Interview with Donald S. Mathewson

Description

Donald S. Mathewson, 1929- . Interviewed 28 August 1976 at Grenoble, length of interview: 45 minutes.

Creator

Papers of Woodruff T. Sullivan III

Rights

NRAO/AUI/NSF

Type

Oral History

Interviewer

Sullivan, Woodruff T., III

Interviewee

Mathewson, Donald S.

Location

Original Format of Digital Item

Audio cassette tape

Duration

45 minutes

Interview Date

1976-08-28

Interview Topics

Work on Criss-Cross; 1958-61 at Jodrell Bank on 250 foot 408 MHz extragalactic observations; plans for and first year of Parkes dish; the nature of the radio astronomer beast, optical versus radio astronomy.

Notes

The interview listed below was originally transcribed as part of Sullivan's research for his book, Cosmic Noise: A History of Early Radio Astronomy (Cambridge University Press, 2009). The original transcription was retyped to digitize in 2016, then reviewed, edited/corrected, and posted to the Web in 2017 by Ellen N. Bouton. Places where we are uncertain about what was said are indicated with parentheses and question mark (?).

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

Working Files Series

Unit

Individuals Unit

Transcription

Originally transcribed by Bonnie Jacobs (1977), retyped to digitize by Candice Waller (2016).

Begin Tape 69A

Sullivan

This is talking with Don Mathewson on 28 August ’76 at Grenoble. Could you tell me about how it was that you went to Jodrell Bank and then what you did when you get there and so forth?

Mathewson

Well, I was working with Christiansen on building the ‘Chris-Cross’ and we’d finished and had done the first six months of observations on the sun. And a letter arrived from Lovell to Bowen, he was the Director of CSIRO, suggesting that an Australian might like to work on the 250-foot telescope at Jodrell Bank to gain experience which would come in useful for planning and commencing operation 64-meter telescope at Parkes. And so this letter was circulated around the laboratory and I put my name down. Then Lovell wrote a letter accepting me as a (?) research fellow.

Sullivan

And what year was this?

Mathewson

This was early 1958.

Sullivan

I’m sorry, I didn’t understand that you were actually working in radio astronomy before you went to Jodrell. So can you tell me about that?

Mathewson

Well I’d commenced work in 1955 at Radio Physics CSIRO. Before that I had been at Queensland University, graduating from there and commencing work in medical physics. I worked in medical physics for several years while I was doing my honors physics course. And as soon as I had finished the honors course, I then transferred from medical physics to radio astronomy.

Sullivan

How in the world did you make that transfer?

Mathewson

I heard a talk by Joe Pawsey and he fascinated me as a scientist, and I thought it was the one thing that I really wanted to do was to get work under a group led by Joe Pawsey.

Sullivan

I see. And then what exactly was your role in building the Chris-Cross?

Mathewson

Chris had already, of course, planned, conceived it, and the reason I was appointed to radio astronomy was actually to help Christiansen. Christiansen and Pawsey interviewed me, and they decided that I would join Chris on that project. Of course it was quite a change from medical physics to go into electrical engineering and antenna building.

Sullivan

And you just sort of learned it from the bottom up?

Mathewson

Yes, well, Chris was my tutor, and a very good one, that’s why it went.

Sullivan

Now did you get involved at all in the scientific results coming out of the Chris-Cross, the solar results? It seems like you did from a couple of these papers.

Mathewson

Yes. Well, I worked for a couple of years at (?) lived at Fleurs where the Chris-Cross was being built. I lived with the construction crew. Then I did get very much involved actually in the data acquisition and the interpretation phase.

Sullivan

Could you just tell me a little bit about what did come out of that? For instance, at the Paris Symposium, - did you go to that meeting or was that Christiansen?

Mathewson

No, actually I was on my way to Jodrell and Pawsey said, “Well look, you’re going to Jodrell, why not give this paper at the Paris Symposium?” So it was the very first – a very young astronomer – it was the very first time I’d met all these names that seemed to me – the big names in Radio Astronomy, Ryle and so forth, Graham Smith. I didn’t talk very much in the restaurants where the crowds gathered, but I just sort of listened to the Burbidges, the Hoyles and so forth. So it was a very fascinating meeting for me, meeting these people. And also, it was the very first international paper I’d given, so it was I guess something always I remembered. And the last pure Radio Astronomy Symposium that ever has been held.

Sullivan

That’s right. It seems to me that it was a very significant -

Mathewson

It was. And everybody remembers it, and I think in the particular group.

Sullivan

In terms of the atmosphere of the meeting, or specific sessions, is there anything striking in your mind?

Mathewson

Yes, I think I’ll always remember the Mills and Ryle meeting over the log-n/log-s counts. I could sense that there was some friction even though I wasn’t fully in on it on that particular (?) being a solar radio astronomer, I wasn’t actually fully aware of the details.

Sullivan

Of course, I’ve heard other people make a similar remark about this, were there any other sessions where there was so much controversy?

Mathewson

No, I can’t remember now. It was all fairly interesting to me, but that was the one thing that stood out. And also the many, many talks in restaurants with these people who were, or listening to them, I should say.

Sullivan

And what was the result that you had in terms of the solar physics that you were presenting?

Mathewson

Well, I think the main result was the fact that the 20 cm – of course, we’d produced these radio pictures of the sun at 20 cm, and the main result was that the emission regions were optically thick and the temperature of these regions were about a million degrees. We could then get the (?) because (?) smaller than the region, we then managed to get a direct temperature of these things.

Sullivan

The title of the paper says, “The Origin of the Slowly Varying Component,” how did you tie that in?

Mathewson

Yeah, well, the origin was just that these, in the lower corona, upper chromosphere, that you had these very optically thick regions. One thing I do remember about the Paris Symposium, or what happened afterwards, was that six months before I left Australia, I suggested to Chris and Joe that we get all countries who had fairly high resolution, at least high resolution in those days, radio telescopes, that were active on the sun that were generally Christiansen arrays in France, Japan, in the States, and that we all combine observations at these different frequencies of operation on one particular sunspot region. And I chose the sunspot region and at Paris we all got together and it was decided that I should reduce the data from these five separate countries and analyze it. So after the Paris Symposium I holed up in a little student quarters in London and stayed there for three months before going to Jodrell Bank. And sometimes I needed equipment, like even just a planimeter and I always remember travelling to the University College in London, which was about a mile away, and seeing, now Sir Harrie Massey, and saying, “Please, I’m Mathewson from Australia, could I please borrow a planimeter, or could I please borrow this.” And so he got pretty used to me in those two months dropping in with these rather odd requests for equipment. But I did finish the project, and then I posted it back to Australia and then Christiansen and Smerd worked on it and a paper was eventually published.

Sullivan

That was in 1960 in Annales d’Astrophysique?

Mathewson

Yeah. I think there were 15 co-authors and –

Sullivan

But I don’t quite get – did everyone bring their data to the meeting?

Mathewson

No, they had actually posted it beforehand. We all exchanged so that everybody had the other’s data. But it was obvious that some one person had to actually be responsible for working it out.

Sullivan

So at the meeting they brought outlines -

Mathewson

That’s right. So it was discussed and then I disappeared into this little hole, London House in London.

Sullivan

Ok, now getting to Jodrell Bank. How was it determined what you were going to work on?

Mathewson

Well, I got there and Lovell suggested that I join 408 MHz cycle, or same megacycle because it was megacycle in those days – group, which was Michael Large who’d been right from Cambridge a few months ago, and a student Glen Haslam. Of course, it was a little bit funny at that point. I was just coming to (?) Research Fellowship, I had this sort of status as a Lecturer. But I thought to myself, well look, in those days you couldn’t get a Doctor of Philosophy in Australia. The top you could go to, the University just didn’t have it. The top you could go to was a Master of Science. So all of the Radio Physics personnel in Sydney were all Master of Sciences or Bachelor of Engineers. And there were no PhD’s, there was not a Doctor amongst us. Lovell then said, "Well, look you’re going to be here for three years or so, why don’t you become a PhD student and whatever research work you do, perhaps you can get a PhD at the end of it." So I then enrolled after working say, for five years or something, I then enrolled as a PhD student. And I was in the rather anomalous position of giving lectures to PhD students in solar radio astronomy while being a student myself.

Sullivan

So this 408 MHz group was something that existed already, apparently?

Mathewson

It had just been formed about two months ago.

Sullivan

Oh I see, so it had -

Mathewson

So there was no really work that had been done at all. It was just a new group, and I met Michael and Glen, and from that point on which I think a tremendous friendship developed between the three of us which exists to this very day.

Sullivan

How did you decide what you wanted to do, this 408? You had a frequency but now you -

Mathewson

We just didn’t know – to be quite honest we were all pretty clueless. Michael Large had been working on lightning thing, electrical discharges in lightning at Cambridge. Glen Haslam had just arrived from out of University, and I’d been working on solar radio astronomy, and here we had 250 foot telescope that towered above us, and dominated not only our visual reactions, but other things. We were all tremendously keen we realized this was a really big moment in radio astronomy. We then – but we were really tremendously inexperienced. But Hanbury Brown, and Cyril Hazard, I think, had been working with the transit telescope – that’s the very big -

Sullivan

The 218 -

Mathewson

Yeah. And they had been doing the normal galaxies and they talked to us and we were very interested in that and we figured that would be perhaps the first good project to do at 408 with a high resolution. And so we did Andromeda, we picked three projects, Andromeda, the Coma Cluster and Cygnus X region.

Sullivan

Right, and those in fact, -

Mathewson

And the Cygnus Loop. That’s right, the Cygnus Loop.

Sullivan

Those four objects were in the title of your thesis which is 1960?

Mathewson

That’s right, yes.

Sullivan

But now can we just go through those? What did you find in looking at Andromeda?

Mathewson

I don’t know whether – I expect we did contribute something when you look back after all this time. I think the most important thing of all was the inspiration. You know, actually getting a signal from Andromeda at 408 MHz. I’ll always remember that first night. Because we had to build everything ourselves, we had to build the receiver, the aerial feed, we had icing problems. And I always remember putting a big plastic – going up with Michael Large and putting a big plastic bag around the feed and filling it up with balloons to try to make – to keep the ice from interfering with things. But I think just – you know, getting the first signals from Andromeda was something that first night. But I think basically what we did do was to, well, first of all, I think was to question the corona, the concept that normal galaxies had haloes around them. And this was a tremendously important concept which had come out from Mills’ work on the Galaxy at the Paris Symposium, that there was this corona. And this had been seized upon, of course, by cosmic ray chaps and it was tremendously -

Sullivan

(?) had been working on it at that point.

Mathewson

And at that point we didn’t get a corona.

Sullivan

In M31?

Mathewson

In M31. And this was something that didn’t come out initially, but did come out later that there was no evidence for a corona similar to what Hanbury Brown and Hazard thought they had from the 158-MHz work on the transit telescope.

Sullivan

Which beam was what, 3 times worse?

Mathewson

Yeah, which beam was much bigger. And they were – so it gave us a break, I think, on the – that was the most important thing that eventually came out and that was something which I followed up on the Parkes Radio Telescope, one of the first things I did. And to show that the three southern spiral galaxies did not have corona. And this was the first thing at the time I think that people started to question, the fact – Before that it was assumed that all normal galaxies had a halo, radio halo. But after the three southern spirals were done at Parkes which really originated from my work on Andromeda, and it showed that they definitely didn’t have haloes, then the concept of it with a halo I think started to disappear.

Sullivan

It seems like you’re saying that years before the Paris Symposium that it was definitely accepted by just about everybody?

Mathewson

Yeah, everybody. If you read some of the very early papers I think, particularly what Hanbury Brown, you’ll see that he actually puts in the coronal size to calculate the total radio (?) of the Galaxy.

Sullivan

I see.

Mathewson

Automatically it goes in.

Sullivan

And now having not found in one other galaxy and then later on at Parkes in three others, you’re saying this was perhaps the demise of this concept?

Mathewson

I think it started it then.

Sullivan

Although it lingered. Even in Baldwin’s ’67 talk, the Nordwijk Symposium, there’s quite a bit about the halo there, is there not still?

Mathewson

Yeah, but the thing is that even with their own galaxy – you see in those days they didn’t realize a lot of high latitude galactic features were present. For instance, the north polar spur was a tremendously prominent radio emission, high latitude radio emission object. Now that didn’t appear in these low resolution maps with particularly Mills. Now he then included all of that looped high latitude emission in his model for a halo. But as we know now the north polar spur is 100 parsecs away. And in fact, they didn’t know what the north polar spur was originally. They thought it was even – could be extragalactic or something.

Sullivan

When was that first recognized, by the way?

Mathewson

Hanbury Brown, I think – or Kraus, Kraus and Ko, I think they perhaps produced one of the first maps showing it in their Ohio State thing, and I think Hanbury Brown also could have been one of the very early discoverers.

Sullivan

About what time would this be? I can check. I’m just curious.

Mathewson

I don’t know. If I have to put a time on it I guess it would be about 1958, something like that. 1957. But that was, of course, a very important point because it dropped the size of the galactic halo, of the halo (?) galaxy, or the strength of the halo (?) galaxy down an awful lot. And then a lot of people started working and the halo really started to get smaller and smaller and smaller.

Sullivan

Now also in the paper you published in Nature in ’59 there was a mention of possibilities of spurs coming out from M31.

Mathewson

That’s right, yeah.

Sullivan

What’s the story there?

Mathewson

Well, those spurs are just radio sources. We thought that they were actually perhaps similar to the radio spur which had just been discovered. And we thought we’d discovered a big loop around the Andromeda, which was similar to this north galactic spur. But it’s really just composed of background sources which we didn’t resolve out.

Sullivan

Ok, moving to the second object, the Coma Cluster. What did you find there?

Mathewson

Well, we found sources there, extended sources and point sources. But the extended sources actually resolved later into two components which could be identified with galaxies in the Coma Cluster. We were trying to look for background emission. They suggested a halo, the Clusters had this broad background emission, but we weren’t successful in that. We basically just identified radio emitting galaxies in the Cluster.

Sullivan

What was the origin of this suggestion of a diffuse - intra-cluster, is that what you’re saying?

Mathewson

Yeah. I can’t quite remember now the people that made it, the people that thought that clusters should have extended magnetic fields.

Sullivan

I see. I can check your paper. Had anyone done any previous observations in the radio of clusters of galaxies?

Mathewson

Yes, I think other people had but not at the same resolution. Ours was the first high, what we called in those days, high resolution survey. And so we could resolve out those sources which other people, I think, thought was extended emission.

Sullivan

Cygnus X, what did you find there?

Mathewson

I guess the main thing that sticks in my mind is, was the discovery of the supernova remnant in the direction of what they called the Gamma Cygni source? Some people, I remember Pike and Drake said it wasn’t a non-thermal source, but it was a thermal source and that we’d made a mistake. And they wrote up a letter in Ap. J. that said we were wrong. Other people did it from Canada – that’s right – at Algonquin I think, Lloyd Higgs. And he showed it was a non-thermal source and agreed with us. And then eventually somebody did it very thoroughly. The thing which we showed is that when you do an extended region, and I think we were the first to show this, that when you do extended regions like Cygnus X which were great clusters of non-thermal, or perhaps non-thermal sources that you must use the same size beamwidth.

Sullivan

At the different frequencies?

Mathewson

At the different frequencies. And so we were I think probably one of the first to really put this down and we were the first to smooth at the – For instance, we did it at 3 frequencies, we would smooth up. If we wanted to get the spectral index out, we’d smooth the high resolution up to the same resolution as the… And then you can directly compare brightness temperatures and get the spectral index directly out for that at each position. But the way people would do it and they made all the mistakes in the world, was to try to compare surveys done with different beamwidth resolutions. And they all fell into the trap.

Sullivan

This is a standard technique now.

Mathewson

This is a standard technique now.

Sullivan

Ok, the final thing is the Cygnus Loop. What did you find there?

Mathewson

Well, I guess the Cygnus Loop has just disappeared from the literature – our contribution. It’s a little bit disappointing. I can remember we were very excited with that, getting such high resolution on a supernova remnant. But I think it was repeated so many times. The Cambridge people did it at the same time, at a lower frequency, and then in the next ten years I think there came out about six or seven surveys with all at better resolution, better frequency. And when you read the papers of the Cygnus Loop, the Mathewson, Large, Haslam contribution has just disappeared. Occasionally people use it for a table flux at 408 MHz. So it really didn’t look – thinking of the contribution now, it was a bit disappointing. But it was one of the surveys that people used, of course, to do the better ones.

Sullivan

Was this all that you worked on while at Jodrell? Anything else before you went back?

Mathewson

We tried to detect polarization in the Galaxy. We were doing it the same time as the Dutch were doing it. We were doing it by rotating the dipole feed at the prime focus of the Jodrell telescope.

Sullivan

At 408 again?

Mathewson

At 408 MHz, which was the frequency indeed that the Dutch first detected polarization, radio polarization from the Galaxy. And we had a little bit of trouble, I guess, with the instrumental parameters I expect. So it was a little confusing – the technique.

Sullivan

Was this ever published?

Mathewson

No, we were actually very close to where the Dutch had discovered the radio polarization. Of course, one could think where to look for it from the optical polarization, in the Perseus direction, around those regions.

Sullivan

You mean as seen in stellar - ?

Mathewson

Yes, in optical polarization, in starlight. But then they came out in the next few months with a very positive detection. But that started my actual interest in radio polarization which I then continued at Parkes and did the southern sky background polarization.

Sullivan

Now was the motivation for this to confirm the synchrotron origin of the (?)

Mathewson

Yes. Polarization just hadn’t been discovered in anything, radio polarization. And this was – the Dutch got the big break, they were the first ones to discover radio polarization.

Sullivan

This was (?) solar system?

Mathewson

Yeah, because, of course, the Crab had been -

Sullivan

(?)

Mathewson

But this is in the broad extended background.

Sullivan

What about this paper by Razin, the Russian, about this time? Am I remembering right that he claimed polarization but that no one believed it?

Mathewson

Ah yes, yes. That’s right. That came out pretty close.

Sullivan

’58 or ’59, I think it was.

Mathewson

That might have even been out because we did this in ’59.

Sullivan

In retrospect, do you have any comments on whether they had it or whether they didn’t?

Mathewson

I don’t know. I wouldn’t like to say. One thing that I would like just to mention very briefly, and that is one thing that really had a – it happened in this period and that was Ceccarelli from Bologna University visited Jodrell. He wasn’t a very pushy person and he was just sort of walking around the place, and he happened to see me and he said, “We’re thinking of starting an Italian Radio Astronomy station.” And I said, “Oh,” because I’d never met him before. He said, “My name is Marcello Ceccarelli.” “And I’m Mathewson.” And he said, “You helped build the Chris-Cross with Chris.” And I said, “Yes.” And he said, “Well, come to Bologna!” So that started a very great friendship between Ceccarelli and myself. During my summer holidays I accepted his invitation and went to Bologna and there got to know the very – it was right at the commencement, I’d been given, I think, a $100,000 by the Italian government. And Ceccarelli had been told to make a telescope. And they offered me the job of actually building the thing. But I was beginning to change. I’d had a lot of aerial building with Chris, a lot of building things for the Jodrell Bank, and I was getting more interested in the astronomical side which actually developed later. So I refused. But I visited Bologna I think at least three times and I would work there for a couple of weeks talking to students who didn’t understand English, drinking lots of coffee and having a tremendous hospitality from Ceccarelli. And from this, I was suggesting various things, aperture synthesis came up, such as towing an aerial around one of the Italian lakes to different positions.

Sullivan

On the surface of the lake?

Mathewson

On the surface of the lake. And then Ceccarelli visited Cambridge and visited Jodrell Bank with a group of Italians, and finally the Northern Cross, as it’s called now, design was hit on. They built a prototype at Medicina, a little Italian village which I visited. That was my last visit. So that was one very big thing which was completely divorced, of course, from the Jodrell research. But it was a very -

Sullivan

But you had a hand in getting it going?

Mathewson

Oh, I didn’t really, I just talked to them and I suggested various things but it was basically all Ceccarelli decisions.

Sullivan

I have talked to him actually about the Bologna development. But did you specifically suggest ideas which were adopted?

Mathewson

I did actually say that the Cambridge type aerials were very good, and they did go to Cambridge and indeed look at the Cambridge.

Sullivan

Cylindrical paraboloids?

Mathewson

Yeah, cylindrical paraboloids. And they did actually go into that. So it was I think some things. But I did help them actually commence. I was the very first consultant I guess one would say. And then, of course, when I left after the three visits in 1960, of course they had many, many other.

Sullivan

Now before we go to the beginning of the Parkes dish, do you have any comments about the atmosphere at Jodrell in these first couple of years? The dish had just gone on the air just as you arrived I guess.

Mathewson

Ah yeah. I’d been doing Sputniks.

Sullivan

That’s right, that was just before you arrived.

Mathewson

Oh, I think it was a wonderful place to be at that time. We were, of course, — my friend there was Bill Shuter, he was working on the Zeeman effect, he was a student. We’ve become firm friends to this day.

Sullivan

What was the name?

Mathewson

Bill Shuter. And, of course, Galt had just started. We were living in the next hut. Everybody lived in huts. So I guess I made some very great friends in those days. I think the reason is that we were all tremendously ambitious, young people, suddenly plucked from various parts of the world and put into this environment which was, I think Lovell infected us all. He had a tremendous aggressive nature which… I mean you really felt you wanted to get something out of this instrument. And the whole thing sort of towered above you all the time, or so it seemed. It was always there and even when you were building your little receivers which these days were, of course were completely outdated, and lugging the receivers across the railway tracks. Which reminds me, of course, on magnificent little story. Well, perhaps I’d better not tell you.

Sullivan

Well, go ahead.

Mathewson

It was Glen Haslam, who was, of course, a member of the group. He broke his leg in a motorbike accident and he had a steel heel in which to hobble around on after it had been set. And he was hobbling around at two in the morning crossing from the actual telescope back to the control room and he lagged behind. I went ahead to get things going and I gave the controller orders to leave the telescope. And then it was very gloomy, very typical Jodrell fog. And I suddenly wondered gee, Glen has taken a long time. And actually I then went back to look for him and I heard this cry of “help” and he’d got the steel toe, the steel heel of the plaster caught in between the two close railway tracks and the telescope was advancing on him. And I always remember that time, I guess Glen will also remember that time.

Sullivan

It might have been the only fatality in the line of duty -

Mathewson

Yeah, run over by a radio telescope.

Sullivan

Ok, so you went back to Australia when?

Mathewson

I went back in 1960.

Sullivan

And what did you work on then?

Mathewson

But before that I sent back – about six months before I went back – I sent back a detailed report to Taffy Bowen, the Director of CSIRO. And in that report – he’d asked me for this report, and he said what sort of advice you give us from your experience working at Jodrell Bank. And I can remember the basic – I said lots of things – actually I sent back lots of photographs of us doing various things like putting the receiver on and so forth. We were one of the very first actually to put the front end up at the aerial feed. Most people, of course, just ran the signal down and they had their preamplifiers and so forth in the (?) laboratory.

Sullivan

This was for convenience that they did it that way?

Mathewson

This was for convenience. We then realized that at 408, you got a lot of loss and we were actually probably one of the first ones – we got a steel box made in Hounslow and we then had to strap it almost below our feed. And this, I think, was, of course, obviously everybody did it after that. We actually bolted it just below. And, of course, after that they put this big box up there in which all the receiver sat, which is a conventional way of doing things now.

Sullivan

But it wasn’t at the beginning -

Mathewson

No, we actually hauled it up on a rope and bolted it there and so forth. Anyway, these are the sort of things I sent back to Taffy. But basically I said that it’s obvious to me that a radio astronomy group should be split into three, you should have your astronomers, you should have your software chaps, because at that stage, of course, we were also one of the first to use the Atlas computer in Manchester to do our galactic plane reduction, the 408 survey of the galactic plane. So that we really entered into data reduction, we were the first group, Michael Large, Glen Haslam, and myself, were the first group to actually enter in. And Glen Haslam actually got tremendously interested in this, and also Michael Large. And Haslam has now developed, I think, into one of the best we, to actually automate the whole sky surveys. Now he does great large sky surveys and fantastically accurate, and never touched by human hand. He works at Bonn, of course. This interest developed in these very early dates when he got involved in the Atlas computer. So I then sent him this recommendation back, that you have to have a computer group. And then it was obvious at that point the parametrics were just beginning to come in and we actually tried to put the first parametric on (?)

Sullivan

(?)

Mathewson

Yeah. And Hanbury Brown helped us here. It failed dismally. It oscillated, it did everything but provide. In the laboratory we fixed it up and it was fine. As soon as we shoved it on the telescope — But I do remember we were the first group certainly in the UK, perhaps not in America, to try out the parametric.

Sullivan

And why didn’t it work at the feed?

Mathewson

I don’t know. I don’t know. We were keeping on developing but it wasn’t the type of parametric that actually was developed later that actually worked successfully. I think it was environment. We had it inside this little box strapped and it was temperature changing.

Sullivan

(?)

Mathewson

I think you just should have a big room in which you can set it up. But these were recommendations, receiver group, computer group, and astronomy group. And these indeed is really why it worked out at the end. Now I’m not saying that necessarily followed from this report which I sent back to Taffy, but I do remember I did send it and really that’s the way -

Sullivan

Do you think there is a cope of that that could be dug up?

Mathewson

Oh yeah, but it’s handwritten and it’s got all sort of photographs in it. I’ve still got it at home. I kept it.

Sullivan

Well I’d very much like to have a copy of that if you’d be willing to send it.

Mathewson

Ok. Yeah. I kept it. Well, I’ll send you the actual report because it would be a bit hard to copy.

Sullivan

Ok, well I’ll certainly return it. So when you got back, the dish was a-building I guess, is this correct?

Mathewson

The dish I think had been built. Oh no. When I got back I used the 60 foot Kennedy dish that had arrived and was just being assembled and I was the first to get that actually on the air at Fleurs. And that was used as a prototype for some of those receivers that were going —

Sullivan

I see, that was its purpose as a testing dish?

Mathewson

Yeah, but it was a bit more than that. We actually did a survey of the Milky Way at 20 cm, the Southern Milky Way which had never been done before. And then we could use the 20 cm data with Mills’ 3½ meter data to get our spectrum (?) and things like that. The same size beamwidth, you see, as Mills. So in other words, it was the first high frequency survey of the Milky Way and I had two physics students working with me, Healey and Rome, and we lived out there for about four months in a little caravan.

Sullivan

And that was published when?

Mathewson

That was published in 1961, or something like that – ’62 perhaps. And then the 60 foot, of course, went to Parkes afterwards to become the interferometer with the 64 meter the 210 foot telescope, and of course we then all moved our attention to Parkes which was the —

Sullivan

Were you involved in the interferometer?

Mathewson

The only thing I did for the interferometer – Bolton surveyed the east-west track and I surveyed the north-south track with the theodolite. And also Bolton and I surveyed, we were the first people to survey the 210-foot dish surface for the acceptance.

Sullivan

Were there any problems there?

Mathewson

No, we even adjusted it. But, of course, now Harry Minnett and Don Yabsley do it all automatically with cameras. But then we used to stand at the middle with the theodolite and sight on all these little nipples, you know, and then get out the best configuration.

Sullivan

Now, in this report with Bowen, did you make any suggestions for the scientific direction of things?

Mathewson

Yes, I did make some, but to be quite honest, until I look at that report I can’t quite— I don’t think there was anything tremendously shattering in the – you know, it was more, I think, the obvious things. I don’t think it was really anything— But the only thing I really do remember was this division into three. And the fact that you should have these specialists and professionals in their area.

Sullivan

Which was a different way than Australian - ?

Mathewson

Oh it was a completely different way.

Sullivan

Which bring us to what we mentioned before we started recording. You made the comment that radio astronomers, even today, but perhaps especially then, were really not astronomers.

Mathewson

Well, you’d better not quote me on this because it might be unpopular. I’m not knocking them because I’m a radio astronomer myself, even though I went into optical 10 years again, I still— But the thing is really a radio astronomer even to this day, I do believe, is more interested in techniques, in pushing equipment. They understand, of course, astronomy, and they understand what they want to push for. But really, to them, I do believe, in pulsar work, and in molecular line work, and in radio surveys in general, that in the aperture synthesis techniques it’s the technique that grabs them and not necessarily what they find out from an astrophysical point of view. I think I’m right here. I’ve looked at both side of the fence and I think I’m right.

Sullivan

I’m going to have a questionnaire which I’m going to send out to -

End Tape 69A

Begin Tape 69B

Sullivan

Continuing with Mathewson on 28 August 1976. Anyway, on this questionnaire, I think I’ll ask a question like that. Do you think that this situation has changed at all over the years that you’ve been in radio astronomy?

Mathewson

No, I don’t believe so. I’ve worked in different radio – you know, it’s not just from Australian experience, from Dutch and I worked in 1970 at Westerbork. And basically I could see there that radio astronomy has drawn attention to some terribly fascinating things in the Universe and without radio astronomy these things would never ever have been discovered. But radio astronomy missed out on, I think, on the glamour part of the whole – of the thing as a whole. It’s always the optical astronomer that has got the glamour of it, and got the big breaks, the big astrophysical breaks. I think this is certainly true in quasars. A radio astronomer is limited, definitely limited in how far he can go.

Sullivan

Only with the radio data.

Mathewson

Yeah. He always come up against a brick wall. And at that brick wall he stops. And then he goes back to his techniques. And, of course, he’s a tremendously clever person, and just because he doesn’t push through into astronomy. Because he’s a genius, all of them are in electrical engineering and in antenna work and software and the fascinating things they’ve done. But they definitely, I think, are a breed of their own. And then the astrophysicist is another breed on his own, and that’s the way I think the subject has gone.

Sullivan

Well, that’s very interesting. I would think it’s debatable and, once again, I think I’ll ask something like that. I mean one could argue, for instance, that microwave background is something that could be interpreted pretty much just on its own and be tremendously important. But your viewpoint is -

Mathewson

Yes, but for instance, you see, it didn’t – they knew what they were looking for. The impetus, direction, to look for microwave background had already come from a cosmologist.

Sullivan

But that’s not how they discovered it. They did not know about this at all.

Mathewson

Ok, but -

Sullivan

You’re saying the subsequent -

Mathewson

It was around though at that point.

Sullivan

The subsequent interpretation was based on an earlier -

Mathewson

Yeah. And so all I’m getting at is that once again, the radio astronomers detected it but they didn’t do much with it.

Sullivan

What you’re saying is that the radio astronomers can’t do much themselves. They’re always relying on the optical data whereas without radio, optical astronomy could proceed and you’re saying the converse is not -

Mathewson

Optical astronomy would proceed in a very dull fashion without the radio astronomers.

Sullivan

But it could proceed whereas the radio could never really make it without the optical. Is that the sort of thing you’re implying?

Mathewson

Ah – I don’t know whether I’m implying such drastic things as that. I think radio astronomers would make a good contribution observationally. That I do believe that the optical astronomer or the astrophysicist is really the chap that takes it to where you want to take it.

Sullivan

Yeah, I see what you are saying.

Mathewson

And the radio astronomer is an engineer and he’s got this word “radio astronomer” and it’s almost a misnomer.

Sullivan

But, not what about – you were in Holland and you see that the radio astronomer there often is not an engineer. In fact, many graduate students today trained in astronomy call themselves radio astronomers. I think I would include myself in that category and I don’t know how to build a receiver. That’s why I was asking you do you think the situation is changing.

Mathewson

Yeah, I guess it - In Holland, of course, you’ve got optical astronomers mixed up with radio and it’s probably not so (?) But even then I’ve noticed that they do tend to concentrate quite a lot on techniques. It forms the major part of the conversation. You know, how will we extend the east-west line of Westerbork and what redundancies do we have, and what signal-to-noise do we have and how many channels we’ll have.

Sullivan

Yeah, that’s right.

Mathewson

If you listen at lunch time, which is a very good indication, I’d bet you that there will, be 90 percent of the talk will be about technical problems, with 10 percent of the talk being about astrophysical problems.

Sullivan

Ok, just a couple more things. The relationship between optical and radio astronomy, at least during the time you’ve been in the field, 1955, I’m interested if you think it’s changed or not.

Mathewson

The relationship between radio and optical?

Sullivan

I mean the acceptance of the optical community of the radio community, this sort of thing.

Mathewson

I think that there’s no doubt. In the early days, it just is that the optical astronomer didn’t quite understand what was happening. Anybody, I think, when met with that sort of situation, a strange situation, he, sort of, tends to shy away from it. But now, of course -

Sullivan

But when did you think it changed, this attitude?

Mathewson

It’s hard to say. I think the biggest thing that ever happened was the quasar, the point of discovery of the quasar. I think that was a time when optical astronomers realized the tremendous impetus that radio astronomers were giving to the fields, and that this was one of the most exciting things that had ever been discovered. And the whole thing was due to the radio astronomer. The initial push was due to the radio astronomer. I think that was the time when things changed quite considerable.

Sullivan

Ok, well, thank you very much. That ends the interview with Don Mathewson on 28 August 1976.

End Tape 69B

Citation

Papers of Woodruff T. Sullivan III, “Interview with Donald S. Mathewson,” NRAO/AUI Archives, accessed December 22, 2024, https://www.nrao.edu/archives/items/show/15039.