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In footnotes or endnotes please cite AIP interviews like this:
Interview of Hermann Bondi by David DeVorkin on 1978 March 20,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,
For multiple citations, "AIP" is the preferred abbreviation for the location.
Interview focusses on early life in Vienna, family and religion; atmosphere in Vienna in early 1930s; growth of interest in mathematical physics; anti-Semitism in Vienna; influence of history teacher and rejection of religion; influence of reading Eddington and Jeans in the mid-1930s; further study in England and contact with Eddington; Trinity College, 1937-1940; study with Besicovitch; collapse of plebiscite and family in Vienna; internment during World WarII; graduate study with Harold Jeffreys; naval radar, 1942; associates during war and circle at Cambridge; development of radar research team with Gold and Hoyle; developing astronomical interests, 1943; early research on accretion and evolution; cosmology; general relativity; contact with Dyson, Lighthill and W.H. McCrae; work in theoretical stellar structure; the problem of red giants; Hoyle's theory of stellar evolution; Hoyle-Lyttleton red giant models; growing interests in cosmology and discussion of Tolman and Hubble; the Steady State Cosmology; reactions to Steady State theory; gravitational theory and relativity circa 1955.
Although most people know about me from my cosmology, in fact I regard as my most important scientific work my work in the theory of gravitation, and particularly gravitational waves, upon which there's a very considerable number of papers by myself, and by various colleagues of mine, roughly speaking, spanning the period from 1957 to '67.
Yes, quite true.
Well, I do think that that was my chief contribution, really. Im perfectly happy to talk about cosmology and stellar structure, but it isnt quite the centerpiece of what I am proudest to have done.
Well, I'm happy to have that on the tape. But given our two hours, and with the certain hope that in the next few years, I or someone else will be able to talk to you again, and continue, I would like to take it in chronological order.
Thats quite all right.
I was hoping to get as far as about 1955.
Yes, fine. Which is just when my gravitational stage started.
That makes sense, So this may be material that you no longer wish to talk about?
No, I am quite happy to talk about everything.
OK. Very good. That will be a good indication for future interviewers, if not myself,
We start with your very early life, I want to identify in detail, as much detail as you care to go into, your early life in Vienna, the backgrounds of your parents, and the nature of your family, what you did,
Quite. Well, the background in Vienna is that my father was a physician, specializing in heart and internal ailments of various kinds, We lived in a quarter of Vienna where many medical people lived, close to
the big hospitals and the university. My father came from a very large Jewish family, He was one of the youngest of a family of 16. And I still knew my grandfather, who was born in 1831. I'm always quite boastful of the longevity of that generation.
He must have been 90 when you were born, then?
He was 88 when I was born, and he died, I think, at 94 or 95, He lived in Vienna. They had originally lived in Mainz in Germany, and moved to Vienna when my father was six, that is in 1884, Now, of course, all the members of that generation have died, None of the brothers and sisters are left, My father was one of the last ones, He lived to the age of 80, 1 had an aunt who I was very fond of who was younger than my father, who was an art dealer and who settled here in London, She was one of the earliest discoverers of Kokoshka and people like that, a very eminent and strong personality in her own right,
My mother came from a very well-to-do family in north Germany, Halberstadt, with some relation with my father's family, but a generation out of step. She was not only much younger but, as it were, a generation down.
Well, it was a very comfortable life, My only sister is 4 1/2 years older than I am. Roughly speaking, the First World War lies between her and me,
We were a very free thinking family, my father with some attachment to the religion and cultural Jewish life, Many of our relations were orthodox, but we were definitely not, particularly my mother who felt quite strongly about that.
You were not orthodox.
No, By no means. Directly hostile.
Did this come from the generation of your parents?
Well, particularly on my mother's side, My father wasn't religious, but he liked the forms and the cultural traditions, and many members of his family were orthodox,
We grew up then in Vienna, I went to ordinary maintained schools, slightly unusual perhaps from this background, but we followed this tradition, All our children went to the ordinary maintained schools in this country.
Can you discuss what the equivalent school would be here, or in America?
The American system is rather different, Of course, all countries differ, In this country, as you know, there's a very large body of independent or private schooling, which is very much used by upper middle class people, In Austria that was a smaller system, but even so, it was just a trace unusual for us to go the ordinary schools, and we have done the same with our children.
What was the reasoning that your parents used for sending you to the ordinary schools?
If they were reasonably good in their education, there was no reason not to. And there were many advantages, or not being exclusive, of teaching one to get on with quite a number of people.
What about the philosophy of the schooling that you would have gotten there, as opposed to the private school? Was there an elitist philosophy?
Well, elitist in the very mild sense that the more academic schools, like the one to which I went, had a selection examination when you went at age 11, which used to be the case here and which is still the case in many parts of the continent. And so, you had to be reasonably intelligent, with a reasonable interest in education, but it still cut a pretty wide cross-section.
On the whole, I think it was a very good education. But of course, the Vienna of those days was not the most pleasant place, politically, and the harsh politics grew out of the truly very considerable poverty. There was a very sharp political division between the Social Democrats, who were very strong in Vienna, but in a minority in the country as a whole, and the Conservative Christian Party, which was always the government, this tension led to actual violence in '27 and '34 and so
on. This was not a very agreeable background.
But I became interested in mathematical physics, as you might call it, very early on — I think I was about eight — through looking at the school books of my sister. As I said, she was well ahead of me. An uncle of mine, also a doctor, was also quite influential in this. And I think I ought to say that my father, would have become a scientist had he been 20 or 30 years younger. But of course when he was a boy, at the turn of the century, this wasn't really a way of making a living.
As a scientist, no. As a medical man, most certainly. But his interest in the scientific foundations of medicine was always very great.
I see. That's quite interesting. Your early home life, leading into your early school, then: could you describe what you would do in the evenings? What were the priorities in the family? Whether you had any particular duties in the family? Were there servants to take care of the domestic chores?
Yes. It was quite a well-to-do household, of course, with servants. That was the normal situation, as it were. But it was a bookish family, shall I say. Reading was very enjoyable. I liked to play a little bridge.
At what age did you play bridge?
Oh, I don't know, about 12 or something like that. Not at all expertly. Family bridge.
Who would teach you the games?
Oh, I think my mother, probably. I wasn't at all sporting in my school days. On the other hand, I always enjoyed, as I've enjoyed all my life and still do today, being in the mountains, walking and skiing. I'm very fond of that. In fact, I'm going skiing again on Wednesday.
Right. The books that you were first exposed to — do you recall any titles?
It is difficult. One or two things come across my mind. There was something, not quite as serious as the SCIENTIFIC
AMERICAN, called COSMOS, a sort of Journal that came out, which I certainly enjoyed very much.
This was from the Vienna area or Germany?
Germany, I think. Well, the general literature of the time. When I was a little older, I was very fond of Thomas Mann. I certainly enjoyed some of the Swiss authors, Conrad Ferdinand Meyer I remember I enjoyed very much — a Swiss author of considerable distinction. I had less interest in poetry, quite an interest in what science fiction there was in those days. There were some very good books in that line. Not only Jules Verne, whom I rather liked. There was a very good book the title of which translated, is ON TWO PLANETS, which was excellent, and various other things that I read.
ON TWO PLANETS, I've not heard of that one. Who's the author?
I don't remember. Nor do I think that it has been translated into English. I just remember the title. It must have first come out maybe 1920 or so. It was by no means a new book.
So this is what you would characterize as your early reading and your family reading. Did you ever have discussions with your family, with your sister, about Thomas Mann?
Oh yes. Certainly. We also quite liked sort of classical stuff, Greek mythology, very much.
Can you recall developing interests, let's say in Thomas Mann and mathematics at the same time — world modeling — something that might bring you into cosmology in the future
I don't think so. In fact, cosmology happened almost like an
accident, 191 come to that,
My early scientific interests were very much in what is sometimes called the exact sciences, Mechanics was a great love of mine from a very early stage. The ideas of the exactness of the law of free fall, you know, Galilean work, and how you could work out one thing and other from it. I enjoyed that enormously. I got hold of and taught myself from a book on analytical geometry and differential calculus when I was about 12 or 13. I really spent a lot of time reading on theoretical physics and the like, understanding some of it.
What were some of the books you read in that area when you were 12, 13?
Well, I dont really remember the titles of that period, When I was sort of 15 or 16, what is still I think a great standard textbook of theoretical physics by Joos, a first edition of that, was a great bible of mine. I very much enjoyed learning about vectors and that kind of thing.
But you hadn't by this time at least encountered anything of serious astronomical interest?
No. Astronomy came much later.
In directing you to any of these books, were any of your teachers in the Realgymnasium influential?
Relatively little from school in that direction, My fathers scientific interests, and his friends, certainly helped considerably.
Was your father doing medical research at all?
Yes. He was. In fact, he was doing research on the borderline of physics and medicine, As I say, the heart interested him very much, and he was very much interested in modeling the origin of heart murmurs, by building apparatus and experimenting with it, listening to it, whether it sounded much the same, and how it depends upon shapes in order to be able to interpret what the medical man heard when he listened to the heart. Very much interested in the structure of stethoscopes and the like.
Quite fascinating. You were interested in exact science. Was this stimulated in you by your father? Because medicine is anything but an exact science.
He was very very conscious of this, He used to refer to medicine sometimes as the pseudoscience,
Then there was no feeling, from his direction, that you would follow in his footsteps? or what?
No, I don't think so, On the contrary, from a very early stage on, I was quite determined not to be a medical man, largely because my father was a very soft hearted man, and he worried terribly about his more difficult cases, When I was quite a little boy, I came to the conclusion that whatever job you do, you worry whether you're successful and earn enough money, but in medicine, you're also so damned worried about your patients why should I have such a difficult life?
Thats very interesting. That's quite an interesting feeling. Do you recall his worrying to the extent that —
The family was aware of it?
Were there any difficulties in the family as a result?
Were there any sicknesses in your family?
Well, nothing at all severe in the close family. I was a very thin little boy, didn't like eating very much, and I suffered a great deal from colds, sore throats, ear trouble, particularly ear trouble, slightly more severe than the normal childhood business,
We had one great tragedy. I mentioned to you the uncle who had particularly directed me to physics.
Yes, what was his name?
His name was Joseph Bondi, my father's brother, His wife was my wife's aunt, The linkage between the two families — but the same generation, in that case, And their daughter died of pneumonia in her midtwenties, when I was a boy of perhaps six or so, Of course, pneumonia was a great killer in those days.
Yes, Was she attended by your father?
Yes, my father and her father, and half the galaxy of Vienna, And this was very keenly felt, She was a very talented pianist, And they were, in fact, her parents were before and after the tragedy, our very closest friends in the family.
You have recollections of this girl yourself?
Very faint. Only very faint.
But you do have recollections of the impact of her death.
Could this be the origin of some of your father's unhappiness or concern for his patients?
I have a suspicion that it dated back before that. No doubt it didn't help, as you say. My sister, I may say, did follow
his footsteps and became a doctor.
Oh, I see. She would be a medical doctor now.
I see. That's quite interesting. Your sister's name?
Now, you're in the Realschule still in Vienna in the thirties. Surely there must have been some anti-Semitism brewing?
Yes. There was. I never felt this as much as some people did, either because of a thicker skin or it seemed to me what there was, was much the general political unpleasantness, than anti-semitism as a particular matter,
Were there any problems at school or in social or educational contacts?
No, I don't really think so. Obviously, some of the other boys were on the Nazi side politically in my later years, but it never seemed to affect personal relations. In fact, although I was probably a rather lonely boy in my early school years, the last four or five years at school, I was extremely sociable, and very much with all the others.
Still in the Vienna period?
In the Vienna period, very much so. I had many very good friends there.
You were socially active. Did you have games, parties?
Yes. As I say, I wasn't keen on sports, but I loved walks, cycle trips, skiing, playing bridge, just chatting I was very fond of.
Did you ever have friends with kindred interests in mathematical physics?
Not really. My father at one stage engaged a sort of young
physics PhD to help me a little in the work.
What was his name?
Adler. I don't remember his first name.
What period of time was this?
Say when I was around 16. Now, let me come back to school. There was one teacher there who had a considerable influence on me, and his main subject of focus was history, and I have from that time an abiding love of history. In my school days, it was particularly Roman history, where again I read a great deal, far beyond what I did at school. There was in particular a great author, in German. Mommsen. You may have heard the name. I absolutely devoured him. In general I was very very interested in that. But my leader also interested me in other periods, and I still have a continuous interest in history — mainly the classical period, and modern. My anti-religious views make me very unsympathetic with the Medieval history. I find it much more difficult to follow.
That's interesting. In your anti-religious views, you're objecting to theology or what?
Intolerance, above all, I find very objectionable. Theology, yes
— but people could get so terribly excited about the interpretation of some phrase or other.
There's a certain attempt at exactitude in the Old Testament, but this is not the exactitude that interested you.
No. Not at all, no. I was very short of sympathy on that side.
Well, is there something in your developing life while still in Vienna that you can pinpoint that caused this aversion?
Well, of course my mother's aversion was very great. I mean, we always had tolerable relations with the orthodox family, though with a strain, because of some of the attitudes and intolerances there.
This is within the Jewish tradition?
I understand that it has a certain element of free will in it. Did you see an hypocrisy in that?
Well, free will, theologically, perhaps. But the sort of thing,
I know, that utterly horrified my mother, and she inculcated that in me very early: that if a member of an orthodox family, a child, changes his religion, you mourn for him as if he had died!
Now, that kind of intolerance I find and used to find absolutely dispicable.
OK, I understand the degree of objection.
My dislike of it has never weakened.
So can we move on through your Vienna years?
Yes. Now, in the later years the great English authors of popular
science, like Eddington and Jeans, I read with the greatest interest.
I had learned English at school, and then, when my school days approached
their end, naturally I was thinking ahead.
This is by the time you were about 17?
Yes, that time, but a little earlier I should say. My birthday is in November. Normally the break is in September but one could get, by a special dispensation, for a child with intelligence, into the older age class, so that my school would finish in the summer before I was 18.
Let me ask, before you talk about that, about the books, Eddington and Jeans — which books?
Oh, any number of them. I can't even remember all the titles. NATURE OF THE PHYSICAL UNIVERSE, ASTRONOMY AND COSMOGONY, there was beginning to be an astronomical part to it, then, but it was even more the physics that interested me than the astronomy.
Now, I had already for some time felt that research and an academic career was the right thing for me. And then one began to worry very much about anti-Semitism, because the university was very much a center of this.
A center of anti-Semitism?
Yes. It was always very much stronger there than elsewhere.
I see. Was this induced by the need for support from the state? Especially in Germany, that was very strong.
Well, they were all stage universities, of course. But there was very strong resentment amongst the non-Jewish side that the Jewish intellectual tradition there meant that a very large proportion of the university population was Jewish. And this led to considerable resentment. That was very much all the time a center of anti-Semitism.
Now, the career possibilities. I didn't think that the chances of a successful academic career in Austria were in play at all. I did think quite seriously about engineering.
That's quite interesting — an outgrowth of your interest in exact science?
Absolutely. And at that stage, with Eddington and Jeans, with Dirac's work, with of course Hitler already in power in Germany, the thought to come to England, and particularly to Cambridge, became very strong.
This is something that welled up in your own mind?
In my own mind.
There were no external suggestions?
No, This was very much my own mind. And that it came to pass, I think, owed its connection to two incidents. You like me to talk on this at length?
In my wider family, there was one and only one person in mathematics, an Uncle once removed I think on my mothers side by the name of Abraham Frankel, a pure mathematician in the theory of sets who was professor at Kiel, in Germany, and then emigrated to Israel, and later became rector of the University in Jerusalem, And my mother contrived, I can only call it that because there was no particular connection between us, contrived that we were simultaneously in the Engadin, a holiday area in southeast Switzerland. It is one of the most famous parts of Switzerland, a beautiful valley, 6000 feet up, with a chain of lakes and mountains. Anyway, she contrived that we met there, not quite easily, because he was very orthodox and stayed in a kosher hotel that we usually had nothing to do with. But he of course was interested in this young member of the family, with mathematical interests, and he had a lengthy discussion with me.
Secondly, Eddington came to Vienna about that time, early autumn '36, I should think and knew a friend of my father's so I met him very briefly then.
And this encouraged me to aim for Cambridge, to Trinity College.
But you already had the idea.
I already had had the idea.
Can you recall the mutual friends name?
No. Not a clue. I wrote to Trinity College at Cambridge, where I got a slightly interested but cool response. The point of course was that they were very interested in taking a young man who was rather brilliant in mathematics, but all the evidence of my quality they had at that stage was from my teachers at school, of whom they'd never heard, naturally enough. But then I remembered having met my great uncle, and told them to write to him, and after his reply, they were very pleased for me to come,
I see. So then you didn't talk directly with Eddington, when you met him, of the possibility of coming to Cambridge?
Yes. It was mentioned, But of course, it wasnt his branch of college life. He suggested who I might write to in college, the senior tutor. It was this chance meeting, as it were, or contrived meeting, that really opened the door. And so I found myself at Cambridge.
Your family remained in Vienna?
Yes. And so I found myself in Cambridge in October, 1937. At Trinity. Reading mathematics.
Now, at Cambridge in those days, there were two ways in which you could do the mathematics course. There were, as it were, four years. You got your degree after three, and you could take either years 1, 2 and 3, or years 2, 3 and 4, if you were very advanced. And of course, you know its a very specialized education here in England, what is now A level, and somebody who had done well in that would start with Year 2.
Well, I have never lacked self confidence. So I naturally asked to start with Year 2. I didnt even know the names of the branches of mathematics, and when it was suggested I should have supervision you know, in Cambridge one has individual tuition — the subject of analysis was mentioned. Well, I thought that meant analytical geometry, of which I'd gotten a fair amount. And so I found myself being supervised by a very great man and a superb teacher, a Russian emigrent by the name of Besicovich. And he asked me a question, and I didn't have a clue about the subject. He asked me another question, and I didn't have a clue. And he said, "Now, look, I really think you're very ill advised to start with Year 2. Why don't you start with Year 1?"
I said, "No."
To which he said, "Now, at the moment, you don't know enough for me to
supervise you. You have to learn a lot more,
"Well," I said, "I can learn."
And he said, "Look I think you're putting too much on your plate. But who knows, you may be right? Come back to me next term if you really insist on starting with Year 2."
Next term, January. So I got a supervisor in applied mathematics, theoretical mechanics or something where I was perfectly all right, and I "beavered" away at learning analysis, and the one and only time in my life I ever suffered at all from eye strain was with all that reading — because after that, I saw him again in January, At the first supervision he said "Good." At the second one he said, "Very good." At the third one he said, "You know all that — let me tell you about my experience in the Russian Revolution..."
That's marvelous, And he of course remembered the initial meeting?
Was this a typical thing to expect of Cambridge first year people?
Well, this man Besicovich was quite an extraordinary man. He died four or five years ago. A great mathematician. But at that stage he was still teaching undergraduates and teaching superbly. One of my friends, several years older than I, says there are only two kinds of mathematicians
those who have been taught by Besicovich, and the others.
My wife, who followed of course a few years later, agrees, that he was the man whose teaching really taught her something. He was a most remarkable man.
Did you do any research papers with him?
No, because my interests, rather to his and other people's regrets, were entirely on the applied mathematics side, and he was a pure mathematician.
Well, then of course, politics came in. In the winter — early months
— I visited home, and had a little skiing holiday, Christmas, '37, beginning of '38. And of course in early '38, trouble started. And I grew very nervous, and when the Austrian government announced its plebiscite, I was quite sure Hitler would never tolerate this, and sent my family a telegram that they must immediately leave the country.
You were back in Cambridge then.
Back in Cambridge, yes, at that time. They did leave. My mother was a little nervous earlier, went to friends in Budapest. My father and my sister left Vienna six hours before the collapse. And then, my Easter vacation was very near, they came around by Yugoslavia and Italy. We met in Switzerland. And then of course I returned to Cambridge. They then came to England. My sister, who was of course a medical student, finished, then went back to Switzerland, where we had a cousin in Basel with whom she stayed, where she got her degree. My father had a rather difficult time in this country, because, a) his qualifications weren't recognized; b) there was a great worry about too many doctors and so on. And so, first my sister and then my parents in fact emigrated to the United States, where they settled in New York. My parents died there. My father in early '59, my mother in '60. My sister still lives there.
In New York.
Yes. Of course, there were some financial worries, but Cambridge looked after me extremely well.
So by this time, certainly by your first year you were very well identified.
Oh, very much so. I was beautifully supported by then.
Never any question of support?
No, nothing. That worked very well. The degree giving exam was the one at the end of the second year of this accelerated course. I did extremely well and everything was going quite swimmingly.
But then, of course, the war started, and my third year started in that. And then in spring, '40, when the war became serious, I was interned, like anybody with Austrian nationality.
Where were you interned?
Various places. First locally at Bery-St. Edmonds. Then outside Liverpool, then the Isle of Man. Then I was sent to Canada.
You were certainly not allowed to continue studying.
No. As far as my degree was concerned, it didn't matter, because you see, what I needed for that was three years residence, and they gladly allowed me the extra four weeks, and I had my degree-giving exam from the year before. I was then sent to Canada, and then, a rather awkward game started.
My parents had meanwhile emigrated to the United States.
You had already acquired British citizenship?
No. That was much too soon. It required at least five years resident. I wouldn't have been interned if I had done that. But after the rather hasty and panicky internment of May '40, the government here was trying to sort out who could be trusted and who couldn't.
Well, at that time my parents were very anxious that I should join them in the United States. And after all, the position of Britain was viewed, in the United States, in late 1940, as totally desperate. But it didn't interest me at all, I've always had considerable interests in historical work, in military affairs, and for me the war was decided in June, 1940, when, after Dunkirk, Hitler did not attack England. I thought: well, if he's too weak now to do this, he'll never be strong enough. And when he turned south, on an already defeated France, from that moment I never had any worry about the outcome of the war.
You were going on the assumption that Hitler was following a logical course, if you thought that he didn't feel himself strong enough to attack England. But subsequently, people seem to recall that he could have if he'd realized that he was strong enough.
Well, he didn't, and that was certainly the best moment for him.
I see, regardless of whether he was strong enough.
Well, it certainly was the best moment. If the best moment wasn't good enough for him —
— then it wasn't good enough.
Then it wasnt good enough. And I had absolutely no concern about the outcome of the war, from early June, 1940 — which made me rather different from many other people. But I never lost a moments sleep over that, after that time.
Did they allow you to maintain your personal interests?
Yes. Yes, and I did a lot of mathematics in internment. Of course one is very fortunate in needing only pencil and paper. I also started what I enjoy very much, teaching, in the camps, and there are quite a few people who learned quite a bit from me there, who remind me of this occasionally when I run into them now.
Did you teach on the Isle of Man, and in Canada?
Mainly in Canada. That's where I spent most of the time
I was interned.
Were you allowed to visit your parents or vice versa?
This really was a serious internment.
Oh yes. Oh yes. We were behind barbed wire and all that.
How did you feel about that? Did you feel any resentment towards the British people?
No. No. Because, you see, there had been a very cursory examination of refugees in autumn, '39, just after the war started. And I had to tell myself, if in the desperate period of May '40 I'd been running the show, I would have taken the same steps. What else?
This is remarkable objectivity, for being treated such, when you had such a glorious future ahead of you at Cambridge.
You see, it was quite clear to me that this would come right. I preferred it to be sooner than later, sure. But I was very very bothered about my parents wanting me to come to to the United States. That is the thing that really bothered me. Because it was absolutely clear that my future was in Cambridge. I had no doubt that would happen at all. And this was an irritating little interruption, but so what?
Well, then your experience with theoretical physics at the time with Besicovich, was that your only primary contact with a Cambridge professor?
I had lots of contact with others, and many of them interested me very much. But he was the outstanding figure.
This is what made you think that there was no other place than Cambridge?
No, I think the whole life in Cambridge I enjoyed enormously, with my contemporaries. I enjoyed the teaching. I enjoyed the exams. I just liked it, in every way. And I mean, so many of my best friends of today still go back to those days and are my contemporaries of that time.
Prior to your interment, had you had contact with Eddington?
Not significantly. I think he once asked me out to his house.
Now, he of course was a most remarkable man, I went to some lectures of his also, in my third year. Though he was a beautiful writer he was an absolutely impossible lecturer and so shy, he couldnt talk at all, I mean, his only occupation when anybody was with him, (and I was not the only one — who experienced this) he played with his pipe, and emptied it and re-stuffed it, and occasionally said a word about the weather. But of course he was a superb writer and a very great astronomer,
When you visited him at his rooms, I suppose this would be at the observatory?
Were you interested at all in the instruments there?
Or any other staff, the people who were there?
Not particularly. He of course was a theoretical man primarily. The practical astronomy didn't interest me at all in those days.
So you never considered engineering in any detail from the very beginning.
No. I mean, you see, when I came to England, of course, I didnt know what the academic career structure was like, and I kept the idea of engineering in reserve, in case there wasn't much hope in academic life. But when I saw, a) that in this country, as a matter of fact, certainly as compared with the Continent, quite apart from anything else, it was a very much better career structure for young people. And b) that I certainly felt, certainly by the end of my first year, that my self-confidence was considerably strengthened. If anybody of my year was going to climb that ladder, it was me. I mean, there was no doubt at all.
Thats a very nice attitude to have. Did you meet any other students or colleagues, who, you felt, could give you a good run for the money? When did you first meet McCrea?
Oh, he of course was much older than I, and I met him only many years later.
All right. I'm trying to identify your contacts.
Well, in my own year, there were two people I could mention, In my own year there was a man called A.R.G. Owen, who is now professor of genetics in Cambridge.
From the mathematical side?
From the mathematical side.
But there was never any question that he wasn't as good as I was. The year senior to me, there was a very nice man, Jim Wilkinson,
who certainly was very good indeed, and who has had a very fine career in the National Physical Laboratory. I know him of course well.
Had you actually gone through the formal examination process at Cambridge, the tripos?
And where did you place?
Well, of course, right up there.
Did they have this first, second place?
No, you see, the publication of the order of the exam ceased in 1908.
Oh, I didn't know that.
It was only classified, but, one knew quite well, and nobody left me in any doubt where I'd been.
I see, thats interesting. I wasnt aware of that, because we kept hearing about these positions.
The first class in mathematics is still called the "Wrangler." But 1908 is the last time that anybody became first "Wrangler."
I see. We've now identified in the beginning at least, your early Cambridge years. You had four years of internment?
No, no, one year, only one year. I came out of internment in August, '4l.
Then you came back here?
To this country, yes, I was asked to come back and of course, I went back to Cambridge, and became a graduate student. Naturally. Now, the subject that I then became interested in was waves, particularly water waves, and the person with whom I worked was Harold Jeffreys.
I see. You had not met him before?
I'd been to lectures of his before, but he was what's now called my research supervisor. At the same time, of course, I was very anxious actually to do something about the bloody war. I pushed in various directions, particularly through a man a few years older than I whose brother had been a contemporary and a friend of mine, himself a mathematician of considerable distinction, a man called M.H.L. Pryce.
In what direction did this take you for war research?
I then went into the Admiralty, and worked on naval radar, starting on the first of April, 1942. And as I like to put it, there was a very short time from my being behind barbed wire because I was so "dangerous", to my being behind barbed wire because the work I did was so secret.
This started first at the Marine Barracks in Portsmouth, where I first earned my living, And then in June we moved away from the coast, which was considered to be vulnerable, to Western Surrey, a place called Witley. I don't know how well you know the geography of this country a delightful area, out 35 miles southwest of London, on the way to Portsmouth.
Now, all of your work here could be described at what level, in radar work?
Well, I was a theoretician, of course, very strictly, and I looked at all kinds of theoretical questions.
What in particular?
Performance of radar sets what wavelengths to do you choose? How do you balance the receivers? I became very interested in noise, I was one of the first to study how a magnetron worked.
In trying to select various frequency ranges and that sort of thing, did you begin to become aware of the transmission, characteristics of the earth's atmosphere?
A little, In 1942-'43 the wave lengths of central interest were long enough not to be affected by the atmosphere. Later we went to wavelengths so short that humidity rarely affected it, But I should mention two names at this stage:
Early on in my internment, I had first met Tommy Gold, And we were together for a large part of that. But since there was never any question of his going to the United States, he came back to England much earlier,
You see, my release from internment was delayed because the authorities, not unreasonably, said, "Now, where the hell do we put this chap? In Canada? We bring him back to England? or send him to the United States?"
And that rather delayed my coming out of internment perhaps three or four months.
If you would have gone to the States they would have let you
out three or four months earlier?
Or if there'd been a decision where I was going, I would have come out earlier.
But in regard to Tom Gold, how does this fit in?
Because there was never any question he was coming back to
England where his parents lived.
He was interned also?
Did you meet him in internment?
In internment. Thats how we met. But in fact we knew of each other vaguely before. Our parents knew each other in Vienna.
Thats quite remarkable, And you started working with Tom Gold in the radar?
Well, I then brought him — just as Maurice Pryce had brought me into this business, I brought Tommy Gold in.
I see. So you had struck up a pretty good friendship.
We had struck up a very good friendship. He was either one or two years junior to me at Cambridge, in engineering.
In engineering directly.
I see. I might ask you some of the early conversations and mutual interests that you had, that made your friendship.
Yes, all right.
Your relationship with Tom Gold, how did it develop?
Well, we immediately liked each other very much. At that stage, that he was markedly junior to me at the university mattered. Also, whereas I had always been a very good scholar, he had emphatically not been one.
Interesting. Now, just to set the record straight, where did you first meet?
No, after we were interned. I think it was probably at Bery-St. Edmonds, England, within two or three days of being interned.
No. That's a village or little town in Suffolk about 40 miles east of Cambridge, which had some army barracks, which was the place where we were first taken.
So you met there, realized you were both from Cambridge, and started talking.
Yes. And started talking. We were both distinguished from most of the other people there by being totally adjusted to England. You were asking me earlier as to whether I was resentful of being interned. Well, I think everybody In that crowd was, except Tommy and me. Both of us with a rather funny outlook on life. But as I say, academically he was very junior to me then. But I was already very much impressed with his intuitive thinking — but in general, I tried sort of to teach him.
He was infinitely better at practical matters, which in internment was rather important, than I. A keen athlete, and I was very bad at practical things. This was partly the sort of Vienna Jewish atmosphere — if you are good at intellectual things, you are not good at practical things. Soon he really taught me at that stage that one can use one's brains just as much on practical matters as books.
Did you talk mutual interests in terms of purely academic interests?
Did this lead into your astronomical interests?
Not then. Astronomy came later, markedly. We still haven't got to that. We were just going to come to it when I flashed back to Tommy.
That's fine, I certainly want to complete your relationship with Tom Gold up to that point, then we'll go on.
Yes. Well, then we. were very good friends in Cambridge, after I
was released, when he was still an undergraduate at Cambridge. (Aug 41 -
I see, so he was released and you were released about the same time.
No, he was released earlier than I, because there was no problem
about going to America or England in his case. His was a simple case.
Because his parents were here?
Ah, I see.
We were then at Cambridge. He was still an undergraduate in his last year. I was a young research student, We had many mutual friends then, and we had a little circle of three or four of us, very close.
Who were some of the others?
Well, somebody I funnily enough talked to again last night on the phone, a man called John Cox. He's not an astronomer at all, He's not a scientist at all. He read engineering, and a girl Lavinia, and a man called Stephen Wheatcroft who is now deputy chairman of British Airways, and three or four others. It was a very very pleasant crowd.
When Gold got his degree, I was very keen to get him into the Admiralty to join us, he and John Cox, both of whom I thought of highly, but particularly of him. He had got a degree, but with a pretty poor result. He got third or a "2-2" or something. That not being his life. And it took me considerable effort and pushing until he joined us.
Yes. Now, meanwhile reorganization had taken place in the outfit where I worked, which I think had a very profound effect, When I went to Portsmouth, we had an outstation at a place called Nutbourne near Chichester, where I was told there was a very brilliant but rather crazy young mathematician by the name of Fred Hoyle, It was some time before I met him.
Who told you that?
Maurice Pryce. It was a little while before I met him, and a little longer before we had much to do with each other. But then Hoyle was effectively moved to Witley, and in fact a theoretical group was formed there, of which he was the head, I was his deputy, and there were three other members, It was a very small group. One was Tommy Gold, The second one was a man called Cyril Domb, who is now professor of theoretical physics at Kings College, and the fifth was a chap called Gillams, who then returned to academic life in Oxford for a little while, but I rather lost touch with him,
Well, then, family circumstances came into this too. Fred, of course, was older. He had married just about the time the war broke out. And there
was a little boy born in I think '41, and they had a house down not far from Nutbourne. And housing of course was difficult.
Now, when I had arrived to work — in Portsmouth, to be precise in the Southsea next to Portsmouth, which was in peacetime a seaside resort
— it was very easy to find quarters. In the little village of Witley in western Surrey, it was not. Originally the government had made use of its billeting powers, and put one onto people who had largish houses there, and there were lots of quite well-to-do people with large houses. I found myself with a very pleasant family called Palmer, and as they had a vacancy for another one, when Tommy came I saw to it that he came there too.
But we weren't teally totally happy living with another family. Tommy, I was saying, was always very good at practical matters, and said, "Why don't we rent ourselves a house?"
And so we did, and the two of us started at the very beginning of '43, to rent a house in a little village called Dunsfold, a delightful little village, and a slightly difficult journey to work. We had to take the first bus of the day, to a place on the rail line, and then walk through the little town and get a train from the other end. But never mind about that.
Of course we became very friendly with Fred, and so he tended to spend much of the week — because his family couldn't move at that stage and it wasn't very easy to get another house with us in our house, quite often, at least. And it was then that my astronomical interests and Tommy's astronomical interests began.
In '43, maybe late '42, through Fred Hoyle.
And one of your early papers was on accretion.
That's right. Now, this of course is quite a fundamental story. Fred Hoyle and Ray Lyttleton had tackled this problem of accretion in a very novel way, shortly before the war, which had found no favor with the astronomical community at large,
Right. But the whole problem at that time was explaining an inhomogeneous giant star. Did Fred talk to you about that at all?
That came a little later.
So what was the original impetus, then?
I think, very much the idea that both he and Ray Lyttleton always had had, and of course I agree with completely that astronomers became far too set on what they could see. You see, I always myself said in later lectures, it's as though a Martian flying over the earth decides, a town is a collection of street lights.
The idea of something else — "what could there be,"— intrigued them very much. The idea that stars were static, they didnt like at all, because they looked like dynamic systems but how do you connect the unseen cloud with the star?
With accretion, I have the feeling, the original impetus in the early papers on that was more from accounting for changes in the suns luminosity, and the ice ages. I think thats right.
Anyway, I was a somewhat raw young man in the field, with very little experience, but very considerable mathematical powers, and I hated any argument that wasn't argued through to the last piece. And so Fred said, "Why dont you take this problem, and see whether you can put it on a proper mathematical basis?"
Of course we did a great deal of that together. We published it as a joint paper.
This is 1944.
Yes, But in fact, the work was done largely in the spring of 43, and the whole mathematical part very much was my part. The background of astronomy, which of course was brand new to me, was Fred's.
Now, I should say that I had done a little work on my own during internment, which was submitted for the fellowship election for the autumn of '42 in Trinity and wasn't successful.
What was the work that you had done?
Oh, I can't even remember. It was some rather general stuff about wave equations. It wasn't very significant. But in '43, I submitted the early version of the accretion paper, and in October, '43, I became a fellow of Trinity.
From that paper?
From that paper, which was a tremendous step. I mean, it really meant that I'd arrived. Attitudes have changed since then, but it is typical of the whole attitude that where I had of course been a graduate student working for a PhD, I withdrew the whole thing then, because its so much more distinguished to be a fellow of Trinity than to be a PhD. Arid in fact I never acquired a PhD in my life. You know, being one of the fellowship of Trinity, that means you are in the cream of the cream.
Does it mean, though, that you can apply for a fellowship at
Trinity regardless of what degree you have at the moment? It's not something you do after the PhD?
Oh no, no. In those days, the more distinguished you are, the sooner you get it. You have to have a bachelor's degree. That's all.
What was Fred Hoyle's position just at this time? He was going to Cambridge too?
No. He had been. He was of course four years older than I am, and he had got the fellowship in St. Johns in about '37 or '38, about that time.
Were you elected to Trinity by Eddington or others?
You mean the fellowship? No, I don't think he was concerned. It's a very stiff contest, and of course, in after years I was often involved in the fellowship elections myself, and it goes in the normal way, that you get the application, you think who are the best referees for a particular paper, you send it to them, you try to get two or possibly three comments. You then have a series of meetings, because of course these fellowships are in all subjects, and you have to decide, how a mathematician compares to a historian or someone else, In those days normally four people were elected each year.
Once you were elected, then, you lost all interest in the d& gree, the PhD degree itself?
Is this unusual?
It became unusual, about ten years later. But I look at it from the perspective of those days if you had a fellowship at Trinity, every university in the country would within five years fall over them selves to have you on their staff.
And of course if you turned out to beat the very top of the tree, you would in the atmosphere of the 40s, wish and be able to stay in Cambridge.
Which you did?
Which I did.
Let's get back right now to the accretion. You had mentioned that Fred Hoyle, in his discussions with you and Gold, had this idea, as did Ray Lyttleton.
They had published on this about 1938.
Exactly. But were astronomers, when you gave this
Martian analogy, too rigid in their ideas of what stars were?
Well, at that time also, people didn't understand what red giants were.
No. I came into that rather later.
OK. So what were your primary interests as they were developing?
Well, at that stage, in the accretion, it was very much the mechanics of accretion that interested me. We then became interested the three of us, because of course we sat together every night arguing
in many questions of astronomy and cosmology. And the cosmological interests really started in those days, '43, '44, '45.
Now, we did a great deal of traveling in our jobs. We weren't toegether an awful lot. I, in fact, spent a good part of that last part, toward the end of the war, '44, early '45, on top of Snowdon, a mountain in north Wales.
Right. This was an actual observing station.
Yes. Now, what happened is that we decided that it would be useful to have a station up there, because it mimicked planes. Planes flew in those days at that sort of altitude.
Oh, I see.
3500 feet. And first, because of the very short waves that were coming into use, we wanted a propagation experiment, between the top of Snowdon and a place in south Wales across Cardigan Bay. Later we became very interested in sea returns, you know, sea-clutter, — how do you see aircraft on the radar screen against a wild sea? And of course Snowdon is only ten miles from the open sea. So this was very good.
Now, as I have mentioned to you, I was a pure theoretician. But I was so fond of the mountains. The idea of being out there made me throw all my theoretical convictions overboard! And I ran this little station.
Was Tom Gold with you at that point?
No. We were very much spread out. He visited me of course at times, as Fred did, and as various other people did. One of the people I saw there quite often was a man called Saxton, who has just retired as director of the Radio & Space Research Laboratory at Slough, which belongs to the Science Research Council. So you see, it was quite a good club.
Yes. It sounds like a lot of fun.
It was very good fun.
Now, this certainly was a lot of practical work.
A lot of instrumentation and that sort of thing. Did you cone tinue on with your own studies?
On Snowdon I don't think that I had a lot of time for my astronomical work. Well, when the war came to an end, really after I returned from Snowdon in February, '45, I wasn't terribly anxious to remain with the Admiralty. I mean, my future was quite clearly in Cambridge, and I couldn't contribute a bloody thing to the war, which at that stage was of course approaching its end.
You started probably realizing at that time that other than radar, there was also something very significant coming out of other research efforts.
One knew that earlier. In particular Maurice Pryce, who left me to go to Chalk River in Canada, for that project.
I see. Did he say what he was doing?
We all knew what it was about. The general tomment on it was slightly skeptical that it's the sort of thing, if it comes off, the significance is infinite the probability of it coming off is zero. So how do you judge it?
Was this understood? Did you talk about it with Tom Gold and Fred Hoyle, from your own different ways of looking at things?
Not a lot, no.
You wouldn't see a different attitude from someone who was very practical like Tom Gold's background — being more positive about the possibility?
Fred was the only one of us who had any grounding in nuclear
physics at all, And he, not all that much.
At that time.
So then this was something that was very very distant. You weren't seeing the incredible connections with astrophysical research at that time.
Not a bit.
OK. So you came back to Cambridge.
Yes. And then I took up my fellowship, and to my pleasure, found myself immediately appointed an assistant lecturer in mathematics, so I had a double job. This was in 1945.
You had your MA in '44?
That was a formality. An MA in Cambridge is a formality, And I was told that a fellow of a college ought to have an MA — I think one has to pay five pounds for it.
OK, thats fine. So your fellowship period at Trinity College was '43 to '49?
Yes. A fellowship, a prize fellowship as its called, a junior one, lasts four years, but of course mine was in suspense while I was away.
OK. Well, what were your experiences in getting back to Cambridge? Was it still the lovely place that youd left?
Yes, I thoroughly enjoyed myself. At first, I was the only young man back, because of course I came back very early,
Yes, well before. I can't remember quite when he came. I came back to Cambridge I think in early July, '45. Fred, I would have guessed, around October, Tommy perhaps March, '46, or something.
They remained in this same radar group?
They remained in that place.
Fine. So then you're back in Cambridge.
Then l'm back in Cambridge, and by no means set on astronomy. You see, I was and am very convinced of the powers of the kinds of mathematical techniques that I had, of the range of application, and I mean, my sort of general attitude was, anybody who can describe a difficult problem should come to me and have a chat with me, and maybe I'll take it up, if I'm interested.
Very interesting. How did you advertise this?
Well, it just went around. And so quite a few things came my way. I was still very interested in water waves. And in fact, in '47, published what I think is a very important paper there.
I haven't been able to locate all your papers.
It shouldn't be very difficult, because almost everything I published is either MONTHLY NOTICES or ROYAL SOCIETY or CAMBRIDGE PHILOSOPHICAL SOCIETY. I doubt that I've published in many other places.
I think about that stage, I also wrote a paper in general relativity , already, in the late forties.
Yes, you did. "Spherically Symmetric Models in General Relativity." At this point you had started to express gratitude to Freeman Dyson?
Was he there, F.J. Dyson? And W.H. McCrea. I'd like to know their relationships with you — they were considerably more advanced.
Let's discuss it. Age matters a great deal in this, When one is very young, a year or two makes a lot of difference. Now, during the war, two very brilliant young people came to Cambridge, Dyson and James Lighthill. They both got fellowships shortly after the war, I would guess in '46. James Lighthill, I may say, was the second case of somebody who got a Trinity fellowship before he was 21, in this century. James I see quite a lot. Of course Dyson went to America and is at Princeton. Our paths haven't crossed a lot. But at that stage, we were very good friends and discussed a great deal, more than with Lighthill, who shortly afterwards left Cambridge for Manchester. We were very good friends.
McCrea, well, let me tell you the story. I'm spending a lot of time on reminscences.
They're important and interesting.
McCrea, who must be something like ten years older than I am, was quite an establishment figure by that time. He was just becoming secretary of the Royal Astronomical Society. And a theoretician of great power. But we'd only met once or twice, when a certain event took place. Again, I'm not quite sure what year it was but it must have been early
I mentioned to you my aunt the art dealer?
Now, in those days she had a little gallery just off Bond Street, and the Bond Street traders had a little sort of tight group. Now, drink was very scarce in this country in those days, and she was presented by her Bond St. colleagues with a case of rum, and very kindly remembered her young thirsty nephew, at Trinity, and so I found myself with a case of rum. And I became extraordinarily popular. McCrea claims he would have died of a cold in that very bad winter of '47, if I had not poured a lot of rum down his throat.
That's marvelous. Let me turn it over.
Well, of course, at that time already I'd met my future wife, around that time.
Yes, you were married just within a year or so of that.
We were married 1st of November, '47, and we had met the previous spring.
Was it planned that you'd be married on your birthday?
No. It happened. Let me describe that too. We met first of all because she was Fred's research student. I of course worked with Fred, and Fred has always been the most difficult person to find, and we bumped into each other various times trying to find Fred.
If I understand right from your earlier comment, you're related.
To my wife? No. My mother was related to my father. My wife is no relation at all.
She as I say was a research student, and she was working on stellar strucure. Then of course she discussed them, the mathematical problems, and that's how I became interested in stellar structure. It wasn't through
Fred, none of my previous work. That really started that whole series of papers.
So your early interest in accretion was completely indepenedent of what you eventually did in '49 to '52?
Coincidence, in other words.
She of course was working on stellar structure under Fred
Yes, but the origin of them both can be traced back to Fred.
Yes. As you became interested in discussing these problems with your wife, what appeared to be the primary question to answer at that time in stellar structure, and how did you divide up the work?
I looked at it very mathematically. She had much more of an astronomical background than I had. To me, it seemed irritating that people were so baffled by differential equations. I've never seen a differential equation as anything that should let one be baffled. And I was really only interested in methods of solving them, more than in the physics of it. And particularly, I have never been interested in accuracy, and I always feel that you can really say you understand a physical problem only if you can give a rough solution. If you have to work it out to the fifth decimal place to get a solution, then you don't understand it.
So it's a heuristic idea in some ways?
In many ways, yes. And so, that brought me into stellar structure, and there was quite a series of papers on that, but very much from a mathematical point of view.
Your wife began with a paper that you followed very quickly in 1950 her paper was on models for red giant stars.
Yes. That was later.
What were the original directions of attack? By 1950 she was trying all possible models for red giants concluding that they must be heterogeneous.
Yes. I can't really remember. Her first paper, she still published under her maiden name which was Stockman. And then we started the joint papers. Originally they were just methods for integrating stellar structure, and then we branched out in various directions.
Were you trying to understand whether red giants were evolved Main Sequence stars?
Yes. One wasn't clear where the inhomogeneity had to come from.
And you had the two models. You could go back to accretion. You have the two causes, accretion or expansion, from the Main Sequence.
No, the expansion would be a consequence, but would not be the basic cause. The expansion would follow. The question was, how does the inhomogeneity arise, how sharp it is, and that kind of question. I'm not sure that I remember it all very well. But of course, the work on cosmology was proceeding at the same time.
That's right. I'm wondering how you divided up your time and interests. Did you let your wife govern the stellar structure work, and you associated yourself with it whenever there was need?
I don't know. You see, we kept a very open house in those days. It's really Fred I want to bring into the picture.
All right, fine.
Fred, when we moved back to Cambridge, now with two children. Housing was very expensive, so he decided he'd get a house 15 miles out of Cambridge.
That's a lot, for around here.
Yes, that's a lot for around here, certainly in those days.
Considering his history, did he want to be away from certain people?
I think more that it was a house that he could get cheaply. We all helped him do it up. And then, first I had nice rooms in Trinity, my rooms became his headquarters in Cambridge. Next, when we married, we got a college flat just outside the college, where we stayed for a year and a half, until our eldest was on the way. And during all this period,
up to spring '49, it was first my rooms in Trinity and then our flat that Tommy and Fred spent most of the day, talking about this, that and the other.
I want to get your recollections of the stellar structure work but I know very much at this time you were working on the Steady State.
Yes. Now, I think interests were divided, Tommy (Gold) was not at all interested in stellar structure, because that was basically a mathematical problem, and mathematics never interested him. Fred was only very partially interested in stellar structure quite differently from me in those days, when we had roughed it out: "It's supposed to be something like that." That was quite enough for him. Very often, with his papers, as with his conversation, I found it very irritating that he'd obviously used entirely illegitimate arguments. And then when I tried to get the thing right, I came to precisely the same conclusion as he had come to. I mean, that's genius, of course.
So my wife Christine and I were very much interested in the mathematics. We were mainly interested in the mathematical side of it. Very occasionally we'd discuss it with Fred, but he really thought he'd solved the problems of stellar structure, at that stage.
At that stage?
Well, the Hoyle-Lyttleton model of Red Giants and so on.
So he had stayed with that theory all through.
Yes. But I didn't believe the mathematics of it for a moment. It was crude and totally incredible. And so we got this into a reasonable form.
But Tommy very much and Fred a good part of the time were very much interested in cosmology. And that was the field where I was the most knowledgeable, I had really studied I don't know quite why, because I'm usually not a great studier — Hubble's work, in very great detail, and I really understood the relativistic equations, better than most.
So this would be Tolman's work, actually.
Yes, but Hubble was better, if I may say. I don't want to be too cruel to Tolman, but what he derived I didn't learn from his book, I derived it myself. I've never been a good one for books. I've always learned by deriving things myself. If somebody else derived them first, good luck to them. But I can't really learn from them.
And so you were taking Hubble's observations.
And analyzing them rather carefully, and criticizing them in places.
This would be in addition to his velocity distance relationships.
Yes, the number counts.
The number counts you did later on.
Which of course are now totally discredited, but we didn't know that at the time.
And then it was that Tommy threw out the idea of continual creation and Steady State.
He started it? (Tommy Gold)
He started it.
Where did it come from?
He's always been a very inventive guy. And I can't remember the details, but I believe Tommy's right when he says that Fred and I said, "Oh yes, that's one of those crazy ideas — well, let's disprove it before we settle down to dinner."
Dinner was a little bit late that night. (laughter)
But then, we all three of us, were pretty well convinced it's right, Tommy and I perhaps slightly more on philosophical grounds, Fred more on the sort of very general grounds. It was just as what led Hoyle to accretion: the whole system is dynamic, it isn't aged. We all said that this was unpublishable, because it was just an idea, and you can't publish ideas. We couldn't work out anything about this.
Right, that's a very important problem at that point. It seems as though, from some of the background reading I've been trying to do, you were very aware of the fact that this was unscientific at this point or unpublishable, and that you wanted to give it some credibility.
Where did that feeling stem from? Because it also dealt with the relationship of astronomy taking on mathematics and physics. You've mentioned that differential equations really were stumping most astrophysicists doing stellar structure at the time, and there seemed to be a feeling at the time that astrophysicists, using physics and math, were really not doing such a good job of it, and this led to a general feeling
that cosmology was really not a science at that time.
'No' in terms of agreeing — or what?
I agree with you that indeed, observers viewed theoreticians with great mistrust.
Did you start getting any of this directly from observers? In discussing things?
I, as we'll say, have a rather sunny temperament. I always had very good relations, Fred less so, Lyttleton even less so. But we were all quite clear about the fact that an unworked-out idea is not something to associate your name with. You've got to have something that comes from it.
Well, we looked at this, looked at that. And then one evening, I
turned back to the Hubble number counts. It's interesting because it's
totally irrelevant in the present state of knowledge.
And suddenly saw — as you sometimes see things quite suddenly that they fitted in absurdly well with what you would predict on Steady State theory. And we didn't have a phone. Tommy lived about a mile and a half south, and I rushed out to the nearest call box, and said, "Look, that's it." I should have thought this was in very early '48, but I can't give you a date.
Your association with the Hubble number count then gave you really something to talk to Tom Gold about.
This is what he could get his teeth into.
This is the peg on which that coat could be hung. Now, Fred wasn't very impressed by this. It seemed to him, unless one had field equations, it would still not be enough.
Deriving it from general relativity?
Yes. And so we decided to publish separately. That was the genesis of it all.
How strong was this split? Because it wasn't very long before you realized that you weren't really talking about different world models at all.
Well, I don't think we ever thought that the world models were different. The depth of the split was never very great. We continued working on all other things together. But Tommy and I were probably a good deal more philosophically minded than Fred. So we came to the view that a mathematical modification which has one purpose and one result only is not worth the paper it's written on. Fred's feeling was that something, a model in which you can't work out the consequences of local deviations, isn't worth the paper it's written on. And these were just the different points of view.
The reason why I'm asking this particular type of question was that it seems as though later on, the support that you got from McCrea and from Spencer Jones and from others seemed to stem from the fact that here you apparently had done independent work, Fred Hoyle on one side, you and Gold on the other.
Fred put an acknowledgement to Tommy in. The linkage was there. And McCrea, as I was saying, was secretary of the Royal Astronomical Society at the time. He dealt with the paper. He said it struck him immediately that this was the answer.
That summer of '48, the International Astronomical Union met in Zurich, and I remember, on the boat trip, McCrea asked me to explain it
it was of course before it came out — to the then president of the Union, the Swedish astronomer Lindblad.
And you did, I take it.
What was his reaction?
His reaction was, "This is certainly an idea that must be thoroughly explored." Which is a very sensible attitude.
Now he, of course, was one of the very very first at showing galactic rotation, and the general idea that the galaxy is very dynamic.
Yes. So there was a general sympathy.
There should have been a sympathy there, yes. That's what I'm trying to identify.
Yes, I think that's right.
Would you say the sympathy was with you mainly from astronomers who had strong feeling for the observational data base?
No. I mean, of course, I don't know, I think thats very difficult to answer.
Because eventually, of course, the community divided up, pro and con.
Yes, I think, on the whole, you could say that most of the relativists were against it, because it didn't fit in with field equations, with the exception of McCrea. Many of the observers looked at this as an intriguing quarrel in the theoreticians field. One of the nice remarks of that time came from O. Struve, who was then of course the director of Yerkes, and he said it often seemed to him it was a general remark about theoreticians, but a nice one as though observational astronomers, with their massive equipment, were like people sailing through space on big battleships, whereas theoreticians blew bubbles from their own imagination, sitting in soft arm chairs."Every now and then," he said, "a bubble collides with a battle ship. To everyone's surprise, sometimes the battleship gets sunk."
Where did he say that?
I don't remember.
I see. Do you think it was a personal statement?
I think it was published. He was a very nice man.
Thats the sort of statement I'd love to retrieve.
I should have thought it might have been one of the more popular things, where he'd said this. I dont know.
It could have been a dinner speech or something.
I think it was published.
I see. Did you have contact with McVittie during this period of time?
Mildly, yes. Not very closely but we did have contact.
He was here in London?
He was in London at the time. Yes, thats right.
What was his reaction?
He was not at all keen on it. But he had a considerable admiration for, in particular, my mathematical skills, I think McVittie's attitude at the time would have been: "It sounds like bloody rubbish, but given that Bondi is involved in it, it can't be as nonsensical as it looks."
I think that would be his idea.
So when you brought out this work originally with Tom Gold, you were no longer considered, either in your mind or in the coninunity, an unknown quantity.
You felt quite established.
I certainly want to identify that.
I think, as a matter of fact, this was enormously important — that various other papers of mine had totally established me.
Prior to '48.
Prior to that. That I was not just a crazy chap in cosmology, but somebody who had done quite a bit of other work. And you know why I'm always very much against people becoming single track cosmologists —
its not a subject to which you should be married.
This is, just jumping ahead though, you had gone into gravitational theory then?
Well, I'd done a little, as you will recall, in relativity before.
And this of course, as far as it leads to difficult differential equations, was already very much my métier. But my real move to relativity came in '55. Now, a man I'd met on one or two occasions before and liked very much, a man called Marcus Fierz — I don't know whether you know of him — a student of Pauli's, who had become professor at Zurich
at the federal technical university — ETH — was very much an influence. Well, I had of course been interested in general relativity, because of the atmosphere of mystery surrounding it, and because of the mathematical complexities.
You chose not to use it though in your cosmology.
No, because it didn't agree with it.
But it did agree with Hoyle's.
By being modified. But I didn't like a modification with a single purpose.
You never really reconciled that, did you?
I see. Now why in '55 did you choose to move off?
Well,of course, I hadn't done much in cosmology after publishing my book, the writing of which probably ceased in '51, and I only published one later paper. I mean, I was out of that field. Stellar structure had similarly died under my feet. My mathematical tools for simplifying it depended on making simplifying assumptions about the opacity of stellar material. Now, you have simultaneously a much better ability to calculate what stellar opacity would be, which gives you a very complicated result, to which my methods couldn't be applied. And you have the coming of the electronic computers, although of course they didn't become really powerful for many years still.
But you saw it specially in the new work — Hoyle had later worked with Schwarzschild.
On some new modeling, structures that were adaptable to computers.
Yes. Began to be. But I never liked complication.
Complication? How does that fit in?
Well, you see, to take a simple law for stellar opacity, as one could do on '47, '48, suited me very well. To work with an exceedlingly
complicated table that some atomic physicist had worked out didn't suit me at all.
I see. So the idea of doing numerical integration in the future —?
— oh, that didn't intrigue me at all. That wasn't my interest.
Could you consider yourself mathematically then to be in the
In what sense?
In the sense that numerical integration didn't interest him at all either. He was looking for exact solutions to the differential equations.
No, I'm different. It's not exactness that interests me. What interests me most is how you can get an overall idea from the structure of the equation.
An overall idea?
An overall idea, and then perhaps, with an absolute minimum of work, a general idea of what the solutions would be like.
In other words, where does convection exist? Where is the discontinuity?
Yes. Right. I wasn't at all interested in the exact radius at which the discontinuity occurs.
But in the fact that it occurs?
That it occurs. That in some areas, there would be a convective zone and in others would not.
So, a general physical feeling, developed by a model.
from a differential equation. Perhaps I can tell a story about a former student of mine, and what he said about my lecturing long ago.
"When you came to differential equations," he said, "then it was very easy, in the lecture. Professor Bondi spoke to the equation. The equation answered back. He spoke to it again. And there was the solution."
"Then,"' he said, "I took my notes home. I spoke to the equation — and it didn't answer back at all!"'
But that was always my way of working at things.
Marvelous. Who was that? This is not an apocryphal student?
No, no, it was an actual student. That sounds very plausible to me. It describes my attitude. I want to see the structure of the thing and how it works out and then, as much accuracy as you can get with a minimum amount of work.
MN 112 (1952) p195.
Proc. Cambr, Phil, Soc. 45 (1947)
MN 1O7 (1947) p.410
MN 108 (1948) p 252 (W.T. Gold)
COSMOLOGY (Cambridge U. Press)