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In footnotes or endnotes please cite AIP interviews like this:
Interview of Margarethe Bohr by Thomas S. Kuhn, Aage Bohr, and Leon Rosenfeld on 1963 January 23,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,
For multiple citations, "AIP" is the preferred abbreviation for the location.
Interview with Margarethe Bohr that is part of the Archives for the History of Quantum Physics oral history collection, which includes tapes and transcripts of oral history interviews conducted with ca. 100 atomic and quantum physicists. Subjects discuss their family backgrounds, how they became interested in physics, their educations, people who influenced them, their careers including social influences on the conditions of research, and the state of atomic, nuclear, and quantum physics during the period in which they worked. Discussions of scientific matters relate to work that was done between approximately 1900 and 1930, with an emphasis on the discovery and interpretations of quantum mechanics in the 1920s. Also prominently mentioned are: Hanna Adler, Harald Bohr, Kristen Bohr, Niels Henrik David Bohr, Christian Christiansen, Paul Adrien Maurice Dirac, Mrs. Heisenberg, Werner Heisenberg, Harald Höffding, James Jeans, Oskar Benjamin Klein, Hendrik Anthony Kramers, John Larmor, Inge Lehmann, Wolfgang Pauli, Johannes Pedersen, Edgar Rubin, Ernest Rutherford, John Joseph Thomson, and Mrs. Trier.
The children had such a very happy home life with this combination of a very intelligent and wise father and a very lovable mother. She was a wonderful woman. She wasn’t merely lovable, she was also very clear in thought. The home was so wonderful because of them. The whole family also meant much. The grandmother of the family Adler had a place in the country, Naerum, which they gave later as a home for children. It’s a wonderful property outside Copenhagen, Naerum Gaard.... His grandfather on the mother’s side was a banker, and they bought this home there. He died rather early, and the grandmother lived there in the summer. Niels and Harald always spent their summers there playing in this wonderful garden, and all these remembrances from the family life meant so much to him all through his life. They stayed out there, and there were also cousins who came to see them and stayed with them there. One can often see his thoughts in those letters from when they were grown up. This grandmother died before I got into the family, I think it was eight years before, and then the home went right away to a children’s home. But a relation lived next door so to speak, so we came out there. This was Hermann Trier; he was a politician, a landstingsmand, who was married to my husband’s aunt, to my mother-in-law’s sister. They had the house, so when I got to know him we also spent the summers there at first. And out in this big garden there he told me of all his childhood in Naerum.
How large a household was it in Copenhagen?
Oh, it was then large. They lived in a house that belonged to the Institute where my father-in-law was a professor. The house was in Bredgade, an old building. They had three maids and three children, and then they had an old nurse who was also so sweet, and she looked after them. And Niels and Harald were so sweet to her, and Niels helped her to sew her buttons on, and Harald played the violin while they did it, so they were such sweet little boys. The sister was the eldest.
What was her name?
Kirsten ... Of the three children the sister was the eldest. 100 I think she was a couple of years older — two or three.
Were they close to her? I mean, I know that the relation between the two brothers was very close.
Yes, it was close because they were so affectionate and good in that way, but of course a girl who is three years older had her own friends and so on. Then when she grew up she was always a nervous child. She was not as healthy as the two others in that way; my mother-in-law had a very difficult birth with her. In any case, she was nervous and caused, in that way, a lot of anxiety. However, she went through school and was very able. She had a very nice personality also, but her nerves gave her difficulty later in life in dealing with other people and so.
Was she ever married?
No, she was never married. No; she was very interested in teaching — that was most of what she did. She didn’t do much work because she didn’t feel so well always. This nerve problem had only caused her to be a little unreasonable, but suddenly after my mother-in-law’s death she turned ill. Then she died here. But, of course, through their whole childhood Harald and Niels meant so much to each other. They both admired each other. Harald was quick to tease Niels a little, but in a very lovable way. They were always very close. ... One can see it here in the letters from Manchester. And when Harald came to see Niels in Cambridge, oh, the admiration and enthusiasm. But as a school boy I only know what these two people have written. I don’t know anything else about him as a school boy.
You spoke of Harald’s playing the violin. Did Professor Bohr also —
No, never, no. He was very fond of music; he liked to hear music and had a very good ear. But he did not play anything himself. To begin with, when Kramers was here, he had very great pleasure with Kramers. And for a long series of years we always had some music, which gave him great pleasure. There was Ehrenfest also, when he came. I know he also said that even if Niels wasn’t musical he was very observant and could hear what was in the music. I remember once Ehrenfest had come to see us at Blegdamsvej. He was sitting and playing for me, something, I think, of Philipp Emanuel Bach. Niels was sitting and working in the next room, which was his study. Then he suddenly came in and said, “What was it you played; it reminded me of a Gothic column.” And Ehrenfest was amused and said, “That was just what it was meant to remind you of.”
Was there a lot of music in the home also? Did either of his parents play?
No, no; none of them played; and Harald also didn’t play at his home. He gave it up; he was too busy, but he was always fond of music. No, it came, as I said, from Kramers and partly Heisenberg, also. It came very, much from Ehrenfest who always played when he came here. Later there was Frisch; he was the last one really. So at that time we had music in the evening when the young people came.
What about other, non-scientific interests? Did he read a lot outside of the sciences?
Oh yes, he did. Yes, he didn’t read much science. To his last days he read a lot outside of science, and very quickly could get through a book. I don’t understand how he could do it. I don’t know how much he read on each page.
Yes. And he was also very conscientious. I remember once, when I came to Tisvilde to work, he had just got a book from this Icelander Gunnar Gunnarsen. He told me, “Oh, I must read it through because I must thank him, and I cannot thank him if I have not read the book.” “I feel like a murderer to see you here. I must finish that book; I cannot begin anything else before.”
I remember the first books he told me about when I got to know him were the Icelandic Sagas. They played an enormous role in his life. He knew them, and when we visited Iceland about ten years ago he was taken around to see things. I heard from the ambassador that Niels could tell even more about it than the scholars in Iceland could. He knew it so well, and he remembered perfectly every little thing from every saga. I think he read them from the time when he was a school boy. Those he read, and another of the first books he gave me was one by Kierkegaard, which he also read very much, but of course as a young student. But what be read as a boy I don’t know; I think he read all the Indian stories, and such things. I know that he had given all of Cooper’s tales to one of his friends; he read them all. Yes, all these he went through. There was Kierkegaard, Stadier Pa Livets Vej, I remember. He wasn’t so deeply interested in Kierkegaard’s thoughts, but he was an extreme admirer of his language, an enormous admirer of his language. He liked to read this piece of the Danish language as Kierkegaard has written it. He never went back to study Kierkegaard’s thoughts; he wasn’t interested in the problems which Kierkegaard put to himself.
He once told me, “It is such a pity to have spent so much art and so much genius in the language to express such crazy thoughts.” He could quote poetry; he remembered whole pieces of poetry.
Ibsen’s poetry, yes. And he was very fond of Goethe and Schiller. Oh, he read that very much; Goethe and Schiller I learned through Niels. Especially in his later years he read the Norwegian Wildenvey. He loved that. There was nobody he liked better than Wildenvey in his last twenty years. I don’t remember any English poetry. He read Carlyle for a time, but he was disappointed by it. At first be was interested in it, but then he dropped the interest. He didn’t think it was really good.
Was he able all of his life to keep on reading this widely?
Yes, all of his life. Dickens he read; he loved Dickens. Shakespeare and Dickens; they were all from our early days. But he was interested in all kinds of new books that came on all kinds of subjects, archeology, for example. All kinds of subjects interested him as soon as it had something in it. Some of the last books: which we read with great interest were about Pompeii and about art. I couldn’t say a single subject he wasn’t interested in when the book gave something, when it gave you some real information. I don’t think he read fiction.
Except for detective stories.
Oh, detective stories! Oh dear, all his life there was no end of that kind of thing. Oh, when we traveled to, Italy, we had a whole suitcase of books with us, especially such little books.
There was Wodehouse. He read Wodehouse when he was tired.
Everything with humor in it he enjoyed.
He read very much. There was the Norwegian author, Harry Fett. He was really the director for the antique museum in Oslo, but he was also a man interested in all kinds of things. He wrote about King Frederik the Great, and Japanese art, and Dutch art. Do you remember, he gave Kramers a book; Kramers was so enthusiastic about his book on Dutch art. Kramers said afterwards that he wasn’t convinced that Harry Fett was quite right, but he had so many ideal that were interesting. He said (Orestel) had really made his paintings in Norway, which probably is true.
He liked books that tried to develop some new idea around the connections between things. He would often become very enthusiastic about that, and tell everybody about it.
In the younger days he read Thackeray. Another Englishman whom he also liked very much was Meredith, The Egoist.
I gather also that another thing which, at least as a young man, took a lot of his interest and attention, was sports. I hear particularly about soccer; excuse me, football.
Yes, yes, but that stopped; he never played football: after we were married. Never. I saw him play football once before I was engaged, but never afterwards. He played tennis in England, but not football. But my brother-in-law went on playing football. He was the brilliant one. Niels was at the goal, I think. He played as a boy very much, but grown up he didn’t have any sport. Skiing, yes, and bicycling and riding on horseback a little, and walking, but not sport in the sense of games.
But in Tisvilde he would always play games like badminton; and we cut down trees of course.
And he played with the children and so; that he did very much, playing ball, and so on.
Had football been important to him in school?
Yes, I have once been to a football match with him before I was engaged to him. We went to watch Harald. But I never saw him play myself, I don’t think. I think he stopped because then he was so busy with his dissertation. But in Cambridge he played tennis, yes.
When people refer to his career or to his and Harald’s careers as football players, is this a University team that they are playing on?
. There was a special club, AB, Academic Ball Club. They mostly recruited players from the students, but not exclusively. But Harald played on the National Team for many years. He was a big star of football at that time. That was different.....
Niels and Harald often went mountain climbing together. They were just out of school when they started, Harald and Niels, and another friend. They were in Norway and in Switzerland and in Austria and various places they went, and the nature made such a strong impression on Niels. I can see it in his letters; he was so taken up by the lights and by the trees. You can see he is really enthusiastically getting something out of it. It wakes all his nerves up.
Did he travel a lot, or did the family travel a lot when he was a boy?
The family didn’t travel a lot, no. I don’t remember my mother-in-law ever traveling. But Niels and Harald went skiing in Norway in the winter with an aunt who always traveled, my mother-in-law’s sister. But my mother-in-law didn’t care for traveling. I don’t ever remember her going out of Denmark; she must have done it sometime, but I don’t remember it. But the aunt went every year to the mountains also. They went to Holmenkollen and those places, and from that he learned to love Norway. She continued this in later years also.
I think with the sports perhaps one can say that my father liked sports very much, but he was not particularly interested in the competitive aspects of sports. That was the difference, you see.
You’ve already said how wonderful his parents were and how close knit a family it was, but how much would he really have seen of his father when there were three servants and a nurse?
No, it was not in the English way; no, they had very much family life there. The father, also was much with the children — as much as he could be with his work. The nurse was not like an English nurse in that way. No, I think that it was one large family.
Did he ever speak of things that he had done with his father? Did his father read to the boys?
I don’t remember that he has said that, but the mother read very much to them. When he was older then he discussed with his father scientific topics and so. The father knew from the time when he was a small boy what was in him. I know my mother-in-law used to tell me that his father saw this when Niels was only a boy because he could answer so well little questions about volume and such things. This was as a little boy of five or six years or something like that. I remember my mother-in-law told me his father always said, “People will listen to him; people will come to Niels and will listen to him.” And then he also said of himself, but this is only after a while, “Yes,” he said, “I’m silver, but Niels is gold.” So in that way he must have occupied himself with him.
Because of this recognition of Professor Bohr’s special characteristics did they make special provisions?
No, no, nothing whatsoever. They just talked of it between themselves.
That you can also see in the things that some of his schoolmates have written. Some of them considered him a very ordinary pupil.
What other adults did he have contact with?
This aunt; she also loved Niels. She was a pedagogue really; she had a school herself.
Hanna Adler was her name.
She had a co-educational school. So she loved these two boys, and she took them around. She was the educational one; she took them to museums, and she took them around and showed them things. She considered this her job to show them things; she did all these things with them. That was her great joy.
In addition to her general interest in education, were there subject matters that she was particularly interested in?
No. She was interested in general education and liked to show them things and take them around and so.
Of course she was interested in the general cultural development and had a great influence on the people here. She was among the pioneers of that time.
Her whole home was very unprejudiced and high; she was very liberal. I know friends often have told me that it was always said, “Where the family Adler is, there it is high to the ceiling.” It is something like that; I can’t express it.
We’ve talked so much about the Adlers; could you tell me a little bit about the Bohrs?
Yes. The Bohrs — that was different. I don’t know as much about the Bohrs. The grandfather was the headmaster of a school; “Professor Bohr” he was also called at the boys’ school. He was also a very good and able man, and a very clever man.
They were school teachers for several generations.
His great-grandfather was also a headmaster of a school in Helsinger, and his great-great-grandfather had a school in Bornholm. But they were what we call good Danish citizens; the quite exceptional human qualities, in any case, came more from the Adler family, I think. The goodness, the interest in all people, that I think is a characteristic for all the Adler family. Also the cousins had this special human interest.
I take it that the aunt was really something of a family leader.
Especially in her later years after my father’s mother died.
There were very funny relations between her and my mother-in-law. They loved each other like Harald and Niels had done — there was the same year and a half between them. But my mother-in-law was a gentle child and Hanna was active and a more strict person and wanted to do things. There were often very funny little episodes there. I remember my mother—in-law was so sweet; she was so independent in such a gentle way. Then when Hanna got older she was deaf and telephoned many times a day, but also every evening, and wanted my mother-in-law to do so and so. She would say, “Have you now been to see these people? Have you now done this?” My mother-in-law never went out to see anybody, and sometimes she said, “Yes, I have; I have done it.” And some time when she hadn’t, she put a tea cozy on the telephone and said, “Now, I wont be disturbed!” They were very witty, yes. Hanna came to see us very, very much, when we were married. She came to stay with us every summer. She was a wonderful personality. She had this school, and she was the first at this school in the morning and was the last to leave it. Then she would come to us from there. You would think she would be tired because she was getting up in the years — she was perhaps between sixty and seventy. Then she would come to us and would play, oh, with the greatest joy with the little children which we had here then. She never got tired of children.
She had no family of her own?
No, no. She wasn’t married. But still you would think she would be tired. She was a little of a tyrant sometimes, but in a good way.
Did she take a special interest in Professor Bohr’s work?
Well, she had taken a degree in physics herself, but even if you take a degree in physics, you can’t follow such things. But she loved him, and she was proud of him, and she wanted to do all that she could for him.
I’m sure if she wanted to read of those physical questions she could understand. She certainly followed everything with him.
What would religious training and attitudes have been in Professor Bohr’s home?
There was not religious training; neither of his parents was religious. I think they didn’t go to church. He wrote very nicely to me once from Cambridge, and he said, “We’ll think it is Christmas Eve,” and he gave a sort of a little picture of remembrances from his childhood. He said, “I think of a little boy whose father took him by the hand and took him to the church to listen on Christmas Eve.” And then he said also, “I think this father took this little boy to the church so that he shouldn’t feel different from all other boys. And his father never said anything about religion to him — not anything.” Then they got christened later. My mother-in-law was a little weak in health, and she got suddenly worried that they should have troubles. It’s no problem now, but it was then. It could be then a little problem if perhaps you were the only one in the class who hadn’t been christened, and so on. So they were christened when they were 13 or 14, or the like. I don’t remember whether my husband was confirmed or not. There was a period of about a year where he took it very seriously; he got taken by it. Then it suddenly all went over. It was nothing for him. Then he went to his father, who had left him quite alone in this regard, and said to him, “I cannot understand how I could be so taken by all this; it means nothing whatsoever to me.” And then his father didn’t say anything; he just smiled. And then Niels says, “And this smile has taught me so much which I never forgot.” So they never exerted any influence, but let them do what they liked. I think perhaps my sister-in-law mentioned this, and that was how I came to know of it. You know, it was often at that age — and I have experienced it myself — that one got very religious and would listen to the minister telling about confirmation. Then it all dissolved. And for me it was exactly the same; it disappeared completely.
How old would he probably have been?
14 or 15 or something like that. And since then it had no interest for him.
He told me that around 1916 he was worried with the social question which was then of course very acute.
Oh, yes. Also this I remember.
He said that he listened once to a sermon of some priest about the social question, and then he recognized that there was nothing at all in religion. It didn’t provide any answer.
When you say the social question –-
He said, “How can one help the poor people? How can one identify them? How can one recognize them, go to them, and try to help them?” And obviously he must have listened to that sermon to see whether there was any argument giving some answer to that, and he decided that there was nothing at all — that it was only talk.
He took very seriously the problem of the poor people, trying to help and do something in this period of his life. I mean, he was always ready to help, but just then he took it up and went into it for a period to see what he could do himself.
What sort of things did he do in this period?
Well, I don’t quite remember how it was; he went to see people and gave what little money he had. It just happened so in those years. But he was always interested and always wanted to help people who had difficulties and were in need and who were really honest. And there came so many to him sometimes; perhaps it wasn’t always so, but he always liked to help.
I know nothing about the situation in Denmark at that time; would there have been anything special for him about his home because of the fact that his mother’s family had been Jewish?
No, none whatever. No, none whatever.
There was essentially a complete integration?
Yes, in any case the father was the family there. That I don’t think he ever has felt here.
Was this characteristic of Denmark in this period?
I would say it was the same in Belgium.
No, it wasn’t; there were problems. I remember others have told me that somebody was going to marry —. Now, you see, it’s a little easier when it’s the father because it was a complete old Danish family the Bohrs. It’s a little more complicated if a daughter married a Jewish person. I know several cases, but I don’t think my husband has ever felt it. Then the family Adler was so loved and respected and had also been here for generations.
Did he think of himself as a Jew, or is this sort of thinking something that never enters the picture?
No. He didn’t think of himself as a Jew; he didn’t think of himself as anything. That only came when Hitler came — this problem that if one of the parents were Jewish, then you would be in difficulty. I thought more of it; I don’t know whether he thought so much of it until perhaps —. But, in any case, I was speculating a lot about what to do if they came.
There was very little connection with the Orthodox things. The whole family considered themselves really a part of the community.
No, they did not go to the synagogue.
No, they were not connected at all with the synagogue.
Except for, the aunt. They were always collecting money among the Jewish members, and she always subscribed. ... The Bohrs couldn’t count as a Jewish family; it was only the pure Jewish families who were approached. She was always giving money to it. It was because of that they came to arrest her. The Germans had all the names in the Jewish community, which was terrible. The synagogue hadn’t destroyed their lists. They came to her house right away, as a result of those lists which they should have burned long ago. That was ridiculous. But at that time when Hitler came, there was a complete integration here. But a generation before it was not all the families who took it like that. For example, the (Koppels). I remember his mother, who is not Jewish, told me that when she came to her father and said, “He is Jewish,” that there was a little problem.
It was in my great-grandfather’s time that the integration took place. He was a very prominent man in the economic life in Denmark. In the middle of the last century when there was the beginning of the industrialization he played quite a prominent role. Then at the same time he also took an active part in the general liberal movement of the time, and that was the time when Denmark got the constitution. And there was the war with Germany, and so on, so he was quite a prominent figure in the community.
This is Professor Bohr’s grandfather?
Yes, his mother’s father. You see, his mother’s mother was English. And it’s her father whose portrait is hanging over there. She came from London. But D.B. Adler was a great personality in the Danish community. He had so many, many ideas in starting also in this very liberal way inside the government. And then he got so ill from overwork and died.
So it was just at that time — 1840, or so — that Jewish families were completely accepted in the community. ... There is a book that tells a little about it. There’s a book written about this Hanna Adler by various contributions that was published a few years ago for her hundredth anniversary. It’s in Danish, of course. But that tells a little about the Adler family, and in particular her father, and so on. And that ought to give a little of the background there.
She had a great sense of humor, this aunt – a very great sense of humor. She has written a wonderful diary. She went over to America when she finished her degree. She was one of the first women students here in Denmark. And when she finished her degree, she went to America; she wanted to study schools in America. There she has written a wonderful diary about conditions in America at that time.
She wrote it down as letters to her mother. It’s a very interesting picture of America. She was so impressed by many things in America — by the progressive developments in education. But then it’s also interesting that she was so deeply impressed with the Negro problem in America that she writes that she almost decided to stay in America to work for the Negroes. But she felt that she had to carry through with her school project, so she came back to Denmark.
Was that diary published?
Only part of it is quoted in this book, but it is available.
But that’s written in Danish; I think Eric has it now; he has never given it back to me.
She was delayed landing because there was cholera on board the ship when she came. And then she wrote also about how all the local politics came into getting permission to land. They got into all these things; it was just like now in America with these things.
Were, there others besides his aunt who would have exerted perhaps particular influence, or been particularly important to Professor Bohr?
I think it was mostly the two aunts there; there was also the old aunt, but she died the year we were married. I think she was a great help to the whole family; I mean, she was unmarried for a long time and lived with her mother. Therefore she could be so much for the family. Then she married later this Hermann Trier, this politician. He had loved her for many years, but she couldn’t decide to leave her mother. Then she married him, but I think they were only married eight years when she got cancer and died. It was just the year we were married, so we went from the wedding to the funeral. Then Niels’ mother had an uncle, Bertel Adler; he was a nice man, but he didn’t play a major role in the Bohr family. He was also a banker and had his own family. They had one daughter, especially, Rigmor, who was then cousin, but she was a good deal older. She must have been several years older than Niels. But she also loved Niels; she had quite a close relation to him all through childhood. No, the uncle married into another family, (Frank). They were a little more worldly, so to speak, even if nice people. But there was not that close connection between them as there had been between my mother-in-law and her sister.
Did Professor Bohr ever speak of school teachers who had themselves had any particular influence on him, or whoa he particularly remembered?
No, on the contrary I remember always when we complained, with regard to our children, that the teachers are not good enough, then he would say, “Well, one of the biggest impressions on children can be when they suddenly understand that the teacher doesn’t understand the subject.”
Was it clear from very early that he was going to go into the sciences?
I think, yes, because of his way of concentrating, his way of taking the foundation of things. He brought problems up to the teacher where he could see that the school books had not always got it quite right. He frightened the teachers a little at first, but it was because he had this understanding of, as I call it, things in their Nature. He could concentrate so enormously.
He never considered going into philosophy? I don’t know, but I don’t suppose he did. He would consider that as something that goes with other things.
He also talked about religion, and toward the last he said to me, “I wish I could write a book about religion.” That was only in the autumn, and I said, “I wish you could.” He was sorry for the role the religion played. So many things which were not true were peeping through, and he thought it was not well for human beings to hold on to things which were, as nearly as one could perceive it, not true.
Had he felt that way about religion throughout the time you knew him?
Yes, yes; he did always. He was sorry for human beings; he felt that they shouldn’t build on something that wasn’t true.
Some people say, “Well, you should take this symbolically in some not very clear way.” That he did not like. He wanted to talk in a way that was consistent and use words according to their proper meaning.
Yes. And he was very interested in the talks he had with Professor Johannes Pedersen, in the later years here in Carlsberg. He has translated the old scripts. And he told so interestingly about all the mistakes that have been put into what you call the Bible, and so on. He said it is completely misinterpreted. He thought it was undignified for human beings to pattern themselves after this and to build their lives on it. And as he always said, one has to give something in its stead. Therefore he always said, “I wish I could write a book.” I mean, he was thinking of the schools and the education, and so on. I wish he could have written it.
I realize, Mrs. Bohr, I don’t know how long before you were married had you known him?
Not so very long.
Yes, but, I mean, you were engaged for two years.
We were engaged for two years, yes. Oh, did you say before I married him? Yes, were engaged for two years; well, he was one year in England.
Then had you then actually met him for the first time?
He studied together with my brother at the university, and my brother told me first about him. Yes, let me think, where did I meet him the first time. I think it was at a dinner party. He was sitting on one side of me. It was at Edgar Rubin’s. I think I met him for the first time there. He was sitting on one side and Edgar was on the other, but I don’t think I talked with him that evening. Then I was invited to their home. I lived in the country together with my brother. There I then got to know him. That must have been in 1909, or something like that. Then he came with my brother to see us. He came to the country and spent an Easter, I think, with us. Then he was also invited to my brother-in-law’s doctor dissertation. I remember we had a party. So I met him a few times; I met him sometimes during the spring. Then he came down to my home. That summer we were engaged.
Was your brother greatly impressed with him from the start?
Yes. And I came with my brother to him, therefore.
I’m terribly interested, of course, in his life at the University. He spoke himself of the amount of time that the special work had taken and that this meant that he did a great deal of his studying by himself.
Yes. I don’t think that he went to so very many lectures. I think he must have gone to Thiele’s in astronomical calculation, and also to Christiansen.
Not the regular Christiansen lectures.
Not the regular. I think he did it himself.
What other subjects did he have? I take it he would have had to take the philosophy curriculum.
Yes; that was with Hoffding, of course.
You see, in his father’s home these four men met. There was Vilhelm Thomsen the very famous linguist, and Professor Hoffding and Professor Christiansen and my father-in-law. And you see they met regularly in one another’s homes for discussion. And Niels and Harald listened very much when they met in my father-in-law’s home. They were allowed to sit there and listen. That played a great role in their lives. And Christiansen was very religious, but the others were not, so there were discussions and they listened.
That other sorts of things would they have discussed?
Probably it was politics and scientific news.
Yes. But Christiansen remained religious till his last days. He was not especially dogmatic about the Christian religions. He was very interested in Buddhism also, I know. The whole family was religious.
Hoffding was a man with very broad interests and in general be was concerned with cultural development and the repercussions in social life. The same was true of my grandfather, I think.
Professor Bohr went to the University in 1903, I think, and got his Masters’ degree, or Magister, in 1909. Was that a typical period to spend, or was that long?
No, it was not very long.
Six years wasn’t long. Did he take six years?
No, I can’t understand he took six years. ... Then it must be because he did things in between. And he sent his work to Lord Rayleigh.
You said something to me Saturday about the manner in which Professor Bohr had always worked by dictating. You said that before he had done this with you he had done it with his mother. Do you have any notion of how far back that pattern goes with him?
Yes. As long as he had any independent work which he was making himself. He dictated to her his whole doctor’s dissertation. In any case, until I came into it, she always did it. And my mother-in-law told me that my father-in-law always said, “You mustn’t help Niels so much; you must let him learn to write himself.” And then she said, “But it was no good because he could not.” He could work in this way, and he could not any other way.
But there must have been school papers.
Oh, those he wrote himself. No, no, no those he wrote himself. It was only when he was making things that he did this. No, no the school papers he wrote himself. No, it dates only from this dissertation. When he was writing that his mother was always helping him; he couldn’t write it himself.
Could that also perhaps have been true of the Prize essay?
That’s quite possible. It was either his mother or me, or Harald sometimes a little, when he had time.
I take it he wrote letters?
Yes, he wrote his own letters, in any case, to me.
We can see that the drafts of letters to Rutherford he did himself.
Has he also written his own to Rutherford in those days?
Yes, those he wrote.
But not after Miss Schultz came; then he never wrote, I think. First of all, spelling was not his strong side, and he often wrote wrong. Then he would have to take a new paper and do it again, and so it was a lot of work for him to write. But I see there are more manuscripts from the student days, and he had taken lectures down. There were several also in that little box I found there.
I think it really interfered with thought to have to write it at the same time.
It was an effort for him, a great effort for him to write a letter.
He gave so much attention to the writing. You asked about the student days. Then, of course, there was a group of his own age that he had considerable contact with. And there was a discussion group, ekliptika, that is described a little bit in an article by Slomann; that’s available. He tells in a very amusing way how the discussions would go as soon as my father and Harald would get started on it. They would take over the scene completely. That is published in a little article in a newspaper. But to this group belonged William Slomann who had written this and who was later the director of the Museum of Art Industry. He was so very much interested in this side. Then, of course, there was Edgar Rubin who was the head of it and was a psychologist.
He was one of those Niels was closest to; he had the same outlook, and he understood Niels so well. They were also related. Edgar Rubin’s mother was a cousin of my mother-in-law’s. She was also English.
How large a group was this in the discussion group?
I was going to say since it was called ekliptika, it must have been that there were just twelve. My brothers were there; one of them in any case; I think both.
Einor Cohn was there; Peter Skov was there also.
He has come into the family again now as a father-in-law.
Ann’s father, yes.
She is married to one of my brothers.
But there were all kinds of different subjects. I think Gudrun Poulsen, (Jenny’s) friend, was there; I don’t remember if my sister-in-law, (Jenny), was there also. But that played a great role then; that was in the student days. But I don’t remember it after we were married.
Among this group was it, except for his brother, Rubin to whom he was closest?
Rubin was the one who understood him so well, yes. And he often said later, when Niels published his things about Complementarity, “You have spoken like that since you were 18 years old.” But my husband was so very close to Rubin’s family; not to him only, but to the whole family. I can’t say that we saw them, but he was always interested if one could do something for them; Edgar’s brother was ill, and so on. He never forgot them.
In the relation with Harald in these years from school into the University, did they work sometimes on a problem together?
No, not really, no.
I don’t think so.
Did they discuss their work?
Oh, very much. I don’t think they discussed Harald’s work because Niels wasn’t a mathematician, but they discussed Niels’ work. Always he wanted to discuss it with Harald; always he liked to hear Harald’s reaction to everything.
That he always wanted to hear, yes.
All kinds of things that he did later in life he discussed with Harald.
Did he write him often when they were apart?
Yes. And Herald came to see him in Cambridge, and Niels was oh, so happy to have him there.
How much of that correspondence do you suppose may still exist.
Yes, that’s something we have to find out about.
Niels hasn’t written very much because he still writes to me, “Give my love to Mother and to Harald and say I’m so sorry I haven’t written; I’ll soon write, and will you tell them so.” So he didn’t write very much to them.
Maybe there is something we’ll have to ask.