find it too overwhelming. But I must say it was a lot of work, and looking back through my notes I wonder how I managed to get through as much as I did. (Well, I managed partly by writing my lectures for the next week on sunday night!)
What was the topic for your initial work with the rockets, and how did you select it? And is it true that the laboratory experiments were pretty well in tandem with the airborne or high-altitude ones?
I looked for simple things to do, and they were pretty simple. We took the absorption of ultraviolet radiation in the atmosphere as the problem, because that was close to the sorts of things I understood, and I rationalised it a lot. The typical absorption thing was the Lyman-alpha radiation function. That radiation was very important because it is the fundamental line of the simplest atom and the dominant radiation when you’re off the Earth. Absorption of all those radiations into the Earth’s atmosphere, in the UV, is what starts off the photochemistry of the atmosphere and the whole plethora of problems that come from that. It was relatively simple to make some detectors. Initially we made Lyman-alpha detectors, which were very like the little Geiger counter I had set up – little cylinders with a rod in the middle and a window in the front. By varying the window and the gas we could make detectors which picked out particular bits of the UV.
The very first experiment we did was on the absorption in the atmosphere of Lyman-alpha radiation from the sun. That turned out nicely and gave a rather simple way of measuring the molecular oxygen density profile over a certain range in the atmosphere. The detectors we built for that – again like little versions of Geiger counters – were filled with a gas which provided one limit on the wavelength, and their window in the front could be varied from lithium fluoride or magnesium fluoride right up to quartz and sapphire, providing the other wavelength limit. So they were bandpass devices. We also built lots of ways of testing the detectors, taking a portable UV source up to the range to test them before they were flown in the rocket.
After a number of such experiments in the daylight, mainly getting molecular oxygen, we were very interested in doing similar experiments at night. We had a rather delightful set of experiments which used the full moon as the light source. Out of that we got the reflectivity of the moon in the UV, which was not very well known, and then using that we worked in the peak of the ozone band absorption, about 2500 Ångstroms, and we got ozone distributions at night, high in each tail. One reason for doing that at night was that light has to be very much in photochemical equilibrium and not dominated by transport as the ozone is lower down, particularly during the day.
We spent a few years on this program, doing a lot of experiments but not as many as I would have liked. I always tried to get seasonal and diurnal variations, but we could instrument only about five or six rockets a year – the limit of what the Salisbury people would fire for us. Ideally one would have liked to let off 20 rockets in one day; we never reached that level of power. But we made a lot of the measurements with Brian Rofe's group at WRE and got out a fair amount of data about UV radiation absorption in the Southern Hemisphere.
Not a Woomera failure at all: launching WRESAT 1
In about 1965-66 there was a big Redstone rocket left over from a Woomera program to study re-entry into the atmosphere, and the good-hearted Americans offered it to the Australians who had been working with them, saying that Australia could probably put a satellite in orbit with it. The WRE people at Salisbury said 'yes', and would I be prepared to provide the experimental package? I said of course we would. I knew we had some very good infrastructure as a basis for testing, including a big vacuum tank – big enough to hold the whole satellite – which I had got built with money from the ARC [Australian Research Council]. But after we’d all accepted, the Americans told us we had to do it all in 12 months because then they would have to go home. So Brian Horton and the rest of the university team worked very hard in collaboration with the Salisbury people, and it was all done in 12 months.
As usual I was up there for the launch. Going to launches of rockets is a funny business: most of the people who are there have strong emotional involvement with the rocket but can’t do anything at the time it is to be fired. On the day the rocket was scheduled for firing, the firing schedule went right down to the last minute but then had to be cancelled because things hadn’t worked quite as they should. Everything was put off to the following day and it was very disappointing to go home that night without having fired the rocket. And the press, who all had been there, called it another one of those Woomera failures. By the time we went out the next day, though, the American crew – a pretty tough lot of rednecks – had belted the rocket in a few places and it went off beautifully, with a great roar.
In those early days, 1967, we were the third country to launch our own satellite from our own site. We were front page on every newspaper in Australia. There was a wonderful feeling of delight when it went up. We were able to read the instruments from quite early on in the flight and we could see that everything was working, and then it came round again and you knew it really was in orbit!
Was anyone doing telemetry for you?
Oh yes. Loads of people around the world tracked it for us; we were able to collect data quite continually. And another marvellous thing was that people were so cooperative and friendly about it. Despite all the occasional criticism there has been of Defence Science, when they had this challenging thing to do in a defined time they were wonderful. They would break any rule and do anything to help. If you said you needed batteries to power the thing, and all the paperwork hadn’t gone through, they would nevertheless get them in from the States – and off it went. That was a great thrill and I was very pleased.
Were the scientific results up to what you hoped?
Yes. I would have liked even more data, of course. The flight lasted just a few days at about 200 or 300 kilometres, until eventually its battery power failed and it was brought down by atmospheric drag, doing a re-entry over Ireland.
Accumulated space research experience
Are you disappointed that Australia hasn’t gone further with satellite work and space research generally?
I am. We missed a lot of opportunities, and we could have built on WRESAT. Its formal name was WRESAT 1, on the assumption that 2, 3, 4 and 5 might come after it. The US in fact offered us some more Redstones, but the powers that be – in their wisdom – decided there wasn’t anything in it for them. It is a great pity. Perhaps we didn’t have as much scientific skill as we needed, but we could have easily built that up. We had certainly built up a tremendous amount of technological skill in handling the rockets, tracking them, knowing what to do with everything. Woomera was the third busiest range in the world at that stage.
In building the satellite itself you must have had to deal with problems such as the need to be awfully careful about outgassing rates in whatever materials you used. Many of those things you had to discover, I guess, by trial and error.
Yes, and nothing succeeds like success. There were a lot of things we wouldn’t have had to bother about later on, having worked out what to do with this first one. We had to find ways of testing for vibration – we used motor vehicle testing arrangements – and we had to test it on temperature, pressure and cycling. I had the nice big vacuum tank which Ewen McKenzie had built in the lab in Adelaide; I had designed it long enough so that we could get our rocket nose cones in it but also fat enough so we could put in balloon payloads. (We were doing a lot of balloon work in the department at that time too.) It turned out to be just big enough to take the WRESAT rocket nose cone, the actual satellite, which was about a metre and a half long.
People were really on the top of a wave at that stage, and an awful lot could have been done. I have always argued, like a lot of other people, that Australia is the country which has got most to gain, in some ways, from the use of space. We have done pretty well out of it on the communications side, and we’ve got a lot of remote sensing and meteorological data. We still get free meteorological data from Japanese, American and occasionally Russian satellites. I can’t believe that we won’t at some stage have to pay the piper for these things. The right way to ensure that we continue to get the benefits, and at reasonable cost, is by being involved in the science and the technology. That’s been a very hard message to get through.
Is anyone else in Australia building anything to go into other people’s satellites?
There’s not much of that now. It may come good again. There is a proposal to set up a Cooperative Research Centre for space work, and that might get somewhere. But to make the most of an opportunity to do something that brings together a whole host of the technologies available in the country, you’ve got to start appointing some young people in those areas and keep the work coming for them. At the moment, the people who have most knowledge of space technology are joining the retired list.
Solving an atmospheric absorption problem
How complementary have the lab experiments and the airborne ones been?
They’re very complementary, perhaps best illustrated by one experiment. I mentioned that we measured the absorption of Lyman-alpha radiation in the atmosphere. The Lyman-alpha is a very fundamental line of any star, being the fundamental line of hydrogen. It is quite a broad line from our sun and has in it quite a bit of structure which means that its absorption in the atmosphere depends not only on the absorbing medium, the molecular oxygen, but also on the shape of the cross-section over the line itself. Nobody has had the resolution to go and make measurements at each point on this broad line. The cross-section across that broad line tends to be dependent on the temperature, which changes in the upper atmosphere according to height.
So in the lab we built a big six-metre monochrometer – a beautiful machine – and as our first experiment we looked at the structure of the Lyman-alpha line and, point by point, at the absorption cross-section of oxygen over the shape of that line. We also looked at its temperature dependence. When we got all that out and understood it, it was perfectly applicable to the atmospheric problem and resolved a lot of anomalies. I’d had arguments for years with people who said there were other absorbers in the atmosphere, because it wasn’t turning out right when they measured the Lyman-alpha absorption. But once this temperature-dependent cross-section was put in, we got all that beautifully sorted out. I reckon that dealing with any problem which solves another big problem is a pretty good experiment.
We had quite a wide group of good people involved in that, especially Brenton Lewis, Don McCoy, Alistair Blake, Steve Gibson and Mohamad Ilias, who is now in Penang, Malaysia. Since then we’ve moved some of the work to the ANU, where we made quite a feature later on of measuring temperature dependence of absorption cross-sections to learn about their systems.
I was pleased about the strength and quality of the research students that used to come through in Adelaide. I don’t think a year went by without one or two – occasionally three – graduates in the honours class whom I would consider as good as you would find anywhere in the world. Brilliant people. Alistair Blake, Gerald Haddad, John Bahr, and Jim Gardiner were some of the earliest research students we had. They did some exciting work on photo-electron spectroscopy, which we started off in Adelaide. At that time most people were using just discrete sources. We found a way of marrying up the photo-electron spectrometer with our one-metre monochrometer and we were able to scan through it from 500 Ǻngstroms upwards. That was exciting work and I’d like to see some more done with it.
We had techniques of understanding the behaviour of excited states by looking at the spectrum, resolving all the rotational states and being able to understand why in some cases you’d go to a wide number of vibration numbers and in others you wouldn’t. This was a means of determining the characteristics of the excited states, and it is a measure then of the overlap between that state and the ground state. We did a lot of work on the properties of the virtual states in the oxygen spectrum, because that laboratory work is today relevant to the absorption problems in the atmosphere.
Feet on the ground: sensible academic management
You referred earlier to taking over the whole department in Adelaide, with the new experiences which that involved. Did you find that as time went on you were drawn more and more into higher-level administration in the university?
I have always enjoyed running things, although I would not quite describe my style as administration. I was pleased to be able to manage the Physics Department, and we had regular meetings of the faculty and somewhat less regular meetings of the whole school, which involved the students as well.
Also, as a head of department, I was automatically a member of the Education Committee, as it is called in Adelaide. That was the controlling body on academic issues, which in other universities would be called a professorial or an academic board. I then became Chairman of that committee, having been Dean of Science beforehand. (We had a system that the deans and the chairmen, when they were going out, had to look for someone to take on the job.) I enjoyed my two years in that job.
There was a lot to run in Adelaide. Most of the time I was there the university administration was very good indeed, with a sensible separation of academic and non-academic matters. There was no sense in letting the Education Committee act as a committee for parking and similar matters. The non-academic or business matters were mostly decided by one person, Vic Edgeloe, the Registrar, who seemed to have the whole staffing and financial side of the university in his head. Most of our academics, I think – certainly most heads of departments – were content to accept his decisions and statements about what was going on in the management side. To me, putting issues of management and business through the collegiate academic stream would have led to a tremendous amount of time-wasting and argument.
On the other side of things, I think there was a clear understanding that the academic matters – things to do with examinations and student progress, the appointments to academic staff, the sort of research programs that people were going to carry out – would be decided by academics themselves. We distributed research moneys through a small research committee which was entirely academic. All those things were well done, with limited bureaucratic involvement.
There were certain crucial things that somebody running a large department like Physics had to do. One of the most demanding was to work out the lecturing timetable and the allocation of lecturing and teaching duties. I always did that myself, asking help from people to put things together, and when I finally got what I thought was a balanced scheme I’d put it to all the staff members. It is very important that one person takes a real interest in that. You’ve got to recognise that some people need more time for research but others get a bit tired of that side and see their future instead as doing worthwhile things in the development of laboratory courses, in particular. I think we had a relatively happy arrangement which gave a wide range of possibilities in how you divide your time up.
Restructuring an ANU research school
The time in Adelaide came to an end in 1978, when you were appointed as Director in what was then the ANU Research School of Physical Sciences. Perhaps you would say something about the perceived challenges and opportunities which led you to make a number of major changes – ultimately even to the name of the school.
I have great affection for the school and for the ANU. Not to be too modest about it, I thought that I could do a better job as Director than anyone else could, because of my background in the school and my experience. Although I realised that not everybody would share my vision about it, being fairly determined I tried to bring out my idea of how the place should go – and mostly I did bring it out.
Fundamental was the idea that the school should be seen as integral and valuable to the Australian nation. I believe that was the original premise on which it was sold to the nation in the 1950s, when Australia wanted to be increasingly involved in nuclear matters and so the nuclear physics side of the school’s work was dominant. Oliphant was out of the top drawer for that sort of work, and determined to achieve it. Things were very different in ’78 when I came back. It was not that any of the work was not important or that some of it was not extremely relevant, but a lot of people outside the school did not see the importance or the relevance. And a lot of people within the school didn’t think it was important to make the relevance more apparent.
I felt we could move towards a lot of work which here we would call good physics but which in American universities would often be part of the engineering schools. At the same time I thought that the structure, and some appointments, needed to be changed. I wanted to make the school relevant to the nation and to be accepted that way by everybody. I didn’t want to chop out anything much, but to make changes by rearrangement. This would take a long time, so you had to be consistent in where you wanted to go and also to be willing to change in the light of the opportunities that came up.
There’s a fair account of it in the book Fire in the Belly, which Trevor Ophel wrote. Not everything he said there is quite the way I would want to put it, but I think the basic ideas of getting ourselves strong in what I call the core areas of physics nowadays – the atomic and molecular work, the laser and EME [electronic materials engineering] work, the nuclear physics – are all central to the aims of the school. I wanted to bring that out.
One way of getting ourselves some protection and being seen as more relevant was to bring in engineering in a more obvious and publicised way, so I recruited Brian Anderson, whom I thought was first-class, the best academic engineer in the country. His strong views about engineering may not be shared by all members of the school, but bringing him and system engineering in did give the school a new complexion.
We had a small addition in computing science, as well. That was an important area to keep in the university, and if we hadn’t set up that small group the university as a whole might have lost Richard Brent, who was far and away the best academic computing scientist in the country.
Reorganising the nuclear, electronic and information sciences links
Were engineering and computing science the only areas of change?
No, there was quite a bit more reorganisation. I tidied up and formed AMPL [the Atomic and Molecular Physics Laboratory]. Even though the electron physics and diffusion research units could operate perfectly independently, they were so much smaller than the other groups in the school that it was very hard to see them represented properly on Faculty Board and elsewhere. So I put those groups together with my own UV physics group as a sort of federation, hoping they would continue to flourish with independent programs and independent moneys but cooperatively enough to have their views put by a head of the department or of the laboratory. The optics group could probably have gone in as part of a highly successful empire, but because optics seemed very important and had shown some flashes of genius, I decided to set up an optics centre.
I deliberately didn’t use the name ‘department’ for most of these new groupings, because I hoped to have a more fluid structure and more fluid links with industry than that word suggests. But some of the existing departments felt very strongly that they wanted to retain that kind of name.
Then EME was set up to bring in a group which would, in my view, be able to draw on all the techniques of not only our basic science groups but also surface science, which is applied mathematics, and atomic and molecular physics and laser physics, and link us in with the Australian industrial base. I think it is doing that, but it’s got a hard road to go.
We’ve now formed another school out of the information sciences and engineering groups. That was strongly opposed by some people outside the school who believed it should be delayed until after the institute review that we were having. I was fairly sure that if we waited till after that review we’d have nothing, so I pushed very hard and sold all my proprietary capital rights in getting that. I hoped it would grow. I thought we were going to get a substantial amount of extra funds from the government at that time. I believe everybody would realise, when they think about it, that the industrial base of the future is going to depend very much on information sciences and the engineering that goes with it.
Do you think the Research School of Physical Sciences and Engineering will revert to Physical Sciences, or even change entirely to Engineering?
We need to keep both aspects in the title of the school in order to have a future in which physics and physical sciences and also engineering of that mechanical and electronic sort are strong. They are both required in building the future industrial base of the country and I am quite sure that we have to look firmly at that.
Because there are problems in Australia, a number of our universities have already run their physics departments down to a level where they can barely survive. It is vitally important that this school survives and flourishes, and in my view we should be looking now to an expansion of its work. We should be adding, say, a materials science group of a strict sort to complement the bits that have now dropped out of the solid state, and once again I think the only way to do it is to have in mind a researcher to bring here. I’d be totally opposed to handing over money for a development in, say, solid state or materials science and just advertising, hoping the best man comes along. We seem unable to do that very well. We need to get a person so good that you can march him off to the Vice-Chancellor and say, ‘Look, this guy wants to come and work here. All he needs is $5 million a year and a few staff, and we’ve got him.’ What is needed is something very attractive, like that, but it’s difficult to get.
We are breaking in some nice new work: the controlled atom, nanotechnology type of work is obviously going to be of great importance in the future, and we should welcome getting into that. There have been a lot of new techniques developed in the school. One that is close to my heart is the laser spectroscopy applications to the UV; Ken Baldwin, Brenton Lewis and Steve Gibson have combined forces to bring in a level of resolution and study that I never thought would be possible to do in the UV. That work is away out ahead of anything else in the world in that field, and we should keep it there.
My own view of the school, and of any large scientific organisation, is that you have got to be able to accommodate people of all sorts of eccentricities. If you want brilliant people, some of them will be quiet and taciturn and want to just get on with their work all the time – and we’ve got some good examples of that. You don’t want to push those people to go out and earn money for you. That’s the last thing we would do. And you’ve got some others who are high flyers and write, who often irritate the rest of their colleagues by their brashness and the enthusiasm with which they sell their stuff. But you need those people, if they are bright enough, to come in. You must be willing to tolerate a range of eccentricities, paid for by the talent that they bring.
Working to position ANU for the future
You were the Director of the research school for 15 years, longer than anyone else, and the enthusiasm with which you were reappointed on two occasions says a lot for the way you steered the ship. At the end of that period, when you were 65, you didn’t retire but were appointed to be acting Deputy Vice-Chancellor of ANU and the Director of the Institute [of Advanced Studies] for a couple of years. Would you say something about your time in those two final positions?
Well, it was a bit of a revelation. I enjoyed the work over there. I found that I didn’t have as detailed knowledge of the whole performance of the institute as I had in the research school, and I set about trying to get that sort of information. It’s absolutely necessary for the top brass in a university to know how the bits operate. I needed much more than two years to influence the way the place would develop as an institute, but I tried – and I made some progress, I think.
I had certain views as to how not only our school but the others should be managed and I wanted to see a comparable level of efficiency everywhere in the operation. I wanted to encourage more graduate students in the university, and we did a little bit along that line. The ANU has great strength in its relationship with government; the social science schools have been able to do some of that very well. And we’ve provided our share of ambassadors and provided our level of training to staff extremely well and very usefully.
Also I did something which I hope will continue in the future: our school split off the information sciences and technology from the engineering school. We also at an early time split off earth sciences. The observatories in my time became essentially an independent group, as did mathematics, in a rather novel way of interaction with the Faculties. That’s the way to go. There should be perhaps a few more bodies in the institute and the future might be to have rather smaller schools, more like the size of the schools that we managed to split off, though they need to grow a bit.
I think the institute is very weak in the humanities. I would have wanted to spend quite a bit of money in developing the humanities research centre into a more substantial operation, and I would like to have seen some separation amongst the social scientists between those groups that are more interested in development and the pressing future of the countries to the north of us and those who go through the scholarly business of the history of some of these areas.
I had hoped that we would have secured the land on the [Acton] peninsula for a national science park – a marvellous way of linking with the main business interests of the country. (We are already strengthening our links with the other Australian academics.) That site is quite a magnificent asset and we are very foolish if we don’t put something down on the bits of it we still control.
The ANU is now 50 years old, which is still young for a university. It’s got to take some crucial decisions about how it is going to finance itself. My belief is that we will not get a further substantial increase in government handouts from either party in Australia. We will have good relations with both of them, but we will have to find ways of increasing the funding and expanding it, doing that because it is what’s needed and it makes us more useful and more effective.
Beyond academia to peaceful uses of outer space
You have done some very distinguished work outside academia, becoming a member of a number of influential national and international bodies. You were Chairman of the UN Scientific and Technical Sub-Committee on the Peaceful Uses of Outer Space; a bureau member of COSPAR, the ICSU Committee on Space Research; the Chair of the Radio Research Board in Australia; the Chair of the Anglo Australian Telescope Board; and also a member and, for a time, Deputy Chair of ASTEC [the Australian Science, Technology and Engineering Council]. And there are a number of others as well. We could spend a long while talking about all of them, but our time is somewhat limited so perhaps we can talk about just three.
Was anything particularly difficult to deal with but important while you were Chair of the Scientific Technical Sub-Committee on the Peaceful Uses of Outer Space?
Well, it was a very interesting committee to be associated with. It is a member of a threesome, or troika, in the UN system: the Committee on the Peaceful Uses of Outer Space and its two sub-committees. One of those is a committee on legal matters concerned with outer space. The other, which I was associated with for some 25 years from 1970 and became Chairman of, was on the scientific and technical matters concerned with the peaceful uses of outer space.
Before I took over, David Martyn had been Chairman of the sub-committee since it was started. The main committee traditionally was always chaired by somebody from a neutral type of country, mainly Austria. The legal sub-committee was chaired by somebody from Eastern Europe, often a Czech or a Pole, and the scientific and technical sub-committee was always chaired by an Australian – I guess as part of the other half of the world. The troika system which survived in these committees was a legacy of Khruschev.
We used to meet every year. The agenda often had a certain sameness about it, but occasionally it had some real excitement. We spent a lot of time working out and discussing, for example, matters concerned with remote sensing and the access rights of states to data taken over their territory. Those matters were fairly harmoniously handled, and what happens now in practice around the world with regard to sharing of remote sensed data is very much as we argued the pattern out.
Don’t mention the crashed satellite!
One exciting matter concerned the crash on Canadian territory, in about 1975, of a Soviet satellite – a radar sensing device which had been tracking American naval ships. It was supposed to operate for a certain time in orbit, and like others in the Cosmos class of satellites it would then be propelled into a higher orbit, at a couple of thousand kilometres, where it could remain for a long time until its radioactivity had died sufficiently. (It had a nuclear reactor aboard as its power source because a substantial amount of power was needed to enable it to operate 24 hours a day, in both the dark and the light.) The transfer from the operating orbit to the higher orbit was a fairly safe procedure, but on this occasion it didn’t work. To put a short tale on it: the reactor and the various other bits of radioactive debris finally entered the atmosphere and landed, mostly over Canada. The Canadians were not particularly pleased.
That happened just before one of our meetings was due to start, and all through this two- or three-week meeting we had a long discussion about the use – and particularly the misuse – of nuclear power sources in space. Most of the arguments and problems and hurts were ventilated through this meeting, which had more ambassadors in it than I had ever seen before in a UN body, and at the end we had certain broad resolutions on the essence of the procedure: nuclear power sources could be used in space, provided all proper precautions were taken. It was a typical UN statement that you can do something if you do something else.
To my amusement, at the end of the whole operation the Soviets objected to any inclusion of this item in the report that we wrote up, because it hadn’t been on our agenda! But there was an agenda item called Other Matters, and we had spent almost the whole time talking about nothing else. Finally they did have to agree that it went into the report as prepared.
Gradually, over some years, we worked through the use of nuclear power sources in space. By the time I finally left the committee, we had some resolutions on principles to be adopted about the use of nuclear power sources in space and the care that needed to be taken. Those were accepted by the main committee and by the General Assembly, and are now the guiding principles for that operation. That was an example of the very sensible way in which the committee worked.
If those guidelines had been in place before that satellite went up, would it have made any difference? Or was there just an unforeseeable technical fault?
I think the pressure in them, including pressure as to notification, would have made a difference. No words on paper can ever stop accidents completely, and there have been two or three other accidents. But the subsequent history has shown that people have learned from these accidents. They have also learned to put in place a framework of principles which assures you of what should be done and gives you a standard by which you can measure certain things. All those things would have been valuable.
There must be a limit to space junk
A paper you wrote about the problem of debris in outer space made me realise there’s far more than I would have expected. Your committee discussed that, I suppose.
Space debris is a topic which a number of us were trying to get onto the formal agenda of the United Nations because it could be a serious long-term problem. We really have significantly polluted the environment. There are about 10,000 tracked objects on which registration papers, as you might say, are kept and which are regularly tracked by groups around the world. There are also very many more objects – little ones like dust, specks of paint, and some like grains of sand.
Already there have been occasional accidents or notable events – the odd chip in the windscreen of a shuttle which is possibly attributable to collision with space debris. A number of unfortunate events early on in the business led to a lot of pollution, with rocket stages being left in orbit but not properly vented of fuel, and much later exploding and putting a large number of objects into orbit. There is quite a peak in low Earth orbits of such debris, along with lost screwdrivers and so on.
It’s important to keep these things in perspective, though. Space is still vastly empty, even with the numbers of objects we have put into it. But there are certain size ranges in which the artificial debris is significantly bigger than the micrometeorites which we now chart and which sometimes can be picked up by radar. We do need to track it.
Fortunately, the geostationary orbit is as yet fairly clean, but it is a limited resource. A communications satellite has to use up some fuel to maintain its orbit – because there are little perturbations, it is all the time going up and down along the orbit it wants to be on. I believe that at the end of the satellite’s mission, when it has made its owners their substantial amount of money, instead of those owners maintaining it in the orbit for, say, another six months they should use a little bit of the remaining fuel to boost the satellite to a higher orbit where it will be well out of the way. Many operators do that. Australia I think has always done so.
That is gradually becoming recognised as good housekeeping practice but I believe it should be mandatory. The chance of an accidental collision in the geostationary orbit, even with the present entry, is still quite small. But if there were a collision, how would one ever clean it up? And if suddenly several thousands or tens of thousands of objects were released up there as the remains from the explosion of a large satellite, that contamination would be very difficult to deal with – in a region of the Universe which is particularly commercially important.
The management of cooperative star-gazing
Let’s return to Earth, John, to your time on the Anglo Australian Telescope Board.
I joined that board, a very enjoyable one, after I came back to the ANU. The university and the telescope had had a somewhat rocky history, with people wanting to have control of things. I believe that the border had settled down when I was involved in it. As a joint operation between Australia and the British it gave great strength to Australia – not least because when one government was trying to reduce its expenditure the other government would say, ‘Well, we’re paying up. Why don’t you pay up also?’ Harrie Massey, who was on the board for a long time, was a master of that particular stratagem, and a number of us who watched him in operation may have used it ourselves when we needed to.
The operation proved a valuable investment for world astronomy, and it gave Australian and British astronomers access to a telescope which is a quite splendid instrument and has been kept valuable by some of the board’s decisions. The last decision which I was associated with was to go to the wide-field objective, which has now been brought into the use of the telescope. That enables one to do substantial surveys, which combined with the ability to take a broad plate instead of just a simple spectrum at one point, say, are useful for statistical work on the distribution of clusters of galaxies and that sort of thing. Any rate, the observatory has kept up its standards, with enough funds to buy and re-equip its detecting systems and to remain as a competitive four-metre instrument.
The control and steering of the instrument was absolutely first-rate, right from the word go, so presumably they’ve never had to do much to that.
Several things had to be upgraded and done, so it has not been inexpensive. The instrumentation had to be fixed up, the computing power needed to be changed. It was one of the first telescopes to be computer-driven, and its computer was ancient and rather ignorant. And in the time I was with the board we brought the Schmidt telescope, which had been managed separately by the UK Science Research Council, formally into the observatory. That and some financial rearrangement ensured that the British would remain partners in the observatory for some significant time.
We can learn a lot from the Anglo-Australian Telescope, which in itself is an asset. It has done wonderful observational work and it provides a model by which we should learn ways to progress big science in other fields. I am disappointed that it was, at least at that time, the only international science facility we were properly involved in – and a bi-national facility rather than a large international one. We need to keep our place in the big sciences, particularly. We need to do them cooperatively with other countries and it would be very nice to have some more international facilities in this country which we could share with others.
Influential advice on science, technology and engineering
You were a long-time member, and between 1981 and ’86 also Deputy Chair, of ASTEC. What were the most important topics of discussion during that period?
ASTEC, in the time that I was with it, was a very influential and powerful body – mainly through Geoff Badger’s chairmanship – which did a lot of good for science and technology in Australia. We wrote advice, really on all scientific matters, directly to the Prime Minister and through to the Cabinet.
One of the important matters was another astronomical proposal, the Australia Telescope, which came up for funding in a year which was particularly tight. I can’t remember a year that wasn’t very tight financially, but I remember that year as a particularly bad one in which all sorts of havoc was being run in the universities and scientific laboratories as they were again threatened with cuts to staff and with projects being cut out. Under such pressure it was pretty hard to fund something as exotic and extravagant as a large expansion of the country’s radioastronomy work. Nevertheless ASTEC, very wisely in my view, took the decision to put the funding of the Australia Telescope right up to the top of the list, at the expense of all other recommendations that were put in. And it was granted. It’s like having work done round your house: sometimes you remember the job long after you forget the costs. That instrument has proved to be marvellous and has attracted back into Australia some very good scientists such as Ron Ekers, who was associated with us in Adelaide early on. Combined with other major instruments in this country it has kept Australia right at the forefront of astronomy.
Perhaps the physicists ought to take a lesson from the astronomers. There has always been a tension between optical astronomy and radioastronomy, but they put their house in order and decided to go for the Australia Telescope on this occasion, even though they might have wanted support for an optical telescope elsewhere. They go in batting hard for whatever they decide as a community, and it seems they get it. The physicists haven’t learned yet to do that quite so effectively.
No, unfortunately. The astronomers have done it in a very statesmanlike way, and I must say my support has always been with the arguments that they put rather than with some of the arguments that have come from experimental physics. As far as I am concerned, physics and astronomy are the same subject, but I do think that by operating so collectively the astronomical community has managed to achieve a lot more. We have now to look at other major activities, including high energy accelerators, synchroton radiation, nuclear research reactors and high flux neutron sources.
It’s no longer the responsibility of ASTEC, is it, since the new fund was created for major capital equipment.
I would sadly say that ASTEC is a shadow of its former self. The influence it had resides elsewhere now. But even though you may have set up a major equipment fund, and have some objects which you think are large at the time, there’s always the problem of the items that are too big to be dealt with by your fund. So I think you will always need to have special pleading and special arguments for the very significant, really major items.
You have long been an advocate of close relations between physics and industrial applications. During your period at the research school its structure and name were changed to include engineering, and also Anutech, the ANU’s commercial and technical arm, was formed. Was that your idea too?
Yes, it was. Other people might also have had ideas about forming a company, but I had an opportunity to do so when Steve Kaneff received a substantial grant from the New South Wales Energy Authority to build some solar stations. I felt that would be much better done in an industrial/management scene than directly through the university. I’ve always believed that physics should be a useful and valuable science. Its interactions, not only with industry but with the other parts of science, have always interested me enormously. I think we should look at science, physics and industry as one web. From my perspective I still see physics as the core of all that, but it must reach out and show people that it is useful. That is why I was rather keen that we got a company – but it was Council that found its name. I’m not sure that I even provided the original $2.
That was probably in 1980. The company has grown to much finer things than when it started in my office. John Morphett had the office next door, as laboratory manager, and Jill Todd was his assistant. Until just recently they were the people who ran the company as a company. John guided its growth from a $2 company to the $X million company that it is now.
These days, it not only deals with technical things but also sells to other users the ANU’s expertise in various areas, doesn’t it?
It does. I have never thought our school should get into routine consulting work, but we do look for support for work we want to do in major areas. In getting outside support you have to find a neat balance, being sure that it is for things which the groups want to do by their own initiative. While you can be encouraged in certain directions by the availability of funds, you’ve got to watch out that you are not perverting the whole course of what the laboratory is about.
I think we have been very fortunate in that. We have been able to develop some fundamental lines of new work in lasers and optical sciences, particularly, which are filled with applications. And then we’ve been able to get groups into the school who are interested in using some of that work and drawing on some of that technology in an applied way. EME, for example, has acted as a bridge to industry and to outside development, drawing on a very wide range of the school’s basic scientific knowledge and skills, not least on the nuclear accelerators themselves.
Commercialising optical fibres and space equipment
You have had a more direct link with some commercial activities. Could you tell me something about those?
We’ve had two or three companies which have done well out of the school. AOFR (which we originally called Australian Optical Fibres Research but now just uses the initials) was formed under a government scheme that gave a grant of $5 million, originally, to exploit some fundamental work which Alan Snyder had done in the school. Inspired by his knowledge of insect vision, he had proposed certain applications in the use of physical fibre optics – very esoteric links.
Scott Rashleigh, who had been in the ANU at some stage, was brought back from the United States with vast skill in fibre optics in order to set up this company and he has been its leader ever since. For the first few years a ‘guiding committee’ helped to steer the company through the canyons of the Canberra bureaucracy which was initially supporting it. Ian Ross and I were both on that joint committee, and I believe it helped the company along quite a bit. The company has now celebrated its new location in Symonston. It is one of the success stories of Australian scientific technology industry, a world leader in the production of optical couplers.
These new high-tech companies can run on their own momentum for a little while but they need always to have something new coming along to follow their bread-and-butter work. So they need to spend a considerable amount of money on research.
That’s very true. We are fortunate to have people of the calibre of Scott Rashleigh, who has held his own in the academic community, the applied science research community and now industry itself. It has been a major help that he so well understands the need to keep up the R&D – particularly the D – side as the company grows.
A company that came out of the ANU even more directly was Auspace, which arose from astronomy work which Don Mathewson and others were trying to get going at the Mount Stromlo Observatory. I was very supportive of it, because it coincided exactly with my own view of the sorts of astronomical developments in space that we could participate in. We were close to a great success on that. Don Mathewson had great enthusiasm and energy, managing to give a rebirth to the Australian space industry.
Perhaps the bravest people of all were the group – led by Ted Stepinski, who had been the chief of electronics at the observatories – that went out and actually formed Auspace. Having got under way by making satellite components and picking up spacecraft contracts wherever they could, they have progressed now to operate entirely in the commercial world. Mainly it has been instrumentation work. For example, they built UV-detecting instruments which were flown in the space shuttle and qualified them as a company capable of making instruments for space use. Their high-grade skills have caused the Australian Space Board and others to put quite an amount of work their way. They are now doing consulting work and developmental work for the defence departments, and are generally a small space company with the potential to develop a long way further. I was pleased to be chairman of that company for quite some years.
The Director’s cut: more work on the Lyman-alpha line
I’d like to return to your own physics research. Wasn’t it customary for ANU to encourage the Director of your research school to continue his research interests?
Yes. One of the first things I did on my return to Canberra was to set up a UV laboratory, which was originally called the Director’s Unit. I didn’t like that title so it was changed to the Ultraviolet Physics Unit. (It later became part of AMPL.) I was able to make a couple of appointments there. When I was interviewed for the directorship, I said I would need two academic appointments, one tenured and one non-tenured, and a couple of technicians and the usual background. And that was forthcoming.
A lot of good science has come out of those laboratory experiments on vacuum UV and your continuing interest in the formation of the early atmosphere. Would you like to say something about what has come out of the work of the unit and your atmospheric modelling?
This work follows on from what I was doing in Adelaide, which was very much directed towards studying in the laboratory the problems of UV absorption in atmospheres. When coming to Canberra I was fortunate to attract Brenton Lewis to the group, and we set up a two-metre instrument in the laboratory which has been extremely valuable for this sort of study.
By way of example of what we were measuring, the absorption of the solar Lyman-alpha line is one of the most important things in starting off the photochemistry in the atmosphere. That broad line has got wings on it and a hole in its middle, due to the absorption of the line by cold hydrogen on the way to us from the sun – so, a rather complicated shaped line.
We also used rocket experiments to measure regularly the absorption of that broad line in the atmosphere, but there were always some peculiar inconsistencies between the laboratory data and what you get in the actual atmospheric experiments. Some people argued that this was due to other absorbers in the atmosphere. There was some truth in that, but I don’t believe it was by any means the whole story. I was fairly convinced that it was due to the complexities of doing broadband absorption work and neglecting what happened to the radiations that went through the absorber. With these broad absorption lines, as you go through the atmosphere the radiation effect hardens, because you absorb first the part of the spectrum which has the highest absorption cross-section and then as you go passing down through the absorber you are left with much harder radiation – radiation which is less absorbed – than you had before.
So one of the things we did in Adelaide and later expanded in Canberra was to study these general problems of the hardening of the radiation as it goes through absorbers and the temperature dependence of the radiation. The resulting host of new information solved a number of these practical problems and also gave a handle on the basic spectroscopy, which I think is now getting to be very well understood.
Modelling how the Earth’s atmosphere evolved
You have spoken about studying molecular oxygen. Has oxygen been the only subject of your temperature dependence work?
No, although molecular oxygen has taken a lot of our time. Some years ago we did some work on carbon dioxide, looking again at temperature dependence of the line – a much more complicated problem, because there are loads and loads of lines, not terribly simplified. It turns out that the temperature dependence of each of all those lines (due to different rotational populations) is important if you’re trying to model the properties of the early Martian atmosphere. We had a lot of work on that sort of thing. At present some of the most exciting work in the lab involves the use of laser UV techniques to get very high-resolution studies of the absorption spectrum of gases like molecular oxygen. That has led us to understand almost the complete spectrum for the UV of that gas.
I have been very interested in the problems of how the Earth’s atmosphere evolved. It hasn’t always had such a rich oxygen base. Also, the theories of the solar system all assume that the sun’s light source is a result of nuclear actions at the centre, and when modelling or theorising about those actions nuclear physicists believe that the sun has brightened considerably since it first joined the main sequence – that is, since the planets were formed. The belief is that during the Earth’s history the sun has been brightening, perhaps by as much as 30 or 40 per cent since it began.
You would think, if that were the case, that in its early history the Earth would be extremely cold and covered with glaciers. Geologists tell us that is not the case. In fact, glaciations are very rare throughout the Pre-Cambrian. You don’t get any until about 2½ billion years ago. I have models of the atmosphere to explain the times of glaciations, at least in the broad area, on time scales of, say, tens and hundreds of millions of years. That sort of model can be tied in quite well with what is known about the couplings to the rate of outgassing of the Earth and the way it changes with plate tectonics. Using some of the laboratory information that we have about absorption by gases, I have been factoring-in a greenhouse which was very much richer in carbon dioxide than the atmosphere is now – so the greenhouse effect was much larger.
It was much larger because it was colder, was it?
It was colder but we were not frozen, so there must have been a much bigger greenhouse effect. And other people have suggested this. My efforts have gone into trying to make an evolving model which is a fairly continuous history of the thing.
Which came first, life or the ozone screen?
There are a lot of quite serious side problems in this. As well as a broad account of the climate, it would be nice to know what the composition of the atmosphere was throughout time. Was there any oxygen in the atmosphere before there was an substantial amount of life? Was there any abiotic production of oxygen? (You can produce it by photo-associating hydrogen and water vapour and letting the hydrogen escape, so the oxygen remains in the atmosphere.)
One reason that’s so interesting is that an atmosphere with no oxygen in it will have no ozone in it either, and you get a much altered penetration of UV. All the UV in the 2,500-Ǻngstrom band can reach the surface. It’s hard to see how living things would develop under such a bombardment, because the ozone – which requires oxygen to be present to form it – and DNA have very similar absorption cross-sections in this 2,500-Ǻngstrom region where the solar UV is very intense. That has led a few people to speculate that perhaps some sort of protective ozone screen was essential if living things were to develop.
When Alistair Blake and I did some modelling of that, some years ago, we found another remarkable thing. If you look at the ozone screens produced by atmospheres with only a small amount of oxygen in them, you find that you can reduce the oxygen to about one per cent of its present level without much effect at all on the ozone screen. So you don’t need to produce much oxygen for a substantial amount of ozone. The details of the photochemistry are enormously complicated, but as you reduce the amount of oxygen, so the absorption of the UV occurs progressively lower in the atmosphere.
One very important reaction in this chain is that if you split the oxygen up to form the ozone, it’s got to be done with an oxygen molecule and another body – any body will do – to take part in the collision, just to conserve the momentum. And the third body you could take as being, say, nitrogen. Of course, as you go lower in the atmosphere, so the density of these third bodies increases and you get essentially the same ozone screen but at a lesser height of the atmosphere. In detail it’s quite different, but in effect you have provided a screen. So if you can get even a little less than one per cent of the present oxygen abiotically, you can have quite an effect on the way that life might have evolved.
Most people still don’t believe that our atmosphere did go through that abiotic production phase. I, with a few others, have always believed that it really is an interesting possibility. I persist in trying to find ways in which you can produce sufficient abiotic oxygen to get an effective ozone screen.
How long can Earth keep its cool?
Does any of your work impinge on the ozone hole crisis?
Well yes, in the sense that we can do some modelling of that, but we haven’t done much on it. It does give you a different perspective, though, if you look at the future of the Earth’s temperature. The control mechanism that has kept the Earth in a reasonable equable set of temperatures for, say, the last thousand million years or so has been such that although the outgassing rate may have changed a bit as the temperature tried to go up, the weathering rate of carbon dioxide also increased and so it pulled the temperature down again, because the carbon dioxide was absorbed into the rocks. Similarly, if the temperature was too low, the weathering rates changed to release some more carbon dioxide. So, through a set of glaciations and non-glaciations, you had a reasonable sort of stability.
I do not think that control mechanism can continue very effectively in the future, because the amount of carbon dioxide is already too low for that. The temperature will try to go up as the solar flux continues to increase in intensity – remember that the increase in the solar flux is due to the nuclear breakup – and the control mechanism that has served us so well in the past will again try to reduce the carbon dioxide. But the carbon dioxide is already much lower than is convenient for a good controller, and if that control mechanism tries to continue to operate, the CO2 level in the atmosphere may well go down and down. If it reaches, say, about a third or a quarter of its present level, the biosphere takes that very badly. The greatest damage to the Earth will come from a reduction in CO2 in an attempt to maintain this equable temperature, rather than from a increase in the temperature. Taking a very long view (over millions rather than tens of years) I think the most worrying possibility is of the CO2 being much less, trying to go much lower than it is now and consequently much lower than is needed to maintain a satisfactory biosphere.
Well, that’s a natural experiment that we’re not going to see the results of. Thank you very much indeed, John, for sharing a few of the highlights of your distinguished scientific career.
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