Professor Robert Street was born in 1920 in Wakefield in Yorkshire, United Kingdom. His life in physics has indeed been a magnetic one. In 1941 Professor Street received a BSc (special) from the University of London. He began his career during WWII working at the Air Defence Research and Development Establishment researching ‘absolute measurement of power’. In 1944 and 1948 respectively, he received an MSc researching wave mechanics and a PhD on absolute measurement of power from the University of London. After the end of WWII, Professor Street was appointed as an Assistant Lecturer in Physics at the University of Nottingham. In 1954 he became a senior lecturer at Sheffield University. In 1960 Professor Street moved to Australia to become the foundation Professor of Physics at Monash University. In 1966 he earned a DSc from the University of London. In 1974 he was appointed as Director of the Research School of Physical Sciences at the Australian National University. From 1978 until his retirement in 1986 Professor Street was Vice-Chancellor of the University of Western Australia.
Interviewed by David Salt in 2005.
Contents
Family background and early life
Robert, you were born in 1920 into a family where both your grandfathers and your father worked in the coalmines. What was it like, living in a mining community?
I was born in Wakefield, in the West Riding of Yorkshire. This was a market town and also the centre of administration of the local county council, but most of all it was the centre of the West Riding coalmining industry.
My father was one of the miners who volunteered to take part in a voluntary rescue team – each mine had a team which would always be deployed when there were fires or explosions underground. I think he must have caught somebody's eye, because by the time I was born he had been invited to be in the permanent team of the West Riding Mines Rescue Station. So he moved away from being an active coalminer.
This meant that we were to some extent protected from the difficulties of the Depression of the late '20s. Whereas the miners were subject to all the economic forces involved with the reduced demand for coal, my father had a guaranteed means of living and a 'tied' house, one that went with his job.
On the other hand, his was a very dangerous profession.
It was. The permanent mines rescue team were the first to be called out to go underground whenever there were disastrous events. There was always a fear that they would never come back again, and I know of at least one member of that team who was killed underground. It was a very distressing period for my family as a whole, and particularly for my mother – yet she never showed it to us children.
My brother and I were fortunate. Our parents provided us with a serene and stimulating childhood.
Your brother seems to have embraced the thrill of danger too, becoming a professional pilot.
Well, yes. He was a Royal Air Force officer during the Second World War: he flew Spitfires over Europe and then went out to Burma to fly against the Japanese. After the war he continued his RAF career in the Middle East. He also took part in the Berlin airlift when that city was cut off by the Wall and a constant procession of aircraft had to carry in everything, including coal. On retirement he joined the training establishment of BOAC (which became British Airways) and later he was concerned with flying as part of the oil discoveries in the North Sea. He had an adventurous life and now lives in Portugal.
And minerals were a part of his life, as they had been a part of your father's and grandfathers' lives and were to be a part of yours. For you the link was science.
School years: important mentors in science
Even at the age of 12 your stated ambition was to become a professor of physics. What factors in your childhood turned you on to science so much?
I have always thought that in almost any endeavour, if you can discover things for yourself – even though they've already been known for many, many years – this is a real encouragement to continue. That is what happened to me when I was 12.
In those days physics and chemistry were taught as separate subjects, and I became anxious to know what physics was meant to be about. It seemed pointless. Even looking it up at home in Arthur Mee's Children's Encyclopaedia didn't help.
Then in one of our physics lessons the teacher talked about temperature scales and put the question, 'How do you convert from Centigrade to Fahrenheit?' All of a sudden, for some strange reason, it occurred to me exactly how you should do it. I wanted to tell the teacher but he said, 'No, wait until next time.' I rushed out, saw the headmaster outside and couldn't wait to tell him that I had discovered the transformation from Fahrenheit to Centigrade! This might seem trivial now, but it was when I decided I'd become a professor of physics. [Laughs]
That headmaster was quite inspiring, a role model for you.
He was indeed. He was a mentor whom I remember very favourably. I was reasonably good at mathematics, in which he took quite an interest, and he was very encouraging. Looking back, I think maybe I was rather different, unusual – perhaps what would be known nowadays as a nerd. [Laughs] But I just felt interested in doing these things.
The other inspiring figure in those early years, I believe, was your father.
Oh, very much so. My father of all people was the real role model for me. When I was eight or ten I would go down with him to his workshop in the cellar (houses always used to have cellars, for example as a place to store coal, and as a cool area for food), where he taught me how to use simple hand tools – planes, saws, all these things, but not chisels. More importantly, he taught me to look after them. We built all sorts of things, including crystal wireless sets and valve sets. In those days our houses had gas but no electricity, and the valve sets had to be driven by great big 'accumulators', lead acid cells, with 120-volt dry batteries for the high voltage. The soldering was done with a soldering iron which quite often was heated by gas. Or, in emergency, you could stick it into the kitchen fire to heat it up.
You used to have to rely on yourself to make the things you needed, and I have always been grateful to my father for teaching me those skills.
Your knowledge of physics flowered at Hanley High School. You greatly enjoyed being there, and you were inspired by many of your teachers. Can you share with us some of those memories?
Well, again I had two role models. The headmaster, EG Laws, was an Oxford graduate in chemistry and taught us in the 'upper sixth'. I should explain that the sixth was divided into lower sixth, sixth form and upper sixth as three years of specialisation in science, classics or whatever. Laws conducted tutorials as a method of teaching and we were expected to teach ourselves. Every week you had to write full-length essays which he would read and criticise. He taught me a great deal about chemistry and about how to study.
The other very important person was the man in charge of physics. He was a Birmingham University graduate who was very interested in the experimental side of physics, and he let me have the run of the laboratory – I don't think I wrecked much, but he was very tolerant anyway. I was able to observe the Sun's Fraunhofer lines and the absorption lines of sodium and potassium. Somehow I failed to anticipate Alan Walsh's development of atomic absorption spectroscopy as an important analytical tool!
At school I found that my ability to make things, to put things together, enabled me to fudge up, say, a spectrometer to look at the Sun, to have a mirror to reflect and hold the position of sunlight on the slit of the spectrometer. We had a good metal workshop there, very much in the pattern of a 19th century workshop, I suppose. It had a gas engine which worked on ordinary town gas and was a marvel. This drove a series of axles, pulleys and belts which powered drilling machines, lathes and so on. So we were able to make quite a bit of ancillary equipment to do these off-syllabus experiments.
In your father's workshop and then at high school you would be learning by experience the fundamental properties of materials – how they perform and what can happen if you do the wrong thing – rather than simply plugging electrical equipment into a power point or getting something off a computer. And you could actually see how the lathes, the cogs, the mechanisms worked, where today's scientists might just buy a black box off the shelf. Perhaps they no longer have a hands-on, intuitive feel for how to produce the mechanism that gives them the result.
Oh, some people do. We have been talking about a time, up to 75 years ago, when life in general was very different and the technology was very, very different. That became especially clear after the war. And nowadays we do get a picture of 'big science'. It is not unusual to find letters in Physical Review Letters, for example, with many tens of authors listed.
But there are other places in physics where the individual imagination to make things work is still a very useful skill. That's the kind of thing I've been engaged in for most of my life. To me, experimental science has always been an important part of any scientific endeavour.
Wartime: Marriage, radar research and wave mechanics
You had hoped that you might attend Oxford or Cambridge University, but instead you found yourself studying in Bristol. How did that come about?
Well, my headmaster at Hanley was a great one for letting people go for Oxford and Cambridge scholarships. These were big events in Oxford and Cambridge, held twice a year, where groups of colleges set scholarship examinations and then pupils from all kinds of school were in residence for a week to do these examinations. I tried one in Cambridge but was not successful, so I went to the group of college examinations in New College, Oxford, where I was fortunate enough to be awarded an Open Exhibition in natural sciences. (I think I must have been noted as a possible award winner, because part way through the week I was asked to go and meet the master of New College, HAL Fisher, who was a well-known historian. I was enormously impressed by all this.)
I found, however, that I could not go up to Oxford in September 1939 as intended, because I couldn't meet the Latin qualification. My preliminary school had been too small to offer classics subjects – Latin and Greek – and so when I went to Hanley I could not take Latin at high school level. In order to get into Oxford I tried and failed two or three times to pass the supplementary examinations called Responsions. I gave up when my translation from Latin into English depicted a troop of Roman soldiers as crossing a river 'disguised as waterlilies'. That was unreal!
So you began studying a Bachelor of Science in physics at King's College, London, with the Second World War breaking out. Can you tell us about your experiences?
When eventually it was clear that I could not go to Oxford, I made a late application to go to King's College, which I entered in January 1940, not in The Strand but in Bristol. Because of the bombing, King's College had been evacuated from London to Bristol – just when Bristol itself was about to become very much a bombing target.
As you walked at night (we were very foolhardy in many cases) you could hear the shrapnel from the anti-aircraft shells tinkling away on the pavements. We never got hit. And there were great fires in Bristol. The King's College library, in the Great Hall of Bristol University, was just burnt out one night. The whole thing went up in flames. Often when you looked out over Bristol you could see fires all over the place.
It could be very difficult to sleep at night, so you went and slept where you might think there would be shelter. It was an interesting psychological exercise not to be afraid of all these things, and on the whole we took little notice of the war. It must have been more awkward for the people who were trying to teach us than it was for us young people.
Also during the war you met and married your wife.
Oh yes, we met in Bristol. It was during an air raid, I think. (Great unifying events, air raids. You get to talk to people, I suppose to keep your spirits up.) She was doing history at King's College. Incidentally, in Bristol she had digs in the place where Alan Nunn May used to be. He taught me optics in the physics course. Later he was convicted for giving away atomic bomb secrets to the Russians. So you could say my wife had a physics connection too.
When my wife completed her degree in 1942 she was sent to Bletchley Park, where the Foreign Office had its code-breaking operations. I was told that I wasn't to ask her what she did there, and I never have. And she's never told me.
At King's College did you do a two-year or a three-year degree?
It was called a BSc Special. The idea was to get people through these science degrees as quickly as possible so they could then go out either into the forces or into defence establishments where their knowledge of physics could be useful. Having entered the university in January 1940, I had five terms of tuition before I went away from there in 1941. The degree was only awarded the following year, when I was considered to have done my time.
After university, where did you go to work?
Well, various committees toured the universities as part of recruiting people for the armed forces or to go in for the scientific war effort. One such committee – which included CP Snow, the novelist, a very impressive man at the time – came to Bristol to interview physics students. The result of my interview was that I was directed to the Air Defence Research and Development Establishment, in Christchurch, on the south coast of England. When I got there the chief superintendent was JG Cockcroft, after whom a building here at ANU is now named.
I was put into the basic research group, led by CW Oakley. (He was one of the people who, after the war, developed scanning electron microscopy.) There were many other people, mostly from Cambridge, Oxford and other universities, who had been seconded from their posts to work on radar in this defence establishment.
What was your main task there for the war effort?
It was to work on 'absolute measurement of power' at centimetric wavelengths. The radars were operating at frequencies corresponding to wavelengths of 10 centimetres and 3 centimetres, which were called centimetric wavebands. My job was to develop techniques for measuring the power output of the signal generators used to calibrate the receivers that were incorporated in the radar sets of all kinds.
After the war you were able to extend this work and publish it as a PhD thesis.
Yes, I did. Again I was fortunate, because the klystron which I used as the power source was in fact made by Oliphant, a well-known name. It was called a VFO7 – which puzzled me until I learned that 'VFO' stood for 'valve for Oliphant'. The government were interested in continuing this work of absolute power measurement after the war and they made available the equipment, including the VFO7s, which enabled me to continue the work and to get a PhD for it at Nottingham.
Another interest which you began to develop during the war was in material science, looking specifically at the nature of crystal–metal contacts in radar equipment. Can you tell us a little about that?
An essential part of the whole radar system was the 'crystals': a carborundum crystal and a wire contact. Without those, it would have been impossible to get the sensitivity you require for centrimetric radars.
Actually, the device is similar to the kind of things we used for making crystal sets: it is a crystal, with just a point of contact, and it works because the electrons in crystals and solids behave not as ordinary particles but as waves. The way in which they are described is called 'wave mechanics', and it was obvious at that time that wave mechanics had quite a bit to do with the fundamental understanding not only of these semiconductors (as they are called) but also of many other solid-state devices.
This fascinated me, and from talking to one or two people during the war I decided to learn some more about wave mechanics. In particular, a man who was a very great encouragement to me from my days at King's College, HT Flint, suggested that in my spare time – if I had any – I should study wave mechanics. And he offered to help me do this for an external MSc of London University.
That was an interesting episode and I learnt sufficient about wave mechanics to get me an MSc in 1944. But I never did really understand how it was responsible for the behaviour of point contacts on semi-conductors.
You commented that you were very close to devising a transistor. Was that connected to this particular work?
[Chuckles] Well, it could have been, but you know how people exaggerate, don't you? If I'd understood the wave mechanics business of the point contacts, just maybe in a million years I would have put two wires onto that crystal to see whether the current through one affected the current through the other. Nowadays it seems such an obvious thing to do, as they did in Bell Telephone Labs, to produce the point contact transistor.
When people first developed the transistor, did they recognise it as the gateway to a more modern age?
I really don't know. But I knew the people who were involved. They were interested in magnetism as well, as I was later. It would have been a very interesting question to ask. I'm afraid my life is full of questions I never asked and should have done.
You have mentioned the evacuation of King's College from London to Bristol. Didn't you experience another move while you were working on the English coast?
Yes. At one stage during the war, paratroopers of the Scottish Border Regiment raided Bruneval, a town in France where the Germans had placed radar equipment on a cliff overlooking the [English] Channel. This was a bit of a nuisance for people flying aeroplanes over from Britain, so it was decided to go over there and take away the important parts of the equipment for us to learn more about them. Interestingly, the raiders got away with it, dismantling the things which they needed to bring back and returning to England by submarine. We had one or two of those bits to play with, but mainly they went to the Telecommunications Research Establishment (TRE), in Malvern.
Then somebody had the very sensible thought, 'If we can do that to Bruneval, what's to stop the Germans from doing it to Christchurch?' A weekend exercise, when we were told to stay out of harm's way in the labs (we worked on Saturdays and Sundays) indicated that the local Home Guard, the 'Dad's Army', even with the locally based battalion of soldiers, could not defend us against an attack from the sea or from the air. They couldn't do anything to stop our equipment from being pinched by raiders from overseas.
So in about a week's time the whole of the road system from Christchurch up to Malvern, in almost the exact middle of England, was occupied by Pickford's moving vans, with all the equipment – everything – piled up and sent off to be reassembled. And the army were absolutely magnificent in moving us up to Malvern. That was an interesting event. People certainly got things done in those days.
Although you have said that in many ways you weren't aware of the war, the fact is that everything you were doing might be changed within a few days. The buildings or the city you were in might suddenly not be there. Perhaps you took the possibility of such change for granted, simply because you were living your life as part of the war.
That's a good thought, yes.
Magnetism research at Nottingham and Sheffield
After the war, I suppose, things seemed likely to be more stable. And in a sense this is when your academic research life took off.
Very much, yes.
You were appointed assistant lecturer in physics at the University College, Nottingham, and began investigating the effects of magnetic fields on the mechanical properties of magnetic materials, the delta-E effect. Can you tell us about this work?
When I went to Nottingham the person in charge was LF Bates, one of Rutherford's students. He was very interested in the magnetic properties of materials, and had made some significant contributions. He suggested that I might be interested in magnetism, and suggested the topic of the delta-E effect.
If you have a rod of a ferromagnetic material, such as iron, you can drive it in resonance, you can make it ring, by using coils in various ways. And the Young's modulus – the mechanical properties of the material – is affected by a magnetic field which you apply. We were interested to look at what this could tell us about the way in which the process of magnetisation occurs in those materials.
So we assembled the equipment we needed. We made solenoids in the workshop, and Bates (who had worked for the Admiralty during the war, on degaussing of ships) was able to get a whole bank of lead acid cells as a power source. We built those up and had charging devices to provide the steady current that we needed for our solenoids and the electromagnets. Also, Bates was interested in permanent magnets and had a connection with the Sheffield manufacturers of Alnico, which was the best material for making permanent magnets in those days. So he got us Alnico rods from the manufacturers.
At that time the government was always very supportive of university research, and commercial firms went out of their way to help.
We set out to measure the resonance I have mentioned, but no matter what we did, we found that whenever we changed the magnetic field, the signals were not nice and steady but were varying. They went off rapidly to start with but then became slower and slower. This was a real puzzle. We chased after this, doing all sorts of experiments, and eventually we found that the mechanical property, the Young's modulus, was varying in time following a sudden change in applied magnetic field.
This led to a lifelong obsession with studying and trying to understand the time dependence of magnetisation, because it tells you quite a lot about what's going on inside a magnetic material. And time dependence, as we saw later, occurs in all sorts of ways in all sorts of systems.
Were you the only people working on time dependence?
No, but our early work continued to be referred to for many years after it was first published. In 1949, Patrick Blackett, a Nobel Prize winner, in Manchester University, had the idea that the magnetic field of astronomical bodies might be related directly to their angular momenta. The Sun has a magnetic field, the Earth has a magnetic field, and for some reason he thought that perhaps the magnetic moment, the magnetic field, of these objects was related to the spinning of the object on its axis. He could only work on the Earth to investigate this, so he began to investigate if the Earth's magnetic field decreased with depth below the surface – a consequence of his hypothesis.
He made many measurements of the Earth's magnetic field down coalmines. He found that his original idea was wrong. But he did find that rocks all around him down there were magnetised. It was later shown that rocks contain a record of the Earth's magnetic field and this in turn was used as data on the drift of continents over geological time.
Now we come to the main question: How does the rock maintain its record of what happened to it when it was laid down or when it came out of a volcano? You've got to understand that there is a process which has lasted for many, many millions of years. How can this be? The time dependence, the stability, of these rocks is obviously of very great importance.
This was being studied by Louis Néel, in Grenoble, in 1949. He discovered that if particles in rocks were small enough and if the material was of a proper kind, then at a sufficiently low temperature you could maintain the magnetisation that had been induced at the high temperature. So he asked, 'What is the stability at low temperature?' And he published a paper on this, entitled 'Time dependence of small particles'.
Néel's work on small particles was quite unknown to us, just as our work on bulk materials was unknown to him. It was interesting that these things happened at much the same time.
Which is a common theme in so much science.
It is indeed. Later I disagreed with the way he presented some of his findings, but I had a long correspondence with him and I knew him quite well in France. He got a Nobel Prize for magnetism.
Your time in Nottingham, then, was very productive for you. I suppose it was the base upon which you did everything subsequently.
Yes.
In 1954 you took up the position of senior lecturer at Sheffield University, where you made a series of low-temperature studies that required the building of a hydrogen liquefier.
To liquefy hydrogen you have to compress it and pass it through heat exchangers. Then it comes through a Joule-Kelvin valve, and you get liquefaction. So you take your hydrogen from cylinders and you put it into compressors.
All we had were air compressors, with fins on, like a motorcycle cylinder. But when you compress hydrogen it's a different proposition from compressing air, because when you compress a gas you heat it, and in the case of hydrogen that heat is really quite large. So although the compressor wasn't quite glowing, it was pretty hot. And we put these compressors under the floor of the room where we had the hydrogen liquefier. We had no hydrogen detectors; it has always seemed to me a great tribute to the people who made the joints in all the piping that they didn't leak hydrogen, because if they had leaked I'm sure I wouldn't be here now, and neither would half the university. It would have been a big explosion, I think.
The professor there was Sucksmith, a very significant figure in magnetism from way back. And I well remember the occasion, very late at night, when the liquefier started liquefying and we got the liquid hydrogen out. Without realising how late it was, I thought it would be a good idea to telephone Sucksmith at home – and he never showed in any way that he was upset at being wakened and told, 'There's a hydrogen liquefier up the road, working.' That was quite an event.
I suppose that in the past you would have used liquid nitrogen in order to work on materials at low temperatures, and in the future you'd probably be using not liquid hydrogen but liquid helium and so on.
Very much so, and even measuring in microkelvins. Magnetism is one of many phenomena where doing things becomes simpler at lower temperatures. So there was a need in the laboratory for our liquefier, and it was also used by another researcher, John Crangle, who was very interested in low-temperature properties of materials.
Across the world to the new Monash University
After several years at two universities in England, and having produced some landmark papers on magnetism and its time dependency, in 1960 you moved to Australia to become the foundation professor of physics at Monash University. That must have been a big leap into the unknown. What possessed you?
Well, I discussed with Sucksmith whether I should apply for the position. He seemed somewhat disillusioned with what was going on in universities in England at the time: there was to be a great expansion, with technical colleges and so on being upgraded to university status. I suspect that Sucksmith thought this was a dilution of the ideal that he and many others had been brought up with and held dear, that a university filled an almost sacred role, one where research should not be displaced entirely by first-degree giving. And perhaps he had reached an age where people tend to become disillusioned with, say, the management of a university. Perhaps all this had combined to make him a 'grumpy old man'.
Anyway, he said he really didn't see much in the way of a future for promotion in the university system, and encouraged me to apply for a professorship with this new university. And very quickly I was asked to attend an interview in Manchester, just over the hill from Sheffield. That started off extremely well even though Louis Matheson, the newly-appointed vice-chancellor of Monash University, appeared for the interview a little late – he was dressed in cricket flannels, because he'd just got away from a cricket match where he'd been batting!
It turned out that he was a charismatic person, filled with the fire of doing something very much worth while in building a university from scratch. Talking to him I found it an extremely appealing proposition. But it was a tremendous leap for me and my family. Australia was unknown to us, beyond the image and the example that Matheson was projecting.
Before making a definite decision I was invited to come out, as they said, 'to enable you to look us over'. I was enormously impressed by the enthusiasm of these people, who had been drawn from many walks of life. The academic as well as the professional and technical staff all seemed to be intent on getting a university up and running in something like four months. And that's what happened. The university opened its doors in February 1961 with 350 students, in about four faculties. (So you can see how small it was.) It went on from there exponentially, until now Monash is one of the really big universities, and an outstanding one.
This was the first of the 'new' universities which came out of Menzies' initiative of reforming the university system of Australia. There was a sort of bipartite arrangement in running universities in those days, and Bolte, the then Premier of Victoria, was very supportive of Monash – no matter what problems he may have had with students later on. Everybody was supportive. It was a delight not to be penny-pinching the whole time but to be able to ask for the buildings and equipment that would make it good.
That seems a far cry from today's economic rationalist times.
It was a different world, completely. And the idea did appeal to me, to build a new university, being supported financially in every way. Strange as it seems now, all you had to do was to ask. So I asked for all sorts of things: a helium liquefier to avoid the possibility of blowing ourselves up with hydrogen, electron microscopes, big magnets, equipment to put in the laboratories, lecture theatres, all these things –and they were there in abundance. We had it very easy.
It strikes me that many of your decisions, including the move to Australia, are based as much as anything else on the feelings of people you respect. Your decisions have been driven by the people you have met and taken advice from, people who have inspired you, rather than the prospect of doing specific research.
Yes. My father started off this kind of feeling in me, and since then many people that I can identify have really cheered me on and encouraged me. It's been very important.
You came out to Australia in November 1960, bringing your wife and your two young children. What was it like to be living in Melbourne in those first years?
Marvellous! Oh, we were very fortunate. People probably realised the kind of difficulties that we would experience in coming to a different environment, and they looked after us well. I've never regretted coming out here. Our daughter and son went to excellent schools and had really very good lives, I think. We have done very well and Australia has been good to us.
And I would suggest that Australia has done well from having you here. To look just at your time at Monash University: above and beyond university science and teaching, you were involved with science education through the development of the Victorian physics curriculum, science communication through an ABC TV science program, professional development through the Australian Institute of Physics, and science policy and funding through work with the Australian Atomic Energy Commission, the National Standards Commission, the Metric Conversion Board and the ARGC, which was the precursor to the ARC [the Australian Research Council].
Admittedly, that was over several years, but still each one of those would have required a significant time investment. What was driving you at this time?
Well, I suppose it was youth. It didn't seem to me to be at all busy, but now you say it, there were a lot of things going on, which is quite extraordinary. [Laughs]
I didn't even list all of them!
When you're interested in things you do them – that's really what was happening.
In particular, have you any memories of the time with the Australian Atomic Energy Commission, in terms of what Australia was doing with its atomic policy?
Oh yes. Philip Baxter, a very distinguished chemical engineer, was the chairman of the Atomic Energy Commission and was another very busy man. He had an ABC TV program called Science Question Time, where I appeared quite regularly (it was fun), and so I knew him reasonably well from that and other kinds of meetings.
He asked whether I would go on a committee to advise the government on the use of atomic energy in Australia. He was very keen for Australia to be involved with atomic energy, and we as a group considered the possibilities of building a nuclear power reactor at Jervis Bay. That is part of the Australian Capital Territory, so it seemed there would be very little in the way of Commonwealth–state argument about the idea.
But almost overnight Mr McMahon, as Prime Minister – who until that time had been reasonably supportive, I understand – decided that it would not go ahead. I think this was a great disappointment to Philip Baxter, who had set his heart on it and did believe, I think, that it would be in the best interests of Australia.
It is very interesting to speculate where we would have been now, if that reactor had been built. There are arguments for and against, of course.
Science and technology and politics have always been strange bedfellows.
[Chuckles] Very, yes.
Directing ANU physics research
In 1974 you were appointed as director of the Research School of Physical Sciences (RSPhysS), at the Australian National University (ANU). This wasn't the happiest of times for you. Can you tell us what the problem was here?
'Not the happiest of times' is probably a correct description. I really knew nothing at all about ANU, and nothing about how the research school was organised and run. I would say I knew more about Australia when we came to Monash than I did about ANU when I came here. I wasn't aware of all the intersecting streams of events and internal politics. In particular, I should have discussed in far more detail the history leading up to the directorship being vacant. Why did that vacancy occur? Was it management initiated, or a personal decision? I didn't ask about any of these things.
I had been asked by the deputy vice-chancellor whether I would submit my name to be director here, and I really wondered why, because there were so many people in the RSPhysS who were obvious candidates. They were grounded in the culture. I thought maybe my invitation to apply was part of the well-known principle of getting someone from outside to gauge the internal people against. But it wasn't. I came up from Melbourne for an interview and very surprisingly I was offered the job – and surprisingly quickly.
But I was very much an outsider, and I soon discovered that none of the people looking after the various divisions in the research school were in favour of my appointment as director.
Because the school was research-only from its inception, it would have been a very different place from Australian university departments which had responsibilities for both teaching and research.
Yes, very different, but at first I was not really aware of the prevailing ethos. In a teaching university the objective is to develop students at the undergraduate and postgraduate levels. Everybody has a concern over the quality being exercised by their fellows and is willing to help them out if need be. Here the departments were all very separate – whether by design or not, I don't know – with separate goals and no reason to collaborate in any way whatsoever. They were separate entities with, as I came to see it, no unifying principle or endeavour, no common purpose.
I had the rather naïve idea that maybe if the researchers were involved in undergraduate teaching there could be two advantages: they could help students in the School of General Studies to see subjects from a different perspective, and an important spin-off would be to attract undergraduate students to the postgraduate work that was going on. In an attempt to implement this idea I went over to the School of General Studies and asked whether they'd be interested in courses on magnetism. They said yes, so I was very pleased to prepare lectures (which I enjoyed doing) even though that had to be fitted in at 4 o'clock in the morning, and to give a course on magnetism to the senior undergraduate people. But no-one else in the research school followed that suggestion. I have often thought it could have been to their own advantage.
You were looking, I suppose, for a unified endeavour such as probably existed at Monash when you were growing it from a small base. It would definitely have been the feeling in wartime England when everyone was pulling for the same outcome.
Oh yes, that's all true. But you can't blame people for wanting to take every advantage of their circumstances. Good luck to them. It was certainly a different environment from what I would have expected, though.
You found special challenges in relation to astronomy, I think.
Yes. As time went on, astronomy seemed to be one of the difficult things, a source of tension. Balancing that, however, is the successful setting up of the Anglo-Australian Telescope.
The UK and Australia had agreed to set up a magnificent optical telescope in Australia. But there was a great deal of tension between the two governments about whether this would be fully a joint UK–Australia endeavour. The site which was chosen for the telescope was Mount Siding Spring, which is the home of the ANU facility – again very nice instruments – with Olin Eggen as director. I think the university management was hoping that the Anglo-Australian Telescope would really be an ANU creature, but the UK were not in favour of that because the telescope could easily be taken over and the whole spirit of cooperation could disappear.
When I was appointed as director of the research school, Fred White (who was on the University Senate) asked me to establish contact with Olin Eggen – because, I later realised, White had it in mind that somebody or something had to settle the tension between the parties. And then the Australian Minister for Science appointed me as the third Australian member of the six-member UK–Australia committee. There was a rotating chairman, who at that time was Fred Hoyle. The other British people were the Astronomer Royal for Scotland and an administrator from the UK Ministry for Science. With me in our group were Paul Wild, a later chairman of CSIRO, and Hugh Ennor, the permanent head of the Department of Science and Education.
Between us we were able to come to agreements which resulted in the magnificent Anglo-Australian Telescope, which was opened by Prince Charles – a splendid occasion. I think it has more than justified its existence and the money that was spent on it, and its reports attest to the collaboration between UK and Australian astronomers. It really has been quite remarkable, one of the great success stories of science in Australia.
So there were highs as well as lows during your time at ANU?
Yes, there were. I must say, in particular, that Ernest Titterton – my predecessor at the Research School of Physical Sciences – was very supportive of me as director. I appreciated his support very much.
A return to magnetism, but now in Western Australia
Following your time at ANU, in 1978 you took up the position of vice-chancellor at the University of Western Australia (UWA). Your move from Canberra across to Perth must have been almost as big as from England out to Australia. Can you tell us about it?
Again I was responding to an invitation, and I was enormously impressed by the people there. The real driver of it was the chancellor of the university, Lawrence Jackson, the Chief Justice of the Supreme Court. He was a most delightful man who always claimed that the only function of the chancellor of a university was to appoint the vice-chancellor. I was very pleased that he appointed me!
I was very pleased also to be part of that university, and never regretted going over there. It was a long-established institution and the people involved took a jealous pride in its being the only free university in Australia. (University education was provided by the state, and by the university. Of course, that's changed these days.) Everybody I met in the university and in the outside community looked upon it as a real benefit to them and cherished it. I felt that people supported it in ways which were quite unknown in other parts of Australia, and everywhere there was a warm welcome as though you were doing something worth while for them.
Was that for you, or for the vice-chancellor of a respected institution, or both?
Oh, I would say both. [Chuckles] The other thing about it is that my wife was received in exactly the same way. So it wasn't just respect for the office of Vice-Chancellor but a real friendship, which has lasted all these years afterwards.
You retired in 1986, but then an earlier chapter of your scientific career reopened for you. Could you tell us how that came about?
During the time I was vice-chancellor, I used to read Physical Review Letters quickly before passing it on to people who had more pressing need for it. Consequently I kept reasonably well aware of developments, though not in detail.
In this way I heard of the discovery of a new range of permanent magnet materials – things like neodymium, iron and boron – based on 'rare-earth' materials, which are not rare at all. These materials, in alloy form, produce extremely powerful magnets, so powerful that if you have a reasonably sized one and you're not careful, you can trap your thumb and break your finger. They come together with a really big bang. I recalled that in 1949 we'd established that the more powerful permanent magnets are, the more pronounced will be the time-dependence effects.
So I got in touch with CSIRO, where two students of mine from Monash who were interested in magnetism were working, and asked whether CSIRO had facilities for making measurements on these permanent magnet materials. They said yes, so I went over and we measured the magnetisation of some samples of these materials as the magnetic field was varied, just as we'd done in the old days. Now, however, the lab was much more automated than in the past.
And one night (all these things, it seemed, happened at night) there we were in the lab measuring, for the first time, the magnetisation of a rare-earth permanent magnet when the magnetic field had been changed. We sat and marvelled as, sure enough, the pen on the chart recorder went shooting across and then gradually moved more and more slowly. That particular process is a logarithmic variation with time – it starts fast and then goes more and more slowly, but never ends. We had predicted in 1949 that it would vary according to a logarithm of time, and there it was. We just sat there watching it, over and over again.
Did it make you feel proud, that basically your theory was the right one?
No, not really. We were just marvelling that we could say what was going to happen and then see it happening!
The new breed of supermagnets that were being fabricated gave you the impetus to set up a magnetics laboratory in 1988, so in effect after being vice-chancellor you were going back into the research stream – and in a field you had helped to pioneer after the war.
That's right. After we did that work in CSIRO, papers were published which led the Australian Research Council (ARC) to support us very well indeed. We were able to buy equipment and build up a laboratory in the Physics Department which we called the magnetics lab.
And again a very important component of that was the technical staff, the laboratory manager, who made all these things possible. Also, one day when I was there a girl came in and said she would like to do postgraduate research. I asked, 'Are you interested in working on magnetism?' She said yes, and that's how Liesl Folks came down into the magnetics laboratory. She really made that place. She worked very well indeed, she was a very good organiser, she encouraged everybody. She read their theses, told them where it was wrong, all this kind of thing. She and Rob Woodward, between them – with ARC support – built up this magnetics laboratory. That's how it happened.
The work in CSIRO opened up new possibilities for you, it seems.
Yes, it did. At about that time, Paul McCormick, the professor of material and mechanical engineering in UWA, was interested in 'mechanochemical processing' (MCP), which I will explain. Suppose you want to make an alloy of something. You try and induce a chemical reaction causing A to combine with B and form an alloy AB. The alloy will be formed if the energy of the product is lower than the sum of the individual energies of the beginning material, and the usual way to bring this process about is to melt the two things together – once you start heating them, thermal energy is produced and you get the alloy.
Paul McCormick's idea was that you should initiate this process by high-energy ball milling: you should take these products together and ball mill them. The energy required to produce the combination would be provided mechanically and not by heat. While the difference may sound trivial, it means that you can really control the speed at which the reaction occurs – if you put in diluents of various kinds, you can slow the reaction. And if you put in diluents of different kinds, you can change the shape of the particles, you can change their size. He had done a great deal of work on this MCP to investigate all these propositions.
With the work going on in the magnetics lab that I'd founded, we were becoming more and more interested in permanent magnet materials in fine particle form. So it was very good indeed that we could collaborate with Paul McCormick – and it was a very close collaboration – to produce materials which had potential as permanent magnets. We took patents out on this, and the whole thing was quite an exciting exercise. I would say Paul McCormick has been the last in the line of my encouragers.
Practical applications and developments
You have also been associated with the company Advanced Nanotechnology, which was an early driver of nanotechnology in Australia and was known for its 'invisible sunscreen'. Could you talk about your association there?
A company called Argyle, in Western Australia, had a deposit of rare earths, and the possibility was that they would be interested in developing these deposits for permanent magnets – which we'd been working away on. The science man of that company was Frank Honey, and I well remember a meeting with him outside the engineering school where Paul McCormick said, 'Would you like to be a member of a company called APT (Advanced Powder Technology)?' We said yes, he said, 'That will cost you $1,000. Done.'
In fact, I don't know where his vision for this came from, but that beginning proved to be quite remarkable, because the university took the proposal on and there were investments from all over the place. In January of this year the company changed its name to Nanotechnology and was floated on the stock exchange – very successfully, I think. It has been really an interesting commercial scientific venture.
It is held up, actually, as one of the first examples of successful nanotechnology in practice. Yet the product it is probably best known for is a sunscreen!
It is a bit of an irony, because with the MCP technique, where you know a lot about how to make particles of specific sizes and shapes, magnets are no longer of interest. The initial connection has disappeared.
This new product contains nanoparticles of zinc oxide, a sunscreen protection screen for use on the face, making the sunscreen transparent to visible light. So you don't have to be seen with zinc cream over your face, and the nano zinc is more efficient than the ordinary visible cream. It has been marketed in Italy and France, and is also used in cosmetics which are sold in Australia.
I believe another suggested use of mechanochemical processing is for safely destroying toxic wastes.
Oh yes. We wrote a letter to Nature stating that any chemical process which has this chemical characteristic, that the product has a lower energy than the things you are starting with, will go with mechanical processing. And by adding diluents of various kinds you can control the speed, and maybe in some cases the quality, the composition, of the final product.
We looked at PCBs – toxic materials that are used in transformers and are awfully difficult to get rid of – and highly poisonous insecticides, which also pose a very great disposal problem. (For example, how do you destroy DDT? If you burn it you may get dioxins, and all that kind of thing.) We did a large number of experiments with typical examples of toxic wastes of various kinds, and we showed by mass spectrometry, which was the nicest way of determining the composition of the end products, that in very many cases you could reduce the toxic material to completely harmless simpler materials. Possibly you could even use mechanochemical processing to destroy nerve gases, which are genetically similar to some of the other toxic materials. Of course, we didn't try that one.
What is more, you would no longer need to transport those toxic materials around. Quite a number of dangerous insecticides are stored away in farm buildings, usually in leaky cans, and it would not be good to try and transport them. Paul McCormick's vision was that you could put a ball mill on the back of a truck and take that, together with your various bits and pieces, to the site where these things were being stored. And there you would just ball mill them to make this chemical reaction.
Although that was written up in a Nature letter, nothing much happened. We approached a few people, including CRA Ltd, but this was not mainstream and so they were not interested.
More recently, however, you have been working as a research mentor at CRA. Is this in connection with the magnetics lab, or with you as an individual?
With me as an individual, I think. CRA – which has now been re-absorbed into the Rio Tinto group – had a research facility called Advanced Technology Development (ATD), at Technology Park, Bentley, in Perth. And it happened that Ian Smith, the father of a PhD student of mine in the magnetics lab at UWA, was there. Ian had come from Queensland University, where he had been impressed by the way in which companies got mentors from a university environment to go and talk about their work to the company people who were involved in the research programs. He asked whether I would like to do that.
I thought that was a pretty good idea, especially as one or two of my PhD students were working for CRA ATD. So I used to go there once a week, and anybody who wanted to talk about anything would come for a discussion. Quite a few interesting ideas came out of that.
Did any actual projects result from those discussions?
Oh yes. One which I think we were very pleased with addressed the problem of deterioration of railway lines in the Pilbara. The Hamersley Iron Company digs out iron ore in huge quantities and runs it down from inland to the coast in huge trains of very heavily loaded trucks. The trains themselves can be kilometres long, and the haulage distance can be as much as 400 kilometres. I have been up there to see this myself, and it is quite an amazing enterprise.
But the rail lines are really very badly hurt when these trucks are coming down. You can always tell which way is the coast, from the direction of the little corrugations you can feel by running your finger over the rail. If a rail breaks and a two-kilometre train comes off the line, you have a real problem.
The company was very interested in the possibility of automatically evaluating the defects in those rails. So Libby Feutrill, a PhD graduate who was one of my research students at the magnetics lab, and Sid Hay were given the job of how to detect defects in rails when you're travelling in a railcar or research vehicle at 80 kilometres an hour. (If you're going to run up and down 400 kilometres, you don't want to spend too long on it.)
Anyway, what we decided was a very simple thing. A rail is made of iron, or steel. If you run a high-energy permanent magnet over the rail, you will magnetise it and any defect will have a stray field associated with it. So what you do is to follow that magnetising magnet by a system of detectors, which you can arrange across the rail so that every time a stray field is detected you can record where in the rail the defect is. You can also tell how far along the rail that defect has occurred, because these rails are welded and every weld has a characteristic signal.
So you know from your continuous record where the detector was, where the defect was and how it was distributed across the rails. You can just run this thing up a rail to give a complete picture of the defects existing at that time. And you can, if you wish, compare that with a record previously taken: you can see the amount of deterioration and identify, before the rail breaks, the parts that could fail and should be replaced.
Would that apply to any steel structure?
Oh yes, so long as you can move something over it. Previously the Hamersley people were using ultrasonics and the echoes from defects. But to do that at 80 kilometres an hour is not very easy. This proved remarkably easy.
It was patented, I believe.
Yes. All these things become, quite properly, the property of the company, and what they do with them has to be driven by commercial interests. So I don't really know what happened to it all, or whether it is still being used. But there was a suggestion that maybe it could be applied to the British rail system, where things were falling off rail tracks and causing losses.
Certainly it had a potential. But these things never fully realise their total potential as you see it initially. Always little snags occur.
Magnetism, I suppose, entwines our very being and our world around us. You have worked on a couple of projects in biomagnetism in recent years. Can you tell us how that came about?
All these things evolve – starting off with permanent magnets, we can end up with sunscreen. The magnetics lab, since its foundation, has evolved in different ways, and one way has been towards biomagnetism, the use of magnetic techniques in medicine, in biology. We have had two significant involvements with that.
The first one arose from a beautiful idea developed by Tim St Pierre, who worked in the lab. The principle is very simple. Magnetic resonance imaging (MRI) is a very good technique for imaging the internal structures of human bodies. It works because there are protons in the water that is contained in the body, and if you apply a magnetic field you can excite a proton into resonance; it will rotate. The idea of MRI is that you can detect that resonance signal and find where it was emitted, and thus you can plot the density of protons in the human body to get a pattern of what's going on. It is a very useful diagnostic tool.
Tim St Pierre thought, 'well, protons, when they are excited into resonance, do something else: they decay. They rotate and then they gradually slow down.' He noted that when protons are near iron, the rate of decay is increased – protons near iron deposits will decay more rapidly than others. He suggested that all you need to do is to change the protocol of the system's data collection, to measure not only frequency and location but the rate at which the thing relaxes. And he called this 'relaxometry'.
Now, why is this interesting and important? Well, there is a whole range of iron overload diseases, chiefly iron overload in the liver. And when he modified slightly the data collection of an MRI machine to look on relaxometry, sure enough, he got a three-dimensional pattern of the distribution of iron in the liver.
The importance of this is that the only other way of detecting iron in the liver is through a biopsy. You drill a little hole, take a cork borer, as it were, and pull out a sample. That is not very nice. It also is very localised – you might be near a whole great heap of iron but you won't find it if you've put in the probe in the wrong way. MRI, however, can give you a three-dimensional picture.
So now a company called Inner Vision Biometrics has been set up to work in this field. It will supply the modified sequence of pulses for a standard MRI to collect that information, and now the clever bit comes: 'You get our system of pulses, you collect the data, you send it by email to us, and we will analyse it and let you have the results in 24 hours, anywhere in the world.' That seems to me a stroke of genius.
And is that actually what's happening at the moment?
It is, and the company has been very successful. What is more, iron overload in the liver is prevalent in Mediterranean countries, particularly in Egypt, where the disease is of such distribution that the government supports any treatment for it. Once you get government support, the shares in the company go up!
Biomagnetism has also been applied in a treatment for liver cancer, I think.
Yes. That too began in the lab, in response to an idea that a professor of surgery at UWA had developed while he was still in Melbourne. He took small proteins in the form of microspheres and directed them through the vascular system to various places, including the liver. So by drug control he could deposit these microspheres in people's liver cancers. He then moved on to load the microspheres with yttrium – which can be made radioactive at Lucas Heights – because radioactive materials can destroy cancer.
Now came a further idea. If you heat any cell to above 45 degrees Celsius it dies. Would it be possible to heat the cancer, perhaps using radioactive treatment and heat treatment jointly? If so, how do you get the heat?
Well, you put in microspheres which have a core of magnetic material. You see, when you have a magnetic material and you cycle it through with a magnetic field, it heats. So you have now a non-invasive way of treating liver cancer. By putting your patient in the middle of a system of coils, perhaps, to produce varying magnetic fields, you heat the microspheres that you have loaded with magnetic materials and deposited in the liver cancer cells.
The original work on the processes responsible for the heating when you are applying magnetic fields was done in the laboratory by PhD students, and then of course it was taken over and developed medically, commercially, in this way. A company operating the process floated on the stock exchange quite some time ago.
So there would be a world of applications there, most of which probably haven't even been thought up yet.
I think that's so.
Do you still have much involvement with the magnetics lab?
Oh, I go in. The real problem is that the young are getting much too clever these days!
Research opportunities and rewards
Robert, do magnetic materials still hold a lot of untapped potential, say for an early-career researcher looking to make a mark in the world?
Yes. An interesting case in point came up from the biological side of things. I was told that at the bottom of smelly pools, almost anywhere in the world, there are a whole series of bacteria which you can see under the microscope and which are magnetotactic: they respond to the direction of a magnetic field. That seems to me quite remarkable. It's not the same as iron filings going and attaching themselves to a permanent magnet. These bacteria know which way the field is oriented.
I've spent many an hour looking at these magnetotactic bacteria under a microscope – which is easy to do, even with a very simple microscope, because some of them are quite big – and watching them respond to a little magnet. You see them swimming one way, and when you turn the magnet over they swim back the other way, and so on. The poor little things become completely confused.
The real problem is: how do they get that way? They assemble within themselves molecules of magnetite, but how do they know which way the little magnets in those molecules are oriented? You see, on their back they've got a little motor of hairlike cilia, which rotate and drive the bacteria in one particular direction only. (I don't think they've got reverse.)
Now, in the northern hemisphere the Earth's magnetic field dips downwards; in the southern hemisphere it rears upwards out of the surface. And these magnetotactic bacteria differ in the north and the south. The motor is on one end in the northern hemisphere and on the other end in the southern hemisphere. They need to find their way up or down in the water, but how do they assemble the little magnets which enable them to find the proper direction?
I think that initially half of them must have their magnets pointing in a direction which means that they'll be able to swim upwards; the other half, unfortunately, must be made so that they have their magnets pointing the other way and they can only swim downwards. If that is so, and if the bacteria need nutrients which occur above the level of the slime – oxygen, for example – the first half will live, the others will die. I think it's as simple as that.
The next thing we can ask is, 'Well now, here I have a system of beautifully regular magnetic particles. They're all very similar in size. What can I do with them?' Of course, if you're interested in time-dependent magnetisation, you say, 'All right, I'm going to apply a pulse of magnetic field. And if it's big enough and long enough, I'll reverse the magnetisation of the bacteria.' Then you can easily see which ones have been reversed, because they begin to swim in the opposite direction to the rest. Now you have a technique for studying time-dependent magnetisation in a natural material, the bacteria.
Not only does this fascinate me but it fascinates PhD students, who can think of new applications. It is interesting that once you get into this biological area, you have an expanded range of people – women – who are ideally suited to this kind of thinking, whereas I suspect that the male of the species tends not to want to be bothered too much about it. So what has happened in the magnetics lab is that girls are a significant proportion, possibly 50 per cent, of the people who come and work on these problems. They're there the whole time, and I think in the biological area it really is quite amazing.
Possibly this field is just opening up, even as we speak.
I agree, yes. And now courses on biomagnetism are being given in the university.
It seems to me that there's a genetic connection here with biomagnetism in these bacteria. At the moment, the common ways to filter out engineered bacteria from those that don't pick up a gene are to use either pesticide resistance or fluorescence, glowing in the dark. To have a magnetic gene might be another way to do this, and could be a whole field unto itself.
Do you want to do a PhD in biomagnetism? [Chuckles]
That kind of thinking, for example in brainstorming sessions, can be quite important. For example, who would ever have thought that you could study time-dependent magnetisations in colonies of bacteria? Yet it does tell you useful information about not only the bacteria but the physical mechanisms in the magnetic cores as well. And now you're saying that there is another dimension which takes it out of the magnetic core and uses that as a genetic marker. I think many people could find that appealing.
Earlier you were saying that Australia has been very good to you, and I think our conversation has highlighted the fact that you have made enormous contributions to Australia. In 1985 you were awarded an Order of Australia, and I believe that this year your daughter was also awarded an AO. Can you tell us a bit about that?
Well, her citation was for services to medicine. She is a haematologist at the Alfred Hospital and a professor at Monash, and very much involved with haemophilia on an international scale. The other thing that she was awarded the AO for was management of transfusion related diseases – things like AIDS and hepatitis, which are very much blood related. So she has done a great deal.
In addition, she's been very active as an examiner in the colleges of physicians and pathologists, and she's taken this kind of activity overseas to the Philippines and other such places where people wish to qualify and then come and practise in Australia. I think her view is that she goes over there to help them achieve this kind of ambition, and also to make certain that their qualifications are up to a proper standard. We are very proud of her.
My final question is more about the arc of your life. You were born in a coalmining community and you now live as a scientific elder in a mining state in a mineral-based country, where there are many mineral-connected applications of the work you are doing. Do you think that the young Robert Street in Wakefield, Yorkshire, wanting at the age of 12 to become a professor of physics, would be happy with the pathway that you've walked down to become a scientific statesman in Perth, Western Australia?
I can tell you exactly what he thinks! I've been very, very fortunate and I wouldn't have changed one item of it for anything. Somebody, I think, has already said that this is rather a childlike existence. I think it is, and as soon as you lose the idea of wonder at very simple things happening to you, you may as well go and be a grumpy old man somewhere else. Life has been very good to our family.
Robert, thanks for reflecting with us today on your 'magnetic career'.
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