|CHAPTER 15 - 1964 to 1970 (1)||
While he continued to work with teeth, John heard of other groups using radioactive tracer methods to elicit useful information about the natural world and began to think of new experiments himself. At the same time the science and medical faculties of the University started a course in radiobiology leading to an MSc and from 1964 John was put in charge of the physics lectures and the experimental work in radiobiology. Students had to do projects and John thoroughly enjoyed helping them to think of suitable experiments and discussing their results with them. He was already collecting material for a book on the subject and the result, "Applications of Nuclear Physics", was published in 1964. The first half of the book went into the basic principles and the associated mathematics of nuclear physics and the second half dealt with its uses in biology, chemistry and dating techniques. John had to fit the writing of this into an already crowded life and he accepted a great deal of help from Reinet who drew diagrams and compiled tables and he even allowed me to do a few of the diagrams. In the final stages, proof reading was done in turn by the whole family with one person reading aloud from the proofs and another checking this against the original typescript: the proofs were in the luggage when we went on holiday to Guernsey and during one lengthy delay at Birmingham airport much progress was made on them. Despite the importance of completing the proof reading, John still threw himself into enjoying the holiday, finding and photographing wild flowers and joining David on a course of lessons in scuba diving.|
Although his work was going very well, John occasionally worried that his career wasn't making as much progress as it should. The next stage would be to become a professor, but there didn't seem to be much chance of that in Birmingham, for Professor Moon was not much older than he was and not very likely to vacate his chair for any other reason than retirement. John kept putting off thinking about applying to other universities when they advertised professorships because of the effects of the upheaval on the other members of the family, but at last the various frustrations of his position got the better of him and he put in applications to the Universities of York and Lancaster, which were advertising professorships some time before they opened. Both applications were unsuccessful, but a couple of years later, Birmingham University offered him a personal chair in recognition of his work in applications of nuclear physics making him Professor of Applied Radioactivity. His inaugural lecture entitled "Impure Physics", which he gave in October 1966, started with a laughing attack on purity in general, then described the various fields in which nuclear physics could be useful and ended with some general thoughts about applying physics. He pointed out that there were already large numbers of people working in pure nuclear physics making it difficult to do anything new without massive expenditure, whereas, he said, applying the techniques to dentistry or archaeology could produce something new in a few afternoons. To complete his sense of satisfaction, David received his PhD at almost the same time and both Jane and I had started University courses, I to read genetics at Edinburgh University, and Jane mathematics at Liverpool.
John's suspicion of theoretical physics filtered down to the way he interviewed potential undergraduates. He would give extra credit to schoolboys and girls who mentioned anything practical among their hobbies, for the kind of physics he wanted them to do would involve them being good with their hands. At the same time, he would take against any applicant who said that he spent the school holidays reading physics books: he thought that anyone intelligent enough for a university course should not need to do this and in any case he was looking for well-rounded characters. At one point, he thought it would be useful to try to find out whether an applicant's performance in his school examinations was of real use in determining how well he would do at university and he collected the final degree results from several years and compared these with both the 'A'-level and 'O'-level results of the students concerned. He was surprised to find that there was almost no correlation with 'A'-level results but that there was a weak correlation with 'O'-level results. As soon as he thought about this outcome, he could see the reason: 'A'-level classes (at that time) were often taught in small groups where teachers could give a great deal of personal help of a type which students could no longer rely on once they were at University. In the years leading up to 'O'-level, children were taught in larger classes with greater ability ranges and so only the more intelligent and dedicated were able to achieve the best marks.
By the mid-sixties, John's life had become so full that there is an increased difficulty in describing it. To give a chronological blow-by-blow account risks descending into chaos, because at any one time John was following several lines of work in his research, not to mention directing several research students, as well as developing numerous activities outside the University. So, in this and the next chapter, I have grouped events and pieces of research to a certain extent but this must not allow us to lose sight of the fact that so much of John's personality was the sheer amount he did, thought and said every day, every week and every year.
Although he had turned fifty, John still said he never felt tired. He could often think of excuses for not doing things he didn't want to do, but lack of energy was never one of them. He found the constant demands on his time exciting and stretched time slightly by arriving just that little bit late for almost everything, but usually so apologetic that he had to be forgiven immediately.
A fundamental part of John's character was his constant interest in why things happened. For many people, the words "I wonder why?" at the beginning of a sentence are purely rhetorical. But for John those words were always an invitation to exercise his imagination and call on his vast store of knowledge, and many was the unsuspecting speaker who found John picking up his question and using it for some well reasoned speculation. Reinet sometimes had to provide explanations for visitors at coffee parties when John might suddenly interrupt with a comment that seemed totally irrelevant to the current conversation. In fact, he would be giving a possible answer to someone who had uttered the magic words a minute or two earlier.
Sometimes when a particularly interesting problem had been raised, John would give it serious thought for a while and then write an article about it. In this way he produced pieces on motion stereoscopy, the probability of life, avian vision, the evolution of morality and ethics, life on other planets, the philosophy of ageing, how ice skates are able to slide on ice and the intelligence of crows and rooks. As he had become relatively well known, he did not find it difficult to get these articles published in addition to a constant stream of papers about his research.
One of his speculative articles developed from discussions of population levels. Generalised worry about the increasing world population was common then as now, usually taking the form of an assumption that some resource or another would run out. John had begun to wonder exactly which resource was going to run out first, because if this was known in advance, perhaps something could be done about it in time. He looked up the basic constituents of the human body and the standard ways in which the materials found on the earth are converted into people and also noted housing and fuel needs. Then he got hold of estimates of the total stores of the necessary basic elements and started to manipulate his collections of figures with his slide rule. However much he checked and re-checked the figures, the answer came out that nothing essential for human life would run out completely until the population had reached extremely high levels.
At this point in his calculations, he started to develop his findings into an article by creating scenes of the type of life people could expect at various population levels. At the time of writing his article, the world population was about three thousand million and was doubling every thirty-seven years. This would give a trillion (a million million million) people in one thousand years' time. Describing this phase, he said that there was enough carbon, hydrogen, oxygen, nitrogen, sodium, chlorine, calcium and potassium in the top ten kilometres of the earth's crust to make a trillion people, although extensive new technology including mirrors reflecting sunlight all the way round the world and total recycling would be needed. By that time, the whole world would be covered by buildings two thousand storeys high and each person would be allowed seven and a half square metres of floor space. While he was actually engaged in writing up this article, he found that there was an interesting limit that came into effect at this stage. He discovered that if the population were to rise any further, it would be physically impossible to design the heat pumps needed to remove the heat generated by all the people and machinery in their roofed-in world and so it would be through overheating rather than through running out of resources that the world's population growth would finally come to a halt. The finished article was called 'How many people can the World Support?' and was published in New Scientist in October 1964.
John enjoyed writing this article and it got a good reception, so he added the subject to his repertoire of lectures, refining his calculations each time he reviewed it prior to an engagement. Then, after a series of television programmes on the same subject, it was suggested that he should write a book, which he agreed to do. Sitting in the evenings at his make-shift desk (a piece of hardboard he had cut in the early fifties to fit over his knees and round the arms of his favourite easy chair) he collected all his material together and formed it into a book called 'Be Fruitful and Multiply', which was published in 1972 and which followed very similar lines to the original New Scientist article, but had the problems and types of technology needed for each level of the population described in far greater detail. It had the same conclusion, that man, alone within the animal kingdom, would limit himself by his own production of heat. John also included a certain amount of philosophy on how people would have to learn to interact to accept living within such high population densities together with a couple of chapters on the choices open to us to prevent such population levels ever being reached.
John's cheerful predictions in the population articles and book appeared to indicate a detachment from the consequences of overpopulation. But even before the book was written, he was already taking an interest in practical ways of limiting world population. He began to support the British Pregnancy Advisory Service (BPAS) that had been set up to help guide women to legal abortions and in 1970 he was invited to become a Trustee. At this time there were still a lot of illegal back-street abortions, permanently injuring or killing some of the women concerned. This was in spite of the 1967 Act, which came into effect in 1968 and which had detailed a number of conditions in which abortion by a qualified and registered surgeon came within the law. The BPAS operated small clinics where qualified advisers would interview pregnant women wanting abortions, explain the conditions that must be met and investigate sympathetically why the abortion was desired. The Trustees met weekly and were responsible for the budget, with the appointment of new qualified staff and the starting of new clinics. As a charity, they did not have to pay tax, but to keep their charitable status they were not allowed to turn down any case where a woman was genuinely unable to pay. John also lent some support to the Family Planning Association. He was quite aware that these were only small contributions to limiting world population but he felt that, in such an over-populated world, there was no excuse for society to force a woman who did not want a baby to give birth to and rear one.
Now that he had a car, John increased the number of lectures he gave outside Birmingham. Each time he went off on such a trip, he investigated the possibilities of the region he was going to and usually managed to find a useful area to visit in his quest for wild flowers he hadn't seen yet. He had collected a number of contacts around the country able to tell him about any rare specimens that were available locally. Before leaving home he would write to or telephone one of these people, or, if none were available, a nearby University botany department, to pick up the latest information about what was in flower, and then plan an extra half day to hunt for what was on offer. To ensure his trips were free from worries about such trivial matters as finding food, he kept a supply of small tins of fish, meat and fruit, a tin opener and a spoon in the car. One day, he had found himself a pleasant picnic spot, chosen a tin of sardines and another of fruit, but could not lay his hands on the spoon. So he cut himself two twigs from a bush with his penknife and, wielding them as chopsticks, enjoyed his meal all the better for having risen to a challenge. The car was also equipped to contribute to these adventures and early in its life was fitted with a shelf to accommodate a small selection of his extensive collection of maps and books about flowers. The car was further embellished with a car compass, a device for boiling water for coffee which ran off the cigarette lighter and a child's toy broom: this last was held to the roof by a clip and was used from the front seat to clear the inside of the rear window of condensation in the days before rear screen heaters.
John also took himself off on a number of flower hunting expeditions to places he was unlikely to visit in connection with work or speaking engagements and in 1964 he went up to Scotland, having heard that a lot of rare plants could be found on Ben Lawers. The Lawers Hotel was full so he got a room at another hotel a few miles away. Over dinner someone mentioned that the Lawers Hotel was always full of flower ladies and so later he drove back there to see whether anyone could give him any information or advice. He was shown into the lounge where he found a lot of people sitting round a determined looking lady who was sorting specimens on the floor. This turned out to be Mary McCallam Webster, a leading British botanist, who had led a number of members of the Wild Flower Society up Ben Lawers that morning. John showed the group his stereo camera and they told him all about the Wild Flower Society giving him the address of its headquarters. After an hour or so he set off back to his own hotel suffused with the happy satisfied feeling that comes after a successful day. When he was about half way he suddenly noticed that his camera on its tripod was lying on the car bonnet and he had an anxious period while he slowed down carefully hoping that the deceleration would not dislodge it.
The Wild Flower Society had been formed in 1886 by a girl who was faced with the task of finding something useful for her younger sisters to do in their long summer holiday. She bought each sister an exercise book and promised a small prize to the one who listed the greatest number of wild flowers she had seen. It was a great success, repeated the following year when more children asked if they could join in. As the children grew up and the diaries continued to be kept, the Society was formed. It appealed to John immensely and he sent off a year's subscription as soon as he got home. This produced the Society's Field Botanist's Diary and John was disappointed to find that he could not rush down Richmond Hill Road and start filling it in immediately, for it was set up to start in March of the following year. The idea of these diaries was that members should complete them with all their finds of wild flowers (which had to be actually in flower when seen) for the specified year, and branches of the society competed on the number of finds of all their members. In his first year, John recorded seven hundred and fifty-five different flowering plants, one hundred and seventy of which were new to him and could also be added to his collection of photographs and he increased his total every year until he became one of the privileged few who could forego filling in every flower they found every year and just enter those that were new to them.
The Society also arranged several expeditions each year, usually at weekends, led by local botanists. These moved at a leisurely rate, giving plenty of time for most of the members to look at the interesting plants, but all the same John usually had to run to catch up after giving himself the necessary time for photography. Occasionally Reinet accompanied him on one of these trips and John found that she made a very useful link woman. While he organised his photographic equipment, Reinet went with the party, listened to the details of the next find, and went back to fetch John to point it out to him while the party once again moved on. She found that she got a lot of exercise this way. The parties usually consisted mainly of women and if Reinet was not there to help, John generally found one ready to lag behind the leaders to show him which way the party had gone and point out the less conspicuous plants. At the society's meetings, John always took his stereo viewer and some slides which became very popular.
One summer, John was out on his own hunting for the lady's slipper orchid, an extremely rare plant, in a location where he believed it had been seen. Just as he found it, a young man came rushing up and asked him if he was looking for something. This was Mike Mullen and it turned out that he was camping nearby in order to guard the very plant John was hunting. When John introduced himself, Mike said that he had heard about his stereo photographs from other members of the Wild Flower Society. A firm friendship started between John and Mike and for some years after this John joined Mike and his wife and baby (who travelled on Mike's back) on several flower-hunting holidays.
John's work on teeth was acknowledged when he was invited to a conference on teeth in Amsterdam. Exploring the city, he came across an exhibition of Rembrandt's work and spent some time there. It was a revelation to him that faces could be portrayed in such a realistic manner, and he came to the conclusion that a face was much more interesting if it was lined by experience than if it was smooth through youth, make-up or kind portraiture.
He was also invited to a peace conference in East Germany and he decided that it was time he tried driving on the continent and took his car. He travelled with someone who was also going to the conference. They had no trouble transferring from West to East Germany at a crossing point some twenty miles south of Berlin, although the procedures for changing their money were time consuming. On a day off from the conference they decided to drive into the country. Neither of them spoke more than a few words of German and John suggested that they should start by finding a school and asking for the teacher who taught English and asking him to take them to a collective farm. They were directed to a boys' school and located a teacher who released his excited class for the rest of the afternoon. John and his friend explained that East Germany was very badly reported in England and they were anxious to get some direct first-hand information to take home with them. They told him of their academic qualifications and of the short paper John would be giving at the Leipzig conference. The teacher took them to his headmaster and they heard him explaining the possible value to the State of helping them. The headmaster tried to get the assent of someone important in the Ministry of Education and from there was referred to a government committee that offered to choose them a farm to visit. John said that this would not give him the reassurance that he was seeing an average farm, and eventually the teacher solved the problem by consulting a farming cousin who offered them the choice of several farms.
They chose one where English was spoken and spent some time there. They began by asking the spokesman whether he could decide for himself what to do and were told that at first they had all been told what to produce and farmers had often been charged with sabotage when they did not meet unrealistic targets for crops which were in fact unsuitable for the type of land. Now they were merely expected to propose suitable crops and livestock themselves each year with an estimate of the expected yield. The spokesman thought that the prices he could get were unreasonably low, but seemed to have good equipment and to have recently built new winter accommodation for his cattle. The visit ended with a ride on a combine harvester, hired for the afternoon, cutting four or five hectares of wheat. From this very small and highly selected sample, John liked to say that he was satisfied that the collective farms of East Germany were not in the parlous state described by the British press!
John was now taking an interest in another subject totally new to him. It was known around the turn of the century that some rocks would glow in the dark when heated to about 400o C, a phenomenon called thermoluminescence. However, once they had been heated, the ability was lost and the rocks would not glow on re-heating. It was later found that irradiation would restore the ability to glow when heated and indeed, irradiation over long periods of time had created the ability in the first place. The mechanism by which this phenomenon works is that electrons within the lattice of a crystalline structure get knocked out of place by incoming ionising radiation only to become lodged in imperfections within the lattice. Heating then shakes up the trapped electrons and as they fall back into place, electrical energy is released in the form of light. By the early nineteen sixties it was found that finely ground and homogenised samples of pottery would, when heated, give out an amount of light proportional to the total radiation dose they had received since their manufacture which should also be proportional to their age: the heating involved in the manufacturing process had in effect set the clock to zero. But as a method of dating, the technique was proving unreliable. When John got to hear about thermoluminescence, he decided to investigate it to see if it could be turned into a more useful dating tool.
At the time, there was in the department a postgraduate student from Thailand, Somsri Srirath, who had got nowhere in her first year and was delighted for John to suggest a new project to her. She helped him to show that the unreliability was due to irregular impurities in the pottery in the form of little pockets of uranium in the clay matrix disguising the smaller amount of genuine thermoluminescence. The only way they could see to get round the problem in the future would be to separate out the impurities. However, the reason why pottery had been selected for the technique was that its original firing cancelled any previous thermoluminescence of the original materials, thus zeroing the effect, which could then build up again during the object's passage through time. So they also tried working on pot-boilers found on archaeological sites. These stones, which had been heated in a fire before being dropped into a pot of water to heat it, also proved non-uniform and unreliable.
One afternoon, John received a visitor, Dr Henry Irwin, an archaeologist from Washington State University, who had been excavating a cave in Spain that had been occupied by people and bats for many thousands of years; between them they had left a mixture of bat droppings, wood ash, blown sand and miscellaneous materials including simple tools and weapons. Among these Henry Irwin had collected a lot of pieces of flint that had been through a fire, and, having seen one of John's publications, came to see if he would be interested in trying to date them. Flints are more uniform in structure than ancient pottery but any dating technique would usually give the age of the original rock from which they came. However, since the thermoluminescent effect is destroyed by heating, John agreed that any flints which had fallen into fires could have the time that elapsed since that happened measured by thermoluminescence which should give the date when they were being used. Flints which showed signs of having been burnt or which were found in places where there was other evidence of fire were tested. At first the flints were powdered before heating to look for thermoluminescence but this also gave unreliable results that turned out to be due to the glow caused by the friction of grinding itself. John and Dr Irwin then developed a system of preparing and testing thin slices of flint and sure enough, they found that the technique gave a relatively reliable dating system that could be used on any burnt flints under one hundred thousand years old.
As part of this work, John visited Henry Irwin at the Washington State University in Pullman, and several years later he visited again. His interest in dating led to several invitations to archaeological sites and conferences in Europe and John accepted as many of these as he could, most of them being of general archaeological interest rather than vital for his thermoluminescence research. Thus he visited Poland, had a tour of prehistoric sites in Brittany and went to Tunisia, Czechoslovakia, Hungary and West Germany.