[Hvatum, 1963]
Hvatum, 1963. (Photo courtesy of NRAO/AUI/NSF)

[Hvatum with his bicycle, undated]
Hvatum with his bicycle, undated. (Photo courtesy of NRAO/AUI/NSF)

[Hvatum, 1980]
Hvatum, 1980. (Photo courtesy of NRAO/AUI/NSF)


NATIONAL RADIO ASTRONOMY OBSERVATORY ARCHIVES

Papers of Woodruff T. Sullivan III: Tapes Series

Interview with Hein Hvatum
At NRAO, Charlottesville, Virginia
May 23, 1985
Interview Time: 50 minutes
Transcribed by Sierra Smith

Note: The interview listed below was either transcribed as part of Sullivan's research for his book, Cosmic Noise: A History or Early Radio Astronomy (Cambridge University Press, 2009) or was transcribed in the NRAO Archives by Sierra Smith in 2012-2013. The transcription may have been read and edited for clarity by Sullivan, and may have also been read and edited by the interviewee. Any notes added in the reading/editing process by Sullivan, the interviewee, or others who read the transcript have been included in brackets. If the interview was transcribed for Sullivan, the original typescript of the interview is available in the NRAO Archives. Sullivan's notes about each interview are available on the individual interviewee's Web page. During processing, full names of institutions and people were added in brackets and if especially long the interview was split into parts reflecting the sides of the original audio cassette tapes. We are grateful for the 2011 Herbert C. Pollock Award from Dudley Observatory which funded digitization of the original cassette tapes, and for a 2012 grant from American Institute of Physics, Center for the History of Physics, which funded the work of posting these interviews to the Web.

Sullivan

Ok this is 23 May 1985 at NRAO in Charlottesville and talking with Hein Hvatum. Well can you tell me first of all what your training was and then when you first came in contact with radio astronomy?

Hvatum

Well, I got to GŲteborg, Sweden in I think it was 1948 and I started studying at Chalmers [University of Technology] for electrical engineering and I was at the same time Professor [Olef E. H.] Rydbeckís assistant, thatís how I started actually so I was not the kind of student who went through the school in the normal way. He arranged for me to take this course and that course and so forth. The whole thing was a random approach to studies, I think, and I got my masterís degree in í53, yeah, I think it was in í53. This is so long time ago. I feel like I belong in the Smithsonian when you ask these questions. Then I continued there and got my Ph.D. in Ď57. At that point, I moved here as a post doc starting in Green Bank and Iíve been here ever since.

Sullivan

Weíll come back to the Green Bank part but when did you first learn about or come into contact with radio astronomy?

Hvatum

Well that was with Rydbeck, of course, he was interested in that. We had a little station outside GŲteborg, a small little cabin there where he did all kinds of experiments with the ionosphere. He had field strength meters, you know, and these graph recorders that you donít see any more and so forth and I got involved in that, keeping that station running for him and so forth.

Sullivan

Was this what became Onsala?

Hvatum

No, this was much closer to it. It became Onsala in a sense but it wasnít the same place.

Sullivan

I see, ok.

Hvatum

And then he got interested in radio echoes from meteors trails and that came about from his friendship with Bernard Lovell and [Robert] Hanbury Brown and those kinds of people from Jodrell Bank. And he wanted me to build a radar at 33 MHz for those kind of investigations.

Sullivan

What stage are we talking about now? For your masterís?

Hvatum

As a matter of fact, that became my masterís thesis in the end. This must have been in 1949-í50 there about that we did this first meteor...

Sullivan

So this was still while you were an undergraduate?

Hvatum

Oh yes, as I said, I was working for him part time. Now you have to realize what he calls half time is 12 hours a day so it wasnít that easy to study at the same time but it worked. And I built that thing which was more or less a copy, a modified copy, of an ionospheric [?] we had had done a year or two before. So I put it up not out at the first station because at the same time, this must have been around 1950, he got this area out in Onsala. It was a donation and we went out there and started digging ditches. You know how things of that sort start and we installed that thing there, the transmitter in a bus in an adjacent area about four or five miles away so we didnít have any interference with the receiver from the ground wave. And we put the receiver in a little house out there and as a matter of fact, when they built that house out there in 1950, I think it was, my wife and I lived out there that winter and we didnít have a road or anything like that. We carried all stuff. It was sort of pioneering but fun. And that was the first thing and we then recorded meteors every night. We were not allowed to run the transmitter, it was high power 100 kilowatts, we couldnít run it during the day because it interfered with the local radio stations. Now Rydbeck wasnít the kind of guy who paid too much attention to the authorities, you know, but in this case he was careful. And then we (?) the whole thing a little bit, I remember we made I think one of the first shift registers in the world using six SM72s and we just shifted the echoes time wise so you could count how many echoes between 100 and 105 kilometers and so forth to make statistics out of it. Nothing scientific came out of that.

Sullivan

Thatís what I was thinking. I donít remember any publications.

Hvatum

No, nothing came out of that. Before Bertil-Anders-Lindblad, who was one of those Lindblad that there are several of in astronomy, he got interested in that and he wanted to correlate optical sightings of meteors with this so we set up a system out in Onsala where he had a bunch of students and they were lying therein chairs and they had a button and I put in on the scope a little dot whenever they pressed the button. And what I did, they pressed the button and I put on the chart where that was and he correlated that with the echo and he published some.

Sullivan

Right. This is B. L. Lindblad, right?

Hvatum

B.A. Lindblad.

Sullivan

B.A. Lindbald.

Hvatum

B.A. Lindbald right. He is a cousin, I think, of [?] Lindblad. I think so because I think it was Big (Bertil?). I think it was his brother but Iím not sure about that.

Sullivan

What was the antenna that you were using?

Hvatum

Well, the transmit antenna was just a half wave dipole, a quarter wave above ground, and the receiving antenna was the same most of the time but in certain experiments where he wanted to concentrate on a certain part of the sky we used one of these WŁrzburg antennas we had and he mounted four [?] on it.

Sullivan

Iíve actually seen that in Onsala.

Hvatum

We used that WŁrzburg only as a support for those four [?].

Sullivan

And the WŁrzburg came from where?

Hvatum

It came from Norway. There were Germans who had put up a whole bunch along the Norwegian coast and all the way down into France actually.

Sullivan

WŁrzburg were never used for passive radio astronomy?

Hvatum

Oh yes, they were.

Sullivan

At Onsala?

Hvatum

Oh yes.

Sullivan

I would like to hear about that.

Hvatum

We picked up four of them in, I think, in northern radar stations and I went up there with a crew from the machine shop who were sent up there with little screw drivers to take out the parts. That was a fantastic time. Well, anyway we got this whole thing shipped to Sweden and put it together. We could salvage only three of the reflectors so we put up one the way we just talked about on a vertical axis, and then we took two other and put it on a polar axis. We just tilted the whole thing like they had done in Boulder, I think that was done in Boulder a year before. We just copied that.

Sullivan

These were the giant WŁrzburgs?

Hvatum

Yeah, 7.5 meters, thatís right. And we put up that one we talked about from radar was just put some place. The others were put on an east-west baseline for an interferometer arrangement.

Sullivan

I see. What time are we talking about now?

Hvatum

We are talking about í50, í51 I think.

Sullivan

That early?

Hvatum

Yeah, that was one of the first things we did at Onsala so if we can find out when the Onsala Observatory actually became serious. There were a whole bunch of things going on there because you wanted it to be protected from interference you know so you had that going on but it didnít become official right away, you know how it goes, we started digging and so forth.

Sullivan

So what was the purpose of the east-west interferometer?

Hvatum

That was for solar work. We made receivers for 10 cm and 21 cm and now thatís all we had on the WŁrzburgs, I think.

Sullivan

This publication quotes 200 for the eclipse anyway.

Hvatum

Yeah right, the fourth WŁrzburg or was it five, no that wasnít a WŁrzburg. Itís so long ago I canít remember. We built two antenna mattresses, we called them, 450 MHz and I donít remember how large they were but there were, I think it was four antennas horizontally.

Sullivan

Four by four?

Hvatum

No, much more than four the other way. They were [?] you see and they could tilt in elevation but if I remember correctly, they were transit instruments but they were also put up as an interferometer and thatís what that frequency was.

Sullivan

To look at the Sun once a day?

Hvatum

Yeah, right. Well once a day lasted sometime [?]. The beam width in that direction was quite wide actually.

Sullivan

And that was two meters?

Hvatum

That was two meters, yeah.

Sullivan

Once again Iím not familiar with any scientific publications that came out of the solar work in the early Ď50s from Rydbeckís group. It sound like you had a lot of equipment there.

Hvatum

I think that Rydbeckís group in those days could be characterized as being engineers and only engineers. We were interested in building this stuff, making low noise receivers, making it work, pretty pictures and so forth but nothing was ever published. There were [?] reasons for it. I was not the publishing kind and the other people who worked, my colleagues, were not either. They were engineers and wanted to do work.

Sullivan

Well, Rydbeck was the leader and was that way apparently also.

Hvatum

Thatís right, he was that way too. He was in some respects I think he was afraid of publishing certain things. He wanted to be sure first so he was a bit nervous about it but he wanted to get into the hydrogen line, I remember that and one job we had was to build a receiver for that and I went down to Holland to see [Christiaan Alexander "Lex"] Muller.

Sullivan

What time was this now? It was discovered in March í51.

Hvatum

Yeah, that was about the next year. It must have been í52 because I visited Muller when they were still were in [?] and the whole thing was on the original German radar antenna there and when I got there, they had just had a fire, I think or there had been a fire.

Sullivan

And that was associated with the discovery.

Hvatum

Thatís right and I think Muller felt that fire prevented them from being the first.

Sullivan

Thatís another whole thing. I can tell you about that later.

Hvatum

So Doc [Harold "Doc" Irving] Ewen and company got there first. And I learned a lot from Muller there. I spent a couple of days with him actually and I also went, I remember, to Phillips and [?] and I met Charles Seeger who was there at the time and he had just developed some low noise, I mean you laugh at it today, but it was low noise at that time, tube preampliflier for, I think it was the 150 200 MHz range somewhere using some [lighthouse?] type tube and [???]. Then we tried to copy and we succeeded in making a pretty good receiver. And then when I got home again, we built and I donít remember the time it took, maybe a year or a year and a half, and we had a simple sweeping type scanning line receiver and we got a line.

Sullivan

So that would be í53 or something?

Hvatum

Yeah, something like that.

Sullivan

But I gather you werenít going to scientific conferences either. You were just reading about these things in journals.

Hvatum

Yeah, thatís right. Our main contact with the outside world was through visits from the outside. Rydbeck was a very well known person and I can remember particularly when [Wilbur Norman "Chris"] Christiansen and [Joseph L.] Pawsey and [Kevin C.] Westfold, I think his name was, came and visited. That was very, very productive for us and useful and I remember Christiansen and I became very good friends. We sort of clicked and we corresponded later and so forth. That was stimulus from the outside. We were also visited by Bernard Lovell and Hanbury Brown once. They came over and wanted to see what we had done in the meteor radar thing because we had been technical types. You know, we had better equipment than they had at that time anyway. Itís just that we didnít do much with it.

Sullivan

Rydbeck, what do you think the main reason that he was known for? It was his ionosphere work?

Hvatum

Ionosphere, oh yes

Sullivan

What more exactly? Can you remind me?

Hvatum

I think that it was something the [???]. He developed something, theory of the reflection.

Sullivan

Thatís what I thought. It was theory actually notÖ

Hvatum

He was a theoretician. There was no question about it but thatís how he became known.

Sullivan

But he became the head of a giant electronics lab?

Hvatum

Well it was normally lab research but his job at Chalmers was to train engineers so he had to be the engineering type so to speak.

Sullivan

So you mean there were some theoretical engineering things going on as well as practical?

Hvatum

Yes, yes. He had in his lab radio astronomy started out in a very small part. It was a graduate student and maybe a technician who fooled around with it. But the main lab was developing traveling wave tubes at the time and things of that sort, vacuum tube stuff, that was the main thrust at the time in that lab.

Sullivan

Ok well letís go back, you got a successful 21 cm hydrogen line receiver, did you do any observations with that?

Hvatum

I did not. I did not do anything. In a way, Iím sorry to say that during that period we just improved baselines and things like that. I think we published some pictures but there was nothing discovered at all during the time I was there. I think later things happened but during the time I was there nothing.

Sullivan

So you sort of moved from one project to the next as soon as the equipment was working nicely.

Hvatum

Thatís right so then came 1954 where we had this eclipse that was total over the observatory and it was one of the longer ones if I remember correctly, I think it lasted for two minutes.

Sullivan

The totality actually passed over Onsala?

Hvatum

Very close, I think we were just at the edge so Rydbeck decided as my Ph.D. thesis I should do the whole thing. So what I did, not alone, there were other people helping there, I built the receiver for 10cm continuum, for 21 cm continuum, and for 150 MHz for these mattresses we had. I also oversaw the building of a scanning ionospheric recorder.

Sullivan

So you see the effect on the ionosphere at the same time?

Hvatum

Yeah, right and we also put together a couple of short wave receiving systems just to measure the field strength from some short wave transmitters, I think, in northern Germany so we can see what happened. We worked and of course, there was a deadline on this and by gosh, even the day before things didnít work the way they should. By then Emile Blum [Emile-Jacques Blum] whom I had known from very early in the game, from 1951 I think, came up with a group and I do not remember the names of those. One was a priest, I think.

Sullivan

That would be [[Paul] Simon?] maybe?

Hvatum

Yeah [Simon?], thatís right. And they had some receivers with them and they borrowed that antenna we had the radar stuff on and I think they also borrowed one of the mattresses but Iím not clear on that. So we did the whole thing together and for some peculiar reason his equipment worked before the eclipse and ours didnít and during the eclipse ours worked and his didnít too well anyway. So that was sort of a strange thing that happened.

Sullivan

So you wrote that up in 1959 it appears as your thesis, is that correct?

Hvatum

No, my thesis was before then but it wasnít published right away. I mean I wrote it up earlier because I got my Ph.D. in í57.

Sullivan

I see so there is a Chalmers report in í59?

Hvatum

Yeah, thatís right. It sort of drifted around for awhile, I think. You see I wasnít interested in that publication thing being an engineer. I just wanted to move to the next project and build something but what we did, I had to do some "science." Equipment wasnít enough. We looked at all the eclipse curves and it turned out that the sun was quiet, very quiet. I think it was unusually quiet at the time and of course at that time resolution was the thing you were after in solar eclipses and since there were no bright spots that were cut by the moon, there was nothing to get out of it, you see, and the brightness distribution on the sun as deduced from the eclipse curve is a very loose coupling in a way. We had all kinds of models that satisfy that curve. I could never make it as good as we thought it should be and then we got this idea that we...

End of Tape 164A

Sullivan Tape 164B

Sullivan

Ok this is continuing with Hein Hvatum on 23 May í85.

The tape is somewhat garbled for the first ~4 minutes

Hvatum

Well, we are taking about this solar brightness distribution and we got such a better match and we thought we had something.

Sullivan

[?] brightening?

Hvatum

[?] brightening, yeah [?] brightening only in the equatorially direction and not in the other and we of course we were [???] and then well anyway that became my thesis and then in that same time frame [???] we had done work with [???] and he showed pictures that had [?] brightening and what I did was I got his pictures and I took this [???]. We didnít have computers at the time and we had to do it by hand and [???] so we were happy about that but we didnít try to make a big discovery out of it because, of course, Christiansen had done it independently in February before we did.

Sullivan

So the solar work was obviously of interest to Rydbeck because it tied [into Onsala?]?

Hvatum

Oh yes, as a matter of fact I think his interest in radio astronomy came from the solar work [???].

Sullivan

Were there any other solar experiments that were done at that time? Was there daily monitoring at that time?

Hvatum

Yes, we did. We monitored at [all these?] frequencies while [?] the eclipse [???] we did but at that time, since I left in í57 you know nothing up to that time had been published, I mean serious. Iím not that familiar with (phrase?)

Sullivan

No, I get the impression until the mid-60s it still continued like that.

Hvatum

Yeah, Rydbeck started [???] well I can remember at URSI [International Union of Radio Science] in...

Sullivan

Was it í54?

Hvatum

Yeah Ď54, I was there and Lovell told me his ideas for a 250 foot telescope and I thought they were crazy and also they [???] when I was in Holland and he told me about his plans for a 25 meter telescope when I came and visited.

Sullivan

[???]

Hvatum

[???]. But during that time frame, Rydbeck [???] and he got this idea [???] but the time I left [???] develop that idea.

Sullivan

That came in the early Ď60s?

Hvatum

Yeah, in the early í60. He also got into solid state, that was actually before I left, and [???] and he had a way of being ahead of everybody else in the idea but his execution was sort of fumbled, I think. For example, the OH line, he talked about that from the time we got the first hydrogen line [???] but there must be something there he said and of course, even with that little telescope, as we know now, we could have found OH [???]

Sullivan

Except the frequencies werenít low enough?

Hvatum

No, but you know that was a thing we could handle...

Sullivan

[absorption ?]?

Hvatum

Thatís right. I mean we could build mixers. I mean this was our strength but anyway we built a mixer but [???] but I still think that when he talked to Bertil, he was more [?] than I was. I think he would claim that if we had put it on the telescope we could have found the absorption or...

Sullivan

The hydrogen absorption?

Hvatum

The OH.

Sullivan

You mean OH absorption, I see.

Hvatum

OH stuff, yeah. We could have discovered all that stuff that Sandy [Sander] Weinreb and company discovered later on.

Sullivan

Ok, I think that covers the Swedish part unless there is something else.

Hvatum

No, I canít think of anything. As I said the main stimulus was visitors. We had [John G.] Bolton came over once, I can remember that, and that was very exciting and I can remember how Rydbeck wanted to milk from him information so we sort of wanted to tape it. We had [wire?] recorders and we had to rig all these things up and he didnít want Bolton to know about it, so all these things went on all the time. We had to figure out how he did it. You see the Australians were very good in equipment at the time. They had all these ideas to stabilize. That was the name of the game, stable amplifiers.

Sullivan

So what was your motivation to go to NRAO?

Hvatum

Well, I knew [John W.] Findlay. Findlay had visited. Everyone with a name was a friend of Rydbeck. Findlay came again back in í53 or about that time and I was at Jodrell Bank. There was some symposium or some radio astronomy thing.

Sullivan

í54 or í55? There were two of them.

Hvatum

Yeah, something like there and Findlay was there and I found out from him that he was going to the United States, you know, to the National Radio Astronomy Observatory. It was the first time I had ever heard about the idea in í55. It wasnít even established yet. There were some ideas. I think there was a meeting in Washington in í54 that sort of started this rolling and I knew Lloyd Berkner.

Sullivan

From the [?]?

Hvatum

No, from Rydbeck again. Lloyd was over many times. He was a very good friend of Rydbeckís and I was always involved in the visiting. We went to dinner together and so forth and Lloyd and I became very good friends. Well, he was much older than I but we were good friends in a sense, you know. And then Rydbeck went to the United States for sabbatical and I was sort of acting in his absence in all things. [???] He is now president of Chalmers. He and I were actually classmates and worked for Rydbeck there. And then I got the idea that I wanted to go over to see what was going on there and I asked him to make some arrangements for me if he could and thatís how I ended up. He called Findlay and he realized, of course, that NRAO was nothing at the time but he knew my interest was building big dishes. They thought that I would fit and so we went over and got here in October í58.

Sullivan

At Green Bank itself?

Hvatum

At Green Bank itself. We lived there. I was a post doc for a year and a half, you know, and that period was the idea and I went back to Sweden for a few months but before I left here I was offered a job as head of the electronics division so I turned around and packed and came over more permanently.

Sullivan

So what did you find at Green Bank and what did you begin working on?

Hvatum

In Green Bank, we came down the road, I remember, and we found this little old farm house next to the road there and out of that door came [David S.] Heeschen. I had met Heeschen and [Frank D.] Drake in Paris. There must have been something going on in í58.

Sullivan

In í58, the Paris Symposium.

Hvatum

Thatís right and I met them there and I learned about Green Bank and so forth, you know, so Heeschen came out and greeted me and I remember Grote Reber came out and to me, of course, he was god.

Sullivan

Thatís the logical conclusion.

Hvatum

Thatís right, yeah, and I was so impressed with the way he behaved and so forth. I was used to this European, you know what I mean.

Sullivan

Right, right.

Hvatum

So then we worked in the farm house. There were no buildings built by us at the time. There was nothing there and we had a little lab in the farm house with two technicians. One is still with us by the way. Dewey Ross is working in Tucson. And I was supposed to work for Findlay but he wasnít there so I got a letter from Findlay that I still have. I can show you. Suggesting things Iím allowed to work on and there was some receivers, you know, to build. So I started with that and in that building we had Frank Drake, Dave Heeschen, and Findlay. Heeschen and Findlay shared an office and [???] and these two technicians and that was NRAO at the time. Well thatís not quite true. That was the testing part of NRAO and we had another building, another farmhouse, where we had some business operations with Frank Callendar and so forth.

Sullivan

But now there is still no antenna there?

Hvatum

No, no antenna. Frank Drake had put up some low frequency stuff for Jupiter, I think. It was an interferometer, a corner reflector type with wires all over it. It was just...

Sullivan

Something to do?

Hvatum

Yeah, I think thatís right. Findlay had started building the Little Big Horn and when he came back, I started worked on switches, front end switches, Dicke switches, you know, using solid state [?] which hadnít been done before and I developed one which became sort of a standard switch for NRAO anyway and then we got receivers. We had a Ewen Knight, I think the company was called at the time, receiver for hydrogen line but, you know, nothing really worked at the time. [?] instrument laboratory I had built a different kind of receiver, a sort of noise compression type thing and that drifted all over and I tried to keep these things running, you know. And then we got the idea letís build our own receiver and antenna instead of buying all these things and at that time the feeling was that we at NRAO should not build things, we should buy. But for some reason either because I convinced them or they, sort of, found out on their own, we sort of drifted into, we got to build it ourselves. So we built up all little lab, you know. We made what we call a standard receiver. It was a cheap way of doing things and the 85 foot telescope was under construction at the time. The building was there when I came, thatís true. The building for that was there but the telescope wasnít and that was put together and to we that was a fantastic thing, a big thing. We had an engineer at AUI [Associated Universities, Inc.] who thought that the telescope was so flimsy that it would fall down in two years and so he canít trust engineers either. And the 140 foot telescope was under construction in the sense that they had just started fooling with it and you know the story of the 140 foot, I guess, all the setbacks.

Sullivan

Well, at the SETI symposium just a couple days ago, we heard it yet again. You know, Frank Drake talked about the early years.

Hvatum

Did you see the film?

Sullivan

No.

Hvatum

There is a film where the whole reflector drops off the crane.

Sullivan

A film of it, I didnít realize that.

Hvatum

We have a film and we were all day there and we had two derricks. The whole thing was a mystery to me, how it would work and one slipped and the whole thing crashed.

Sullivan

And you happened to be filming then?

Hvatum

Filming then, yes, and there was a film of the transportation of the main shaft. If you are interested in that kind of thing, you should try to get a hold of it.

Sullivan

Well, I have seen a film on the construction of the 140 foot but I donít remember seeing the dropping.

Hvatum

Yes, that should be in there. Maybe we no longer show that anymore. That was sort of a blunder.

Sullivan

Let me just ask you going back to the Little Big Horn, as you called it, were there two horns for Cas A?

Hvatum

No.

Sullivan

There was just the one horn?

Hvatum

Yes, there was that long 128 foot horn and that was being built. That was Findlayís project to do this absolute calibration.

Sullivan

Yes, Iíve talked to him about that.

Hvatum

And then he wanted me involved in it because he didnít want to do it alone so I worked with him on that and once it was all built, we did all the work and that ended up as a publication by Findlay and myself and Bill Walter, who was in on it too.

Sullivan

About the standard flux of Cas A and so forth?

Hvatum

Yeah, right and we did everything over and over and over again. We measured every night, you know, and we calibrated. All these things sound easy today but at that time it wasnít that easy to get an absolute calibration and we did all kinds of things. We even used the 85 foot telescope to measure the background around Cas because it has a narrow beam so we could sort of [convolve?] the Little Big Horn beam with the [???] so you can resolve Cas only. We did that and the interesting thing if you look at the paper, although we checked every figure ten thousand times. We were so mad at the whole paper in the end but Findlay said it has to be right. We were off by a factor of 1026. We forgot that factor in the end.

Sullivan

Better that than 20%.

Hvatum

Yeah, thatís right. We also discovered, I remember, that Cas changed, drifted, the intensity changed and dropped.

Sullivan

This was after the result from Cambridge came out?

Hvatum

Oh, yes. Sorry, I shouldnít say that we discovered it. I was wrong. We confirmed that discovery. We did it through an absolute measurement. We did not compare with Cygnus.

Sullivan

And they were going back to observations from eight years before so you had much more accurate data on a shorter baseline so you could actually see the effect.

Hvatum

We could see the effect without comparing the other source because I think the question asked that was asked at the time was what is it that varies. Heeschen have these 42 foot thing. You donít remember that transit telescope in Green Bank where he did long term comparisons between a number of sources, I forget which they were.

Sullivan

And what about that?

Hvatum

I forget now what came out of that.

Sullivan

And Cas A was one of them?

Hvatum

Cas A I think was one of them, Cygnus, and then Taurus. You know, general sources for the time, I think.

Sullivan

What was the purpose of the 40 foot?

Hvatum

That was just to do that, the long term comparison of the intensity of the sources.

Sullivan

That was the main reason the antenna was built?

Hvatum

Yes, that was because Heeschen wanted a cheap antenna that could stand there undisturbed so it was totally automatic...

Sullivan

I see.

Hvatum

As a matter of fact, I can remember we made a test thereby, we had a thermal problem in the lab so we experimented by digging a hole in the ground and making an underground laboratory. Youíve seen it, havenít you?

Sullivan

Right.

Hvatum

Right, itís dug under and it turned out to be successful. It was a very stable temperature unit.

Sullivan

You havenít mentioned Otto Struve?

Hvatum

No, no.

Sullivan

He wasnít there when you arrived?

Hvatum

No, he wasnít there. The director of NRAO was Lloyd Berkner. He made himself acting director when I arrived.

Sullivan

But did he work at the site?

Hvatum

No, no, you know he was one of the big, big wheels.

Sullivan

Yeah, thatís what I thought. In absentia director.

Hvatum

That was no director. I mean there was Findlay, Heeschen, Drake, and myself and we were sort of drifting around having a good time. Thatís all it was at the time.

Sullivan

So when [Otto] Struve arrived what a year later after you arrived?

Hvatum

Yes, he did. He actually arrived either just when I went back to Sweden or when I was there because he was the director when I came back again.

Sullivan

Now did that change the mode of operation there?

Hvatum

Not really.

Sullivan

Did that change the atmosphere in any way?

Hvatum

Well, yes it became more of an observatory but it didnít change anything I can think of.

Sullivan

What do you see his role as in the couple of years he was there? Was it pretty minimal or do you think that he had a major influence of some kind?

Hvatum

I donít think that there was anything to remember about what he did. He was stability. I donít think he fit in completely. He was an old timer and an optical man. He was a good guy and we liked him, I think.

Sullivan

But he knew nothing about radio techniques?

Hvatum

No, he didnít know anything about that and of course, at that time we had the first troubles with the 140 foot and that probably kept him busy too, you know, and he wasnít the kind of man who liked to deal with those kind of problems so in my view of his tenure as director doesnít stand out as being anything particularly good or bad and anything like that. I might forget something.

Sullivan

That only lasted till í61, I guess it was.

Hvatum

Then [Joseph L.] Pawsey.

Sullivan

Then the Pawsey story.

Hvatum

Yes and I remember I was so happy because I knew Pawsey quite well from before and when he came, he and I traveled up to AIL [Airborne Instruments Laboratory] to, I remember, to look at something. We were supposed to go. We went up to New York and he had something else to do there and all of a sudden I got the call and he said that he didnít feel too good and couldnít go so I went to AIL. I thought he had a cold or something and then later he was back in Green Bank again for a few days. He wasnít officially the director yet. I think he hadnít taken affect so to speak yet and then we learned about his serious illness. And I think, Bill Sweet, who is one of the trustees of AUI, who is a brain surgeon at Boston General Hospital, got involved in this.

Sullivan

Yeah, he did go to Boston.

Hvatum

Yeah, and I remember that sort of in confidence Bill Sweet told me there is nothing that can be done about it and he died...

Sullivan

Very soon after. He went to Australia for a few months.

Hvatum

Thatís right and then, of course, came that interesting period where they were searching for a director and I was part of some of those meetings, you know. [Isidor Isaac] Rabi, of course, was the driving force at AUI at the time and they were searching all over for a director. All of a sudden, Rabi, out of the blue- probably not out of the blue but from my point of view it was-decided Heeschen should be acting director. Well, that was fine with me but that was sort of a surprising.

Sullivan

They were looking for someone of Pawseyís experience.

Hvatum

Well, the Pawsey, Struve kind of level, you know, and here was a young guy fresh out of school, so to speak. And it didnít take long for me to realize that they had made a good choice. No question about it. And as you know, he became permanent director the next fall.

Sullivan

Yeah, a year later. Well, looking over those early í60s years, once you had an 85 foot dish and I guess, you were building receivers primarily for that dish as well as working with the horn there, what do you remember as the outstanding events of that time? Of course, you werenít participating in the scientific results so much but still.

Hvatum

The most exciting thing for me was the Jupiter thing because Frank and I were neighbors and we were good friends. We talked a lot about things like that and he probably taught me more about radio astronomy than anyone else and he came one day and said, you know I think, it was [Russell M.] Sloanaker had discovered something at 10 cm.

Sullivan

Right, an excess of radiation.

Hvatum

Yeah, thatís right. There was something wrong...

Sullivan

At 10 cm. More than you expected from thermal.

Hvatum

Yeah, thatís right. I think Frank called it something wrong with Jupiter and I didnít catch on. This whole thing didnít mean all that much to me but then he said he did some measurements at 21 cm and we had a feed horn on the 85 foot that combined 21 and 3. That was a coaxial arrangement there and he came to me and said that you know we got the measurement at a much lower frequency, could you make a feed for 400, 450, that there about, that I could use on this telescope at the same time I have the 21 cm feed on so we can do comparisons. I said sure we can do that. And I built it with my own hands, you know, cutting out the big thing for these dipoles and the trick, of course, was to do it so that it didnít disturb the patterns of the other frequencies and at the same time have the right pattern. You know, all those sort of things and match and so forth. So it took me a week or two, I guess, to get that done and then we put it up on the telescope and to my surprise, I was more surprised than anyone, it worked. You know we didnít have any more problems. And then the first night we had it up there, Frank said letís try. So we went down there and we went on off Jupiter, on off Jupiter, on off, on off, you know, and you could see it. It wasnít anything that you had to fish out of the noise. It was really strong and he was very, very excited about the whole thing.

Sullivan

This was 68 cm apparently, looking at it.

Hvatum

Yes, 440 MHz I think it was. And we did some quick calculations and Jupiter set, I remember, so it all disappeared. We did some very quick calculations. I think the brightness temperature must have been 30,000į or something or that sort and Frank said, "Boy, we have really gotten on to something here." And we continued those measurements for some time and everything matched, you know. So there was an URSI in London.

Sullivan

Thatís right, 1968.

Hvatum

And I was there. I left that fall to go back to Sweden after I had done these measurements and I was there and somehow there was some other person who had done something similar and claimed that our results were wrong. I forget who that was. Frank and I couldnít understand what was wrong with it and when I came back again, we measured again and it had changed. Frank claimed that had to do-well, first of all, his idea of the Van Allen Belts came up at that time and he claimed it had to do with a burst. There had been a flare on the sun the right number of days before we happened to view Jupiter so all these things matched. But I was still concerned about the whole thing, you know, so I went back and measured what we called anti-Jupiter. It is the point where Jupiter was when we did the measurements and there was a little bump there.

Sullivan

A little radio source.

Hvatum

Yeah, right. So I mapped that whole thing very carefully and subtracted that map and now still there was an enhancement, there was no question about it. But now the curve wasnít going like that...

Sullivan

You reduced it considerably. Thatís interesting.

Hvatum

And then at some stage, we said we had to publish it but Iím not the writing kind. At that time, I donít think Frank wanted to write it either. So we talked about it and we kept teasing each other. Have you written anything- I said no. Have you written anything? But he published it. The only publication that we ever came up with was an abstract for AAS [American Astronomical Society] meeting.

Sullivan

Right, the meeting was in August í59.

Hvatum

Yeah. That is the only publication that ever came out of that measurement.

Sullivan

Because you didnít quite have the confidence?

Hvatum

Thatís right. Well, and once we had the confidence we didnít want to do anything more about it. I think if either Frank or I had been excited enough at that time to write something about it I think we would have done it but we never did.

Sullivan

Well in closing let me ask you about the concept of a national observatory, which was a new idea relative to other radio astronomy groups, now talking only about these first five years at Green Bank or so, do you think it worked well or not? What do you see as the pros and cons of the idea of a national observatory as opposed to a university group or something like Chalmers?

Hvatum

I think that it has potential for disaster in the sense that as has happened at other institutions of this kind they become their own thing. I think that without knowing in that NRAO was in a way on the wrong track in the beginning because we had all the money. We were actually swimming in money and there was not that much at the time but relative to what we were able to do and the people we had, it was nothing that we couldnít get right into. And I think there is potential disaster in this kind of thing. And I think it was Heeschen and only his ideas and how he pushed the user concept that we are a service organization for the users and that the users get involved and also this idea of having our own scientists compete with the outside on an equal basis. They had no privilege. He saw to it that there was absolutely no privilege or no advantage of being an NRAO staff except that you were here.

Sullivan

For access to telescope time?

Hvatum

Right, now more access at all. As a matter of fact, I think that he mentioned [?] in private that his idea was that the size of the staff of NRAO should be adjusted in the long run so that they only got 25-30% of the time and he never wanted to decide that. The goal was 25-30%. If it was too high then he didnít hire people and if was too low then he hired people and thatís the way you can make it totally democratic is not the word but you know what I mean.

Sullivan

But no this is getting more into the Ď60s?

Hvatum

No, he started that right from the beginning. I think that was sort of an idea he felt. I think he saw the danger himself.

Sullivan

Now letís discuss this danger you are referring to. You had lots of money, you were a small group of young radio astronomers, and what is the danger precisely?

Hvatum

The danger is that NRAO or such a national organization can dominate the whole thing and take all the money and we have been criticized for being rich. You know a university had a grant for $200,000...

Sullivan

Still today that argument is going on.

Hvatum

Yeah, right but I think today that the VLA and those instruments could not exist without...

Sullivan

Nevertheless, the arguments still go on but at that time even then the argument would go on, why do they get such a high amount of money per person.

Hvatum

I think it was a wait and see period in the early stages where the university people felt this is probably the right way of doing it, letís see what happens. Boy, they have a lot of money up there; we are struggling here but letís be quiet for a while and see what happens, give them a chance. And I think if Heeschen hadnít become director, I shouldnít say that, if some director hadnít seen that I think NRAO could have been sort of a center of excellence in science in its own right and sort of to the exclusion of these outside things. I think with the referee system we had and all that that Heeschen introduced I think we made it.

Sullivan

Well, thank you very much.

Hvatum

Ok.

Sullivan

That ends the interview with Hein Hvatum on 25 May 1985.


Modified on Tuesday, 29-Jan-2013 14:22:57 EST by Ellen Bouton, Archivist (Questions or feedback)