[Wade, 1971]
Wade, 1971 (Photo courtesy of NRAO/AUI/NSF)


[Wade]
Wade, undated (Photo courtesy of NRAO/AUI/NSF)


NATIONAL RADIO ASTRONOMY OBSERVATORY ARCHIVES

Papers of Woodruff T. Sullivan III: Tapes Series

Interview with Campbell M. Wade
At VLA site, New Mexico
May 1, 1978
Interview Time: 58 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 talking with Cam Wade on 1 May í78 at the VLA site in New Mexico. So can you tell me when you first came into contact, I guess at Harvard, with radio astronomy, how that came about?

Wade

First real contact was with Bart Bok. I returned to Harvard from a little sojourn in the Army before the spring term of 1952 and I was rather brash, full of ideas, no respect for difficulties, and also being very sick of playing solider. I was anxious to do something that was solidly civilian so I button-holed Bart Bok about seeing if there was something we could do in radio astronomy at Harvard and he had been thinking along the same line himself so he was very receptive and there were a couple of graduate students there who also had similar interests named [David S.] Heeschen and [A. Edward] Lilley and so Bart Bok put together a little group consisting of two graduate students and one undergraduate; I being the latter.

Sullivan

And you were a junior or something like that?

Wade

I was a junior. I came back as a junior, an elderly junior as I was 21 years old but at least I was draft proof and didnít have to worry about looking good to a draft board which actually was an advantage over the next few years. And anyway, we went down to see Doc [Harold "Doc" Irving] Ewen. This was within a year of the time when Ewen had found the 21 cm line and his original receiver was still set up in the original place in the Cruft Lab. The horn antenna was still sticking out the window over one of the entrances to the Cruft Lab and all of the stuff was there so Heeschen, Lilley, and I went down there and Doc Ewen showed us the equipment, how you set it up, and I was first introduced to Ewenís rather remarkable collection of jargon. I found out that there is no such thing in a vacuum tube in that receiver. They were all bottles and there were terms that sounded rather quaint to me at the time and setting up the frequency, of course, you had to pull various crystals and so on. There is a 10 megacycle reference frequency piped through the lab, you can tap into it in any room, and there is a set of, as I recall, three crystals and beating these in various combinations, you got the frequencies you needed in the system. And so Doc began talking about beating these crystals against a rail. Well, I had the idea of taking and smashing them against a piece of railroad track but that turned out that wasnít it, quite another context. Somewhere I still have quite a set of notes on how you set up that equipment and some block diagrams and maybe even some schematics but it was very flashed up but anyway, the three of us learned how to set up Ewenís receiver which was a very primitive thing.

Sullivan

Yeah, Iíve seen pictures of the thing.

Wade

And we had very vague ideas of how we would use it but it was setting there unused.

Sullivan

It had been unused since the original discovery, I think.

Wade

I believe it had been, yes, to my knowledge it had been unused but it still worked and Ewen was fond to pointing out that it was certainly a reliable rain gauge. In fact, where the horn came in through the window, it went into a bit of an elbow and then it went straight. It had that set up so it would catch Orion at transit and at the bottom of the wave guide when it made the bend, there was a cork and a huge jar underneath so in rainy weather, you just pulled the cork and the rain would come in, of course, and there was pretty good collision cross-section for raindrops- nasty collection of water he had there.

Sullivan

You say it was set up for Orion. I havenít heard that before. I thought they set it up at a [convenient?] angle that they knew would cut somewhere through the Milky Way.

Wade

Well, we are going on a long stretch of recollection here but it is my recollection that he set it up to catch the Orion nebula transit. This would be what, -5į back. My visible image certainly has that horn pointing at about the right elevation.

Sullivan

Yeah, they were near 0. They went through Ophiucus, I know, in the galactic plane. I canít quite remember what the exact dec was but thatís an interesting point. Iíll check on that. I havenít talked to Ewen yet.

Wade

Yeah, you check on that because Iím just going on my recollection here and that was 1952, itís now 1978, thatís 26 years- one can forget.

Sullivan

But it was not adjustable in any sense. There was one declination.

Wade

There was and you made discoveries at that dec and that was it. Of course, there was a big, fat beam and with the [hydrogen?] line, you filled the beam. Of course, we didnít really fill it in any one velocity, I suppose, in those parts of the sky.

Sullivan

Let me ask you another question, you mentioned the Cruft Laboratory?

Wade

Cruft.

Sullivan

I thought it was the Lyman Laboratory.

Wade

There was a complex of buildings. Iíve always thought of that as Cruft. I could be wrong. Doc Ewen could straighten you out on it but it is my recollection that it is Cruft. It could be the Lyman too. Itís all one complex and you could walk from one to another without getting wet on a rainy day.

Sullivan

So what were you going to do with this thing?

Wade

Well, that was very vague. The main thing was to get a signal and weíd figure it out. Well, somewhere along that spring, the receiver disappeared. It turned up in Washington at Merle Tuveís operation, DTM [Department of Terrestrial Magnetism], and nobody in the Harvard Astronomy Department was any the wiser until the thing was accomplished. Well, Doc Ewen was, of course, starting his company, Ewen Knight at that stage, and he naturally offered to provide a receiver which turned out to be the one we used for several years- the basic receiver, we modified it- but my thesis and quite a few others came off that several years later. Well, we waffled around. There were problems getting financial support. We needed an antenna. It was obvious that we werenít going to do any serious science with that thing sticking out of a window there. It was all wrong and we did need proper equipment. It was really no loss in retrospective to miss out on his original receiver. It had done its job and I believe it never did integrate things at DTM either.

Sullivan

So you never did get a signal out of it again?

Wade

Not while I was watching. I donít know if Dave and Ed went down and maybe coaxed something out. I doubt it. So letís see, I canít recall dates. Things looked so discouraging on the financing that Bok actually got out of it at one stage and [Donald H.] Menzel and [Fred L.] Whipple took it over and they were going to exploit their contacts in the military. This is back when things were sort of free and easy on the military funding of research and well, they retained the students but Bart Bok got out. And I was appalled, well not quite- perhaps youíre not going to print this [???]- Menzel and Whipple took us three students to lunch- where was it?- the Commander Hotel in Cambridge sometime in í52, Iíve forgotten just when, and I sat there aghast listening to them discuss how they would set this up so that it would look good to the military. I kept thinking, my god, if they canít do it honestly, why do it. It surely has merits, you know, but I was very young and green and idealistic- still am- but the point is that it came to naught. Bart Bok picked it up again and managed to get money from the anonymous donor, Mrs. Aggasiz of course. We wound up getting a 24 foot antenna from Kennedy and, if my recollection serves, we were erecting that late in í53- see a fair bit of time had gone by. In the mean time, Doc Ewen had designed and built the receiver which we wound up using and the 24 foot antenna was largely a student effort. We bought the thing but to make it work, student work, it had a hydraulic drive and right ascension. It was a real kluge but it worked. And the way it went together, Dave Heeschen and Ed Lilley worked very much on the antenna, getting things aligned and so on. I worked along with Doc Ewen on some of the receiver assembly. I didnít understand what we were doing. I didnít do any design but at least I put things together. Tom [Thomas A.] Matthews and [T.] Kochu Menon had come into this and they built the hydraulics that drove the thing and by early í54 if I recall, we were actually getting 21 cm profiles. We had a lot of baseline problems and so on but that was normal at that stage. This was a scanning radiometer and it was a kluge. Iíll not go into details but, according to procedure, to get it set up, locked then tracking in frequency.

Sullivan

All of this was supported simply from the Agassiz money?

Wade

I donít recall now. You would want to talk to Bart Bok if you could on this.

Sullivan

I talked to him several years ago but I didnít ask him detailed questions.

Wade

You ought to check him on this because he had to live with it. His recollection would be far more trustworthy than mine and I was an undergraduate still doing courses and didnít live with it and lose sleep over it like he did. In fact, I was basically paid to sweep the floor in the place.

Sullivan

Thatís right, you were still an undergraduate at this stage.

Wade

Yeah.

Sullivan

Did you do an undergraduate thesis or anything like that?

Wade

I didnít. It wasnít expected at Harvard. You could do one if you wanted to but I didnít. Iím lazy. So anyway, we got on the air and certainly in í54 things were running pretty well. Iím having a bit of a question in my mind. I may have been a year wrong. My recollection was late í53 we got that antenna on there but it may have been early í53. This sort of thing you can check out.

Sullivan

These dates Iíve checked out. Was there an anxiousness among the group because you knew the Dutch, for instance, were mapping away at this time?

Wade

Yeah, there was some. I didnít feel it myself. I mean here I was a green undergraduate and all that but Bart Bok certainly felt it, the competition. There was a lot of pressure. I remember so many times he said, "Remember if we donít do it, somebody else will." And I donít think I had the notebook here. I believe it is in my office in Socorro and I ran onto to it when I was repacking moving out here. Anyway, it has a New Yorker cartoon that came out about that time. I cut it out; this was my thesis notebook, loose leaf binder. It was a Charles Adams cartoon showing a couple of headmen getting suited up in their leather jerkins for the dayís work, axes lying in the background and all that. One of them saying to the other, "Well, well, look at it. If we donít do it, someone else will." And so I kept that in my notebook as inspiration. Itís in Socorro. If you want to see if sometime, I will show it to you. It seemed so appropriate at that time. When I found that thing, it carried me right back. Well anyway, we charged along. Bart Bok, I remember, was extremely concerned that we were pointing the antenna correctly and, of course, it was a valid concern. We had it was a 1.4į beam width as I recall, half power beam width. It was a 24 foot antenna at 21 cm in other words. And ok, that by modern standards, [can conceal a great deal of grief?]. At that time though, Bok was concerned, not without reason, we were pointing 2į or 3į wrong. We never had any real problems but I think he was spooked by the fact that, unlike any other telescopes that heíd ever worked with, there wasnít a guide telescope that you could look through and make sure you are pointed right. And there were very few radio sources suitable for pointing.

Sullivan

At 21 cm?

Wade

Yeah, this was the thing. We wound up doing a great deal with Taurus A at relatively flat spectrum. Anyway, our pointing was certainly as good as the beam justified. That never proved to be a problem. We did take care with it though because we never had a chance to forget it. Well, Heeschen and Lilley got started fairly early on their thesis projects and they finished up about November í54, as I recall. Tom Matthews and Kochu Menon came along next and they finished up, pretty sure Kochu finished up early in í56 and I believe Tom was ahead of him by a few months, might have been in í55.

Sullivan

Thatís alright. Iíve talked to them.

Wade

Youíve talked to them, yeah.

Sullivan

I would be interested in asking you how it was decided who worked on what? Was Bok more of less sort of divvying up the sky amongst the different grad students?

Wade

Well, not at all. I think people picked out things that looked interesting to them. Dave Heeschen was certainly interested in galactic center and Ed Lilley was interested in the possible correlation between 21 cm and absorption. He went looking for correlation; he found an anti-correlation and little surprise there. But the field was so new, everything was wide open. There was no need to have a traffic cop. And Kochu worked on the Orion association. There was the optical ring; well, they found a radio ring. I picked my topic by a process of evolution. I thought it was would be interesting to look at several OB associations, smaller than the Orion thing, and look at several areas of the sky smaller than Kochuís and see how similar one of these things were to another. Now Kochu had a big one. He could look at that one area in great detail. Well, I was fending along and, I guess, time to pick a thesis late í56. I decided on this and I was newly married and I picked out, I believed, four associations that looked good- they were well placed, you know, and so on. And I decided, well, I might as well have a picture of each of these areas of the sky so I went down and dug out Harvard patrol camera plates more or less centered on each one, went to the dark room, made contact prints- a very simple thing to do- and my new wife was looking them over and said did you set a coke bottle down on this one and I said no. Well, this was the Orion 2 association, the lambda [Corionis?] thing...

Sullivan

The regular nebulosity?

Wade

No, this was a dark ring.

Sullivan

Oh, a dark ring?

Wade

Yeah. It shows up here. You can see it. I happened in have a photograph in H alpha and that ring fit the nebula beautifully. H alpha is right in here. Heck, this looks good. Itís about 7į across so we can get reasonable resolution. So I decided to hell with the other associations, Iíll work at that. Thatís where I get my thesis and thatís how that worked in those days. You didnít have to be systematic approach. See Iím talking like an old timer. Iím not even a grandfather yet by anyway.

Sullivan

Well, it is an old time for radio astronomy.

Wade

It is as radio astronomy goes, yeah. But anyway, I chugged along. I took my first observations late í56 and finished early í57. By this time, weíd got the 60 footer on the air so my thesis was the first one off the 60 foot antenna and Iíd started at the 24 actually.

Sullivan

Were there any particular problems getting the 60 foot going?

Wade

No serious problems. We had a receiver that was supposed to go on the air with it that never did work so we wound up using the old receiver. That receiver is a multichannel thing, the one that didnít work. It was just a little bit too far ahead of its time. Weíd get all these channels balanced up and they matched, go off to lunch and be completely out of whack again.

Sullivan

Was it just a DC thing?

Wade

Iím trying to remember now. I think it was DC amplifiers, stacks of filters.

Sullivan

I was just talking with John Murray and others at [CSIRO Division of] Radiophysics a few weeks ago and they were talking about the great difficulties they had with a multichannel receiver.

Wade

Yeah, later on I did work with Johnís a little bit but it was a darn sight ahead of...

Sullivan

Iím sorry. His was an improvement, thatís right, he was called in.

Wade

He had 54 channels or something that actually worked.

Sullivan

Right, but [Frank J.] Kerr and someone else were working on one when it was DC thing that they just never really got working right and then John came as a trouble shooter, more or less, and sort of redesigned the whole thing.

Wade

I donít recall now what the specs were on that thing. It was again a Ewen Knight effort. I remember the day spring of í56 when we dedicated the 60 foot antenna though. Bart Bok was out there.

Sullivan

Iíve seen the program for that. It was a big occasion.

Wade

It was a big occasion, much ballyhooed and Alan Waterman of NSF [the National Science Foundation] was up and, oh boy, well there were a lot of empty cabinets there. The panel worked fine in the control room.

Sullivan

So Bok had been able to get some money out of NSF this time?

Wade

Yes, by that time he was getting NSF funding.

Sullivan

Because he had an established group that was putting some results?

Wade

Thatís right and it was pretty paltry dollars by present standards but then it made all the difference. Of course, a dollar went a lot farther then. This was over twenty years ago now. It doesnít seem like it.

Sullivan

Let me just ask, are you going to have to catch the 4:30 bus?

Wade

No, I drove up today.

Sullivan

Ok, good. Another general question is obviously Bok is primarily an optical astronomer and it seems like all this group were very oriented towards looking at things that were optically interesting and in your course work I think you probably had pretty much a traditional graduate student astronomy education?

Wade

Very much so.

Sullivan

Which strikes me very much because it is very different from the other radio groups at this time who, in fact, I just finished interviewing [Anthony Richard] Thompson and he said first of all they didnít have many courses of research [?] at all and if they had them they were simply to so with radio techniques or radio astronomy per se.

Wade

Well, an early radio astronomer rediscovered the precession of the equinoxes, thatís part of the problem. You may know the story on that.

Sullivan

You mean at Cambridge?

Wade

Iíve heard the story in two versions. One has it that it was [Martin] Ryle that learned it the hard way. The other one is it was Mills that learned it the hard way.

Sullivan

Now, [Bernard Y.]Mills himself has told me that he did it and Iíve heard about the Cambridge group but I canít remember if it was Ryle or Smith but I have heard about one of them.

Wade

Well, itís not surprising when you think about it. Precession is not really public knowledge. Itís not a fact of daily life.

Sullivan

Well, in fact, when I was working at NRL [Naval Research Laboratory] as a grad student an X-ray astronomer came in and the same thing happened all over again. Precession? He opened his eyes.

Wade

No, the training we had at least we came out of graduate school knowing the difference between mean and apparent time and a few old traditional things like that.

Sullivan

You had pretty much the same education as the more traditional graduate students who were going on into optical astronomy.

Wade

Oh yeah, the same as any other person we had in astronomy. Itís always been a point with me that radio astronomy is not a separate subject anyway. Itís just astronomy. We just use a different technique but itís silly to talk about 100 inch astronomy and 60 inch astronomy. Weíre still looking at the same universe.

Sullivan

Now, the other side of the coin though, Iíd be interested in your opinion is, that it also seems that the 21 cm results in the late Ď50s, mid í50s had some faults, some errors were made and Iíd be interested in your opinion on how that came about. Was it because the people that were using the instruments really were not the ones who were building them and understanding them completely or was it just optimism...

End of Tape 104A

Sullivan Tape 104B

Sullivan

Continuing with Cam Wade on 1 May í78.

Wade

Ok, well, you mentioned various things that confused people in the early days, lead to some blunders that would not be excusable now. I think there were many causes. Part of it is the whole field was very new. We didnít really know what we should reasonably expect to see out there so this indeed did lead to problems with [bumps?]. An example was I know at Harvard we had seen the 3 kiloparsec expanding arm about the time the Dutch did but we reckoned it was something wrong with our receiver baseline. It was certainly that possibility. After the Dutch came out with it, it was pretty obvious that we had been looking at it too. We could have beaten them.

Sullivan

That was a case where you were on the conservative side?

Wade

We had seen it but they recognized it, you see. Ok, not knowing the equipment, the fact that the equipment was primitive and highly capable of doing some highly original things on its own. An example from personal experience, I never published my thesis. Why, after it was all duly accepted and I had a piece of paper saying I was a learned doctor, before I left Cambridge I got playing around with it and found that the divider chain we used for putting on our frequency markers and then setting our radio velocity scale was subject to jumps and so my radio velocities were not reliable. Now, I could have gone through and reconstructed it but I never did because I left for Australia about that time so my thesis really remains unpublished but that was a case of not knowing the equipment adequately. Every time I starting an observing run, I carefully checked it out, set up the thing, but I made the mistake of assuming that once set, it would behave itself. Well, no, it didnít do that. It would go into episodes of dividing by 11 when it should be dividing by 10 and this did unworthy things to my frequency markers.

Sullivan

How long was your observing period, a couple of weeks?

Wade

No, no, no. This was every day.

Sullivan

So you set it up every day and check on it?

Wade

Yeah, I would set it up every day and check it out and then remember this was a scanning interferometer and I was scanning [?] velocity and frequency. Yeah, it was a scanning receiver so each observation would take an hour to two hours and Iíd check things out at the end of that. Sometimes Iíd find- is that alright, oh what the heck. Iíd tweak it up and I realized later on that I should have been a little more alert to wonder why it didnít look like it was quite the same as when I set it when I started. But after all you are in a hurry and I had set myself a time scale for getting a thesis done, all that stuff. I actually made my time schedule which amazed me. Certainly there was not an adequate appreciation for what noise could do. There was not an adequate appreciation for the limitations one has in accurately drawing a pencil line through noise on chart recorders. It was too much of an unawareness of a psychological hazard of being influenced by what you expect to see or want to see when you are drawing a line through noise. This is not a question of honesty; it is a question of being impersonal. And since we are still all of us descended from the apes and think like apes, these mistakes get made and itís not hard to find things written in those days including certain Harvard theses which people take rather a little pride in later on. This is one of the hazards of being a new field. I donít think people should feel too badly. I think the Dutch got rather gleeful in pointing out other peopleís sins through there but I wonít go into it but they had a few sins of their own too.

Sullivan

Sure.

Wade

Which they were quieter about but thereís certainly a spirit of competition that wasnít all together nice in those days. I donít think I ever felt it myself but I know it was about and I think itís mild compared to some of the dirty pool Iíve heard rumored of contemporary molecular line work. Thatís filthy, some of what you hear even if only a fraction of it itís true, itís still appalling. Usually we avoided that and I would say certainly that in the competitive aspects, itís to Bart Bokís credit that he took a defensive view, not offensive. He just wanted to make sure that our noses were as clean as could be. He was not interested in trying to get out and put anyone else down. He is a gentleman.

Sullivan

Go ahead.

Wade

Actually I think my thought was tailing off anyway.

Sullivan

Why was there never any survey undertaken, large scale survey? Was it thought that that would be left to the Dutch and perhaps the Australians and Harvard would concentrate on special regions of interest?

Wade

That was pretty much it as I recall. The survey, for one thing, was a pretty time consuming thing even with a 1.5į beam and remember also that we had no computer help whatsoever in handling the mass of data. There were no hired hands, paws that you could put onto the data. Graduate students are always in a hurry doing a thesis so I think what you say is right. The Dutch and the Australians were set up to handle a sort of production thing. It seemed much better, more appropriate in a graduate school environment to find interesting regions where you could milk out some science from a restricted amount of observations then go to work on it. Remember the field was wide open then. You didnít have to be terribly clever or well informed in order to pick a good topic for a thesis. It was brand new.

Sullivan

It seems like also that you did theses faster in those days than people do today?

Wade

It varied. I imagine that might be right. In my own case, I worked pretty quick.

Sullivan

You mentioned that Heeschen and Lilley sort of finished up within a year.

Wade

Well, they did. And I had done some thinking ahead of time but from my first observations until I had the degree wrapped up, it would not have been over about a year and serious observations were done in a span of about four months and then there was another about five or six months on top of that that I was writing it up, working it up, defending the damn thing, and so on. I was racing the stork. First child was supposed to come at the very time I was having my oral exam but it held off twelve days. So there was that, the fact that I wanted to support my family. I had a job in Australia lined up, blah, blah, blah, so I definitely pushed it. I think I finished about as fast as anyone.

Sullivan

Let me ask you another general question about the group. Did you see yourselves as a different kind of group from the other radio groups in the world? It seems to me, in retrospective anyway, that it was very different in this graduate school environment, training really astronomers more than radio physicists as they were doing in England and Australia plus they were not really connected- well, they did have graduate schools but not in astronomy anyway?

Wade

Well, I think the orientation at Harvard at that time was definitely from the direction of astronomy rather than from the direction of radar people wanting to find something to do with their techniques or radio physics or atmospheric physics- even some of that got into that. Iíd suppose there was awareness of this and certainly in the head of people like Bart Bok. In my own case, I didnít even think about it. I had tunnel vision. I had my project. I was going to do it and I really didnít get a hoot what they were doing elsewhere. I felt I had enough to do to get my thesis done and get it wrapped up. I was getting pretty sick of Harvard by that time. I just wanted to finish and get out and so I say tunnel vision.

Sullivan

Ok, one other question about that group. As you are well aware, virtually all the graduate students of that time have gone on and stayed still in radio astronomy and many of the leaders of U.S. radio astronomy came out of that group. Itís sort of striking to me. Is this just by accident? Did they happen to get in at the right time, do you think?

Wade

A lot of it was getting there first.

Sullivan

Thatís what Iím saying.

Wade

Yeah, and plus the fact that I believe there were ten theses that came out of that, ten people actually went to the doctorate out of the Harvard radio astronomy project. I was the fifth. You had a reasonable good cross section of abilities in there.

Sullivan

There is only one name that I know that has faded from the scene. That is [Robert S.?] Lawrence. I donít know what happened to him.

Wade

He didnít do a thesis. He was there for a year from Bureau of Standards. He had a job there. But he worked with it but he was never attempting a doctorate, as far as I know. The only person I can think of right now who completed a thesis on that project but did nothing subsequently in radio astronomy was Bob Davis. I might be wrong on that.

Sullivan

Iíd like to put together a list of those theses sometime.

Wade

Yeah, that certainly can be done. Well, Heeschen and Lilley certainly were heard of. Tom Matthews was, Kochu Menon,I hope Iíve been, Nan [Nannielou H.] Dieter, Frank Drake, and then thereís Bob Davis and that leaves me missing two. Who were they? Iíd have to think. Wait, May Kassim absolutely. Her thesis was one of the best out of it. See I sort of lose track of those who follow me.

Sullivan

Thatís alright.

Wade

But donít worry about it. Alright.

Sullivan

Ok, so where did you go to work in Australia?

Wade

CSIRO Division of Radiophysics.

Sullivan

Right and what did you work on when you got there?

Wade

Well, I worked on what I damn pleased because I had the great, good fortune that Joe [Joseph L.] Pawsey was out of the country at the time and I learned later on that had he been there I would have certainly been assigned to one of the groups. And in fact Iíd seen him on my way to Australia. He was at the University of Michigan so I sat down and had a session with him, went on to Australia. He came back a couple of months after weíd arrived down there by which time Iíd written one paper, the only theoretical paper Iíve ever done, but on the strength of that he said, "You seem to be able to manage on your own. We wonít force you to join a group." And I thought thank god, you know, and I worked with groups and at least, had association. It was mainly Frank Kerrís that I really got anything out of in terms of stuff in print but I certainly had a lot of association with Bernie Mills and Wilbur [Norman "Chris"] Christiansen

Sullivan

So your horizons were broadening in terms of the Sun and radio sources?

Wade

Absolutely, yeah. The extragalactic thing certainly was inspired much by Mills. In fact, it was Mills Cross data that I used for Centaurus A, subtracting the [?] source.

Sullivan

Well, letís talk about these papers. I guess the theoretical one you referred to is about HII region emission?

Wade

Yes, a very simple minded thing but at least, there was a means of getting electron temperatures, not as good as you can do now and so on. You could measure the spectrum and knew the geometry of the nebula- thatís the weakness because we couldnít map the thing. We had to assume that the radio brightness distribution was about the same as the optical which is a fair approximation. Ok, we got electron temperatures in the right vicinity.

Sullivan

And you also did some observations of Eta Carinae. I guess doing a follow up on that?

Wade

There was that. That was certainly trying to get physical parameters of the nebula. At the same time, we did some Centaurus A at 1400 megacycles. Continuum observations in both cases and this was using the 36 foot antenna out at Potts Hill, the reservoir. It was a transit instrument so we [could get?] a paraboloid, a homemade paraboloid, and that was an interesting place to work. They closed it down shortly after I was there but it was on a reservation for the city water supply for Sydney and you had to be a little bit careful going outside there because there are packs of wild dogs roaming the place so if you wanted to get up on the antenna or do something, you just sort of kept an eye open. There was an outdoor toilet and well, if you wanted to head down there, again you just sort of kept your ears and eyes open on guard because there were cases of well-known radio astronomers spending time in trees. Those things were vicious and I never had any trouble. I never saw one except in the distance but it lent a certain air of adventure to this. But occasionally youíd have to climb the antenna and checked something out, make sure that your position readout inside was matching what was on the antenna. You could change the declination with pushbuttons inside but sometimes it was easier and more reliable to get outside and use the hand crank. I certainly preferred using the hand crank myself.

Sullivan

And there was an analog readout inside?

Wade

Yeah, Iíve forgotten the nature of it.

Sullivan

A dial or something?

Wade

Iíve really forgotten how it worked. Jim Hindman was the guy who really knew the thing but Frank Kerr could fill you in on this pretty much too. It was basically Kerrís dish but I did a fair bit of observing out there. It was through the night. The first hour youíd have to be rebuilding the receiver to make it a continuum receiver and then the last hour you were out there, youíd be making it into a line receiver again, checking it out, and starting up their program.

Sullivan

What did you have to change for this transformation?

Wade

Well, letís see if I can recall the details. Well, for my continuum work, it was a comparison radiometer, comparing online to offline. Well, that wouldnít help me in the continuum so I had to take one of those channels and put it on a battery and this kind of thing but then you had to make sure everything was lined up and balanced right. There was all this monkeying and Iíve really forgotten the details now. You see, this was mainly í58 I was doing that. Thatís twenty years and since I have no basic interest in electronics whatsoever it doesnít really stick in my head. I learned what I needed, did it, and then forgot it when I didnít need it anymore but I do remember it took about an hour at each end of the observing run.

Sullivan

So now what came out of looking at Centaurus at 1400 MHz?

Wade

Ok, Iíd say the first thing that came out was from 85 megacycles to 1400 the spectrum seemed to be about the same from all over the source. That was not true at still longer wavelengths because Alex Shane had the high resolution observations at 19.7 megacycles. It had the central source relatively much weaker as compared to the great extended outer part. But anyway from over quite a wavelength range the thing had pretty uniform spectrum. There was that and, of course, there was our observations there that got me interested in the problem of the damn thing which led to my playing around with the Mills Cross observations that had higher resolution and eventually I made a model of the contours and [?], "My god, thatís the beam shape sticking out there in the middle." So I played around subtracting that and here was the source so now this was the second double source we knew and I made the daring statement in my little paper on that thing that there might be quite a few double sources out there. This was extrapolating from two cases out of two.

Sullivan

This was the 4 arc minute double?

Wade

Well, we saw that as a point source in his observations. The Mills Cross had a 50 minute beam. Incidentally, when I was saying 1.5į beam for Harvard thatís wrong, that was wrong. It was 2į. It was the 36 foot in Australia that had 1.4 minutes. Ok, see as time goes these things get a little shaky. It was over 2į on the Harvard dish. I think it was 2.4į or something.

Sullivan

But back to Centaurus can you tell me more explicitly exactly what you did? You took the Mills Cross observations...

Wade

Yeah, it was Kevin Sheridanís paper.

Sullivan

Resolution of 1į or so?

Wade

Yeah, about .8į for beam width and that was the first really good map of the source, remember, and began playing around with it and I got fascinated with that thing. I wondered what structure was lurking in that thing and here you had 25% of the flux right in the middle and the rest of it was spread out over the sky because of the large angle, surface brightness was much lower. And what I did was just make a three dimensional model of the contours and just cut it out just to try to visualize the thing better. I remember I sat there and it dawned on me that the bump in the middle really was just like the beam. So I got busy, made a grid of the values, subtracted the thing out, experimented once or twice so, you know, it all goes and you donít leave a hole. Thereís something that looks like what the interferometers were suggesting Cygnus A must be. And I got it into The Australian Journal of Physics fairly promptly as my two years were nearly up.

Sullivan

That was in í59 that was published?

Wade

That was í59, thatís right. And actually I sent it in and Alex Shane walked in one day sort of grinning and said, "You know that thing youíve send in. It looks like youíve just beat them," and I said, "Beat who?" He said, "[John G.] Bolton. Bolton and [Barry G.] Clark at Caltech have done the same thing on the strength of their 960 megacycle observations." And theirs came out then a few months later so I sent a copy of what Iíd done to John Bolton. I didnít know Barry Clark from anybody else then. He was an undergraduate student working with Bolton. I beat them cleanly but it was interesting and, of course, their picture when it came out looked just like mine. Weíd done exactly the same thing and again this shows sort of the uniformity of the source over quite a range of frequencies because their frequency was over ten times higher than mine. Ok, this was all gratifying. It was nice to see somebody else get the same conclusion.

Sullivan

What differences did you see in the style of operation at Radiophysics from the Harvard group?

Wade

Itíd be shorter to say what the similarities were. There were hardly any. It was very different because, for one thing, very few people at Radiophysics had any real background in astronomy. I can think of Eric Hill who had actually gone off and worked with the Dutch. I shared an office with him for awhile. But most of these people had come in through the radar or in Bernie Millsí case, I think it was accelerators. And so, things were much more hardware oriented and that certainly showed up in the quality of the equipment. I was always very impressed with the quality of, well, workmanship, ingenuity and design, incisiveness of concept, and so on that the Australian group showed. It was a real education to be there and I came away after two years loaded with admiration, very happy Iíd spent my time there. There was so little overlap with the style at Harvard that I felt it was an utterly different experience and redundant in no way. I certainly learned more radio astronomy in Australia than I did at Harvard.

Sullivan

Even after this time, I mean, many of these people had been in radio astronomy for thirteen years at that point? Youíre saying that their astronomical background was weak?

Wade

They had been going ten years. Sure, it was good as astronomical but it wasnít the kind Iíd had of sort of the classical optical and the things they learned, they learned because they had to not because astronomy was intrinsically interesting. It was just a different approach to getting into the field. And the other thing that certainly impressed me very much- it still impresses me in retrospect- was how well organized the effort was down there. There were several groups in the place. Paul Wild had a solar group going. Bernie Mills and Wilbur Christiansen- known as Chris, of course- had their crosses going. Each had a cross and then Alex Shane, sort of on the fringes, had a cross going, 19.7 megacycles.

Sullivan

Kerr with the line group.

Wade

Kerr with the line group and then there were various theoreticians around, [John "Jack" Hobart] Piddington as an example.

Sullivan

Jim Roberts.

Wade

Jim Roberts. Roberts had a pretty close association with Paul Wild through a lot of what he was doing.

Sullivan

Yeah, this was very striking to me and I talked to the people also, this group structure. Many of them had their own field site.

Wade

Yeah, they did.

Sullivan

Especially in the early days, they barely saw each other very much.

Wade

That is very true and it is all tied together at the top, mainly through Joe Pawsey. Now, the quality of the organization- each group had excellent technicians within it. The man on top knew what was going on. It was definitely Mr. Xís group but there was a great deal of democracy in there. There was just a very good, compatible set of personalities in each group which played a large role in the success of these groups. They had many talents and they worked together well. I think while there were variations, all of the groups were effectively led. This is despite considerable personality clash and so on between the chief of the division and the assistant chief. The chief was Bowen and the assistant was Pawsey but Pawsey managed to insulate radio astronomy very well from the intrigues at the top and from what I saw myself, this was definitely Pawsey on these things. [E. G.] Taffy Bowen is a brilliant character but I wouldnít want him marrying my sister. The capacity for viciousness was impressive at times.

Sullivan

From what I gather Pawsey was sort of the exact opposite, a very gentle?

Wade

Pawsey had a very gentle style but he was no...

Sullivan

[???]

Wade

Oh, he was a very strong character but his style was not to stand up and present a rigid target to anyone which I think was the right way to go.

Sullivan

Now you havenít mentioned anything about strains that were developing at that time between the groups because simply there wasnít enough money to go around for big plans?

Wade

There were some such strains and I was fairly well insulated because I was very junior and not actually a firm member of any group. The one that was very obvious and led to obvious results was the strained between really Taffy Bowen and everybody else initially over the Parkes telescope because that was going to soak up all the money. As a result, Christiansen and Mills left and went to the university. They got their own funding for their big cross, the Molonglo cross. Paul Wild sort of managed, I think, through his own skills to stay out of the Parkes thing and build theÖ

Sullivan

[?].

Wade

Ulgors Ring. He was working on that for many years before it came to fruition, of course, and then Kerr left Australia not long after that. John Bolton went back and it was really a new group that Bolton started that accomplished the great things at the 110 footer.

Sullivan

Now, Kerr didnít leave till í66.

Wade

Not fully but he was out of the country an awful lot, as I recall, at that stage.

Sullivan

Maybe I donít remember.

Wade

He traveled around a lot.

Sullivan

He took a lot of data on the Parkes dish in the first few years.

Wade

In the early days thatís true but I think very quickly became a Bolton dominated sort of thing and Bolton returned a few months after I left down there. And then thing began moving very rapidly on the 210 footer and, of course, it was a great project. Itís done great things down there.

Sullivan

Well, is there anything else about your stay in Australia youíd like to comment on or that we havenít covered?

Wade

Well, probably not at this point. Weíve covered quite a bit actually in a rambling fashion. Remember I have even thought in any connected way about a lot of this stuff for years so you are really getting this off the top of my head.

Sullivan

Well, Iím use to that. When you look at the transcript you can think about it a bit more.

Wade

Ok.

Sullivan

So you came back and you joined this new group at Green Bank and what year was that?

Wade

Well, that was early 1960. I left Australia at the end of 1959 and took a month on my own and went to Green Bank in February.

Sullivan

And was the 85 foot existing then?

Wade

85-1 was existing and in operation. It had a 10 cm receiver, I believe, and a 21 cm continuum receiver. Iím trying to think if there was anything else.

Sullivan

I think thatís right. How did that group strike you as we are talking about styles of groups and so forth?

Wade

Well, this wasnít a group at all in the sense of the Australian thing where they were the solar group and the 21 cm group and so on. There were several individual scientists who shared the telescope and these were Heeschen, Drake, Roger Lynds and myself. I believe we were it there for the first few months. We were actual full time astronomer. Of course, Otto Struve was the director at that point but he at no point got involved in any observing. I wrongly thought that he was too old to learn all these mysterious new tricks. He conceived of this whole matter of radio astronomy was far more mysterious than it was but he was getting old, you see. In fact it was only a couple of years later that he died.

Sullivan

What role did he play, would you say?

Wade

I think his effect was mainly moral. For whatever reasons, I donít know, he never had the real trust of the Board of Trustees. They were always having him watch dogged. His hands were tied and that was too bad. I think other people would be better to ask about that than myself but it was an unhappy time. For me, I was very glad to have the association with him though. He was a wonderful man to know. Some of his stories about astronomy or even his service in the Russian Revolution were very fascinating and I felt very enriched by being exposed to him. Also, he was no longer the tiger he was reputed to be for so many years and he didnít force us to be in there at 8 oíclock in the morning after observing all night or something as he had a reputation of doing in other places in previous years.

Sullivan

What about astronomy itself? Did he help at all in the education of the staff, would you say?

Wade

My feeling is that he had very little direct effect on that. He certainly provided encouragement. From personal experience, the first observing at Green Bank, the first serious thing, he did have an effect in retrospect. Alex Shane had mapped Virgo A with his 19.7 megacycle cross and it looked like there was a bit of an extension on one side of it. Well, that looked like an interesting thing to go into. Again, exploiting the numerical integration capability we had with the paper tape output.

Sullivan

Now, tell me that now. You said that before we started taping here.

Wade

Oh, did we? Well, the thing is at Green Bank I had my first chance to use a computer with data. We recorded on punch paper tape. We had an IBM 610 computer where you feed it through and do simple-minded reductions. And the important thing here though is that you could do impersonal integration on faint signals so I decided to exploit that with the 85 foot antenna which gave us about the same beam width as the Mills Cross in Australia at 21 cm. I did this both at 21 and at 10 cm, I believe. The 10 cm observations were the ones that really counted later on. Well anyway, I mapped this. The extension- remember it had to be fairly big for Shane to see it, that as I recall was about a 1.5į beam with that cross. That thing went out in the same direction as the jet. Well, I mapped the thing with the 85 foot at Green Bank and it was evident that the extension wasnít an extension. It was a separate source but there was possibly a bridge joining the two. The second source happened to be centered right on Messier Sky which fortuitously happens to be just in the direction the jet points at least in our two dimensional projection we see. So anyway, I put in a little paper in The Observatory, I guess, and Struve as delighted with this. He thought this was great. I never could understand why he thought it was so great but anyway this was great encouragement here and you feel very insecure at this stage; you only a research associate starting out on a one year appointment so anything that pleased the boss was alright with me. And then I followed it up with the 10 cm receiver where there was a clean separation. There was clearly no radio bridge. It was clearly a separate source et cetera. But Struveís encouragement there, the fact that this was the type of astronomy that he understood and was all fired up about definitely helped me. I didnít think at the time, I still donít think that this was all so great as he seemed to esteem it. I think what he like was here is somebody doing something with the radio spectrum that he can actually understand in optical terms.

Sullivan

Connected with a photograph.

Wade

Exactly right, yeah.

Sullivan

His style of not having groups at NRAO, and I think it is still true, individuals pretty much work by themselves. If two happened to have similar interests, itís almost by accident.

Wade

Yeah, you get together but formal groups, absolutely not.

Sullivan

Was that because it stemmed from Struveís doing that or was it part of the original charter of NRAO?

Wade

No, I donít think there was ever anything deliberate about it at all. It just happened to be a style that suited the temperament of all of us.

Sullivan

It just evolved that way?

Wade

I donít want to be involved with a group for two reasons. First, I donít want to be a member of somebody else group. Second, I donít care to be in charge of one. This leaves me being an individual, ok. So thatís the thing.

Sullivan

Thatís quite different from Cambridge and Jodrell and Radiophysics, of course.

Wade

Yeah, but youíve got to remember also that one reason for having the groups was to build the equipment and maintain it where that was a house function all along at NRAO.

Sullivan

Well, ok, letís talk about that. This is perhaps the first time- although it was getting that way at Radiophysics, I think- but it was the first time when the engineers were sort of distinct from the scientists as users of the equipment in the development of radio astronomy.

Wade

Yeah, that was certainly always a distinction of NRAO in my time. Well, youíd have things like John Findlayís operation with the Little Big Horn where he sort of filled both roles but that was unusual. And certainly for people like myself, if somebody else will do the engineering- great. I wasnít interested in that. I wanted to do astronomy and the less I had to learn about the equipment, the better.

Sullivan

Well, it makes sense. It evolved from the Harvard experience which had a large input, I suspect, on the formation of NRAO.

Wade

It certainly did.

Sullivan

Although NRL and DTM also were important in getting NRAO going and they were different. They were not that style. They were build it yourself.

Wade

Three of the first four radio astronomers were the Harvard products. Lynds was not and heís back to optical, in fact, but itís not surprising there was a Harvard bias. It wasnít deliberate. Itís just the way it worked.

Sullivan

Now, when did the 300 foot come on the air?

Wade

That was late í62 as I recall.

Sullivan

And I guess you and Heeschen got involved pretty early in your survey of normal galaxies?

Wade

Yeah, that was the first full-fledged program published off the thing. I think we actually got started earlier than the 3C survey with Ivan Pauling-Toth involved but that was a much larger thing that came out later.

Sullivan

And what was the inspiration for looking at normal galaxies?

Wade

Ok, the inspiration was that through work done at various places it was known that a number of apparent normal galaxies were radio emitters. On the other hand these were selected because they were well placed or they were bright or they were famous. There was no uniformity but what we decided to do since we had this huge collecting area was to make a systematic survey of Shapley-Ames galaxies that were accessible to the thing, north of -19 or something. And thatís what it was and we looked at some hundred. I think we cut it off around the 11th magnitude but we looked at something over 500 hundred galaxies.

Sullivan

It was a very controlled sample.

Wade

Yeah, well the effort here was to have it selected on non-radio criteria. We just wanted the brightest galaxies and that was it. It was a simple concept but I think it was a good one. The idea was to have a general survey. We werenít out to discovery galaxies but we worked just to look at them.

Sullivan

Well, in fact, it was the first time that sort of thing had been done, I think, for radio sources of any kind.

Wade

Yeah, things that were chosen by optical criteria, go out and just try to look at all of them and I donít think of another that would have come earlier.

Sullivan

I mean people had obviously looked at stars and bright nebula before but I donít think anyone ever looked at a nice, controlled sample of either of those categories.

Wade

I think thatís right but again I think the optical background that both Heeschen and I had was showing through here in the way we conceived the program, the reason we felt it should be done this way, and so on. But the thing that we then struck when we were trying to make sense out of our results was the lack of uniformity in the optical data. Thatís a problem. A lot of them were done at different time by different people.

Sullivan

The Shapley-Ames itself was not really as complete, as well-defined sample as you thought it was?

Wade

Well, itís well defined but modern photometry doesnít exist in there; basically eyeball all estimates of magnitudes, not too bad but what they would do is take plates where the galaxy looked almost stellar and then compare it to stars. Thatís how Shapely-Ames got their magnitude so it wasnít anything but a shopping list type of set of data we worked from.

Sullivan

Ok, well I think that is sort of a natural place to cut it off. Any other things that come to your mind about radio astronomy as youíve seen it.

Wade

Not really. I have no axes to grind here so I donít have any prepared speech and all this has come out of the top of my head. Things might well occur to me by the time I see your typed script. Remember most of this stuff is being dragged out of my head absolutely cold which perhaps is best from your standpoint.

Sullivan

Well, yes and no. Thank you. That ends the interview with Cam Wade on 1 May í78.


Modified on Wednesday, 30-Jan-2013 09:42:37 EST by Ellen Bouton, Archivist (Questions or feedback)