Interview with Gart Westerhout on 19 February 1993

Gart Westerhout, interviewed by Steven J. Dick at the U.S. Naval Observatory, Washington D.C. on 19 February 1993.

Papers of Gart Westerhout

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Oral History

Gart Westerhout

Audio cassette tape

1993-02-19

This transcript is PART 1 of a series of seven interviews of Gart Westerhout by Steven J. Dick conducted between 19 February and 29 July 1993. The transcript of all interviews was checked and corrected by Dr. Westerhout in October 2000. The original audio tapes were deposited at the U.S. Naval Observatory. Because the interviews were conducted while both Westerhout and Dick were federal employees, there are no copyright restrictions on the interview. The interview is posted here as a supplement to the Papers of Gart Westerhout at the suggestion of Dr. Dick, who provided the transcript, with his permission and that of the Westerhout family.

Please bear in mind that: 1) This material is a transcript of the spoken word rather than a literary product; 2) An interview must be read with the awareness that different people's memories about an event will often differ, and that memories can change with time for many reasons including subsequent experiences, interactions with others, and one's feelings about an event.

Additional Materials About Westerhout Series

Begin Tape 1 Side A

Dick

I usually start with some background questions. For the record, your date of birth and place of birth.

Westerhout

My date of birth was 15 June 1927, in The Hague, Netherlands.

Dick

And your parents' names?

Westerhout

Gart Westerhout and Magde Foppe.

Dick

And their occupations?

Westerhout

My father was an architect, a rather well-known architect in Holland, and my mother, before she was married, was a secretary and a writer, wrote a number of books.

Dick

On?

Westerhout

Novels. And thereafter she took care of the family, and I think she ran my father's business for a while, too, as the bookkeeping person and so on. He had a large architect firm. She stepped in at one point.

Dick

And your educational background.

Westerhout

I went to Leiden University,1945 to '58, I was at Leiden University, got a candidate in 1950, doctoral in 1954, and Ph.D. in 1958.

Dick

How about before Leiden University.

Westerhout

I went to grade school and to high school in The Hague. I lived at my father's place.

Dick

Do you remember your first interest in astronomy?

Westerhout

Oh, yes, I do. That came about when my father was building a sanitarium for people who were always lying flat on their backs--I think it was for TB--in 1939.

Dick

In his role as an architect?

Westerhout

As an architect. Right. He had an old book by Flammarion, in Dutch, and he decided to paint the ceiling of the recreation hall with signs of the Zodiac and stars and constellations and so on, but my father didn't get an artist; he did that himself. He had his office make cutouts of stars and cutouts of constellations, and he gave that to the house painters on the scaffolds, and the house painters were painting in all those constellations. As a reward, he gave them a little booklet, a popular booklet on astronomy, and he gave one to me.

I read it, and I was interested. I went to the Zeiss Planetarium in The Hague, and there I got absolutely fascinated by the director, which was a Dr. Raimond, who is the father of Ernst Raimond, who is a well-known Dutch astronomer now. Ernst Raimond was about two or three years behind me in school. Raimond was an absolutely fascinating teacher. He set up these planetarium shows. So through him I got interested, and I decided not to become a bridge-builder, which was what I wanted to do, but to become an astronomer instead.

Dick

How old were you at that time?

Westerhout

Twelve.

Dick

So by the time you went to Leiden University, then, you knew you wanted to be an astronomer?

Westerhout

Oh, yes! In fact, my father, during the war years when I was still...the last year of the war, I was out of high school, but the university was closed, and I wasn't allowed on the streets because they picked up young men of that age to dig ditches on the front. So I basically spent a year locked up. But my father made a trip to Leiden on his bicycle, to talk about education in astronomy. He got to talk to Van Herk. Van Herk at that time had a long beard. There were quite a few Dutchmen who let their beards grow out of protest. I can never imagine Van Herk with a beard.

Dick

This is the Van Herk who--

Westerhout

The Van Herk who later came here to USNO for a while. So he informed him about the rigors of astronomy education and stuff like that, so we were well armed. He got advice that I should take mathematics. I took private mathematics study the first year at home, before I could enter the university.

Dick

So war had a considerable effect on you as a young boy in a general sense.

Westerhout

In general, yes, of course. I spent basically my entire high school time under German occupation, with all the rigors and problems of that. I can spend hours talking about that, but that has very little to do with astronomy, except for the fact that, of course, the sky was unbelievably black because everything was always blacked out.

I can tell you one particular story about that. In the little suburb where we lived, the house across the street from us, about half a block down, where there had been Jewish people, of course, who had been sent to the concentration camps, was a German headquarters, a very small one, you know, a platoon headquarters or something like that. But they always had a guard walking up and down. We kids, you know, you knew these guys. You didn't talk to them, of course; they were the enemy. One day I was looking for a stable thing for my little telescope, which I had built, and I propped it up against the front fence rail. I was looking through it, and suddenly the guy from across the street shouts, "Hands up!" in German. I sort of arose, and the soldier on the other side, the German soldier, said, "My God, it's you! Don't do that to me!" He saw this shiny thing sticking up over the fence post, and he said, "My God, they're going to shoot me." He says, "I could have shot you dead. Don't ever do that again."

Dick

You mean the telescope?

Westerhout

The telescope was sticking out over that fence. That poor German guard thought, "My God, they're shooting at me!"

Dick

So astronomy can be a dangerous activity!

Westerhout

Absolutely. Thank God he didn't shoot. He sort of sheepishly said, "Oh, God, it's only you." It was clear that he was just as scared as I was. So I never did that again. I always did it in the back yard.

Dick

Was that a telescope you had built?

Westerhout

That was a telescope I had built myself with a shipping tube. In those days you went to the drugstore...no, to the optician, to buy lenses--the glasses man who sold glasses. you got a one-meter focal length lens and you bought a very strong magnifying glass. The things that you use also on looking at photographic plates. Those two elements are a one-meter focal length thing and a thing with 1 cm focal length, gave you a magnification of 100, ratio of focal lengths. You learned that early.

Dick

Dutch lensmakers were famous, anyway, right? Lippershey.

Westerhout

They were famous. Lippershey. Absolutely. You know the story of Lippershey, of course. I always like to tell the story of Lippershey. I told the story of Lippershey in my class, in my Astronomy 100 class.

Dick

At Leiden?

Westerhout

No, here in Maryland.

Dick

Oh, you told it.

Westerhout

I tell that apocryphal story, but this was in the sixties and early seventies when there was all this anti-Vietnam and anti-military stuff going on. I told them about Galileo, how Galileo had really gotten the idea from this fellow Hans Lippershey, and Hans Lippershey, of course, worked for the military. I said he applied for a contract with the Dutch military to get the Dutch Navy to get a better way of looking at the ships, the enemy ships, much closer, and the Dutch Navy gave him a contract. He worked on that contract for a while, but then his graduate students discovered that he was doing military research, so all his graduate students immediately disappeared and started protesting in front of his house. But he kept on working, and he finally invented the telescope for the Dutch Navy. Then Galileo got to hear of it, and somehow or other got the project declassified, and then Galileo got a lens from him. That's what you call embellishing the story.

Dick

Right. Slightly. [Laughter] By the time you went to Leiden University, you went in as an astronomy student. It was a Department of Astronomy you went into? What was it like at that time?

Westerhout

There was a Department of Astronomy, but your undergraduate education was some astronomy courses, but mostly physics and mathematics, of course, as it is nowadays. The Astronomy Department was like any astronomy department. They had elementary courses and advanced courses. There was no such thing as courses for non-science majors. The elementary astronomy course was already a very intensive course. You took that in your first year, and you were already supposed to know at that point differential calculus and little things like that.

Dick

Who taught that? Anybody well known?

Westerhout

Yes, Woltjer, the father. His son L. Woltjer, after he got his degree at Leiden, worked around a little bit, then became head of the Astronomy Department at Columbia University, then became head of ESO for quite a number of years, and is now a private astronomer at Haute Province and is the next IAU president after Boyarchek is finished, after The Hague. Woltjer the son came to the observatory, came to Leiden about three years, four years after I did, and was finished exactly the time as I did. He was an unbelievably hard worker, absolutely brilliant--still is.

But Woltjer the father taught the course, and the course was given at the Leiden Observatory in the lecture room, which had a potbelly stove sitting in the middle, with a pipe going out the roof. In fact, the people working at the observatory, when the course was given, they had to temporarily go into the cold rooms. As soon as the students were out, they immediately moved back to the lecture room, because that was the only place where there was heat. So people sat there.

One morning people came in, and there was old Woltjer sitting by the stove, with all his pads of paper, calculating, dead. Dead as a door knob. He simply got heart attack or whatever in the middle of the night. Of course there was nobody there, so when they came the next morning, there was Woltjer. So then Oosterhoff, who was a young whippersnapper at that time--Oosterhoff later on became secretary general of the IAU--suddenly had to start teaching the course out of nowhere, and I still have the notebook that I made of Woltjer's lecture and then how it changed to a completely different course that he taught, of course. He worked his tail off. You suddenly have to give a course that you never prepared for before. So that was interesting. That was my first year, 1945-46. You didn't have semesters there. Those were year-long courses.

Dick

That was as an undergrad?

Westerhout

Yes, first year as an undergraduate. I was seventeen.

Dick

So did you have much contact with the people in the Astronomy Department as an undergrad?

Westerhout

No. As an undergrad, you had maybe contact with the teachers, but the classes were usually...particularly the advanced classes, were small. So you got to know these professors. They had never heard of written exams; all exams were oral. So somehow or another you got to know the professor that way, too.

I remember my class in physics in...what was that? It wasn't quantum mechanics. It was an undergraduate class. It was some fancy physics class which was taught by Professor Fokker of the Fokker-Planck equations. He was a Dutchman. He was an adjunct professor. His office was at some fancy institute in Haarlem, so you had to travel to Haarlem to your exam. And I failed the first time around. I got to know that Professor Fokker quite well. His son also became an astronomer, a solar astronomer.

I also took quantum mechanics from Kramers, a very famous physicist in the twenties to forties. He died also in the middle of a class. Kramers was always known for doing examples. He would say, "Let us take a random number--37." And his random number was always 37. He then started working out an example with that "random number," plugging it into some equation. I presume he had done that for thirty years, so he knew precisely how the equation would read. His multiplications were always very quick, because he already knew the answer. But he always used the same "random number," 37. [Laughter] The students started figuring that out after a while. So there were quite a few neat people around. Of course I took several courses from Oort, who was the director of the observatory.

Dick

Even as an undergraduate?

Westerhout

Even as an undergraduate.

Dick

So by the time you came to the end of your undergraduate, there was no doubt that you were going to do graduate work in astronomy?

Westerhout

Oh, yeah. Sure.

Dick

What was the thrust of your interest then? What were you going to focus on?

Westerhout

Somehow or another, I don't quite know why, but I was interested in electronics a little bit. So they promptly put me to work with Walraven. Walraven is a famous photometrist who built all sorts of equipment. I later worked with him for a year in South Africa. Walraven was building an amplifier with two tubes in it. He had invented some circuitry that would be oblivious to fluctuations in the current. The amplification would stay exactly the same. If the voltage went up from the mains that you plugged it into, somehow or another, the amplification would go down and it would compensate.

So I was working on that for a while. That was in '50. Then the 21 cm line efforts started in 1949. There was an engineer by the name of Ho, who was working on that in a place near Kootwijk. The whole thing burnt to the ground, the whole little lab that he had there.

Dick

He was working particularly on 21 cm?

Westerhout

He was working to develop the equipment to do 21 cm line observations. Had he succeeded, had he been a better scientist, he would have discovered the 21 cm line long before Ewen and Purcell. But the whole stuff burnt to the ground. Somehow or another, he came to Leiden and he was sitting in the same room that I was sitting, so I got to talk even more about electronics.

Dick

And Van de Hulst had predicted the 21 cm line.

Westerhout

As a graduate student in 1944, as an assignment from Oort, who said, "Find for me spectral lines in the radio spectrum, because this work by Reber looks very interesting. You see all this continuum emission. It's clear that the whole Milky Way is full of radio emission, but that doesn't give us nearly as much information as if we had any spectral line stuff in there.” It's clear that we could see the center of the galaxy, it already became clear from Reber's maps that the strongest radiation came from the direction of the center. And, of course, people had already figured out that apparently it penetrated through interstellar dust and so on. Oort argued that there must be spectral lines there. And, of course, when the 21 cm line was discovered, that indeed suddenly opened a vast new field ... just as spectroscopy did to astronomy. Astronomy was astrometry until the 1890s when spectroscopy came about. Suddenly astrophysics was born. The same happened to radio astronomy.

Dick

How had the interest in radio astronomy developed at Leiden? Was it Oort entirely?

Westerhout

That was Oort entirely, through that conclusion about spectral lines. It was in '44. During the war years he was working on that.

Dick

How did you become involved in that?

Westerhout

Immediately after the war, he then got in touch with people that he knew in the Dutch Post and Telegraph Services, who salvaged a few of the old giant Wurzburg 7.5 meter-diameter radar dishes from the Germans, set one up in Kootwijk.

Dick

This is Oort?

Westerhout

Oort. Oort got in touch with people in the Dutch Post and Telegraph Services, who saved some of these dishes for him. One of them set up in Kootwijk, and that's was then given over to Oort to do this work.

Dick

How do you spell Kootwijk?

Westerhout

K-O-O-T-W-I-J-K. That was the Dutch radio communications station. That's where they did the short wave transmissions all over the world. There were antennas there that you could walk up to the antenna with a screwdriver and draw a spark off the guy wire of the antenna, and in the spark, you heard the fellow talking. Somehow or another we did radio astronomy in that kind of environment. Instead of going to a receiving place, we went to a transmitting place. But I got involved in the astronomy scene then later on in that first year.

Dick

In the radio astronomy.

Westerhout

In the radio astronomy. Because Bolton and Westfold, two young Australian astronomers, had made a big map of the Southern Hemisphere, including the Milky Way, and had corrected that map for the effect of the antenna beam, which was 17 degrees wide, and thought they had eliminated that effect, and they came up with a beautiful map. They were traveling around Europe, so they spent a few days in Leiden, gave a few lectures, and we got all very interested. Oort said, "That distribution of radio waves looks very much like what would happen if this material is distributed like the stars." So I then got assigned the project of looking at star distribution. That was my first paper--Westerhout and Oort, 1951.

Dick

Let's see. The first paper in 1951, "A Comparison of the Intensity Distribution of Radio Frequency Radiation With a Model of the Galactic System", Westerhout and Oort.

Westerhout

I think Oort was always very gracious in putting his graduate students' names first. Of course, I did the majority of the work, but I couldn't have done anything without him, obviously.

Dick

Which instrument were you using for that?

Westerhout

We weren't using any instrument. We were simply using that data we got from Bolton. It was rather an interesting paper, because we did a whole lot of things of figuring out how would this compare. Hanbury Brown had just made the first measurements of the Andromeda Nebula, so I could stick in there, if the Andromeda Nebula was the same as the Milky Way, would you indeed see that. Things came out right. We put in the effect of the interstellar medium and concluded that the interstellar medium really didn't have much of an effect here, because it was too thin a layer and it was clearly not shown. It was a few years later that it became very clear that when you correct for the antenna beam, you, of course, don't get infinite resolution. You, at most, get the Nyquist sampling theory that tells you what you can get down to 60 percent of what your original beam was. So this was still smoothed over 10 degree surfaces. So no wonder you didn't see the 2 degree wide layer of the galaxy. It is kind of interesting that you realized relatively shortly afterwards how naive we all were.

And therefore that paper, which basically said when you look at star distribution, the ellipsoidal distribution of the stars and so on, it sort of gave a relatively good presentation of that, but in reality, the layer was very much thinner than the layer made up by the average stars, because the layer in which the radio emission occurs is much more associated with the interstellar medium. However, we already did come to the conclusion that there was a halo, a galactic halo. There was no way you could interpret that observation without having sort of a global distribution of radio emission.

Dick

If Bolton and his colleague had that data, why didn't they use it.

Westerhout

Because they were electrical engineers. All radio astronomers were electrical engineers in those days. In 1952, I gave a colloquium in Cambridge about the 21 cm line for all the greats, like Ryle and Baldwin and Shakeshaft and Hewish and all those sort of people. I gave a colloquium then. I made a comment to Oort later, saying, "Those guys, I have no idea how they have become so famous. They know nothing about astronomy!" I had to explain galactic structure and so on to them. They had no idea. They were fascinated. Later on, of course, they grew into astronomers, too, but they all were in the school of physics, doing electrical engineering experiments.

I was just reading--I took it home again--a book in German from Peter Metzger, who is a German colleague, who wrote a popular book sort of describing that scene. He said it very, very exactly, how in the beginning there were these people and then there were the Dutch, and the Dutch started at it from a completely different angle.

Dick

And why is that?

Westerhout

Because Oort was the astronomer who saw a new means to an end--namely, the structure of the galaxy, later on the structure of the universe. Whereas these people, they had read something about, "There seems to be radio waves, seem to be radio waves coming from the universe. Let's look at that and see what we see." And they found point sources after a while. "Boy, what are those?" Then, of course, in 1952, Baade and Minkowski identified one of those point sources as Cygnus A, and Cygnus A turned out to be a galaxy God knows how many millions of light years away. Then everybody raised his hands and said, "God almighty! If that is the brightest one, these things must be all over the place." Then suddenly the whole business of finding point sources came to trying to figure out the structure of the universe.

Dick

Wouldn't you say it's true that in the late forties, maybe in the early fifties yet, there were people who didn't think that there would really be a radio astronomy, that there was anything that you could see very much using radio wavelengths?

Westerhout

No, it became clear that there was a lot to be seen, but there was very little connection with the optical astronomy yet. That was basically both the Cambridge group in England and the Australian CSIRO group, that did most of that early work in the late...well, started in '46, actually. '46 to '56 is when a lot of that started. They declassified some observations made by Hey in 1944, in Malvern, who had actually seen the sun. They were working at such low frequencies at the time, that the sun was not a very strong source of radiation, except when there was a solar outburst. The quiet sun simply was not visible, and that was another one of these mysteries. It was quite clearly a completely different kind of radiation that was emitted.

Dick

How did your interest develop then in radio astronomy?

Westerhout

So you can see exactly what happened there. It came from the interest of Oort in the structure of the Milky Way--and where are these objects, are these objects associated with regular stars, or what is it? So I got interested. I got obviously into stellar dynamics, because that's what that was about--stellar dynamics, the distribution of the stars, the force of Z perpendicular to the plane, which has something to do with how thick the layer is. All that stuff got into that paper. It's chock-a-block full of equations. I couldn't understand them anymore, but -

So that, in a sense, then, got me interested in this whole business, so I started reading up on it. Then in '51, when the 21 cm line had been discovered, in the summer they needed people to go and help observe, so I moved to Kootwijk to help observe the 21 cm line, and that's how basically I got involved, got to reduce some of the data and so on and so forth.

However, at the same time I was extensively doing photoelectric photometry on the 20-inch telescope in Leiden, in collaboration with a graduate student who was doing that for his thesis, named Andre Muller. Andre Muller was measuring variable stars, so I was heavily into variable stars. In fact, I took over his program while he went to South Africa, and when he came back, it sort of became clear that I was the most experienced young graduate student to take over in South Africa. In the meantime, Walraven had taken over the Leiden station in South Africa, so he was there. But there was an observer needed, so I then went to South Africa for...I think it was a year, almost a year, I'd say. That was in '52.

From March until December of '52, I was in South Africa, and I did photoelectric photometry, but the main task was taking plates with the Franklin Adams camera, the big variable star survey that had been started by Van Ghent in 1925. And plates had to be taken at short intervals, at intermediate intervals, and at long intervals, so that you could get variable stars for periods of many years, as well as variable stars for periods of a day. So that was very carefully worked out, the people managing that program, and, of course, you pretty soon got to manage that yourself, trying to figure out what plates are in the collection, what further fields need to be observed, should we really start a new field. We very soon decided we were not going to start any new fields. The program basically finished about three or four years after I was there. I decided there was enough done. That had been an extensive program for many, many, many years.

Dick

Then you went back to Leiden?

Westerhout

Then after that. Of course, I was doing photoelectric photometry. There was this Franklin Adams camera, which was a ten-inch or so, and then there was the so-called Rockefeller telescope, which was built by a grant from the Rockefeller Foundation, which was a twin telescope with a blue and a red lens, and we did photoelectric photometry on that, all sorts of fancy stuff.

I must relate another story there. We also went to observe with the 76-inch telescope at Radcliffe Observatory, which was in Pretoria, only fifty miles north or so. Once we had decided that Walraven had a star that had a period with whole other beat periods in it, too, but its basic period was five hours, really fast star, and could we look at the spectrum of the star at that rate, how did the spectrum fluctuate. Of course, these stars weren't all that bright, so you had to integrate.

So we courageously decided that we would take the spectrum at the Cassegrain spectrograph of the Radcliffe 76-inch telescope, but we'd integrate on that spectrum by blocking it off, blocking off a section of the spectrum, so you get a little strip of spectrum only, observe that for ten minutes, then block that off and go down and get another strip of spectrum. Then after two hours when the star was back in its original phase, you'd go back and go through it. So you integrated for three times or four times ten minutes. So I was the person doing that, and for some reason--and I shall never know what it is-- when I developed the plate, it turned out it was a plate that had already been developed. So we had spent twelve hours, because this was in the middle of the winter, twelve hours observing, both at the Leiden station and at Pretoria, and the result was absolutely nil. I had observed for twelve hours continuously in the dark dome with that thing, and there was nothing on the plate because I had taken it out of the wrong box somehow. How I did it, I'll never know whether somebody switched boxes or something, because I'd been using that before, so I knew exactly what to do.

Then another interesting experience there, and then I'll stop about South Africa, because there again, of course, you can go on and on and on. There were so many things going on. I went to Bloemfontein, to the Harvard-Dunsink-Armagh Observatory. This was a collaboration between Harvard and two Irish observatories, and they built an observatory in South Africa, about 300 miles south of Johannesburg. Among other things, there was a Schmidt telescope there, so I went down there to take some plates of fields that I was interested in with the Schmidt, in the red. We had a blue telescope. So I took my first plate, and that was a Schmidt telescope that was absolutely unbelievable. It had backlash that was so terrific that you were guiding, and so you pressed the button to steer the telescope a little bit, and absolutely nothing happened. You kept pressing the button, and suddenly the telescope would start moving, but it had moved too far. So you pressed quickly the button on the other side, and you sat there for ten seconds before the gear had caught up to go the other direction again. You learned, after an hour of doing that, exactly how long to keep that button pressed before it caught on. Boy, that was terrible, but fortunately I had learned, so I did not take all my plates and then develop them. I took my first plate and ran to the darkroom to see how it came out. It came out fine; it was completely black, because I kept the red light on in the darkroom. I'd forgotten I had a red plate. I had worked with blue plates, and you always had red lights on. You could walk around in that darkroom and do everything you liked, because the blue plate gave was not sensitive red light. So I kept the red light on. [Laughter] Fortunately that only happened to one plate.

Dick

But it's interesting you were doing optical work.

Westerhout

Oh, yes, very much so. Very much so.

Dick

Why had you gone off to South Africa at the time when this radio astronomy stuff was all so interesting?

Westerhout

Because that's what I was assigned to do. And besides, I was observing optically and so on. I was the guy to go to South Africa. Interestingly enough, Oort kept us very much--and kept me, in particular--very much up on what was happening, because he knew my interest. So as a result, with all the messages I got from Oort, I could give colloquia on the subject. That's how I came to give a colloquium in November of 1952 in Cambridge on the way back from South Africa, on what they had done at Leiden, even though I hadn't been in Leiden for nine months. But I was always on the lecture circuit. I was giving lectures, not only scientific colloquia, but lectures for the amateur astronomers, which is a very well-organized group in Holland. They had chapters in almost every town, and sometimes I would give six or seven of those lectures a year. They pay for your travel and they feed you dinner. It was always nice.

Dick

Why was Holland so into astronomy, apparently at the amateur and professional level?

Westerhout

Apparently at the amateur and professional level, that's right. The professional level has to do with the school. Some were, along the line, people like Lorentz, Kapteyn, DeSitter. There were a few greats that attracted students, because Kapteyn attracted Van Rhijn. Oort took a few lectures from Kapteyn, but then Kapteyn died, and Oort took lectures from Van Rhijn, Kapteyn's successor. Van Rhijn didn't become famous, but Oort had heard Van Rhijn and had heard about Kapteyn and got attracted as a bright young man into astronomy. And the same in Leiden. People like DeSitter were very famous, so that attracted astronomers. Somehow or another that built up. And I suspect because those astronomers did a lot of writing, there was a lot of popular writing, the newspapers were interested. I've been on quite a number of television shows in the early days, when television shows were live. It wasn't taped. So there was no such thing as tape; they were live. You'd better make sure that you said everything right, with props and slides that you showed, and so on.

So what was I saying about that? Oh, you were asking why was I into optical astronomy. I think that's what you were asking. Hey, I was into optical astronomy simply because that interested me, there were things to do, but my main interest, because of Oort, was, of course, in galactic structure.

Dick

So once you got back to Leiden, then you took up radio astronomy again?

Westerhout

I took up radio astronomy again, but again as a means to an end. There was a paper by Kwee and Westerhout on the rotation curve of the Galaxy. We went into an extensive observing program, as quickly as possible, to figure out how did the Galaxy rotate in its inner and outer parts, and we got some damn good results. That was basically a classic.

I did that experiment later in Maryland for the Maryland Science Center, or somebody like that, who still do that. They teach courses for high school students on Saturdays and all sorts of things. I did that a number of times. I once had them derive the rotation, and from that the mass of the galaxy. I took them to Derwood, Rockville, where the Carnegie Institution had a radio telescope, and a good 21 cm line receiver. I had each of them in turn handle the tape recorders and the buttons and so on, write things on the chart. We took about ten line profiles, which took about two hours of observing. That was interesting, because they got sort of an idea -- it was about ten kids--how the telescope works. Then the next Saturday we worked those out, and from observing those line profiles, you could determine the way in which the angular rotation of parts in the inside of the Galaxy minus the angular rotation at the sun, what those numbers are. That was that paper of Kwee and Westerhout (1956). But we did that in two hours in 1970. It was a multichannel receiver with high sensitivity and all that.

I had them look at those things, and asked the question, "Where exactly is the end point of that line profile?" and all these sort of questions, and had them sort of make up their own minds. The curves that came out in the end were quite remarkably the same as came out of the old article of Kwee and Westerhout. Then I gave them the one datum that you need--namely, how fast is the sun going around, and then you could use Kepler's laws a little bit, and come up with a rough idea of the mass of the Galaxy. Just like that--boom! High school students. It was really fun. Many years later, my daughter for several years gave lectures on architecture for the same organization.

Dick

You mentioned receivers. The receivers you were using in this early work must have been pretty primitive.

Westerhout

They were pretty primitive--yes, sir.

Dick

Just vacuum tubes sort of thing?

Westerhout

Certainly vacuum tubes. There was nothing else. The first ones were sitting in a row on a table . . . you'll find that in several of the radio astronomy history books. There are pieces put together. Pretty soon, however, since we were working in this environment of transmitters, everything was in racks, and the racks were very well shielded. Lex Muller, who was the engineer appointed after Mr.Ho left, took over and in half a year after he started, he had the receivers ready and could measure the 21 cm line, albeit three months after Ewen and Purcell had done it. That was a pity. We could have so easily done it earlier.

But that shielding in order to protect you from all these weird influences, Muller later said must have been part of our success, because not only did he shield against outside influences, all this equipment was shielded from each other, and that equipment had all sorts of transmissions in it, you know--local oscillators and so on, that other people had terrible troubles with, that pieces of your equipment interfere. Well, it didn't, because he had a much bigger external shield.

A very funny thing there is that the Germans heard about that, who then built 21 cm line equipment in 1959, and they had Telefunken build it. They all came and looked at how well things were shielded, so the German receiver, when it finally appeared there at the Stockert Mountain, you could see no wires. Every rack was connected to every other rack with a great big metal tube, and all the wires went through those metal tubes. It was the weirdest radio astronomy construction you've ever seen. There was not a single wire, because they had heard the message: make sure that everything got thoroughly shielded. Of course, they were in the wilderness. There was no radio interference that could have come from anywhere else. [Laughter] The German Grundlichkeit had arranged for that.

Dick

I have to turn this [tape] over.

End Tape 1 Side A

Begin Tape 1 Side B

Westerhout

We're still in radio astronomy. But I think that now you've begun to realize is that what you were always after was not using this new fangled thing to see what you saw, you went for a very specific thing. We then went for a long observing program to map the entire galaxy as seen from the Northern Hemisphere. That resulted in BAN 452.

Dick

When did that start?

Westerhout

The first one started in.

Dick

You're still a graduate student.

Westerhout

Yes, I've been a graduate student the whole time. Well, no. In 1952, when I came back from South Africa, I got an assistantship, research assistant, whatever you call it. When I got my doctoral exam, which meant at that point you were finished with your courses, you had to do a rigorous exam, again oral. A number of different professors sat together and asked you questions on physics, mathematics, and astronomy. And I passed that. Thereafter I became assistant first grade, or something like that. No, no. At that point I already became scientific officer. In 1954 I became a scientific officer.

Dick

What does that mean?

Westerhout

That meant I had a government job, a government position, a real government position.

Dick

But you're still a graduate student?

Westerhout

At that point, once you had your doctoral exam, you were not really considered a graduate student...some people never went for their Ph.D. thereafter. But I was, of course, working for my Ph.D., but I was working all sorts of other things, too, because there were two 21 cm line surveys. The first one, which was done in a hurry, and in which I participated in the observations, the reductions, and at one point the whole observatory did the data reductions. We were all put together in that same lecture room, which by then, of course, had central heating, and everybody took parts of the reduction. All those line profiles had to be measured that were all on charts and so on. Two weeks, all the data reductions were finished. That was in 1952.

Dick

Give me a little better idea of Leiden Observatory at this time. Who else was on the faculty there? The observatory is connected to the university?

Westerhout

Right. The university is a government university. It's like the University of Maryland, a state university. So everybody was a government employee. And I'm now getting a Dutch pension from the Dutch government, because I was a Dutch government employee for ten years, from 1952 to 1962. That gave me a pension.

Dick

So in a sense, it's a national observatory, I guess, since it's funded by the government.

Westerhout

All of them were national observatories. Utrecht Observatory was also a government observatory. Groningen was also government. It was all government.

Dick

Leiden had the longest history?

Westerhout

Both Leiden and Utrecht. Leiden had the longest history as a university in Holland, but Utrecht came relatively soon. By the way, as undergraduate and graduate students, you got together once a year. All the astronomers in Holland got together once a year for two days, two or three days, in some resort. That was a youth hostel, of course. The resort, of course, was a youth hostel or something--I mean, very primitive. For lectures, handball, shows, you tried to outdo everybody else, putting on a better show, you know, homemade shows.

Dick

Who coordinated that?

Westerhout

One university after the other. I went to my first one in 1946, as a young incoming graduate student. So that's another thing where you got to know the astronomers, your colleague undergraduate and graduate students at your own university and at all the other universities, and the professors. Everybody got together. Later on it became, I presume, too big to do it that way.

Dick

Who else was on the faculty in astronomy at Leiden at this time?

Westerhout

Let me think. There was Oort, Oosterhoff, Blaauw. That's it. Then later on, Van de Hulst joined the faculty in about '48 or so. He got his Ph.D. around that time.

Dick

So who would have been the biggest influence on you during your time?

Westerhout

Oort. No question about it, although I worked with Van de Hulst, and, in fact, Van de Hulst was my thesis advisor, because by the time I got ready for my Ph.D. thesis, he was a professor and could therefore do Ph.D. thesis advising, and I was his first Ph.D. student.

Dick

What was your subject?

Westerhout

That's another whole story. We're not there at all yet. But the second 21 cm line survey, I was basically the person who organized that, and that was in about '54 to '55. That was two years of hard observing, while all the younger students come to Kootwijk to observe and take data and so on.

Dick

Is this the one that resulted in the map that you always see now of the 21 cm map of the galaxy?

Westerhout

That's the one that you always see out there. Right. A great big fat publication, because Maarten Schmidt then took the inner part of the Galaxy, and I took the outside of the Galaxy, and together we produced two different papers, one by Westerhout and one by Schmidt, BAN 475.

Dick

Where was Schmidt at the time?

Westerhout

At Leiden. He was another graduate student. We were all graduate students together.

Dick

Who else was a graduate student with you?

Westerhout

Everybody! Everybody. Tom Gehrels was never a graduate student; he was an undergraduate student there. But Schmidt and Kwee, who's still there, Van Houten, Van Woerden. That was sort of a foursome--Van Woerden, Schmidt, Kwee, and Westerhout. In fact, we went on vacations together, all crammed into a little car, because Schmidt was very tall. One day we arrived in Switzerland, I was absolutely mad at Schmidt because he brought a huge big Dutch cheese which was packed on top of the car. "Damn it, the car's already overloaded, and you're bringing a whole big cheese!" So we ate it. [Laughter] Kwee and Schmidt and I went to the eclipse in Sweden in 1954.

Dick

How do you spell Kwee?

Westerhout

K-W-E-E.

Dick

He's one of your co-authors. That's right.

Westerhout

He just retired.

Dick

In doing your 21 cm work, you had no competition outside the Leiden group who were considering doing the same thing?

Westerhout

No. No. The Australians were with Frank Kerr doing the same thing for the Southern Hemisphere, and I got to know Frank Kerr extensively in 1955. I mean, he's what you call an old friend, too. He was always around. We always saw each other. Frank Kerr got into the 21 cm line work in 1951, when he spent a year at Harvard and took courses in astronomy, among which a course in astronomy from young Van de Hulst.

Dick

And Ewen and Purcell were there, I guess.

Westerhout

And Ewen and Purcell were there. So Kerr got a lot of astronomy education at that time, and that's how Kerr got interested in 21 cm line work. Then when he came back to Australia, Christiansen and somebody else had sort of quick also made some observations and then dropped it again. Kerr then built up the 21 cm line group in Australia.

Dick

Your mapping effort went over a period of years, then, until--

Westerhout

In 1957 we then had the big paper--the big fundamental paper.

Dick

Which one is that?

Westerhout

BAN 475--Bulletin of the Astronomical Institute of the Netherlands. That's the big publication with a paper by Muller about how the equipment worked, the paper by Westerhout, paper by Schmidt.

Dick

You also have some papers here with Seeger. Seeger was at Leiden at this time?

Westerhout

What is the first one with Seeger? '58?

Dick

There's one in '57, "Observations of Occultations of the Crab Nebula by the Moon."

Westerhout

Right. Okay. Now we get to that. When is the date of that 21 cm line paper, BAN 475? It's 1957, right?

Dick

475--that's the volume number or what?

Westerhout

No, it's the -

Dick

"The Distribution of Atomic Hydrogen in the Outer Parts of the Galactic System"?

Westerhout

Yes.

Dick

That's 1957.

Westerhout

'57. Right. That's what I thought. But that was the culmination of work of observations we really started making in '53 and '54, in Kootwijk. In the meantime, we were building the Dwingeloo radio telescope, the biggest one ever, because when it became operational, Jodrell Bank wasn't quite finished yet. And Americans haden't built 85-foot telescopes yet, so it was for a little while the biggest radio telescope ever built. Of course, I was heavily involved in that. I was involved in it in the design of the guiding ... it was an altazimuth telescope and it had an analog, hour-angle-declination/altitude-azimuth converter, synchronous motors in it and so on, the whole testing and calibration and adjusting the axles exactly and so on. That was all my work. Then when the telescope was finished, aligning the telescope, and we did that with stars. I had mounted a little optical telescope on it and tried pointing and then making sure did I really look at that star, and you found correction values there. You first, of course, had to set the little telescope to be more or less parallel to the radial optical axis and so on and so forth. That was a long and extensive work.

Seeger came to Holland in '52 or '53, also to do radio astronomy, and Seeger was going to do polarization work. In order to do polarization work, he had to build receivers, and he built, in the end, a back end of a receiver which was so unbelievably complicated, nobody ever used it. But he was a fantastically enthusiastic fellow. In 1955, regarding that Dwingeloo telescope, there were two occultations of the Crab Nebula by the moon, and the next time it was going to happen was eighteen years later.

So what do you do? Well, the telescope was sort of...the dish was there, but it couldn't be moved yet. It could be moved in azimuth direction with the great big motor, couldn't be moved in elevation. The occultation took place very close to the horizon, the first one, so we got the contractor to set it at such an angle that during the occultation, it would sort of pass through the beam in declination. It was sort of a 7-degree elevation angle. And in azimuth we could follow not with the fast motor, but with a hand crank, which I had fastened to a pipe that came out, which was quite clearly attached to the azimuth motor. So I attached the hand crank to it.

Now, how do you read it? Well, there was another little part coming up which turned relatively fast, so I bought an alarm clock, attached it to the pipe, calibrated the alarm clock, and that read azimuth. So one person was standing there, cranking azimuth. It was a great big table giving the setting of the alarm clock as a function of time. At the top, in order to follow, the focus of the antenna was attached to one mast coming out of the middle. It wasn't a tripod. That mast could be lowered to get to the antenna.

So we calibrated, and I was the person responsible for all of that, with my pure astronomical background. Most of the other people were radio engineers. I calibrated that antenna beam, that mast, and that was lowered very slowly, because that raised the beam as the Crab Nebula rose. There was a strip of paper attached to the cable with indicators on it, and that gave the elevation. So during that occultation, we moved the telescope in altitude and azimuth to follow the Crab Nebula, and we got the whole bloody occultation.

The second time, the next month, the elevation motor worked. We still did the same in azimuth, but at that point the elevation motor worked, and indeed the telescope could therefore be moved. So we tracked the Crab Nebula by bursts on the elevation motor. The fine motion didn't work; the rough motion worked. And it was much higher up, so we did not move the feed anymore, we just moved the telescope back and forth. That also succeeded.

Dick

What were you trying to learn by observing this occultation?

Westerhout

Find out what the structure of the Crab Nebula was in fine detail. I mean, there were maps of the Crab Nebula with accuracies, with beams of, say, 2 degrees or so. By occulting with the moon, you could find the exact distribution with accuracies of a minute of arc or better, albeit smoothed by the fact that it was a circular thing that went across. But the second time, that circular thing went across in a different angle, so you could get at it that way. That was also a neat experiment, and all that work was in preparation for a survey at 400 Mhz. This went parallel to what Muller was doing at 21 cm line...two different--

Dick

Those were at 400 Mhz.

Westerhout

400 Mhz. Right. And there was a smaller antenna at the site which we used as an interferometer against a big one to measure the precise flux density of Cassiopeia A. That's probably in there somewhere, too. Maybe it isn't. Maybe that was Seeger entirely.

Dick

In the same year you had "Observations of Discrete Sources: The Coma Cluster of the Moon and Andromeda Nebula, Wavelengths 75 cm."

Westerhout

Right.

Dick

That was with Seeger and Conway.

Westerhout

Conway! My God, he was there, too. Robin Conway from England. He was there for two years. There were all sorts of people in Leiden, of course, from abroad. You asked who was the faculty. In addition to the Dutch faculty, there were all sorts of researchers from outside.

Dick

By what time was Leiden considered a center for radio astronomy research, would you say? By the early fifties?

Westerhout

By the early fifties, yes. Definitely. And there was in 1947 established the Netherlands Foundation for Radio Astronomy. In fact, it was called the Netherlands Foundation for Research in the Radio Waves from the Milky Way and the Sun. It was much more complicated, but later on it was called Netherlands Foundation for Radio Astronomy, NFRA, and that's still their E-mail address.

Dick

You have another paper in '58 on "Survey of Continuous Radiation From the Galactic System."

Westerhout

That's my Ph.D. thesis. So finally the telescope was completed, and we first made a quickie survey, because it couldn't be steered yet. So we went around and around and around the sky at different elevations. This was an idea of Van de Hulst. We found a whole lot of bright objects that nobody had ever seen before. And then in October of '56, there was still no 21 cm line receiver. I calibrated the antenna thoroughly and the receivers and did a survey of the Milky Way. Now, the 1390 MHz, 1420 is the 21 cm line. This was a receiver which used double sideband. It was a 30 MHz intermediate frequency, so it observed at 1420 and at 1360 at the same time, but the 1360 was, of course, useless for 21 cm line work, but it doubled my bandwidth for the continuum, and the average of that is 1390. That's where the number 1390 comes.

Dick

I was going to ask you that. [Laughter]

Westerhout

Later on they sort of found electronic means of canceling that second sideband and thereby have less sky noise in there, but in many cases having the second sideband is actually an advantage because you get double bandwidth.

You mix on the intermediate frequency of 1390 with whatever comes in. The signal comes into the antenna, goes into a detector. In that same detector goes a 1390 MHz signal from a local oscillator. What comes out of the detector is fed into a 30 MHz amplifier. What will that 30 MHz amplifier therefore see? The sum of 30 and 1390, but both in the negative and positive. So it's 1390 plus 30, and it's 1390 minus 30 that you get out in that 30 MHz back end, and that's where the amplification was. Pre-amplifiers working directly at 1420 MHz came much later. They didn't come until the sixties. People didn't work that. So all the amplification was done at the intermediate frequency. Of course, because you did line work, there was a great requirement on the local oscillator. It had to be very precise, because it determined what frequency you were looking at.

Dick

In the U.S., thinking of Drake's Project Ozma, he was using a parametric amplifier.

Westerhout

Exactly.

Dick

And that was the first time it had been used.

Westerhout

Exactly. Exactly right.

Dick

I assume in Leiden--

Westerhout

And I used that same parametric amplifier at exactly the same time as Drake, in the same place.

Dick

At exactly the same time?

Westerhout

Well, almost exactly at the same time.

Dick

You were there for Project Ozma?

Westerhout

I wasn't there for Project Ozma; I was there to do a survey of the Milky Way at 3.5 cm.

Dick

That would have been April of '60.

Westerhout

No, he was building the stuff for Ozma. That's right. It was April of '59.

Dick

Okay. So you were on some kind of a leave from Leiden then?

Westerhout

Yes. That was in '59. So the 1958 paper was my Ph.D. thesis, of which I got the observations in '56, and that Ph.D. thesis consists of a chapter on how to calibrate a radio telescope from beginning to end, derivation of refraction corrections, the whole kit and caboodle--flexure of the telescope.

Dick

What was the main astronomical result?

Westerhout

And the main astronomical result was a map of the radio emission of the Milky Way and the discovery of catalog of about eighty sources, some of which I could identify with optical objects, some of which I could not identify with optical objects.

Dick

These are the ones known as the W objects.

Westerhout

Exactly. Some of the ones that were not identified ever had to come from that catalog, so somebody later put a W in front of it, and they were always laughing about the fact that the moon...people always ask, "What is W81?" Not always, but in the olden days. That's the moon, because the catalog was in order of right ascension, but I had observed the moon for a number of different days. So I had to put that somewhere at the end of the catalog. [Laughter] W81 was the moon. So that was my Ph.D. thesis.

So I made the observations in '56, and I didn't get it completely written up until '58, till the summer of '58, because, as you may notice, in '57 I got finished with that great big 21 cm paper, which was certainly material for a Ph.D. thesis, too, but by then I was so interested in the new telescope that I wanted that to be my thesis. And that's what often happened in Leiden. You can look at papers from people who got their degree in Leiden, like Schmidt and Woltjer and so on--a whole series of important papers before they finally got to their Ph.D. That simply happened, because once you were working with one of those faculty members and so on, hey, you started producing papers.

Dick

It was such a new field, there was so much to learn.

Westerhout

No. No, I mean in astronomy in general. I mean, think of Schmidt. Schmidt went to Kenya with van Herk for the famous Leiden declination expedition, and observed there for a year, and at one point had his car turned over and broke a leg, so he was in the hospital there for a while, too. All that sort of stuff. So he went to Kenya and I went to South Africa. We all went somewhere. I think Schmidt got his Ph.D. on the Milky Way, on that same BAN, where I did the outer parts and Schmidt did the inner parts. I think that was his Ph.D. thesis. Immediately thereafter in '57, he went to Cal Tech, spent two years at Cal Tech and then came back to Leiden, and then decided after a little while that he was going to go back to America for good. And the same happened to me in '59. I spent a year out of Holland and came back, and three years later we came to this country.

Dick

In '59, that's when you were at NRAO.

Westerhout

Among other things. Right. So what happened during that time, then, well, I got married, we had a baby, and so on and so forth. We had lots of fun. Then in '59, I got a NATO fellowship to visit and study at North American universities--just like that. That vague. I also got promised a CSIRO fellowship to work with Frank Kerr on the 21 cm line for three months.

Dick

In Australia.

Westerhout

In Australia. I had no restrictions on any of those fellowships. My Dutch salary continued, and my trip was paid. My airline ticket was paid. So with all that, I bought an airline ticket for my wife and child, and we went on a trip around the world. We left in February and we returned at the end of November.

Dick

In '59?

Westerhout

'59. Of course, at that time I'd been active in all sorts of IAU meetings already, and every Tom, Dick, and Harry wanted me to give colloquia Being a poor Dutchman, I got honoraria everywhere. When I went to NRAO, they paid me a salary, in addition to my NATO fellowship. At NRAO, the work there didn't succeed. I rediscovered the fact that there is an Earth's atmosphere at 3 cm. The guy who built the amplifier was Ewen (discoverer of the 21 cm line); Ewen-Knight Corporation had built parametric amplifiers, and they went wild. They went up and down by several degrees. I was looking for a signal crossing the Milky Way of half a degree wide or so. Jack Campbell, I still remember it, he would come back several times and they would work on that. They got it real stable, it was real stable, and two days later, it would go like that again. Finally, I associated that with clouds that came over.

So I dug up the book in the M.I.T. series, radiation lab series, very important set of books, writing down all the big theoretical and practical stuff they'd written during the war years at M.I.T. for military use. It was the standard work, about ten books, an M.I.T. Series book on the atmosphere, and there was an article by Hogg explaining exactly in detail how the radiation from the atmosphere worked and so on and so forth, and giving the formulae, and plugging the formulae in. Then there was, depending on the humidity, you would expect the temperature of the counter to fluctuate by several degrees. So that was the end of my 3 cm survey.

Dick

Who was the author?

Westerhout

Hogg. A Hogg from way back when. I mean, a Hogg who was famous in that general radio physics area in the forties.

Dick

What do you remember of NRAO when you were there? Because that was very early in its history.

Westerhout

That was great fun. That was great fun. I was the second outsider observer. George Field was the first. George Field wanted to look at...there was already a rudimentary 21 cm line receiver on the 85-foot telescope which had been put into operation in March. I got there in early May.

Dick

But they were going to look at the Zeeman effect or something.

Westerhout

No, Field was looking for galaxies of very large red shifts. I forget exactly what the detail was.

Dick

Of course, Frank Drake was there at the time.

Westerhout

And Frank Drake was there, and Frank Drake had set up...I think it was called the Iron Maiden, a huge machine to measure the brightness of the planets. The idea was that at these short wavelengths, 3 cm, it was the first time there was a telescope available that could go all the way to 3 cm. At these short wavelengths, you could do a very good job of measuring the temperatures of the planets, but they went overboard and the machine never properly worked. Then I started that survey on the telescope, so basically I was the third thing that was being done with that, and that survey did not succeed.

Dick

When you were there, did you talk to Drake about the Ozma Project that was going on, or was that not a subject of discussion?

Westerhout

That was not really a subject of discussion, no. I'm sure we discussed it, but I can't remember it as a subject of discussion, because that was just about the time that Morrison and Cocconi wrote their first paper. I'm sure we all discussed that, and I wouldn't be surprised that it was in that period that it was sought out as something we should do next year, because it was done in 1960, wasn't it?

Dick

No, Drake had actually been working on it for about six months when Cocconi and Morrison came out in September of '59.

Westerhout

Okay. So Drake was already...so we must have discussed it, but I can't recall that we did.

Dick

And Struve would have been the director then.

Westerhout

Struve was the director.

Dick

Did you see anything of him?

Westerhout

I saw a little bit of him. Struve was just coming when I left. I saw him, because he came to inspect the place, but he wasn't actually director yet. Heeschen was acting director. Then Struve came. Of course, one of the things Struve demanded was a 36-inch telescope. He didn't get a 36-inch telescope.

Dick

You mean an optical telescope. [Laughter]

Westerhout

Yes.

Dick

Not being a radio astronomy person. What's the story there? Why was Struve made director of a new national radio astronomy observatory when he had nothing to do with radio astronomy?

Westerhout

I don't know. That was basically...they wanted the biggest name. The board of trustees wanted the biggest name they could find, and they found Struve willing to do it. Then, of course, they tried to get Pawsey, and Pawsey had just accepted the job, and then Pawsey got sick and died here in Washington. I visited him several times, because I knew Pawsey and his wife well, of course. Pawsey was great. He was a great radio astronomer, led that whole group in CSIRO for all those years. It would have been a real coup, but unfortunately he didn't make it. At that point Heeschen was acting [director] again, because Struve simply pined away within two years. Struve had pined away there, and he wanted out. So Heeschen was acting again. Then they finally, when Pawsey died, they made Heeschen director. It was clear, very clear, that Heeschen made a most excellent director of the place. But, you know, the guy came there young, and you know how a board of trustees is. They don't look at the young guys; they want to get somebody who's a big name and so on and so forth. We'd already got the best man here since 1957. What the heck are we looking for any further? Heeschen built up the NRAO, no question about it.

Dick

What was your impression of NRAO, though? They must have been full of all kinds of ideas for projects at that time. Here you'd been working on this for a number of years. Was there cross-fertilization there?

Westerhout

There was cross-fertilization, but there were quite a few of these people at NRAO who all came from Harvard, under Bok. So there were lots of Bok products. I mean, there was Heeschen and Drake, for starters. I think Menon joined the group pretty soon. Also Wade. I have all those Ph.D. theses there in a row, because it was all at the same time. We all got our Ph.D.s sort of between '56 and '59. So it was a group that knew each other well, so it wasn't as though they came up with...I mean, they were impatient because the big telescope simply didn't come off. I mean the big 140-foot. They were already building that in 1959.

Dick

That's right. They had a lot of problems. In fact, that's why they did the 85-foot, so they could start some observing.

Westerhout

Exactly. Drake had built a Jupiter antenna out of wood, something to look at the bursts of Jupiter, and that was there in '59. And, of course, when that telescope came into operation, the 85-foot, the Howard Tatel telescope, Howard Tatel designed it. Howard Tatel was an astronomer at the Carnegie Institution of Washington here, in the Department of Terrestrial Magnetism. He designed an 85-foot telescope, and then DTM didn't have enough money. So they built a 60-foot on the Tatel design. But the design for the 85-foot was then used by Michigan and NRAO to build that. The 60-foot is the one that blew down in Florida last August. We finally got it.

Dick

That was originally Carnegie.

Westerhout

That's the old Howard Tatel DTM, Howard Tatel design. That's the one with which I did those experiments with the high school kids.

Dick

And the 85-foot, which was the original at NRAO, is still there?

Westerhout

It's still there. Still there.

Dick

But not being used?

Westerhout

Yes, it's part of the interferometer.

Dick

Part of our interferometer?

Westerhout

Yes.

Dick

Okay.

Westerhout

Two of the antennas are...one of the two ends are the interferometer. The one in the middle is the VLBI telescope. And the interferometer is used for studying intensity fluctuations of quasars.

Dick

Why don't we wrap up on the Leiden years here. You went back after '59 to Leiden.

Westerhout

I went back after '59 to Leiden.

Dick

And apparently stayed only a couple of years.

Westerhout

Stayed a couple of years. We had already before I left been working extensively on the Benelux Cross. That was another thing. That was Seeger's baby, and Oort believed in it, so Seeger worked on the Benelux Cross. That was the first cross antenna with 325 85-foot telescopes. First it was an antenna made up of cylindrical paraboloid of a mile this way and a whole lot of cylindrical paraboloids that way. That design, on a smaller scale, was frozen, because the Italians liked it so much that they quickly built one. That's the Bologna radio telescope. I'm sure it's still there. Then it was, as I say, 300 or 285 85-foot telescope. Grandiose ideas we had! I even showed what the thing would look like when projected. I made a model on a map of Leiden, and we showed that around.

Dick

You had 300?

Westerhout

It was 300 radio telescopes.

Dick

[Laughter] That sounds like a Project Cyclops.

Westerhout

Yes! It was huge! Then it was at that point...maybe it was 300, but it certainly was over 100. Maybe it was 125. It was the Benelux project. There were quite a few Australians involved in that too, like Christianson. Högborn was also very heavily involved in that. He was a Swede. All sorts of people kept concentrating on Leiden in that project, which was a great time, always an enormous amount of stuff going on.

In '60, I then got in charge of finding out where the hell we were going to put that thing, and first there was a requirement that it should be put on the Belgian-Dutch border. That turned out not to be such a crazy requirement, because that's where the roads from Belgium end into a little path, and the roads from Holland also end, and there are a few main border crossings with fifty miles in between, with nothing. So that wasn't all that difficult. Indeed, I inspected a number of different places with all sorts of planning people from the provinces and the head of this and the head of that, and then the Belgians would come from the other side and we'd meet on the border and discuss how one leg could go along this canal. Then we found that there was a future main road to pass through there, so I went to the railroad authorities to find out how could you build a Faraday cage for three miles, how much would that cost to build a Faraday cage using railroad beams, the overhead wire type.

Dick

A Faraday cage being--

Westerhout

Over the highway that was going to be built there in the future.

Dick

What is a Faraday cage?

Westerhout

Faraday cage is a metal gauze stuff with holes considerably smaller than the wavelengths so that nothing can go out. That's a Faraday cage. If you put your experimentation inside the Faraday cage, you can be guaranteed that nothing of it goes out, but also it's completely radio quiet inside the Faraday cage.

Dick

So what became of the project then?

Westerhout

Well, then the Belgians sort of dropped out, so I then went and worked with the Polder authorities, who were slowly but surely draining the Zuidersee, and at that point they were working on the next Polder, of which they had put the dikes, but they hadn't drained it yet. So we worked with them for a while to see whether they could still change their plans to accommodate that radio telescope in there before they dug all the canals in there, in that big drained area and started building the villages. We got a lot of collaboration there, too. But I was starting to doubt how stable that was going to be. It was still a cross at that point.

Then I went to America permanently, and then a few years later it became an array of twelve telescopes in a line in the northern part of Holland. By then, of course, the amount of space that they needed was a mile, no longer five-by-five miles in a cross. So the problem became easier and easier as time went on. So I was quite involved early in that whole design business.

Dick

So why in the midst of all this excitement did you decide to leave?

Westerhout

Ah! Okay. So we went to the States in 1959. When we came back from the United States, we said, "God almighty, what a lousy country." All the shopping centers, all those tiny little things. No, we'd never want to live there.

Then we got back to Holland for a year and a half, and we suddenly began to realize that there was an enormous amount of freedom, you could do anything you liked, and we got more and more restricted in Holland, restrained from doing things and so on. Cars were much easier. Housing was much easier. We still lived in an apartment, and there was not much chance...eventually if I had made it to professor, which I probably could have relatively soon thereafter, because when I announced to Oort that I was going, he says, "What can I do to keep you here? What job can I offer you?" basically. He did that with Woltjer, too. Woltjer also left. But, hey, that was the way the cookie crumbles.

So we decided, for completely personal reasons, that we wanted to go to the States. So I made it vaguely known to some friends in the States, and, of course, I started getting offers from all over the place--even calling on the phone. [Laughter]

Dick

There would have been lots of opportunities in the States.

Westerhout

There were.

Dick

You'd seen NRAO.

Westerhout

That's right. I was hesitating between a job at NRAO and a job at Berkeley. And I went to Maryland. This offer from Maryland came out of the blue, a five-page offer, extremely well written and so on, all the things they do, all the things they have. And the fact that they were starting astronomy, they wanted me as their new full professor, director of the Astronomy Department, to start it up. "We have already hired Uco Van Wijk [phonetic] and Bill Erikson has promised to come and join us next year." Bill Erikson had just arrived in Leiden at that point. So this was in December, so I took the plane in January and went and inspected it. Henk Van de Hulst said, "You're crazy! That's a football college." It had been a football college, because "Curly" Bird, the president then, built up the football team and did nothing else. Then Elkins was hired as the president of the university. He had been a Rhodes Scholar, he had been a football player in his young days, and they thought, "Oh, here we go." Well, Elkins abandoned the football team and made it into a scholarly place, and that had been going on for about four years. Elkins had hired this young guy Toll to head up the Physics Department, and Toll in turn hired a number of bright guys, so the Physics Department was way on its way up. I checked with a number of other people around, of course. So I came back and I said to Henk Van de Hulst, "You're wrong. It ain't no longer a football college. That's where I'm going."

Dick

We've only got a minute left.

Westerhout

The interesting part of that, of course, was the fact that we went strictly because we didn't like Holland anymore, not because we didn't like Dutch astronomy. I simply wanted to start a new life. The challenge of starting from scratch a new astronomy department was very strong, although I would have been very happy an NRAO or working with Harold Weaver at Berkeley also.

Dick

Is there anything you want to say just to summarize the Leiden years, then? And the next time we'll start with Maryland.

Westerhout

Summarize the Leiden years?

Dick

I think we've pretty well covered it.

Westerhout

We've pretty well covered it. I see. This is the Leiden years. A very small fraction of the Leiden years, is all I can say.

Dick

Good.

End Part 1 Tape Side B