Gerhard Herzberg - Session I

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ORAL HISTORIES
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Interviewed by
Brenda P. Winnewisser
Interview date
Location
National Research Council, Ottawa, Canada
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Interview of Gerhard Herzberg by Brenda P. Winnewisser on 1989 February 28,
Niels Bohr Library & Archives, American Institute of Physics,
College Park, MD USA,
www.aip.org/history-programs/niels-bohr-library/oral-histories/5029-1

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Abstract

Early life in Hamburg, Germany; education at Darmstadt; postdoc period in Göttingen, and Bristol, England; setting up his own lab at Darmstadt as Privatdozent; origins of first of his series of books; departure due to Jewish heritage of wife; fresh start in Saskatoon; more books; limited war research; first direct contributions to astrophysics during the war years; three years at the Yerkes Observatory; forty years of work at the National Research Council in Ottawa; Nobel Prize. Experimental techniques include high resolution grating spectroscopy with photographic plates, very long absorption paths, continuous and flash discharge emission and absorption. Contributions in molecular quantum mechanics, quantum chemistry, astronomy and astrophysics, planetary and cometary atmospheres. Leitmotif is hydrogen: H, H2, H3, H3+. Also prominently mentioned are: National Socialism and World War II.

Transcript

Winnewisser:

Gerhard Herzberg was born on Christmas Day, 1904. That much I know. Would you tell us something about your family?

Herzberg:

Well, I was born and raised in Hamburg. My father was what you might say, a businessman. He was an assistant manager or something like that in a very small shipping company in Hamburg. I mean, a company having perhaps four or five employees, this order of magnitude. I don't remember of course the details, particularly since my father died rather early. But I do remember vaguely, that his office was in a building near the center of town. In front of that a monument of the German poet, Heinrich Heine. Because Heine was Jewish the monument was destroyed soon after the Nazis came to power. I think it's fair to say that in my family, both my mother's and my father's families, there was not really any academic interest or training so that whatever I became interested in was my own initiative, except of course for the influence of teachers. I had one brother, just one year older than I, born in the same year. He was born in January and I was born in late December. My father was anxious that both my brother and I should have a good education. At that time, there was what is called the "Volkschule" and then there was the other schools like "Realschule" or "Oberrealschule," or whatever, and they had their own first three years. After the First War, I think this was all changed and everyone went through the Volkschule for three years or four years and then came the dividing up. But at that time, as an indication that we were perhaps somewhat better situated, and that the interest in good education was strong, we went to this Vorschule and it was at the end of the Vorschule that actually my father died. The Vorschule my brother and I went to belonged to the Oberrealschule in Eppendorf (a Suburb of Hamburg), which is still in existence (but not the Vorschule).

Winnewisser:

So your father saw to it that you had the best education available, from the beginning.

Herzberg:

Yes, although his own interests were rather limited, as far as intellectual things are concerned.

Winnewisser:

Your brother became a pianist, is that right?

Herzberg:

Yes. Yes.

Winnewisser:

So both of you indeed went into careers that are quite demanding and certainly far from the business world.

Herzberg:

Ah yes, quite so. Now, I might perhaps go one step further back and say, my father came from a small town in Thüringen, which is now in the East Zone of Germany, called Langensalza. There's a famous battle of Langensalz, but I don't remember the history that accurately. At any rate, it is actually not very far from Göttingen, sort of half way between Göttingen and Leipzig. It's close to a town, Gotha, which is better known because it was a small province that had its own ruler in the previous century. So it's quite close to Gotha and then not very far from Eisenach, which is famous for Luther being there at the Wartburg, and so on. It's in that area that my father grew up, in a large family. My grandfather was a grocer, and apparently a reasonably prominent grocer. One of my cousins tried to follow back the genealogy and found she could do so to something like 1550, so they were all living always in that town. Now, I've always been wondering, there's a town also in the neighborhood of Göttingen, in the other direction, which is called Herzberg, with the same spelling. And I have been wondering whether the origin really of the family Herzberg was in this village or town in the Harz Mountains, which I never saw until just a few years ago when I visited in Göttingen and one of my colleagues took me to this town Herzberg. As a matter of fact, the same colleague sent me a postcard at Christmas time with a picture. They had just visited Herzberg, a pleasant little town with a little castle on the top of a mountain and all this. It was really rather late in life that I ever saw it, and was fully aware of it. But I was aware of the fact that in Göttingen, when I was a postdoc there, there was a Herzberger Landstrasse, which went right straight to this town by the name of Herzberg. Whether there's any connection, I have not been able to find out.

Winnewisser:

It might go further back.

Herzberg:

It might. But in the study of my ancestors of this cousin of mine, it came also out that occasionally there was a pharmacist or somebody like that in the branching genealogy, but no indication of any strong academic interest, no connection with the university of any kind as far as I can make out.

Winnewisser:

And on your mother's side of the family?

Herzberg:

Well, even less in my mother's family, I would say. My grandfather on my mother's side was a master glazer.

Winnewisser:

OK, that's a technical profession.

Herzberg:

Yes. And he came from East Prussia to Hamburg. He was a curious kind of a man. I never recall him—he went actually, of all places, to Canada, two years after I was born, in 1906, I think, and ended up in Vancouver, whether in his job or not I don't know. He was also an adherent of Christian Science. It was when he came to this continent, in fact, apparently that he got involved in that. Now, the other point that perhaps is worth mentioning is the fact that my mother was 13 years younger than my father, and she was only 17 1/2 when she married, and my brother was born when she was 18 1/2 and I was born when she was 19 1/2.

Winnewisser:

She came very fast to her responsibilities.

Herzberg:

So my father died when I was ten years old or eleven years old, just on leaving the Vorschule.

Winnewisser:

That was in the middle of the First World War, then.

Herzberg:

It was just at the beginning of the First World War. When my father died, an uncle by marriage, that is, the husband of one of my father's sisters came to Hamburg for the funeral. He and his family lived in Frankfurt, and he thought that I should come with him and have schooling in Frankfurt. So I went with him, not directly but very soon after, to Frankfurt, and went to the Liebig-Oberrealschule in Frankfurt for half a year. But I was a small boy, and I got very homesick, and this uncle of mine was somewhat rough with me. That's exaggerating it a little bit, but I felt —

Winnewisser:

— from your perspective he was.

Herzberg:

From my perspective, yes. So that I even talked about just leaving and not telling anybody and this kind of thing, but that came out somehow. At any rate, they sent me back to my mother.

Winnewisser:

Having just lost your father, I'm not surprised that you needed at that time your mother.

Herzberg:

Yes. I was only ten and-a-half at that time. So these events are still in the back of my mind, as an experience that I won't forget. When I came back to Hamburg that same year (that was 1915) I started with what was at that time called the Realgymansium des Johanneums. It was a very famous old school, THE school in Hamburg. It was a gymnasium, but this was a branch of that which was close to where we lived, and I went there starting at the so called "sexta" and going all the way up to the "Oberprima," and we had some really very good teachers there, and it's there perhaps more than anywhere else that I started my interest in atomic physics. We had one very well known physics teacher, Wilhelm Hillers. He was not normally teaching in our class, but he taught a special class, towards the end of my schooling, on the then-new Bohr theory. There was also a very good mathematics teacher, and so I think I owe it really to the teachers at this school, that I got really started in my interests in mathematics and physics.

Winnewisser:

They gave you excellent teaching and they also aroused your interest, apparently.

Herzberg:

Yes.

Winnewisser:

They also, from what you've written, led you to voice a desire to become an astronomer.

Herzberg:

Yes. Well, that goes actually back a little further, in the sense that I had a school pal, Hans-Werner Döring, with whom I built a small telescope, very primitive, just a cardboard tube and two lenses and so on, and we did a little bit of observing, but it was on a very primitive level. But ever since that time I tried to read some astronomy books, and I still remember going to the public library in the center of town, in fact very close to where my father's office was. The building is still there, but it's now just a Burger King restaurant. But it was actually a public library, and I got my first astronomy books from that library.

Winnewisser:

So sharing an interest with your pal also stimulated your interest and furthered it.

Herzberg:

Yes. But it was another school pal, Alfred Schulz, who joined our class somewhat later, because his parents moved from the Rhineland to Hamburg, perhaps when I was in the "Tertia" or somewhere around there, and I became, as a young boy, you might say, acquainted with both these families. The father of the first one was a dentist, and the father of the second (Schulz) was really a high-class salesman, if you like, of fabrics. The interesting thing from the point of view of my biography is that when I finished high school, that is this Realgymnasium, with the "Abitur" as we call it, of course the question was what to do. I wanted to go to university, naturally, because I was always close to the top of the class, and it was only natural that I should go to university. But, of course, my mother had no funds of any kind. In fact, that's another side of the story that perhaps is not relevant.[1] But so, one evening I was at the second school pal Alfred Schulz's place. We talked about this problem, and Mr. Schulz (senior)[2] said, "Why don't you write to Hugo Stinnes?" Now, Stinnes was famous at that time as a very big industrialist in Hamburg. He had a shipbuilding concern and it was really a big place, and I first thought, what a crazy idea, how can I write to Stinnes? But nevertheless, in despair I did write, and lo and behold, there was an answer! They wanted more information. And after a while, I got a fellowship, a private fellowship, from this Hugo Stinnes or his company, if you like, and that enabled me to go to a university. Now, the question was, which subject should I choose? And of course, I was very anxious to get into astronomy. So I went to the vocational guidance people who existed at that time in Hamburg, the "Berufsberatungsstelle."

Winnewisser:

In the school?

Herzberg:

No, this was a separate organization. I don't remember now exactly where it was. They took my problem quite seriously. They wrote to the director of the Hamburg Observatory, who was a very well known astronomer by the name of Schorr, and he wrote back to the vocational guidance people "Well, if this young man has some private funds then of course it would be lovely if he goes into astronomy, but if he doesn't have any private funds, there's no way of making a living." And so the question was then, well, what else could I do? I was interested in physics, mathematics, chemistry, and the vocational guidance people suggested that I should choose a new subject that was coming up, which was technical physics, meaning really what we now would call I suppose engineering physics or applied physics, and they said that at one university, they had started a regular course in this subject. It was in Darmstadt. And so I followed the advice and I went to Darmstadt.

Winnewisser:

One question. Astronomy of course is a purely academic pursuit, and then you went all the way to the technical physics which is sort of on the edge of engineering. Why not the traditional physics?

Herzberg:

Well, of course, at that time I didn't know how these things went at a university, you know, and I made a mistake!

Winnewisser:

So you basically relied on this suggestion.

Herzberg:

That is right. That is right. That was all the advice I could get. And, I mean, it wasn't called engineering physics, it was called "technische Physik", meaning technical physics.

Winnewisser:

Of course, Darmstadt was a technische Hochschule.

Herzberg:

It was a technical Hochschule — now I think it's a technical university, because Hochschule has another connotation in the English language.

Winnewisser:

So then you were fortunate in the advice you received.

Herzberg:

Yes, I think I was. I think I was quite fortunate. And I chose the right place. I went to the summer semester in Darmstadt, that is, it started about end of April 1924. I went through the summer term or summer semester, and at the end the question was, what do I do during the vacation time? An opportunity arose that I could be an apprentice for a few months in the workshop of the institute, of the physics department, and I took that. I don't remember whether I was paid for it or anything. Somebody must have paid-well, I had my fellowship of course. So at any rate, in that way, I got some contact with the people in the physics department, and I soon found out that there was a professor of technical physics, but I soon found out that he was not really very competent or progressive person, and that the head of the physics department, straight physics, was far more active and competent or I don't know how I should put it, and that was a man by the name of Hans Rau. He was, he came from Wurzburg and he was "Bayerisch." But he was a very fine person, all through his life. Unfortunately, in a way, he accepted so many duties at the university that he hardly published any more of his own work, after he had started this professorship at Darmstadt. But he gave very extraordinary, good lectures, I always tell this to people who say you must divide the class up into I don't know how many sections. We had at that time 500 students in this class of physics. All the students in engineering had to take physics. And therefore, I mean, even though the Technische Hochschule at that time perhaps had certainly not more than 5000 students, practically everyone, certainly everyone in electrical engineering....

Winnewisser:

There was only one version of the physics course?

Herzberg:

No, there were actually two versions. The second version was given by this other professor, and it was not a very good one, from what I heard, so I didn't even start. Well, the lecture was in a very large lecture hall, but one could hear him. There was no amplification or anything at that time, he didn't have this sort of thing. He was an extremely good lecturer.

Winnewisser:

Was this a demonstration lecture?

Herzberg:

With demonstrations, yes. He spent a lot of time on these demonstrations and they were very cleverly done. He followed the model of people like Zenneck. I don't know if you have heard the name, in Munich, where Rau came from, I mean scientifically. Rau was a student really of Willie Wien at the University of Munich. Zenneck was the professor of physics at the Technische Hochschule in Munich. He gave a very similar lecture to Rau's (or rather, Rau's was modeled after Zenneck's) also to 500 or so students, and he was known to be an extraordinarily good lecturer, I myself never heard him, but I heard about him. I met him perhaps once or twice when he was retired. He together with Pohl in Göttingen were the two outstanding lecturers in Germany at the time, and Rau was sort of following the model of Pohl and Zenneck, in this matter. And so with this extraordinarily good lecture, my aim was set. Physics was it! Pure physics!

Winnewisser:

This is where you found the pure physics.

Herzberg:

Yes. And I must admit that I was helped in this decision or in realizing what was going on in the institute, how to compare this and the various subdepartments, by a graduate student who befriended me while I was working in the shop there, in the summer vacation, by the name of Heinrich Peters. He never got his degree. But he was there for a long time, and he was a friendly kind of person. I learned something from him, but particularly about the various subdepartments and whom to work with and this kind of thing. Although he himself certainly was not a terribly good student, he was actually a graduate student of professor Rau, and was trying to get his PhD. The joke really is that the problem that Rau had given him was to try and see whether he could find the spectrum of H3. ...H3, of all things. Of course, there was no clear distinction between H3+ and H3 at that time. Rau was a man who had done a lot of work on positive rays, or as we said in German, "Kanalstrahlen." That was how he had made his reputation. And so he had asked this student to use the positive rays in hydrogen, where it was known that H3+ was one of the ions, since the work of J.J. Thomson, not so very much earlier, but it was known that H3+ was there. I would say this was known soon after the First War.

Winnewisser:

Through mass spectroscopy?

Herzberg:

When the first mass spectrometric studies of hydrogen by J. J. Thomson showed, that in a discharge in hydrogen you get not only H2+ and H+ ions but you also get H3+ ions. And so Rau thought that, now, if we look at the spectrum of a discharge, we find the atomic lines and we find these many lines, so-called many line spectrum. Is this many line spectrum due to H2 or H2+ or maybe H3+? And he gave this student the idea or the problem, try and find the spectrum that arises when you have separated H3+ in a combined magnetic and electric field, and then look at the emission. I was quite fascinated by that. And then I heard Rau's lectures about positive rays, Kanalstrahlen, in his general course. If you have a combined electric and magnetic field, then you get a parabola for the deflection of the beam cross section (because of the different velocities of the ions).

Winnewisser:

— the velocities?

Herzberg:

Peters had put a slot of a parabolic shape in his apparatus. Ions of different velocities would come at different parts of such a parabola. And I found Peters had the parabola the wrong way around. And I talked to him about it, and he finally agreed, yes, it was the wrong way around. So he had been working for two years or something like that, with the parabola the wrong way around, and hadn't seen anything! But of course, even when the parabola was changed around, he didn't see much. And we know now why. But nevertheless, in my work for the equivalent of a master's degree, which was the "Diplom" — I was after all at an engineering institution, so that the first degree that I was aiming for was Diplom Ingenieur. I did some work that was a little more complicated.

Winnewisser:

There was a research requirement for this engineering degree?

Herzberg:

Oh yes. It was more like a master's degree at a small university, where that is, the end-degree, and then you have to do some research. Well, I did some research. Actually it so happened that there was another student of the same professor who was also not terribly competent, a lady whose name was Blumenthal, and Rau told me, "You try a little bit on hydrogen and help this girl get finished." She had been around for quite a number of years, apparently. And so I started on hydrogen, and this led actually to more or less my first two real research papers, on hydrogen, partly connected with the first observation of the continuous spectrum of atomic hydrogen. In the emission it corresponds to the direct combination of electrons and protons, you know. At any rate, in this work you'll find in this paper I published, I still left open the possibility that some of the parts of the many line spectrum of hydrogen are due to H3, and that had been suggested by other people, and I seemed to believe that that was quite possible. But the joke on me is of course that I forgot about this completely. Later on, the many line spectrum of hydrogen was fully analyzed by various people and it was all H2 of course and nobody ever thought about H3 in that connection. Ten years ago, when I actually did find H3. In a way, I could have found it at that time. But I didn't.

Winnewisser:

Because the features are so broad that even with the resolution that you had then....

Herzberg:

The first feature was broad, but then there are very sharp lines, you see, which were somewhat later found, but still, I could in principle, but of course there were only a very few lines amongst all this H3 and it was.... But the strange thing is, I never actually thought of this old work until much later. There was really a strange — not another connection, but a coincidence — that this H3 problem had come up before in the place where I was doing my PhD degree. Anyway, that's perhaps a little off the subject.

Winnewisser:

One thing I would like to ask on this, among these early papers that you wrote when you were a student in Darmstadt with Rau, that apparently even in these very early papers they are published only under your name. In other words, as "Doktor Vater" he did not insist on having his name on the papers?

Herzberg:

That is right. The way he presented a problem to me was, when I asked him that I wanted to take my PhD, he said, "You read Sommerfeld." Sommerfeld had written in 1924 his famous book "Atombau und Spektrallinien." "And then you see whether you have some good idea." Well, I don't know whether I had any good ideas, but it was really much less planned than they want you to plan science nowadays. My first idea was a very obvious one. There was the hydrogen spectrum, that is of atomic hydrogen, then there was the He+ spectrum, which was so similar to the hydrogen spectrum. Then of course the next step is Li++. I thought I must try and get Li++. Well, it has taken many many decades before really a spectrum of Li++ was found, and I wasn't the one who found it! I do remember that we decided on a particular kind of discharge tube we were going to use for this Li++ and there was a glass blower's shop, not in our institute but across the corner, an independent glass blowing shop, very good one, actually, and we got this tube prepared and so on. But when I then started to work with discharges, the first thing I came across was the afterglow of nitrogen. You just put air in there, you get an afterglow, you put nitrogen in there, you get a different kind of afterglow, and so I got intrigued by that, and I did quite a bit of work on that, and that really was part of my PhD thesis, or rather my thesis for the doctor of engineering degree.

Winnewisser:

Yes, you were still in the engineering school.

Herzberg:

So that was one part of my PhD thesis.

Winnewisser:

Rau obviously encouraged your independence.

Herzberg:

That's right.

Winnewisser:

Now, you obviously very early had a very high standard of thoroughness and accuracy in this work that you were doing. Would you say this came from the school or from your own standards? Did your university education help reinforce or complete this development?

Herzberg:

I think probably it was the general university education which fostered that. Rau was a very busy man because he soon became dean and then he became "Direktor, and he had very little time. It was quite an art to get hold of him, but once you did he was always very interested and had some good suggestions. There was never any idea that it was a joint piece of work. And he certainly didn't publish any on his own.

Winnewisser:

I interrupted you in the middle of your thesis work.

Herzberg:

Oh yes. The second part of the thesis was another spectrum that was well known at the time already, but I found a new feature in the spectrum of the N2+ ion, connected with the fact that, in the sequences of band heads (sequence meaning that the vibrational quantum number changed by the same amount: zero zero, 1 1, 2 2, 3 3, and so on, you know, or 0, 1 1, 2 2, 3 and so on) these various groups, these sequences, converged or diverged. That somehow hadn't been seen before. The vibrational structure of diatomic molecular spectra had not been fully recognized at the time. It was just one small addition to that; it was a recognizing also of the fact that in sequences you can also have a parabolic dependence of the position of the band heads as a function of the vibrational quantum number.

Winnewisser:

Each of these things had to be observed the first time.

Herzberg:

But it was at the same time that another spectroscopist in Berkeley, F. A. Jenkins, found the same thing for CN. He found the same sort of thing for CN, and of course CN and N2+ have the same number of electrons. The two transitions are very similar. In fact, the N2+ 0-0 band is at 3914, and the CN 0-0 band is at 3883, so the spectra are really very similar indeed. And this shows up in that particular feature also of convergences within these sequences. Jenkins found the same thing, and I think our papers were published almost at the same time. Later I met Jenkins, he was a very fine person. He unfortunately died rather early of cancer. But he made some very fine contributions to molecular spectroscopy.

Winnewisser:

Can you say something about the spectrometer that you used in Rau's lab?

Herzberg:

Oh yes! Well, Rau, coming as he did from Munich, had somehow a close connection with the C.A. Steineil-Söhne Company (spectrographs) who at that time were making mainly prism instruments. Gratings were practically not available, at least not simply available. There were a few. Rau persuaded the Steineil people — he had some personal connection with them, I think — to give him the blueprints for their three prism spectrographs. In our shop we had a very good man who was in charge of the shop, and under his guidance, these spectrographs were built in the shop, two or three of these were built, and I used one of them. They had either a long focal length or a short focal length, depending on whether you had low intensity or high intensity. The original one was glass, a three prism glass, and then there was a three prism quartz instrument, and it was these instruments with which I did all my early work. It was only after I came back from my postdoctorate years that we actually got a grating, from R. W. Wood at Johns Hopkins, and set it up and built an instrument by the same "Werkmeister" by the name of Sting.

Winnewisser:

Since you mention that, how did you get a grating from Wood? There were only so many of these gratings being turned out.

Herzberg:

Well, it's a strange thing. I don't really remember now exactly how it worked, but I think I just wrote to R. W. Wood, asking whether he could rule a grating for us. He must have seen that at that time there was some production, so that it was useful to—and he sent actually a very fine grating, a 3 meter grating with exceptional blaze, and very good definition, and freedom from the usual kinds of ghosts. In fact, he considered it one of the best gratings he had ruled, and he sent it to us for $500!

Winnewisser:

That's basically at the cost of production, then.

Herzberg:

Yes.

Winnewisser:

My goodness.

Herzberg:

When I met R. W. Wood for the first time after the last war when I visited at Johns Hopkins, his first question was, "What happened to my grating?" And of course, Darmstadt had been bombed very heavily and nobody knew where that grating was.

Winnewisser:

Well, if he hadn't known how good it was before he gave it to you, he saw from the results that came out how good a grating it was.

Herzberg:

So in that respect we were very lucky. And of course later on when I came to Saskatoon, again the problem arose, how to get a good grating, and I wrote to R. W. Wood again, and he sent again a very good, but not as good a grating as I had in Darmstadt. So that was the same the old Rowland machine, really, modified by R. W. Wood, that ruled the gratings.

Winnewisser:

So Rau was at least responsible for providing the foundation for your work in that he had these prism spectrographs built.

Herzberg:

Yes. There was the Helmholtz Foundation, that gave us some minor grants for war equipment. I remember it. And then there was some group of "Friends of the Hochschule" who gave some money, and so with all that, I didn't have too much trouble to get equipment, I would say. I didn't have to write long proposals and all this kind of thing.

Winnewisser:

Even though money was very tight at that time.

Herzberg:

Money was very tight, but Rau looked after that.

Winnewisser:

Now, you've mentioned that you were exposed to Schrödinger's work very early.

Herzberg:

Oh yes.

Winnewisser:

How was that?

Herzberg:

Well, this was during my student days. Well, I was already working in the lab, if you like to put it that way, on my master's degree or the equivalent thereof, and then I noticed, I often went to the library, it was a small library but they had the Annalen der Physik and the Zeitschrift für Physik, and I saw in the latest issue of the Annalen a paper by Schrödinger, "Quantisierung als Eigenwertproblem." At that time I had just taken classes with a very well known mathematician at the university by the name of Horn on partial differential equations, so I was familiar with the expression "Eigenwert." I was immediately intrigued by this because I knew about the Bohr theory and "Quantisierung" and so on. So I read the paper and tried to understand it fully and I think I did, and indeed I think I was the first in Darmstadt at any rate to report on this paper in the colloquium, and I was only a third year student. That gave me then, already, a reasonable opportunity to learn how to give a colloquium.

Winnewisser:

Was this your first colloquium then?

Herzberg:

Yes, I think it was my first. I talked in the physics group and there was also a colloquium in the department of mechanics (what do they call it?) This was an engineering department but they had a good man there by the name of Prager, a younger man who later left Germany and ended up in the United States, and he encouraged me to talk about this in their colloquium. Now, I don't remember which came first, but I felt very pleased that I could do it. Subsequently, Rau heard that Schrödinger was giving a lecture in Freiburg, and he sent me down to Freiburg to listen to Schrödinger. I met Schrödinger at that time, a very charming person with a very nice Viennese accent. I don't know whether he was born in Vienna, but he was a real Austrian. He was a very fine lecturer, and a very sincere kind of a person.

Winnewisser:

So you were exposed to molecular spectra and to the beginnings of quantum mechanics just at the same time.

Herzberg:

About the same time. I had read already — before I went to Göttingen as a postdoc — some of the papers by Hund and Mulliken and Van Vleck and so on. But it was really the year that I was in Göttingen, 1928-29, that was a very important year for spectroscopy in general. There was this famous paper by Wigner and Witmer on the correlation between the atomic and molecular states, and then there were several papers, the more important ones by Mulliken in the same year, and as I say, in this document here, it was a vintage year. And so I learned a great deal when I went to Göttingen. This was right after Darmstadt. It was in 1928. I had been in Göttingen before, giving a talk in their colloquium, and I was so much impressed by James Franck that I was very anxious to spend a year there in Göttingen.

Winnewisser:

You gave a talk on your experimental work?

Herzberg:

Yes.

Winnewisser:

So having had the contact there and from the interest that you had developed in Darmstadt, it was almost natural that you would want to go to Göttingen.

Herzberg:

That's right, yes. And then in Göttingen, there was a visit for six months by Lennard-Jones, who was a theoretician and was very much interested in the kind of work I was doing. I had already started writing an article on an extension, if you like, of what Hund and Mulliken had written. It later served as my thesis for the "Habilitation" in Darmstadt. When I came to Göttingen I talked to Heitler (of Heitler and London, the famous paper on the hydrogen molecule). He was in Göttingen as a "Privatdozent" and he was quite interested in the experimental results that I quoted in this, what you might call semi-theoretical paper. We published together a paper that turned out later on to be quite wrong, but it was stimulating, at least to me, and very shortly thereafter the two of us published a paper that was to my mind one of the more important ones, but I don't think it ever found the recognition that it deserved. It was largely, if you like, Heitler's idea. I had pointed out to Heitler that the intensity alternation in the Raman spectrum of nitrogen observed by Rasetti is opposite to that in hydrogen, and he became quite excited about that. It was he who realized that it meant that the electrons don't influence the statistics of the nuclei, in nitrogen in particular. I think it was the stimulus that Heisenberg needed in order to start talking about neutrons in the nucleus as soon as the nucleus was discovered.

Winnewisser:

Can you say something about the course on spectroscopy that you offered in Göttingen? There were various people involved in molecular spectroscopy in Göttingen, but it was you who ended up giving this series of lectures.

Herzberg:

Well, actually, the strange thing was that this was a course in the other physics institute. There were the "first" and the "second" physics institutes. James Franck had the "second" physics institute; Robert Pohl had the "first." They worked there on rather different things from what James Franck was doing: crystals, crystal spectra, sodium chloride, and things of that sort. But they were interested in hearing some more about the general development of gaseous spectroscopy, and they asked me if I would be willing to give them a few lectures on the subject. It was quite a small group, but there were a number of graduate students attending, amongst them Weisskopf and several others, and there was also a visitor in Franck's lab from Erlangen, G. Scheibe. He had some connection with a publisher, and he asked me, wouldn't you like to publish this as a little book? And of course I, being a young man and having a chance to publish a book, that seemed like something very interesting. And so he made the connection with Steinkopff who was the German publisher who published my first book. Originally the idea was to write one little tiny book on atomic and molecular spectra. The course that I gave at the I. Physikalisches Institut was mainly on atomic spectra. They wanted to know about spin and J and various quantum numbers that matter in an atom, and this kind of thing. I think that's what it was. Maybe there was also some molecular spectroscopy involved. That could be. I've forgotten that. If I dig hard enough I might even find some notes. That was the connection with Scheibe. He was already at that time a fairly well known chemical spectroscopist. In fact, we did some work together, while I was in Göttingen, and that was on the ultraviolet absorption spectra of the metal halides.

Winnewisser:

Yes, I noticed that, and I was rather surprised. It seemed a rather ambitious project at that time.

Herzberg:

Yes, in a way it was but for example metal iodide gave a very nice absorption spectrum. Of course it was only vibrational structure that we could resolve. We didn't have a big vacuum grating, we had just, this was again a prism instrument, a fluoride spectrograph.

Winnewisser:

Is that approximately equivalent to what you'd been using at Darmstadt?

Herzberg:

Less dispersion and you need more dispersion in the vacuum UV region because of the inverse ratio between lambda and nu.

Winnewisser:

That's right.

Herzberg:

At any rate, it was really low dispersion. But it was certainly the first study of the ultraviolet absorption spectra of these fairly important compounds, methyl halides.

Winnewisser:

Very polyatomic.

Herzberg:

Yes, really polyatomic, that was really my first effort on polyatomic molecules.

Winnewisser:

What was the reason for choosing them? Partly you knew they had a spectrum so you would have something to see?

Herzberg:

No, we didn't even know that. But some reason that I don't recall. May be Scheibe had some idea that these might be or should be investigated. And lo and behold, they were quite interesting.

Winnewisser:

And they are still being studied today.

Herzberg:

Yes, they are being studied.

Winnewisser:

So your pedagogic abilities were recognized certainly at this time.

Herzberg:

Well, if you want to put it that way, yes. Of course the history of my books is also explained in here,[3] that originally it was to be in fact 160 pages, and that it was to be a book on atomic and molecular spectra. Well, it became obvious after a little while, when I started writing, that it would fill, much more than 160 pages, and so I split off atomic spectra. It was published, back in 1936. I read the proofs when I was in Saskatoon, just after I arrived in Saskatoon. I went to Saskatoon in '35. There I had very little equipment, so I started writing the second volume of this work covering all of molecular spectra. And the same thing happened again. As a friend of mine pointed out: "Es war das Ring der Niebelung von Wagner." Originally Wagner wanted to write one opera, "Siegfried's Tod." Then he wrote "Rheingold" as a "Vorspiel" and then he found that the rest of the work were to be two, but it finally ended up in three operas. And that's what happened to me.

Winnewisser:

Well, obviously the fact that you did not compromise with the desire to be thorough, is part of what makes these books maintain their position.

Herzberg:

Well, maybe so. Most people I think agree that volume 1 (Diatomic spectra) was really the best because it covered one subject. The Van Nostrand Co. decided recently that they had had enough of those books (the volumes on molecular spectra), but they wouldn't keep reprinting them, even though they were still selling some 300 copies a year. But they referred me to a reprint publisher, the Krieger Publishing Company in Florida, and they would take over similar to the way the Dover Publications had taken over the book on atomic spectra. Of course, I wanted to correct some obvious errors and some things that were too outdated, so I did a fair amount of work on that. But this is now ready to be published. (It appeared in July 1989).

Winnewisser:

Which one?

Herzberg:

Volume 1. And I'm now just in the process of working on volume 2, which needs revision much more: it was written before the whole development of microwave spectroscopy. There was only one paper, that was the paper by Clayton and Williams, on NH3, and that was the only paper on microwave spectroscopy published at the time that my book was written. Now, of course, I couldn't begin to take on the job of describing the whole of microwave spectroscopy, but in this new version that I'm just getting ready, at least I give some references to microwave spectroscopy, I am also revising a number of tables that are obviously so outdated that they are useless, and adding a few remarks here and there, rather more than in volume 1, so it was quite a bit more of a job. I am now working on volume III.

Winnewisser:

I'm sure it's a big job. There's no doubt about that.

Herzberg:

Yes, but, it's not easy just by little things to make these books more useful, but I hope they will be, that's the best I can do. A new edition is just out of the question. It would take me ten years, and I don't know whether I have ten years to do it in. I wouldn't want to spend the last ten years of my life on that, you know! I've done enough of that. But this brings me back now, every day I try to do five or ten pages, and don't always succeed.

Winnewisser:

Well, I'm very glad to hear that the books will continue to be available.

Herzberg:

Actually, volume 1 was sold out about a year ago, but now it is available again. As for volume 2, when Van Nostrand gave it up, there were still 300 copies or something like that in stock, and they transferred this stock to the Krieger Publishing Co., so that you can still get volume 2 if you hurry, if you're short of a copy. It will take a year I think before they really have this out now, the volume 2. Volume 3 I think will again be simpler because it was published in '66. Remember volume 2 was published in '45. So it's well over 40 years old, and it is in a way surprising that a large part of the manuscript still stands up to reasonable criticism.

Winnewisser:

Yes. We send our students back to those books very frequently.

Herzberg:

I see. Well, I'm glad to hear that.

Winnewisser:

Just partly because the subject was newer then, the explanations are—

Herzberg:

—more elementary.

Winnewisser:

Yes, that's one word one could use, and it's sometimes what our students need. We are in the physical chemistry department, and they don't have enough quantum mechanics to absorb it easily so your books are very valuable indeed.

Herzberg:

Well, I'm glad if they're useful. Anyway, I will hopefully finish this reprint of volume 2 with some modification. I have 50 pages left to correct.

Winnewisser:

Oh, that's not far to go then.

Herzberg:

But I really worked quite hard for a while to keep up a reasonable schedule.

Winnewisser:

I congratulate you. But then I know you established those habits while you were writing the books originally. Before we leave your student period in Darmstadt completely (we have already but that doesn't matter), you mentioned Heinrich Peters, and you mentioned a Miss Blumenthal. Were there other graduate students working for Rau, or did he not have time to direct them?

Herzberg:

There was one other whom I remember and who actually did get I think his Dr. Ing. That was a man by the name of Rodenstock, and he was the son of a very well known optical firm in Munich. I don't know whether it still exists.

Winnewisser:

Yes, that still exists.

Herzberg:

Roden with a "d," that's quite right, yes. Yes. That's right. I don't think it was a Jewish firm. I mean Rodenstock would be a Jewish name, but Rodenstock I think was not. So for that reason the firm probably still exists.

Winnewisser:

So he got his degree also about the time you did?

Herzberg:

He worked simply on work on Kanalstrahlen which was the favorite subject of Rau. And what he was doing, I don't remember exactly now. It was just a little closer to what Rau was doing, but he still didn't put his name on the paper. If it ever was published. I don't know. But those are the only three that I can remember (see however below). When I came to Darmstadt, Rau had been there no more than three or four years.

Winnewisser:

How old a man was he at the time?

Herzberg:

At the time, he was probably in his late forties. I just the other day saw the announcement of his death, by the university, in some file that I opened up. He was an extraordinarily fine person, and all through the Nazi period, he behaved just 1 A.

Winnewisser:

That's an important statement.

Herzberg:

I mean, he took a great deal of trouble to help one person on the staff, "ein getaufter Jude" Baerwald, well, anyway, he was a lecturer. He had been a" Privatdozent" and was made into an extraordinary professor. At one time, you didn't get a salary for that. You were still a "Privatdozent" only you had the title, this kind of thing. Anyway this man was not really a very great light. He had been a student, actually, of all people, of Lenard. The top Nazi, Nazi party number 3 or something like that. But at any rate, this was long after I left Darmstadt. He had very considerable difficulties and was put in a concentration camp. Somehow or other Rau got him out and arranged that he went to England. He had a very tough time. He died rather early.

Winnewisser:

Well, I think this whole later period in Darmstadt, this is I think worth a whole session in itself.

Herzberg:

Oh, there was one other, you asked about the graduate students. There was another graduate student. That was a man by the name of Lion and he worked also on positive rays or Kanalstrahlen in some other way. I don't remember the details. He did finally get his Dr. Ing, but he had to leave. He was Jewish, and he had to leave. I didn't have to leave because I wasn't Jewish myself, so it was only when the Nazis got worse on the people who were married to Jews, that I had to leave. But this man had to leave because he himself was Jewish, and so soon after he left he went first to work with Dessauer who was originally a professor of medical physics in Frankfurt but then had to leave because of the Nazis and went to University of Freiburg in Switzerland or is it Freiberg. After a fairly short stay with Dessauer Lion went to U.S.A. and ended up as a professor of biophysics at MIT. But he died quite a few years ago now. He was a very skilled experimenter. I was quite friendly with him and I learned quite a lot from him in physics and otherwise.

Winnewisser:

So there was some transfer of know-how among the graduate students.

Herzberg:

There were so few that, there was a reasonable contact between them. Another person who was in Darmstadt and might just be mentioned for a moment is a man whose name is very well known to anyone who knows anything about X-ray diffraction. He was a man by the name of Knipping, Paul Knipping. He did the experiment for von Laue. Von Laue, Friedrich and Knipping were the three that had their names on the final paper on the first X-ray diffraction work. This man Knipping was a funny chap. He suffered a little from a persecution complex, and for example, one particular door he always locked. He had a motor bicycle, put it in the hallway next to his office. He thought people would put sugar into his motor bicycle. Such crazy ideas. But he was actually a very good physicist. He had once worked with James Franck. In fact, the first experimental determination of the ionization potential of helium, was by Franck and Knipping. And so he certainly was a competent physicist. Later on the University gave him a small institute on X-ray diffraction and this kind of thing. But he was killed in a motor bike accident. He was quite a character. There was another person there in the same row of offices where I also had an office, who never made it to the "Privatdozent." He was a man by the name of Behagel. I don't know what ever happened to him. My first contact with these people was as a student in the lab. They had to instruct in the lab, you know. And all these 500 students that Rau had in his class had to go through a lab.

Winnewisser:

So Knipping and these others, they all had sections of the lab.

Herzberg:

Yes, including myself. After I was Privatdozent. I earned my living by being an assistant. As "Privatdozent" I didn't earn any, practically no money.

Winnewisser:

So then you knew these people through the shared teaching responsibilities?

Herzberg:

Right.

Winnewisser:

Were there also what we would call now problem sessions, as part of the teaching?

Herzberg:

That I don't recall. No. I don't think there were. The Anglo-Saxon, if you like, emphasis on problem work in these classes didn't exist in Germany when I was there. When I came to Saskatoon I first had to learn to solve these problems in mechanics. I gave a lecture course in mechanics, and I had a tough time with it! Solving all these problems that I had to give the students!

Winnewisser:

That's right, I believe it. It's certainly part of the teaching tradition in physics now in Germany.

Herzberg:

It is now, yes.

Winnewisser:

I didn't realize that that came later.

Herzberg:

Oh yes. You need it, of course.

Winnewisser:

It's very valuable. It was certainly important in my education.

Herzberg:

I had to set exam papers in Saskatoon, you see. When I was first there I had a tough time setting these exam papers, but I decided I'd ask some simple questions in the exam, in an elementary class, you know. I don't refer now to the mechanics class but to just Physics 2, as we called it. I asked such simple questions: what is a dyne? A unit of—and you can imagine the difficulties that students had to answer that simple question. My colleagues to whom I showed this, we sort of compared our notes for exams, you know—they were rather raising their eyebrows that I had such trivial questions in it!

Herzberg:

They had only problems.

Winnewisser:

That's all they were trained for?

Herzberg:

In the exam, you see. No descriptive questions, I mean, "describe such and such" or this kind of thing.

Winnewisser:

I'm sure it was a good thing for them to have this component of their education in Saskatoon.

Herzberg:

Where shall we start?

Winnewisser:

Probably your stay in England. We can come back to Göttingen if there's something we skipped over.

Herzberg:

Yes, OK. Well, it was actually due to Lennard-Jones who was visiting Göttingen for six months, and with whom I had a fair amount of contact because he was quite interested in my ideas, in fact my "Habilitationsschrift" was about molecular orbital theory. He was writing a paper on molecular orbital theory, and found that I was on similar lines to what he had to say, so he suggested that I should come on another postdoctoral fellowship, to Bristol where he was the theoretician, and I accepted that offer. I don't know whether I foresaw the fact that eventually I would end up in the English domain. At any rate, it turned out to be very useful for me to be fluent in English for my later work on this continent. And it meant actually that when I came to Saskatoon I could start lecturing the first day.

Winnewisser:

It also gave you an acquaintance with the Anglo-Saxon culture, if you like.

Herzberg:

That's right.

Winnewisser:

Did you find differences in Bristol from Germany?

Herzberg:

Oh yes, there certainly were! Well, there were substantial differences, I would say. You had to dig a little deeper if you wanted really to find the evidence of different attitudes to life and all this kind of thing. I soon got acclimatized in Bristol, and indeed, I got married from Bristol, at the end of that year, which was 1929.

Winnewisser:

Oh, we did skip something important in Göttingen. This is where you met your wife.

Herzberg:

I met my wife in Göttingen, that is correct, in a seminar with James Franck. She came from Nürnberg, and was studying physics. She didn't finish her studies before we got married, but did so later. In fact, in Darmstadt. For various reasons, she couldn't take her degree in Darmstadt while I was "Privatdozent."

Winnewisser:

I was wondering about that, because I noticed her degree was from Frankfurt.

Herzberg:

Yes, the degree was from Frankfurt. It was just at the last moment, so to speak, before the Nazis closed the situation completely, that she could get the degree. In fact, her examiner was K. W. Meissner, an atomic spectroscopist, a very well known one at the time, who in fact was in a very similar position as I was. His wife was Jewish. But he had no difficulty at that time because he had a full professorship, and they couldn't fire legally without a new law the people who had Jewish wives. But I was only a Privatdozent and lived from my salary as an assistant, and therefore my contract was simply not renewed, so I had to leave in '35. Meissner I think only left in about 1937. He went to Purdue University, where I met him a number of times. He also visited us here in Ottawa.

Winnewisser:

So your wife got her degree around '33 then?

Herzberg:

No, no, it was after the Nazis came, so it must have been in '34, maybe as later as the beginning of 1935.

Winnewisser:

It was obvious to you then that it might become impossible for her to get the degree.

Herzberg:

Oh yes. It was just touch and go. But she did get the degree.

Winnewisser:

OK. So while you were in England then you came home to Germany to—

Herzberg:

—get married.

Winnewisser:

And you took her back to Bristol with you.

Herzberg:

Yes, that's right. Actually she had much earlier been on this continent, because she had some relatives over here, so that her English was actually better than mine.

Winnewisser:

So she had no difficulty in Bristol then.

Herzberg:

No.

Winnewisser:

She also worked in the laboratory there?

Herzberg:

Yes. One thing that she tried in Bristol at my instigation was to try to find a spectrum of C2+, and that has only really recently been properly found. Here in the lab, we tried again, and one of the postdocs got a spectrum but it didn't involve the ground state. We didn't know that at the time, but the ground state spectrum has only been discovered a year or so ago.

Winnewisser:

Another idea that was before its time.

Herzberg:

Yes. We tried quite a few things, and I'm still doing that sort of thing, not with very significant success, but I feel that I can afford to spend some time on projects that are risky in the sense that they might not lead to any positive or worthwhile result. That's what I'm doing at the moment.

Winnewisser:

Indeed, you can afford to do so. Certainly past events show there is no reason to doubt that you might find these things.

Herzberg:

Well, we'll see.

Winnewisser:

So in Bristol then, you were working with Lennard-Jones: but he was a theoretician.

Herzberg:

The head of the lab was really A. M. Tyndall (no relation to the Tyndall of the Tyndall Effect), a very fine person. But I was again really on my own, because there was no person there interested in spectroscopic things as I was, in molecular spectroscopy. There was one person whose name you may have come across, that was Skinner. Indeed, this man Skinner, he was a real experimentalist. I think he got his degree in Cambridge. He was a lecturer or something like that, and he was sufficiently interested in what I was going to do to design a two meter vacuum grating spectrograph. I didn't have anything, I didn't have to spend any time to get that done, and he got it done in a fairly quick order.

Winnewisser:

This was a grating spectrograph?

Herzberg:

A grating vacuum spectrograph, yes.

Winnewisser:

So this was your first contact with the grating spectrograph?

Herzberg:

Maybe it was. That's right. That was my first contact with grating spectrographs. You're quite right. And so I think there are a number of things that came out of that work, like the spectrum of P2. Another thing was CP. Another molecule on which more recent work has been done. The vacuum ultraviolet work was really only this here, I just noticed, the ultraviolet absorption spectra in acetylene and formaldehyde. Which I think was done for the first time there. At that time, 15N just been found, spectroscopically, by King and Birge, I think it was. And I got some fairly strong spectra of nitrogen, and lo and behold, 15N was very obvious there, so I wrote a little note about that, because it wasn't generally known. Well, I mean, in new surroundings one couldn't expect too much, but I felt quite happy about that year in Bristol, and certainly the facility it gave me in English was invaluable. Invaluable.

Winnewisser:

Was there a difference in the way the laboratory was run, or life in the laboratory?

Herzberg:

Well, I can't really remember any specific thing. It certainly was different. The freedom that was there was much the same as in Darmstadt at that time. One thing that we didn't have in Darmstadt was a regular tea every afternoon, where most of the people in the lab would come in. There was the porter, or the lady at the front door, she prepared the tea, and everyone would come around to that area and have tea, and that I thought was a very good invention, to get people together and get them talking. We had that here until they started rebuilding what I might call the tea room. It isn't really meant for that.

Winnewisser:

So you learned to appreciate this communication?

Herzberg:

Yes, later on I think they had the tea actually in another room, but anyway the tea was always an important function in England, and this lady, I don't know really what her main job was, she prepared some sandwiches and things that one could eat. As far as I know it was without charge. I don't know who paid for it! But it was a very nice atmosphere, and I think it was helped by the fact that a number of people from the Continent came over. I don't know whether it was before me that, from Basel, Wehrli came over, and then Max Delbrück went there also, you see. We must have overlapped, because I remember he was there. He was very good friends with this man Skinner, and so there was a good atmosphere.

Winnewisser:

Was there an interplay between the theoreticians and those who were in experimental work?

Herzberg:

Oh yes, I think so. There could have been more, but I think it was fairly good. Of course, this was the early time of the development of theoretical molecular theory and all this, it is now so that you couldn't possibly understand a paper in that field unless you worked very hard. But at that time it was still possible. That was the time shortly after Heitler and London, and London was there for a visit at one time, and Mott was there, I learned to know him. And many other of the British physicists.

Winnewisser:

As visitors.

Herzberg:

Yes, as visitors.

Winnewisser:

Lecturers?

Herzberg:

Not so often lecturers; sometimes lecturers, but mostly sometimes just visitors. It was not very far from London.

Winnewisser:

You mentioned here that while you were there, you went to Cambridge and visited the laboratory of Blackett.

Herzberg:

Yes. I had a letter of introduction from James Franck to Blackett. You know, Blackett and Franck once published a paper on hydrogen, H2. I went to Cambridge, and I saw Blackett, but he was a busy man at that time; he referred me to Oliphant, the Australian physicist who spent a lot of time in Cambridge but later went back to Australia. This was just at the time before the first artificial disintegration by protons. Cockcroft and Walton were just setting up their equipment, and I met Cockcroft and Walton at that time, and they were all young men like all young men like I was; so was Oliphant. Much later Oliphant for a while was governor general of Australia, you know. He was an interesting man.

Winnewisser:

Was this just a one day trip up to Cambridge, or did you stay several days?

Herzberg:

I think it was more than a day. But I wouldn't be able to tell where I stayed.

Winnewisser:

Another contact you mentioned in your written report here was Asundi.

Herzberg:

Oh yes. When I first went to Bristol, it was just the time when there was a meeting of the Faraday Society and at that time the meetings of the Faraday Society were particularly good and well organized, and just a few days after I arrived in Bristol there was this meeting of the Faraday Society. At that meeting I met Raman and I think I mentioned this in the printed version you have. The first speaker was O.W. Richardson, and he was a mumbler. I didn't understand a word of what he said, both because my English was still rather poor, and because he was mumbling. And I don't know who the second speaker was but very soon after, Raman came on the podium and gave a lecture, and he was an extremely good lecturer. I could understand every word he said, and he was quite interesting. I met Raman, and Raman asked about this work with Heitler on the nitrogen nuclei. He was quite interested in that. So I had several chances to talk with him, and I was really very much impressed by his personality. As a consequence, when I went to India much much later, in the fifties, I went down to Bangalore, where he had his lab, and he was active on things like diamonds and fluorescence of crystals and many things. He came to see me at the hotel each evening, for three successive days, and I had quite a good time with him. And among other things - it was in the evening, you see — he said suddenly, "Have you ever seen the zodiacal light?" Now, I knew of the existence of the zodiacal light but I had never seen it. I said, "No." "Well, you come with me," and he took me in his car, a chauffeur-driven car. We went out into the country where it was dark, really dark. And there was the zodiacal light, no question about it, we saw it beautifully, which impressed me not only because I had never seen the zodiacal light before, but also because it showed that Raman was really interested in physics and interested in educating people to physics, or educating physicists! But one thing he did not do, which disappointed me, if you like, he never showed me his famous collection of diamonds.

Winnewisser:

I've read about that collection.

Herzberg:

He showed it to many people, but not to me. Whatever that means!

Winnewisser:

Maybe he thought you were only interested in the gaseous phase.

Herzberg:

That could be, yes. That's a very nice excuse. So while we are on Raman, maybe I could just mention other contacts with Raman. Later when I was on my second or third visit to India, there was a meeting of the executive of UPAP. At that time, Bhabha was the president of the physics union, UPAP, and he invited the executive to come to Bombay, and we had a very interesting visit there. I also saw of course, I saw Asundi, whom I had met in London while I was at Bristol, and he said, "Raman will be in town tonight giving a lecture. Would you like to go and hear him?" And I said, "Yes, I would certainly be interested." So we went to listen to Raman who was lecturing on fluorescence or something like that. As I said before, he was a very good lecturer, and the people liked it very much. After the lecture, we waited around, and there were a hundred students or more who wanted his autograph. They surrounded him. But pretty soon he discovered us in the background, and he came over and pushed off the students and we had quite a lengthy conversation there. This was very much later, long after I had been at the Yerkes Laboratory and had my office right opposite to Chandrasekhar's office. At the time it was not clear to me that Chandrasekhar was a nephew of Raman's. Chandrasekhar's father was a brother of Raman. I was really almost touched by the fact that I had known Chandrasekhar for quite some time and he told me a lot about Raman, you know, but he never mentioned that Raman was his uncle. Perhaps I should also tell the story which indeed Chandrasekhar had told me before my encounters with Raman on these Indian trips. When I was in Bangalore Raman told me himself the story about his Nobel Prize; he had been elected to the Royal Society of London in 1924 on account of his work with violin strings, the sounding of violin strings, or some such work in acoustics. He told me that he was then at the University of Calcutta, and the university had arranged a dinner in his honor on the occasion of his election to the Royal Society. He was obviously sitting right next to the vice chancellor, who was, so he told me, complimenting him on this wonderful honor that he got, and Raman said to him, "Mr. Vice Chancellor, it's really nothing. The only honor worth having in science is the Nobel Prize. And mark my words, Mr. Vice Chancellor, in five years I will have it!" "Well," he said to me, "I should have got it in 1929 but I only got it in '30, because Rutherford wanted Richardson to have it first." I heard that story both from Chandrasekhar and from Raman himself. I had a bit of a feeling that it's not the right attitude toward the Nobel Prize! I have found actually that Indian scientists have a somewhat warped idea of the importance of the Nobel Prize. Indeed, before I made my first trip to India, in 1956, was it? It doesn't matter. I had a large letter from an Indian person, with a manuscript in it, and it said on the manuscript "For your nomination to the Nobel Prize," meaning that the author wanted me to nominate him for the Nobel Prize. I had never heard of him before. Well, the paper was obviously crackpot stuff. He had some funny things on his plate which wasn't even a photographic plate, and he thought that was a big thing which should receive the Nobel Prize. This was before I went to India, and then I went to Calcutta. One day I was in Calcutta, in my hotel, there was a call for me, and a voice said, "I am Mr. So and so and I would very much like to pay my respects to you." I said, "Come tomorrow evening at 7 o'clock," or something, I said. It so happened that I was in my hotel room at 7 o'clock the next day, and there was a knock at the door, and a man comes in and says, "I'm So and so and I wanted to show you this paper again." And lo and behold, it was the same paper I had received 2 years or so before in Ottawa! I tried to get rid of him as fast as I could. That's why I say, there are some people in India who think the Nobel Prize is everything, whether it's good or bad science doesn't really matter, it's the Nobel Prize.

Winnewisser:

Maybe because of the tremendous prestige that was brought to Indian science by Raman, and his Nobel Prize.

Herzberg:

Exactly. But even Raman's attitude to the Nobel Prize, to my mind, wasn't quite right. I mean his attitude before he got it. I mean, you can wish for getting the Nobel Prize in your heart, but you don't have to tell other people!

Winnewisser:

He was not known as a modest man, apparently.

Herzberg:

No, I don't think you could say that of him. And indeed there are other things against him. Apparently he didn't treat his sons very well. For a while his sons were forbidden the house. They had to meet secretly with his wife—their mother. Things like that, you know. I've since met one of his sons at a meeting. He is a radio astronomer, a very nice person, very interesting to me.

Winnewisser:

Your Indian contacts have been quite fruitful, then?

Herzberg:

Oh, they have been. Certainly Asundi was a very fine person. He would never have said what Raman said about the Nobel Prize. Certainly Asundi really understood spectroscopy. His contributions were not overwhelming, but he had some good papers, and he is really responsible for the fact that a very good group on molecular spectroscopy was established at the Bhabha Institute. In fact, on various occasions Bhabha asked me what I thought of Asundi's work and so on, because he wasn't quite sure that he wanted such a group. But Asundi helped actually the atomic energy group very substantially by using molecular spectra monitoring the isotope separation, and they had very good isotope separation in Bombay at Trombay.

Winnewisser:

Yes, they have obviously maintained a strong molecular spectroscopy group.

Herzberg:

So far, yes. I knew the successor—Asundi was never in charge, but he was—well, he had much the same position as I have as far as this lab is concerned. I'm not in charge! But Asundi at that time, insisted that Narasimham, a very competent spectroscopist, was put in charge.

Winnewisser:

I've seen the name.

Herzberg:

Narasimham was certainly a very capable spectroscopist, there's no question of that. After him was a chap by the name of Krishnamachari. He has just retired about a year or so ago. I don't know the successor.

Winnewisser:

The head of the spectroscopy division is now Kartha.

Herzberg:

Yes, that's the name.

Winnewisser:

He was here at the NRC in Ottawa I believe for a visit a few years ago.

Herzberg:

Yes. So how well this will go ahead, I don't know. Such changes take place. They may be connected to other changes.

Winnewisser:

You met Asundi at Bristol?

Herzberg:

He was in London where I first met him. He was actually getting his PhD with R.C. Johnson, and that was at King's College. And of course, my connection with King's College later on was very important because John Spinks came from King's College, and he was the one who got me to Saskatoon, and Mr. Soosmith, my technician for twenty years, came from King's College. So King's College was quite important for me.

Winnewisser:

Your brief visit there during your year in Bristol was the basis for this contact?

Herzberg:

At least I was aware of King's College and I knew whom to go to and talk to and so on.

Winnewisser:

Well, that's actually one of the interesting threads in this story. Such contacts can be. Well, perhaps we should leave the Bristol period now and come back to Darmstadt at the end of your year in England. This was just one academic year.

Herzberg:

One year. I think it was 13 months.

Winnewisser:

And you had already submitted your "Habilitation"?

Herzberg:

Actually the "Habilitation" took place while I was in Bristol. I went to Darmstadt for the purpose.

Winnewisser:

For the formal lecture.

Herzberg:

Yes.

Winnewisser:

So you could take up your duties as "Privatdozent"?

Herzberg:

Yes, if there are such duties!

Winnewisser:

You offered a lecture.

Herzberg:

I offered a lecture.[4] Sometime later when the Nazis were already there, Professor Baerwald whom I mentioned earlier had been relieved of his" Lehrauftrag. He was not fully a "Beamter" he was not a full professor or even what you call a "Planmässiger Ausserordentlicher Professor." (There are two kinds of ausserordentliche professors, or there were at the time, one "planmässig" and one "ausserplanmässig" the latter one only a title.) Baerwald earned his living, so to speak, by being asked to give a course in theoretical physics, and that was repeated every year. But when the Nazis came, this was stopped. And I was asked to substitute until they found a successor. Which was good for my soul to learn classical theoretical physics, you might put it that way, but I did that only for one year or something like that. I think I was paid for the Lehrauftrag, I don't remember whether that was anything substantial.

Winnewisser:

So you had several years in Darmstadt before the Nazi takeover began to overshadow things.

Herzberg:

Yes, I had three years. I came back in 1930, and the Nazis came in January '33. In '34 John Spinks came to Darmstadt. He had written in 1933. Because the University of Saskatchewan was in very poor straits—it was the Depression time—and they didn't know how to pay the salaries, so they called together all the faculty members who were young and unmarried, and told them, "Here, you get $500, take leave of absence for one year, good-bye." I don't know how many were involved, but John Spinks was one of them. He wrote to me in Darmstadt, whether he could work with me, and of course I'd never heard of him, I'd never heard of the University of Saskatchewan, for that matter, never heard of Saskatchewan! And so I wrote actually to Professor Allmand, with whom he had worked at King's College, asking what he thought of Spinks. The answer was very encouraging, so I said to Spinks "Please come." He had his own money, 500 whole dollars, with him, and he had a good time.

Winnewisser:

And that was the beginning of another story, then.

Herzberg:

Yes. At the time we lived in rented rooms with a Jewish family by the name of Juda who owned a fairly big house. It so happened that they were able to rent another room to John Spinks. So we had a fair amount of contact with him all along this year that he was there.

Winnewisser:

So you fed this bachelor every now and then?

Herzberg:

Yes.

Winnewisser:

And discussed things?

Herzberg:

Yes. Of course, at that time we didn't even know what was going to happen. Anyway, when he went back, he made a little propaganda, so eventually, I had this offer from the Carnegie Foundation. It was even more complicated, because the Carnegie Foundation had offered to Canadian universities to support a refugee scientist for two years, as a guest professor, and then the university would be asked to at least consider whether they could take him over on their own budget. And that's what they did in Saskatchewan.

Winnewisser:

How did things develop in Darmstadt as the Nazi problem became more and more intense? You've said that Professor Rau did his best for the people, where he could offer some protection. Was there any effort at rejection of these policies, or was there a conflict in the university?

Herzberg:

Well, it's a terribly long time ago, and I don't know whether I could answer the question properly if I understood it right. But you mean, whether there were...?

Winnewisser:

My question was worded rather vaguely. I was trying to see what you might indeed remember, if you hadn't chosen to forget it in any way, it is for this generation of course difficult to see how it could happen that step by step people who were Jewish were forced out and then you were forced out, and then even the full professors by '37 were forced out. And even people of integrity like Professor Rau were just left standing there.

Herzberg:

Yes. Well, for them it was a particularly terrible time. I remember we knew quite well another "Privatdozent" in geology, by the name of Jüngst. He was a member or had been a member of "Stahlhelm." I don't know whether you know the history well enough to appreciate that at one time Stahlhelm and the Nazis went together.

Winnewisser:

I've heard that they were originally competitors, and then that the "Stahlhelm" was absorbed by the Nazis.

Herzberg:

Something like that. But this man, Jüngst, was absolutely shocked by all these things, and he was actually killed in action during war; he was conscripted into the army and at the beginning of the war. In 1979 the physics department in Darmstadt had arranged a little Festkolloquium in honor of the 50th anniversary of my "Habilitation" and on this occasion, the widow of Dr. Jüngst was there, and we met her. (My present wife had, of course, never met her before). Which I found quite touching, because they were also of course terribly upset by the whole development, because while they were against Socialism, they were not Nazis.

Winnewisser:

Your wife got her degree, just barely, you mentioned. Was she able to continue to work in the laboratory in Darmstadt?

Herzberg:

That still was all right, particularly with Rau as the head of the laboratory. There was never any question of that up to the time we left. I did actually also take a precaution, in that I bought some optical parts, prisms, for a spectrograph that then was built in Saskatoon.

Winnewisser:

—What did you bring with you, some prisms?

Herzberg:

Yes, prisms and the lenses for the collimator.

Winnewisser:

Specifically the optical parts?

Herzberg:

Yes, optical parts. For the rest, they had a reasonably good shop and a good man in the shop in Saskatoon. There were only two people or one person in the shop. But there was no difficulty for me to buy these things at the time. This is what I wanted to say. Indeed, there was a, how shall I put it? It was like a "Tarnkappe" that is, I was going on a guest professorship, you see. In their eyes I was spreading the gospel of pan-Germanism really! So when the customs people came to our house to check what we were sending over, of course we had to explain about these optical pieces. But there was absolutely no trouble about that. Because I was guest professor. Indeed, the consul in Winnipeg afterwards wrote to me and wanted me to act as a "proper German!" I never answered his letter.

Winnewisser:

This allowed you to take the most important things with you, then.

Herzberg:

Yes. There was no problem. Of course, we didn't have much. A "Privatdozent" hasn't much. Except that my in-laws of course were at one time quite well-to-do and they could help in our taking a few more things along than we would otherwise have taken.

Winnewisser:

Well, from the side of the students at the university, was there any unpleasantness that you were exposed to?

Herzberg:

No.

Winnewisser:

Active Nazi students?

Herzberg:

Well, there was one thing. It was not an unpleasantness, but I had one very good student by the name of Gradstein and he was from Poland and Jewish, so he was doubly marked. He worked in fact on the fluorescence of formaldehyde. I had one paper on this with a previous student, and then Gradstein who did really what might be called the final work as far as we were concerned on the subject. The original intention was that we would have this as a joint paper. But at that time, Rau considered it wise not to put my name on there. The paper was published in the Zeitschrift für Physikalische Chemie.

Winnewisser:

This was a protection of your name really, then?

Herzberg:

That's right. "Jüdisch versippt" [was my category].

Winnewisser:

Oh yes! But the journal was willing to publish a paper by a Polish Jew?

Herzberg:

At that time there was no question of that. Apparently. At least I never heard of any. Gradstein had quite a bit of bad luck at the beginning. He found a job actually, this man Gradstein, with Phillips in Holland, in Eindhoven and then he fell ill with tuberculosis. The Phillips Company (he had only been there for six months or something like that) sent him to Switzerland to a sanatorium, and he was well again after two years or so. Then he went back and took up his position at the Phillips Company. But then the war came, and the Germans marched in, and I never heard from him, and so I wondered what had happened to him. But it turned out he survived, because he in the meantime had married a Dutch girl, non-Jewish, and the family hid him and they survived. I saw a fair amount of him after the war when I first went to Europe, and I was very pleased when I found that he had managed to survive. He ended up as the editor of the Phillips Review, a magazine that the Phillips Company published with semi-popular articles, but not quite popular articles. And he was a good editor.

Winnewisser:

His education in your laboratory was not in vain, and your efforts, in any case.

Herzberg:

Yes, that's right.

Winnewisser:

John Spinks was one postdoc. Did you have more people coming from other laboratories to work with you?

Herzberg:

Yes. Indeed, there was another interesting connection. My first postdoc in Darmstadt was a man by the name of Woo. "W-o-o" was his spelling, or if you like, it's English spelling. He had been working at Caltech as a postdoc with Badger, and you might recognize the name. So he was reasonably well recommended, and he came to Darmstadt to work with me. That was before the Nazis came. Unfortunately I was not very lucky in the subject I chose for him. It was about CS2. It was the first work with a long path absorption tube, and he did quite a lot of work with that, but nothing was ever published on that, I'm sorry to say. I kept in contact with him, until things happened either in China or in Germany. I don't quite remember now the details of this history. In China the Japanese were marching, you see. So I didn't hear from him, and I thought he was long gone, until shall I say six years ago.

Winnewisser:

After the Cultural Revolution?

Herzberg:

Yes, after the Cultural Revolution. And I found out that Henry Mantsch of NRC had a request from China for a person to work with him, and it turned out that this person was the son-in-law of this same Woo that I knew. I hope I have this straight, but it doesn't really matter. There was this kind of connection. And when he found out that there was this connection, that I was here, I got a very nice letter from him. Eventually it ended up in an invitation to come to China, and that's the reason we went to China. And we did, he was in Chan-Chun in Manchuria, and we had quite an interesting trip in China.

Winnewisser:

And you met the senior Woo then?

Herzberg:

Yes. Indeed. He survived. With difficulty.

Winnewisser:

Was he in a university or a research institute?

Herzberg:

That was a research institute of the Academy. During the Cultural Revolution, he was very badly treated and mistreated. He lost one eye and other things. He told quite a few stories. He was forced to clean the toilets and this kind of thing. But after the Cultural Revolution, he was re-installed as the director of this institute.

Winnewisser:

So he's the director of the institute.

Herzberg:

Yes. Well, he died three years ago, I think, one or two years after we had visited him. So I was really quite happy about our visit in China.

Winnewisser:

Yes, I'm sure, I can see that.

Herzberg:

It was quite interesting. It was also one of the few times that we were actually in the home of somebody in China, which at that time was still very rare. As a matter of fact, Woo also asked one of his senior people to come with us on the rest of our trip through China, and he did, and for us, the embarrassing thing was that we thought, well, we'll go to Shanghai, shall we say, and obviously we have supper together. No way. Breakfast together. No way. Apparently, the supposed reason was—which was only mentioned by other people who were surmising that—that our meals are very expensive, but the Chinese could live on meals of only one-tenth the expense of what we were having.

Winnewisser:

He was only given a limited traveling budget for this task.

Herzberg:

I mean, he was of the type of a senior research officer around here, it was somewhat embarrassing that we should not be able to ask him to join us. We would gladly have paid for him.

Winnewisser:

But you weren't sure how far to push, of course.

Herzberg:

Quite. No, we didn't want to embarrass him, you see. I wouldn't have minded to embarrass the bureaucrats!

Winnewisser:

That's different, yes. So Woo came after being in the United States?

Herzberg:

He came to work in Darmstadt, yes.

Winnewisser:

So your laboratory in Darmstadt was already indeed quite well known.

Herzberg:

Yes. Then there was another postdoc by the name of Funke from Sweden. He was a very good man. He worked on the photographic infra-red spectrum of acetylene, and had quite nice results. Then for some reason he was anxious to have this paper on his own, and I didn't insist that I have my name on it. It was intended originally to be a joint effort. Anyway, he was another one. Then there was still another one, and that was James Curry. He was from Williams College in Massachusetts. And I don't know why he came to me, but at any rate he did, and he was quite an interesting man. We have, I don't know, we have more than one paper, but one paper I remember was about oxygen. One of my favorite molecules. This was about the Schumann-Runge bands of oxygen, for the first time under higher resolution than had been done up to that time.

Winnewisser:

This was with your Wood grating.

Herzberg:

Right, the R.W. Wood grating. But the new point in it was that we had found a method by means of part of a cylindrical lens to separate orders, and so we could take this spectrum with a continuous background in the third order of the three meter grating that we had from Wood. Up to then, people had never worked in that region in any but the first order.

Winnewisser:

And then they didn't get as much dispersion as you were getting in the third order.

Herzberg:

Yes, right, and resolution. Well, it wasn't a world-shaking paper, but I think it was the first step toward a better understanding of the Schumann-Runge bands of Q2. Six months ago or so, I got a paper from Dr. Lewis in Australia, maybe a year ago, about the same spectrum, but now taken with a much higher resolution than we had.

Winnewisser:

Well, that's fair enough nowadays. There's one name and project that's in here, the predissociation of N2 with Büttenbender, a graduate student.

Herzberg:

Yes, he was a graduate student, and he was my last graduate student in Darmstadt. He was really a school teacher, and he had come to the university to get his Doktor's degree, and he did get it.

Winnewisser:

And did he go back to teaching?

Herzberg:

He went back to teaching, as far as I know. But I had no contact with him after the Nazi business was over so I don't know what happened to him.

Winnewisser:

Is there some record of your students? You must have some list. Or would that be in Darmstadt I suppose in the formal student records?

Herzberg:

Until not so very long ago, I kept the theses that the students wrote, but I'm not sure whether I could find them now, after all these moves and after the condensation in order to accommodate all the journals, whether they have remained. Büttenbender's, of course, was a joint article, a joint paper in the Annalen der Physik.

Winnewisser:

OK, that was published.

Herzberg:

And I think I was in that case justified in insisting that my name was on it, because Büttenbender was not the kind of top student who would run away with a subject and do on his own what I wanted to do! I picked one of our previous postdocs, John Johns, and offered him the job, you see. Alec Douglas told me later that he was very apprehensive, because he wasn't quite sure whether John Johns was a good enough man. But it actually turned out, he was too good for the job. When I was on a trip and came back, he'd done the job! And that was no good for me, you see, as far as the original aim of having him was concerned. But fortunately we could keep him on the staff, because at that time we were not so limited as we are now, and so there he is where he is, he's now the section head! But I mean, he was obviously too good a man for just being a helper of me, and would publish together and this sort of thing. Well, we published actually two papers together, you know. On BH2 and CH2.

Winnewisser:

I remember the CH2 paper.

Herzberg:

The other one was published in the same year. So that was certainly worthwhile undertaking, but I felt almost embarrassed to put my name on it, because he went too fast!

Winnewisser:

That's a nice kind of problem.

Herzberg:

Yes.

Winnewisser:

Were there any other students or projects that we should talk about? Well, your long cell. In every laboratory you had, you built a longer and longer cell.

Herzberg:

That is right, yes. Well, in Darmstadt, I was of course a complete newcomer and nobody had built a long cell except possibly Mecke who was at the time doing his experiments in Ludwigshafen at BAS-F. I think he had made some arrangements with them. He was actually teaching at Heidelberg and he had made some arrangements with BAS-F to do these experiments there, and he had a long path, but I think that was after I had started it, actually, and I had the idea. I thought of gases, and you have to have a glass tube. I had glass tubes about 8 cm in diameter in sections, and the whole thing was 12 meters long, in the basement of the physics building in Darmstadt, and the light would go if I stand in front of it, from there in and back.

Winnewisser:

Double pass.

Herzberg:

Double pass, yes. That is all I could think of as feasible. And with that I discovered—I mean, I wanted to do many things. For example, when Dr. Woo was there, CS2 was one of them, but before that was done, I think O2 (Oxygen) was the first one I put in. And I thought I knew what might come out. And I remember, I took long exposure times, with this quartz spectrograph built in the shop, you know, no grating, and the plate was exposed, and for some reason or other, I had to leave, so I couldn't develop the plate, and the next day I developed the plate and lo and behold, there was what are now called the Herzberg bands of oxygen. I had a little bit of a—how should I say, discussion or quarrel, if you might call it with—do you know the name Finkelnburg?

Winnewisser:

I know the name, yes.

Herzberg:

He had, together with a man by the name of Steiner, done absorption experiments in oxygen at high pressure in short tubes, you see. He had told me about that, before I did my experiments. They had found some absorption in the region around 3000 angstroms. But I had somehow conveniently forgotten that, and when I found my band system, which had nice fine structure and everything. I was quite enthusiastic about that and published it, without mentioning Finkelnburg and Steiner. Well, it turned out later that what they had was something different from what I had. They had a spectrum that you might call of O4. Because they had high pressure. And I had a spectrum of O2. I don't want to go through the details, but that was the final outcome of that. Their spectra were different also in type because they had triple peaks. There were a number of bands, the same kind of spacing as my bands, but they had triple peaks, and mine consisted just of single Q branches, one head each. But it took me quite a while to appreciate that and to convince Finkelnburg that I was justified.

Winnewisser:

He soon saw the difference in the two spectra?

Herzberg:

Well, it took quite a fair amount of time. Oh yes. It did. Later I took spectra at Yerkes Observatory, where I had another long tube (we'll come to that later), and it turned out I had both the analog of Finkelnburg's bands, in O2, namely, the triplet delta state of oxygen, therefore three peaks, you see, as well as the—my new bands if I may call them that, on the plate, so that there could be no more question left that there were two different things. The triplet delta ones occurred also with O4 for some reason that I can't explain at the moment. But the triplet sigma bands occur only in O2, and they are quite important actually for the production of ozone in the upper atmosphere. Very important nowadays.

Winnewisser:

Indeed, yes.

Herzberg:

I think it was actually Mecke who pointed out to me the importance of the continuum of this spectrum—I had the discrete bands, and the continuum was presumably there but I couldn't really see it very well. It was only found later by people who went further into the ultraviolet. But it also gave a very definite value, or confirmed the value of the dissociation energy of oxygen. But that was one of my, I would say, my proud moments, when I saw this spectrum of O2 in this region.

Winnewisser:

You mentioned this was done with the prism.

Herzberg:

Quartz prism spectrograph, yes. Yes, home-built. But modelled according to Steinheil.

Winnewisser:

This was before you got the grating, then.

Herzberg:

—yes.

Winnewisser:

Coming from the oxygen then, I read here your account of taking the sun and taking the photographic infra-red spectrum of the sunlight into your 3 meter grating spectrograph—

Herzberg:

—right—

Winnewisser:

—and using the new Agfa infra-red plates. These were very special—were these plates developed in response to the needs of the scientists, the spectroscopists?

Herzberg:

Well, I don't know whether they were, whether it was in response to the spectroscopists.

Winnewisser:

How did you get hold of these?

Herzberg:

Well, I had apparently established somehow good relations with the Agfa Company. And they were making these ordinary infra-red plates that go up to 8000, 9000 angstrom but then they became interested in that and tried to go further down, and they managed to get what are now called "Z" plates of Kodak. I don't know what the Agfa people called them, but at any rate, they are reasonably fast only up to 10,500 angstrom but if you have the sun as continuous background, and expose long enough, then you can go all the way up to 13,000 angstrom. And I did. And it's still the limit. Nobody has gone photographically beyond or even repeated the work at 13,000, and they don't need to because now there are good infra-red spectrometers that do much better. But at that time and for a long long time afterwards, that was the only high resolution work in that region, and I found the singlet delta state of oxygen there. Of course it had been predicted by Mulliken and suspected to be there by Ellison and Kneser but they had a little tiny peak which they thought might be this singlet delta transition, but here was the whole spectrum of singlet delta with all the details that you could imagine. There was absolutely no question that the upper state of these bands was singlet delta, and the lower state the ground state of oxygen. So I feel that the singlet delta state of oxygen was discovered in this way. Experimentally, I mean; it was predicted before.

Winnewisser:

This was the first real experimental observation of it.

Herzberg:

Yes. Incidentally those plates were taken along to Saskatoon, and the final evaluation was only done there. I mean the evaluation in detail. There was a note in Nature about it from Darmstadt just before we left there.

Winnewisser:

It's one of many plates that you took with you?

Herzberg:

Yes. That's right. If the Nazis had known that, they probably would have smashed the plates!

Winnewisser:

You mention here a meeting in 1931 in Leipzig that Peter Debye had organized on molecular structure.

Herzberg:

Oh yes. The "Leipziger Vorträge." I saw a copy over there just a moment ago.

Winnewisser:

Certainly what we are still living on in the transitions probabilities and so forth, much of that was worked out then in some detail. Amazing, so fast, in those few years.

Herzberg:

Yes. But I talked there essentially about my Habilitationsshrift.

Winnewisser:

"Elektronenstruktur der Moleküle und Valenz"

Herzberg:

Yes.

Winnewisser:

You mentioned the distinction between bonding and anti-bonding orbitals?

Herzberg:

Yes. In that way, I think I introduced that, but that's my only contribution really. I never worked out the theory in more detail or anything like that, it's not really a theoretical paper, but I'm still quite satisfied with it.

Winnewisser:

"Bindende und lockernde Elektronen." It apparently has stayed part of the vocabulary.

Herzberg:

Yes. And Lennard-Jones who was a real theoretician, you know, he made use of it, I was pleased to find.

Winnewisser:

That's a valuable little volume (Leipziger Vorträge).

Herzberg:

Yes, that's quite an interesting volume, historically at any rate. There are perhaps quite a few other things around here, but they're hard to spot. It just happens that I looked at it this morning, I wanted to put something away and I saw this volume there, and I knew how it looks.

Winnewisser:

You mentioned Mecke, Placzek and Hertha Sponer

Herzberg:

Yes.

Winnewisser:

And Heisenberg and Teller were also at this meeting, right?

Herzberg:

Yes, that's right. That was really my first look at Heisenberg. I'd never met him, how shall I say, very closely.

Winnewisser:

You'd both been at Göttingen but not at the same time.

Herzberg:

That's right. There's one interesting item perhaps historically. During the time I was in Göttingen, there was a meeting of the German Physical Society. This was, I remember still, in the lecture room that Pohl had for his big lecture. At the same time, there was also Leon Rosenfeld, I don't know whether you know the name. He is really or he became a nuclear theoretician, but at the time, he had explained to me some topic. I probably could find out what topic if one looks at this book. At any rate, it doesn't really matter what the subject is, it's the personalities that I want to explain. Rosenfeld as you probably know turned out later on to be quite an authority. He was in Bohr's Institute, and very well known as a theoretical physicist. But at that time he was a young man, and at that time I think he was together with Witmer (the same one Wigner and Witmer, you know). They told me about some particular thing which I found quite interesting but I couldn't judge it because I'm not a theoretician. And then at this meeting, after one lecture, I was standing there with Rosenfeld, at least I was observing. Rosenfeld was talking to Heisenberg about this same thing, you see, and Heisenberg listened and made some comments and then Pauli came along. Heisenberg tried to explain it to him and Pauli said, "Oh, forget this silly business," and took Heisenberg away. This characterizes just the difference between Heisenberg and Pauli. Pauli of course was a great physicist, and sometimes he could also be very nice, but he was also very rough. I remember another occasion with Pauli. I had given a talk at a meeting at the hundredth anniversary meeting of Rydberg in Lund. Pauli was there, gave a very fine lecture on the history, and I gave a lecture on my first attempt to get the Lamb shift of the ground state of the hydrogen atom, in the 1S state. The first result was that the effect was different from what was predicted, much larger or whatever. Well, I said so with all precautions and qualifications, but nevertheless, the next morning I ran into Pauli in the hotel lobby, and Pauli said to me, "Herzberg, it's experimental error." Just like that! And he was right! So he was certainly an extremely clever and deep physicist. But he also was the one who discouraged Kronig from publishing the idea of the electron spin. Before Goudsmit and Uhlenbeck published it. Kronig sent his paper to or showed his paper to Pauli, and Pauli said, "No, it's nonsense." And Kronig accordingly didn't publish the paper. Goudsmit and Uhlenbeck didn't ask Pauli, and published the paper.

Winnewisser:

Sometimes he was right but not always.

Herzberg:

That's right. Even he could make mistakes. Like we all can.

Winnewisser:

Oh yes. So Heisenberg was not quite so abrupt.

Herzberg:

Oh no. Not at all. He was a very friendly kind of person.

Winnewisser:

And Edward Teller, he's just about your age too, isn't he?

Herzberg:

He's somewhat younger, perhaps he's two years younger than I am. Well, at the time, I knew Teller fairly well. Of course Teller did some very remarkable things for molecular spectroscopy. He was the one who really knew what degeneracy means in spectroscopy. Remarkable, remarkable. And indeed, I have at home a biography of Teller written by two newspaper people, not a very good biography, but these people at the end asked him, "What do you think is your most important and satisfying work in physics?" And his answer was, "My work in molecular spectroscopy." Which I find rather interesting.

Winnewisser:

I'm sure that was interesting to you.

Herzberg:

Now, of course, Teller is all gone. I mean, SDI and all. Just terrible.

Winnewisser:

It's a different perspective of physics he's involved in now, yes.

Herzberg:

Having seen and heard Sakharov here in Ottawa, you know, we had Sakharov up here two weeks ago. Oh, you hadn't heard that?

Winnewisser:

I knew he had been in America, but our German newspapers didn't report that much about it.

Herzberg:

Well, he had come here, you see. He had a long standing invitation from a group in Winnipeg that I'm really not much familiar with, but he was also invited here in Ottawa. He was getting an honorary degree from the University of Ottawa, and actually our newspaper had invited him to some extent. They have a Russian-born reporter who is quite able, if you like. I don't particularly care for this reporter, but anyway, Sakharov was here. Sakharov also had the idea of the hydrogen bomb, within a month of Teller. But he knew what terrible things might happen. While Teller for some reason doesn't.

Winnewisser:

Did Sakharov talk about some of this history stuff or about the SDI?

Herzberg:

He didn't talk about SDI. Well, he may have answered some questions at the news conference, but no. From all that you read about Sakharov, I mean, he's a very remarkable person, there's no question of that. I had five, ten minutes with him. The trouble is he doesn't speak English easily. The only time he can speak English reasonably well is when you talk about physics to him. That's what I did, at the very end of his visit, for five or ten minutes. That is all I really had. But he is a great man if there ever was one.

Winnewisser:

It's remarkable, after the isolation he's been in for so many years, how he has stepped onto the world stage.

Herzberg:

Yes. Exactly. He's a most remarkable man.

Winnewisser:

Had you met him earlier?

Herzberg:

No. This is the first time.

Winnewisser:

Of course he was never out of the Soviet Union before.

Herzberg:

That's right. Indeed, I was in Moscow in the Lebedev Institute once, and my host was Professor Mandelstam who was the director of the spectroscopy institute. This was before Sakharov was banned to Gorki, and I said to my host Mandelstam, "I would like really to pay a visit to Sakharov." "Oh no, you can't do that. You are invited by the Academy. You can't do that." Two weeks ago Sakharov was invited by the Russian ambassador! Things change.

Winnewisser:

A remarkable story.

Herzberg:

Yes, remarkable. The same Mandelstam also told me, on a walk across the Red Square when nobody was listening, "If you think this will be any better in fifty years, you are mistaken." That was only ten years or fifteen years ago.

Winnewisser:

Well, in forty more years we will know whether he was right or not.

Herzberg:

Just for one moment coming back to Teller, of course I saw a fair amount of Teller when I joined the University of Chicago, that is, Yerkes Observatory. He wasn't at Yerkes but I went into town, not frequently but once a month or something like that, and so I saw Teller, and at that time in 1946, he was traveling all over the country lecturing on world government. If you believe it or not. And it has been confirmed by other people.

Winnewisser:

At universities or wherever he could get an audience?

Herzberg:

Yes. So much so that his colleagues at Chicago University were a little worried that he didn't do enough for the university. And then he suddenly switched, why or what, I don't know.

Winnewisser:

But he certainly indeed has had great insight into these molecular problems.

Herzberg:

Oh, no question about that, yes. Absolutely no question. In fact, I once had a rather interesting experience. There was a Gordon Conference on Electronic Spectroscopy. Don Ramsay was one of the organizers, and at one stage he asked me, "Would you like to give a lecture at this Gordon Conference?" I said no. I really had too many things to do, forget it. And he said, "Would you come if I get Teller to introduce you?" I said, "Yes." At that time there was no SDI, mind you. And he wrote to Teller and the answer was, yes, he would. So I was stuck!

Winnewisser:

And Teller was stuck.

Herzberg:

And Teller was stuck. But the point, the reason why I'm telling this story is that Teller arrived one evening, just in the middle of the meeting, just the day before my talk was going to be, and just during the meeting he came in. And it wasn't ten minutes and he had found the thread of what we were talking about, exactly, and it was something about the Jan - Teller effect and all that. He had it all in his mind. He didn't have any further preparation. He could make remarks in the discussion. It was just amazing, the way he could, after not having done anything in the field for twenty years, take part in the discussion of degeneracies and things in molecules.

Winnewisser:

Yes, that is amazing.

Herzberg:

Oh, he was, and perhaps still is, an amazing person, if he could only get rid of this SDI stuff. I talked to Chandrasekhar somehow about Teller at one time, and he had been with Teller on some high level committee, I don't know what it was. The point was that according to Chandrasekhar, Teller was anything but generous. He just dismissed people as if he knew everything, and he was just a completely different person from how I knew him when we, for example, wrote this paper, and when I had discussed other things with him in the course of the years. So I don't really understand Teller, I mean, what has got into him, and how it could be. But incidentally, according to the newspapers there was a meeting between Teller and Sakharov. At least at one particular occasion they met.

Winnewisser:

That was certainly a historical encounter.

Herzberg:

Yes, I'd say.

Winnewisser:

In any case. They're both remarkable men.

Herzberg:

Remarkable.

Winnewisser:

So in that regard, they were not disappointed I'm sure in confronting each other.

Herzberg:

But I think Teller could have been a Sakharov. But he isn't.

Winnewisser:

They might even have suffered the same fate in the 1950s.

Herzberg:

Yes. Another interesting little story is this, that a long time ago I was elected to the Hungarian Academy as an honorary member and as a consequence, I got to know the future Hungarian ambassador. At the time he was only a charge d'affaires. When he came here, his first step was to present me with a certificate of election to the Academy. That's only by the way to indicate that I knew this ambassador. I talked to him at one time about Teller, and he said that he, Bartha, was in Washington for a while at the Hungarian Embassy, and one day there was a call to the embassy from Edward Teller, and Teller inquired whether it would be possible to get an exit visa for his mother, who was at that time living in Budapest. This man Bartha realized who it was that was calling, and he said, "We'll look after it and let you know tomorrow." And tomorrow he had it all straightened out, the visa, everything was settled for Teller's mother. Teller was completely amazed at that. He had called with the idea that he would be refused, this kind of thing, you know.

Winnewisser:

So the respect for his personality and achievements was greater than the ideological barrier.

Herzberg:

Yes. I would have liked to have asked Sakharov what he thought of Teller.

Winnewisser:

He might have had a hard time formulating it.

Herzberg:

Such questions were impossible through an interpreter. Although Sakharov was quite willing to answer questions from anybody. But I didn't feel like bothering him.

Winnewisser:

It wasn't the same as a private conversation.

Herzberg:

That's right.

Winnewisser:

Well, I think it's quite fantastic that he was able to come.

[1]His mother, after various efforts at earning money, including running a sewing establishment with another woman, left Germany in 1922, at the height of the great inflation. She went to Wyoming, where she was engaged as a housekeeper for the son of a friend. When this did not work out as planned, she went to Seattle, where she had a sister. She ultimately remarried there, and had one other child, a daughter. At the time she left, her sons were 17 and 18 years old, respectively, and the money she sent back paid for their rent, initially, at the home of a woman with whom she had had the sewing venture. At that time Gerhard's brother had left school with the "Realschulabschluss" and was apprentice in a business firm. [B.P.W., From conversation with G.H.]

[2]Alfred Schultz was my second wife's uncle, that is, his father was her grandfather.

[3]Ann. Rev. Phys. Chem. 1985, 36, 1-30.

[4]1930/31: 1)Einfuhrung in die moderne Spektroskopie und ihre Bedeutung fur die Chemie; 2) Ausgewahlte Kapiteln aus der Atomphysik. Quoted by P. Brix, Physik in Unserer Zeit 11, 1-2, 1930.