Interview with Campbell M. Wade
Description
Creator
Rights
Type
Interviewer
Interviewee
Location
Original Format of Digital Item
Duration
Interview Topics
Start Date
Notes
The interview listed below was either transcribed as part of Sullivan's research for his book, Cosmic Noise: A History of 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.
Please bear in mind that: 1) This material is a transcript of the spoken word rather than a literary product; 2) An interview must be read with the awareness that different people's memories about an event will often differ, and that memories can change with time for many reasons including subsequent experiences, interactions with others, and one's feelings about an event.
Series
Unit
Transcription
Sullivan
Ok, this is talking with Cam Wade on 1 May ’78 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 didn’t 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 Ewen’s 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 wasn’t 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 Ewen’s receiver which was a very primitive thing.
Sullivan
Yeah, I’ve 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 haven’t 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, -5° 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 can’t quite remember what the exact dec was but that’s an interesting point. I’ll check on that. I haven’t talked to Ewen yet.
Wade
Yeah, you check on that because I’m just going on my recollection here and that was 1952, it’s now 1978, that’s 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 didn’t 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. I’ve 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. It’s 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 we’d figure it out. Well, somewhere along that spring, the receiver disappeared. It turned up in Washington at Merle Tuve’s 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 weren’t 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 don’t know if Dave and Ed went down and maybe coaxed something out. I doubt it. So let’s see, I can’t 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 you’re not going to print this [???]- Menzel and Whipple took us three students to lunch- where was it?- the Commander Hotel in Cambridge sometime in ’52, I’ve 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 can’t 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 ’53- 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 didn’t understand what we were doing. I didn’t 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 ’54 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. I’ll 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 don’t 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 didn’t 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 didn’t 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
That’s right, you were still an undergraduate at this stage.
Wade
Yeah.
Sullivan
Did you do an undergraduate thesis or anything like that?
Wade
I didn’t. It wasn’t expected at Harvard. You could do one if you wanted to but I didn’t. I’m lazy. So anyway, we got on the air and certainly in ’54 things were running pretty well. I’m having a bit of a question in my mind. I may have been a year wrong. My recollection was late ’53 we got that antenna on there but it may have been early ’53. This sort of thing you can check out.
Sullivan
These dates I’ve 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 didn’t 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 don’t do it, somebody else will." And I don’t 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 day’s work, axes lying in the background and all that. One of them saying to the other, "Well, well, look at it. If we don’t do it, someone else will." And so I kept that in my notebook as inspiration. It’s 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 1.4° 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 2° or 3° wrong. We never had any real problems but I think he was spooked by the fact that, unlike any other telescopes that he’d ever worked with, there wasn’t 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 ’54, as I recall. Tom Matthews and Kochu Menon came along next and they finished up, pretty sure Kochu finished up early in ’56 and I believe Tom was ahead of him by a few months, might have been in ’55.
Sullivan
That’s alright. I’ve talked to them.
Wade
You’ve 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 Kochu’s 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 ’56. 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. It’s about 7° across so we can get reasonable resolution. So I decided to hell with the other associations, I’ll work at that. That’s where I get my thesis and that’s how that worked in those days. You didn’t have to be systematic approach. See I’m talking like an old timer. I’m 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 ’56 and finished early ’57. By this time, we’d got the 60 footer on the air so my thesis was the first one off the 60 foot antenna and I’d 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 didn’t work. It was just a little bit too far ahead of its time. We’d 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
I’m 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 John’s a little bit but it was a darn sight ahead of...
Sullivan
I’m sorry. His was an improvement, that’s 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 don’t recall now what the specs were on that thing. It was again a Ewen Knight effort. I remember the day spring of ’56 when we dedicated the 60 foot antenna though. Bart Bok was out there.
Sullivan
I’ve 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
That’s 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 doesn’t 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 didn’t 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, that’s part of the problem. You may know the story on that.
Sullivan
You mean at Cambridge?
Wade
I’ve 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 I’ve heard about the Cambridge group but I can’t remember if it was Ryle or Smith but I have heard about one of them.
Wade
Well, it’s not surprising when you think about it. Precession is not really public knowledge. It’s 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. It’s always been a point with me that radio astronomy is not a separate subject anyway. It’s just astronomy. We just use a different technique but it’s silly to talk about 100 inch astronomy and 60 inch astronomy. We’re still looking at the same universe.
Sullivan
Now, the other side of the coin though, I’d be interested in your opinion is, that it also seems that the 21 cm results in the late ‘50s, mid ’50s had some faults, some errors were made and I’d 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 ’78.
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 didn’t 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 didn’t 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 I’d check things out at the end of that. Sometimes I’d find- is that alright, oh what the heck. I’d tweak it up and I realized later on that I should have been a little more alert to wonder why it didn’t 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 it’s 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 don’t think people should feel too badly. I think the Dutch got rather gleeful in pointing out other people’s sins through there but I won’t go into it but they had a few sins of their own too.
Sullivan
Sure.
Wade
Which they were quieter about but there’s certainly a spirit of competition that wasn’t all together nice in those days. I don’t think I ever felt it myself but I know it was about and I think it’s mild compared to some of the dirty pool I’ve heard rumored of contemporary molecular line work. That’s filthy, some of what you hear even if only a fraction of it it’s true, it’s still appalling. Usually we avoided that and I would say certainly that in the competitive aspects, it’s to Bart Bok’s 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 1.5° 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 didn’t 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. I’d suppose there was awareness of this and certainly in the head of people like Bart Bok. In my own case, I didn’t even think about it. I had tunnel vision. I had my project. I was going to do it and I really didn’t 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. It’s 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
That’s what I’m 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 don’t know what happened to him.
Wade
He didn’t 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
I’d 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 I’ve been, Nan [Nannielou H.] Dieter, Frank Drake, and then there’s Bob Davis and that leaves me missing two. Who were they? I’d 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
That’s alright.
Wade
But don’t 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 I’d 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 we’d arrived down there by which time I’d written one paper, the only theoretical paper I’ve ever done, but on the strength of that he said, "You seem to be able to manage on your own. We won’t 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 Kerr’s 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, let’s 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- that’s the weakness because we couldn’t 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 you’d 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, I’ve forgotten the nature of it.
Sullivan
A dial or something?
Wade
I’ve 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 Kerr’s dish but I did a fair bit of observing out there. It was through the night. The first hour you’d have to be rebuilding the receiver to make it a continuum receiver and then the last hour you were out there, you’d 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, let’s see if I can recall the details. Well, for my continuum work, it was a comparison radiometer, comparing online to offline. Well, that wouldn’t 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 I’ve really forgotten the details now. You see, this was mainly ’58 I was doing that. That’s twenty years and since I have no basic interest in electronics whatsoever it doesn’t really stick in my head. I learned what I needed, did it, and then forgot it when I didn’t 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, I’d 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, that’s 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 1.5° beam for Harvard that’s wrong, that was wrong. It was 2°. 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 2° on the Harvard dish. I think it was 2.4° 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 Sheridan’s paper.
Sullivan
Resolution of 1° or so?
Wade
Yeah, about .8° 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 don’t leave a hole. There’s 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 ’59 that was published?
Wade
That was ’59, that’s right. And actually I sent it in and Alex Shane walked in one day sort of grinning and said, "You know that thing you’ve send in. It looks like you’ve 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 I’d done to John Bolton. I didn’t 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. We’d 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
It’d 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 Mills’ 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 I’d 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? You’re saying that their astronomical background was weak?
Wade
They had been going ten years. Sure, it was good as astronomical but it wasn’t the kind I’d 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. X’s 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 wouldn’t 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 haven’t mentioned anything about strains that were developing at that time between the groups because simply there wasn’t 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 the…
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 didn’t leave till ’66.
Wade
Not fully but he was out of the country an awful lot, as I recall, at that stage.
Sullivan
Maybe I don’t 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 that’s 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. It’s done great things down there.
Sullivan
Well, is there anything else about your stay in Australia you’d like to comment on or that we haven’t covered?
Wade
Well, probably not at this point. We’ve 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, I’m 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. I’m trying to think if there was anything else.
Sullivan
I think that’s right. How did that group strike you as we are talking about styles of groups and so forth?
Wade
Well, this wasn’t 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 don’t 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 didn’t force us to be in there at 8 o’clock 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 1.5° 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 wasn’t 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 Struve’s encouragement there, the fact that this was the type of astronomy that he understood and was all fired up about definitely helped me. I didn’t think at the time, I still don’t 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, it’s almost by accident.
Wade
Yeah, you get together but formal groups, absolutely not.
Sullivan
Was that because it stemmed from Struve’s doing that or was it part of the original charter of NRAO?
Wade
No, I don’t 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 don’t want to be involved with a group for two reasons. First, I don’t want to be a member of somebody else group. Second, I don’t care to be in charge of one. This leaves me being an individual, ok. So that’s the thing.
Sullivan
That’s quite different from Cambridge and Jodrell and Radiophysics, of course.
Wade
Yeah, but you’ve 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, let’s 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, you’d have things like John Findlay’s 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 wasn’t 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 he’s back to optical, in fact, but it’s not surprising there was a Harvard bias. It wasn’t deliberate. It’s just the way it worked.
Sullivan
Now, when did the 300 foot come on the air?
Wade
That was late ’62 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 Pauliny-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 that’s 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 weren’t 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 don’t think of another that would have come earlier.
Sullivan
I mean people had obviously looked at stars and bright nebula before but I don’t think anyone ever looked at a nice, controlled sample of either of those categories.
Wade
I think that’s 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. That’s 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, it’s well defined but modern photometry doesn’t 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. That’s how Shapely-Ames got their magnitude so it wasn’t 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 you’ve seen it.
Wade
Not really. I have no axes to grind here so I don’t 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 ’78.