Interview with Frank J. Kerr on 3 October 1971

Sullivan: 00:02

Okay. This is October 3rd, 1971, interviewing Frank Kerr en route to Charlottesville. First moving interview. So would you like to start off with the early days of postwar and how CSIRO got involved in radio astronomy?

Kerr: 00:21

It's probably worth going further back still and just say that Australia started off early in what you'd call radio propagation work or radio physics generation, but there was a pretty strong school of ionospheric studies going, well, I guess in the early or fairly early 1930s even. And that grew up because of the importance of radio in a big country like Australia, especially a country of low latitudes where there's a lot of static and so on. So it made interest in the study of propagation conditions inside the country, and also short wave of links to the other parts of the world, so that there was a big group that started off in ionosphere work that centered on Sydney University. And the first radar people really came out of that group.

Sullivan: 01:28

Was this CSIRO even before the war?

Kerr: 01:30

No. It was an organization called the Radio Research Board, which was a funny sort of entity and it had representatives from the Post Office, the Army, the Navy, I guess CSIR as it was called then, and perhaps a couple of others. And it ran a couple of labs, one in Sydney and a smaller one in Melbourne. And some of the early people such as, well, Piddington certainly, and [inaudible] and Martyn and Webster, [Pully?], a few of the others that came into radar in 1939 from that direction. And the Radio Research Board actually continued to exist, but it stayed in ionosphere work, and CSIR set up the Radiophysics Laboratory in 1939. And the secret conditions that would work on this great new thing that at that time was called RDF, radio direction finding.

Sullivan: 02:51

Was this in conjunction with the English, I assume?

Kerr: 02:53

Yeah. The name radar came in somewhat later. It was the American name of course, but it was adopted in the other countries only a few years later.

Sullivan: 03:05

What did CSIR stand for?

Kerr: 03:08

That's a good question. CSIR is Council for Scientific and Industrial Research. It started well, 1919, 1920 or so, and existed in that form until 1947 or '48 when the organization was changed and then it became CSIRO, which was more definitely a government department or government agency, Commonwealth Scientific and Industrial Research Organization. It did the rather unusual thing when it was formed. The circular went round everywhere to give the official spelling and the unusual thing was that the organization was spelled with a zed, whereas the common English spelling, of course, is with an S. And so the radar started up in 1939 and a fairly large lab was set up of 20 or 30 scientific people, quite largely coming out of electrical engineering in Sydney or from physics in Melbourne, the two principal sources. I personally joined it in 1940, in August. At that time I think we had about 8 or 10 people in and out. They equipped it rapidly after that. The first Chief was DF Martyn, M-A-R-T-Y-N, then about 1941, Fred White became Chief, about 1943 or so Taffy Bowen joined the place, firstly as Assistant Chief of and then he became Chief in '45.

Sullivan: 05:32

Let me just ask now, this was before-- well, when did Australia declare war? I mean, this was solely in support of the British effort in Europe?

Kerr: 05:44

Well, Australia declared war at the same time, essentially, as Britain did.

Sullivan: 05:50

Oh, they did. Okay.

Kerr: 05:51

But the entry of the Japanese was essentially regarded very much in Australia as a new war. And as far as radar went it changed the directions of the effort considerably because-- especially around '43 or so, '43, '44, when the Allies started on the island hopping and going northwards up the Pacific towards Japan. The Australian radar efforts specialized on easily transportable equipment and stuff which you could take in from a ship upon landing and set it up in an hour or so and have it working, whereas the British and America equipment usually took several days to get going on any new site. And that was a special direction of the Australian work, especially later on. More so there was a lot of emphasis on what was called tropicalization. That is making condensers that wouldn't grow fungus on them and so on.

Sullivan: 07:18

Right. I imagine it led to more miniaturization also, and obviously portability.

Kerr: 07:23

Yeah.

Sullivan: 07:24

And was this of some help as far as putting radio receivers at [foci?]?

Kerr: 07:30

I'm sure it was because of it meant the acquiring of a lot of skills and abilities and that sort thing. The first glimmerings of radio astronomy, let me see, have-- all the time during the war there was a quite extensive information network as classified and secret information exchanged between the, firstly Britain and Australia. And then the Americans came in and they came in on this network. So we received information from Britain and America about all the things that were happening in radar and associated subjects under this sort of classified system. And that's where the first news about radio astronomy came in really. Of course, Jansky and Reber were sort of heard of before, but nobody took much notice of them.

Sullivan: 08:52

All right. Are you talking about now about Hey’s?

Kerr: 08:55

That was the first one, yes. The story came through about - what do I call them? - the special sort of radar sets, G something. Round something. A fairly long wave radar set that worked on four or five meters. It was one of the early ones extensively used in England. The G.L., I think it was, gun laying. And they reported that they were often shooting at things which didn't seem to exist and that the operational research people in England studied this and eventually showed that the common object they were shooting at which didn't really exist was the Sun. And so I guess Hey was involved in studying this. That was the first real the first real report of something excitingly new, because obvious it was connected with the active sun that showed promise of being quite an interesting subject.

Sullivan: 10:29

I wonder, was it near a sunspot maximum? I never have looked that up.

Kerr: 10:33

Well, as a matter of fact the sort of bench point I've got is that 1944 was the sunspot minimum.

Sullivan: 10:44

So is there a minimum?

Kerr: 10:45

In fact, the comment has always been made that the Allied advance across the Pacific up to Japan was greatly assisted by having a sunspot minimum at that time because it was all done in terms of short wave communication at that time and there were no radio fade outs or anything like that that could have upset communications. This study of Hey’s was about 1942, so it was when the Sun was fading down toward the minimum. It was still moderately active, I think.

Sullivan: 11:28

Right. There were no other sources detected accidentally this way like Jupiter?

Kerr: 11:36

No.

Sullivan: 11:36

Well, obviously not Jupiter, because that I was discovered later, but.

Kerr: 11:40

This work of Hey’s and the discussion of it afterwards really threw light on the mysterious events that had been reported mainly by amateurs about 1935 and '37 or so. The amateur journals like Radio News and so on, were always carrying odd reports of the strange noises being heard just before the Sun’s radio fade out. Probably at that time was when the fade outs were first recognized as being something significant. And quite a few reports of the very strong hissing noises occurring just about the time of the fade out. And they weren't understood at all at that time. Of course, the Hey investigation showed that those must have been solar noise also. But that was the first time that that was really understood. And so that was that one, and about I guess a year or two afterwards, we heard about the work of Southworth at the Bell Labs, getting solar noise at a much shorter wavelength. I'm little uncertain at the moment what the wavelength was, but may been about 10 centimeters. But that was, I presumed from the quiet Sun, it was a fairly steady sort of level. And the report about that came through too. So it was clear that the Sun had these two types of phenomenon that made activity at long wavelength and something happening at shorter wavelengths.

Sullivan: 13:52

Now Southworth was during the War also?

Kerr: 13:54

Yes. But apparently not connected with the War. As far as I know, it was just sort of accidentally at that time. Well, I guess it was connected with the War in the sense that the wartime radar work made it possible to build decent receivers at 10 centimeters. And so it was an investigation I suppose that was sparked by the War.

Sullivan: 14:24

Was this published or did Southworth--?

Kerr: 14:27

I believe it was published shortly after the War 45 or 46 or something. And it might be something like a Journal at the Franklin Institute, but it was published, yes.

Sullivan: 14:43

What about Hey? Did he publish right after the war?

Kerr: 14:46

I don't think it was published in a proper scientific manner, but you could undoubtedly find articles or discussions of it, I think, somewhere in Nature about the end of the War period. But probably at about the same time that they were writing up all the work on radar in a public style. These were generally not scientific papers, but in the form of reviews rather of what had been going on.

Sullivan: 15:26

In fact the one I'm familiar was the MIT Radar series. They might have some mention of itin there.

Kerr: 15:33

It'll be certainly there. I was thinking more of the journals, undoubtedly find some things in some journals as well. But I'm sure it would be in the Radiation Lab series. Yes.

Sullivan: 15:48

Well, now still there had to be someone-- was there someone that had been an amateur astronomer or something like this that just had an interest in astronomy, or was it--? I mean, what was the-- was it Bowen who directed it?

Kerr: 16:03

Bowen and Pawsey. The father of radio astronomy in Australia was certainly Joe Pawsey. I guess his title was Assistant Chief or Deputy Chief or something in charge of research during the war. And he was the one who was most concerned with all the radar propagation studies with antennas with TR switches. Do you know the TR switches?

Sullivan: 16:42

No, I'm afraid I don't.

Kerr: 16:43

Transmit receive. A switch which is an essential part of a radar set. It usually involves a diode or something that blanks the receiver off at the time when you're transmitting a pulse.

Sullivan: 16:58

I see.

Kerr: 16:59

And he was a wizard on the antennas and the transmission lines and the switchery and wave guides and all that. And so he was the main person connected with the research end of the radar work. And he was really the one who first drew the conclusion from these two pieces of overseas intelligence that here was an interesting subject to start thinking about as a postwar thing to do. And there were two sort of part time attempts to do something. It's still during the war, but he and Ruby Payne-Scott had tried out something on the roof of the lab building. And that I think used a very small dish, probably in the 10 centimeter region, just poking it at the Sun to see what could be received. And they didn't spend long enough on it to get anything out of it. And as mentioned in that article of Pawsey's I gave you a copy of, I tried something too actually in the backyard at home. That was with the Yagi antenna and the receiver from one of the radar sets.

Sullivan: 18:49

This was to try to pick up the Sun also?

Kerr: 18:51

Yes. I had something like a few meters, but it too didn't get anywhere. But this was because in each case we didn't put enough effort into it [inaudible]. Thinking about it there wasn't time to do it. But still, the idea was there in the background of several people's minds, especially Pawsey's, and so as soon as the end of the War could be seen to be coming, he had started thinking pretty actively about it. And this was thought of as a good subject for the Lab to get into in-- well, partly in order to keep the Lab in being, because it was a collection of good people, well trained in the arts of radio, and especially at that time, there was a feeling that it had been of main national value to have had the Lab. And so it was possible to sell the idea to the authorities that the group should be kept in existence as a national asset, so to speak. And so radio astronomy really started in that sense. They said it was something that the group could do and it would be a good thing to support anyway.

Sullivan: 20:30

So there's no one that had a large interest in astronomy per se other than a natural curiosity?

Kerr: 20:36

Just the curiosity. Several of us had various degrees of amateur interest in astronomy at one time or another, but none of us really knew anything about astronomy much, and it was just in training sort of thing to get into.

Sullivan: 20:59

Excuse me, can you put the interior light on it? Unfortunately, there's no indication except to look at this thing to see if it's come to the end. And it's still going, but let me check how much. Okay, thank you.

Kerr: 21:18

And the other great thing that, of course, helped a lot at that early time was we had a lot radar equipment about. We has antennas and receivers and places of waveguide, pieces of transmission line, and so on and so on. And in fact, the very first work, I think, was done on an Air Force early warning station at a place called Collaroy, C-O-L-L-A-R-O-Y, on the coast north of Sydney in the northern suburbs. That was a station that had been operating for several years as a radar warning station on 200 megacycles. And so the first thing they did was to start playing around with that. And it was the first radio astronomy work, was actually being done while the Air Force still ran the place. I can't exactly recall whether the War had actually ended or not or was in its fading stages.

Sullivan: 22:42

What were the advantages of this place?

Kerr: 22:45

Well, it was an existing setup, you see, it was a complete antenna plus receiver. And Pawsey and McCready and Payne-Scott were the ones who were who did the first work there. And they found the pen recorder somewhere and attached it to the receiver and they were in business. And that's the place where the connection between solar noise and sunspots was first discovered or first demonstrated.

Sullivan: 23:22

Sunspike grew up here.

Kerr: 23:24

Yes, and the principle of the sea interferometer was the first use of radio astronomy there.

Sullivan: 23:34

As described in Pawsey and Bracewell. Pretty much.

Kerr: 23:38

Yeah, of course, they sea interferometer had long been used in radar, and this, of course, was one of the great advantages of having this group skilled in radar coming onto radio astronomy. But we knew all about the propagation of radio waves in the space above the sea and the interference pattern produced by the signals reflected from aircraft. They came in directly and by reflection from the sea. And so the way that you worked out how high an aircraft was, was to see how quickly it went through the lobes of the interference path.

Sullivan: 24:29

I see you actually did use it. That couldn’t be used at too high an altitude, could it?.

Kerr: 24:35

No, it's only for low flying. Well, it's a long distance though. But yeah, quite high aircraft could be picked up that way at long distances.

Sullivan: 24:46

What was the typical altitude limit [inaudible]?

Kerr: 24:50

In those days, a fairly high flying aircraft was about 25,000 feet anyway.

Sullivan: 24:57

But in terms of angle, a typical ship, how low would it have to be in altitude [crosstalk]?

Kerr: 25:03

A ship or an aircraft?

Sullivan: 25:04

How low do the altitude of the aircraft have to be, the angle altitude, not the--?

Kerr: 25:12

Yes, this kind of set up that we had worked with the broadcast-- sorry, the broadside array, the dipoles. It would give, I think, just roughly lead width of, say, 10 degrees in azimuth and 10 or 15 degrees in elevation, or so. But you can still see an interference path up to 2 to 15 degrees. So it was very natural to apply the system to the Sun and just watch the Sun coming up through the lobes. And the position of the lobes in the sky was perfectly well known from the radar work, including what happened with refraction and so on. And so it was a straightforward business to demonstrate that the sources of activity on the Sun were related to the visible sunspots.

Sullivan: 26:23

And these lobes were, I guess, a few minutes of arc in size?

Kerr: 26:27

Or perhaps bigger, perhaps even up to a quarter of a degree.

Sullivan: 26:35

That's half the size of the Sun. But you could still see it go across the Sun, I guess.

Kerr: 26:43

Yes. Yes, you're right. They must have been there. At least you could direction find to say two or three minutes of arc. That's right. The lows were probably, say, 15 or 20 minutes of arc, a few minutes of arc quite easily?].

Sullivan: 27:05

Sorry, can you switch the light back on a second?

Kerr: 27:07

Okay.

Sullivan: 27:11

Okay, we've got about two minutes left, right.

Kerr: 27:14

So the early work was essentially done on the Sun. And it wasn't until-- or perhaps a few months or a year later that anything was done on the Milky Way, except just in passing.

Sullivan: 27:38

This solar work was published?

Kerr: 27:40

Yes, there are letters to Nature. All the early publications at that time were in Nature really. That's where you can find all the early stuff from England or Australia.

Sullivan: 27:52

And I think these references were all Pawsey and Bracewell, aren’t they?

Kerr: 27:56

I should think so, yeah. And you can get the exact chronology there. So it's probably boring [inaudible].

Sullivan: 28:06

Right. Actually, I've never sat down and gone through that book, so I'm not familiar. But you say he does have the chronology of the history of what went on?

Kerr: 28:19

I was thinking more you could get the exact chronology from these papers.

Sullivan: 28:22

All from the papers. Yeah, that's true.

Kerr: 28:24

Because they give actual dates and so on at which the particular stations were being used or they're being used on and so on. Because the start of the Collaroy and shortly afterwards, the station of Dover Heights was used for the same purpose. It was an Army radar station more interested in looking at ships. And it was also around 200 megacycles, but they probably had something at 10 centimeters as well there, I think. Now some of the early work was done at 100 megahertz. I’m just trying to think, that must have come after the Army left. Is our two minutes up?

Sullivan: 29:23

No, I'm listening carefully now. I can hear a very slight click when it ends, so.

Kerr: 29:27

Okay. The Collaroy station didn't last very long after the end of the War. It was closed down when the Air Force moved out didn’t want it any more. And the work then moved to Dover Heights. That's the southern side of Sydney Harbor and almost directly east of the Radiophysics Lab at the site, at Sydney University, where it was then. So it was an easy half-hour trip from the Lab. And they started off also on solar work, but they got into intergalactic and extragalactic work. The common word in word in Australia is cosmic actually. If you're talking solar noise, cosmic noise, cosmic referring to anything outside of the solar system.

Sullivan: 30:34

That's what Reber called it in his papers, cosmic noise.

Kerr: 30:37

That's still used at the Radiophysics Lab as the the organizational distinction between--

Sullivan: 30:48

Now, you didn’t mention-- I assume it must have happened, but that the group’s switch over in emphasis to radio astronomy was approved by the authorities. Okay.

[brief pause]

Kerr: 31:14

Okay. We should now.

Sullivan: 31:14

Yeah. You were saying it was approved.

Kerr: 31:17

Stage one was probably an internal manner only, internal matter just to get agreement from inside the lab to do a quick pilot study just to see what could be seen on that particular radar, whether it was worth continuing with. And then the effort gradually grew. The step by step, it was approved at higher and higher levels until certainly by the end of '45 and early '46, it was a quite well recognized, well approved activity that happened I guess into-- that's officially budgeted for and so on.

Sullivan: 32:10

When did the Radiophysics Division per se become established?

Kerr: 32:15

Well, it became established in 1939 [crosstalk].

Sullivan: 32:18

Oh, so it was called that even before.

Kerr: 32:20

That's it. It was just a straight carry on from that. The only difference, at the end of the war, the doors were opened and the public were allowed in and it was no longer secret. And instead of radar, there was work done on radio astronomy and on civil aviation work, that is applying radar and so on to developing navigational aids for aircraft. And there was still some work being done on valves, vacuum tubes, for a while, but that plays down after a while. And then later on, the other big effort that started up on the study of clouds and rain.

Sullivan: 33:10

I knew we just passed a memorable Tasty Freeze just for the record. [laughter]

Kerr: 33:15

Is that very memorable?

Sullivan: 33:16

You don’t know that Tasty Freeze.

Kerr: 33:18

Oh, that is your favorite Tasty Freeze. Oh, I know. [laughter]

Sullivan: 33:21

I thought you did.

Kerr: 33:23

I'll bow down before it whenever I see it again.

Sullivan: 33:28

Now we don't need to do that. We usually stand for an ice cream. Interesting point comes to my mind is when did the term radio astronomy start to come into vogue? Can you remember that?

Kerr: 33:45

That's interesting question. It must have been around for a long time because I cannot recall any specific start into it. But I think it was in use pretty early after the war. It must have been used-- I'm sure it was used to describe this work in the plans and programs of the Lab quite early. I don't know when it developed in England, but it's an old phrase. Now, [I don’t know?] where the comments on organization, you can see that the cloud and rain work of the Radiophysics Lab also grew out of radar, especially in working around 3 centimeters, so people were very conscious of it because of the rain storms and so on. So now that grew out quite naturally. The other thing I was going to say, I just briefly said was the doors were opened up at the end of the War. It's worth just mentioning that they-- that the changed from CSIR to CSIRO. What occurred in 1947 was a result of what would be-- of what would be called in this country a McCarthyist sort of operation. The CSIR became politically unpopular in some circles because of a supposed defending some left-wing people inside this organization. And there was an argument as to whether or not the organization should be doing any secret work or not.

Sullivan: 35:56

I see.

Kerr: 35:57

And the upshot of it was that the only division that was still doing the secret work-- that was when they connected with aircraft. It was taken out of the CSIRO and put somewhere else. And ever since then, there's been nothing secret in CSIRO. But the organization was rather changed and it became somewhat more civil service in style.

Sullivan: 36:26

I see.

Kerr: 36:27

But the great name at that time, the person who was head of CSIR was forced to resign in the changeover. There was a person called Ribett or Ribette. R-I-B-E-double T. So David Ribett. But he's very important in any history of CSIR, having broken up from the early days, essentially [except for?] [inaudible] [last one?]. [inaudible] right through.

Sullivan: 37:01

Let me ask a general question while I think of it. Namely, are there any sort of archives of history of the Radiophysics Division in Sydney?

Kerr: 37:09

Yes. All the old files still exist and were-- and there have been a couple of projects connected with writing a history of the division. But I don't think it ever led to any-- [very final?]. There was one project-- the person who was librarian during most of the war years, a person called Marjorie Barnard, was going to write a history of the lab within the late '40s. And she probably went quite a-- quite a long way with it. But I don't think it was ever published. But she actually was a novelist. Or she and somebody else wrote together under--

Sullivan: 38:04

I see. So there might be a manuscript of that, anyway.

Kerr: 38:10

Yes, quite possibly. Also Arthur Higgs was, at one time, interested in writing a history. But I don't know if it-- if it got anywhere.  [Note added in 2025:  see Radio Astronomy: draft manuscript by Arthur J. Higgs, CSIRO, written 1968-1970, intended for publication by Thomas Nelson (Australia) Ltd. but never completed. https://science.nrao.edu/about/publications/radio-astronomy/]

Sullivan: 38:19

And who was he?

Kerr: 38:21

He had the title of Technical Secretary for a long time. He was a person who had been in the ionosphere business, so he was a scientific type. But he was the Chief's [off sider?] for many years. He was someone like Bill Howard in NRAO. And he's only just recently retired, actually. So he was in it for a long, long time.

Sullivan: 38:57

So it might be good to get in touch with him anyway to see [inaudible].

Kerr: 39:02

Yes. Yes, probably would.

Sullivan: 39:06

Well, okay. Back to early days. We have these two experiments at these stations. When was it that actually-- or is the next step, I should say, a station built specifically for radio astronomy?

Kerr: 39:28

Well, that came sometime later, really. And still at Dover Heights. It's worth talking about some of the things that happened there. I guess late 1946 or early '47, John Bolton joined the Lab. And he began working at Dover. But he and Gordon Stanley got interested in the cosmic noise and they produced a map of the galactic radiation, essentially, over the sky at a hundred-and-something megahertz.

Sullivan: 40:32

This is in Nature?

Kerr: 40:35

That was in The Australian Journal of Scientific Research, I think. The predecessor of The Australian Journal of Physics. And that was a sort of a 15-degree kind of resolution. It showed peaks in the Cygnus and Carina directions. And probably for the first time, they started talking about the local [spiral arm?] running through the sun. And also, shortly after that, the first radio source started to come into consciousness. The first thing on that was a report by Hey, because Hey had first recognized the existence of a discreet or a small-diameter source. And he recognized it through seeing fluctuations. This is somewhere in Nature. This was what we now know as Cygnus A. And his first letter merely says that they found fluctuations in a cosmic signal from the approximate direction of the constellation Cygnus, and the presence of fluctuations must mean a small diameter source. And it was not until some time afterwards that the source was located more exactly. The first source that was actually located in position or-- yes, located in position or identified with anything is the Crab Nebula. It was shortly after Hey’s discovery of fluctuations and suggestion of a small diameter source that the people at Dover Heights, presumably Bolton and Stanley, they recognized the existence of a source in Taurus, and they found this position from the sea interferometer method and identified it with the Crab Nebula. That was the first location and position for the discrete source. And the first identification with anything.

Sullivan: 43:30

And this was published in Nature?

Kerr: 43:31

I guess so, yes. And then a year or so later, '48 or so, '49 maybe, by that time they had something like six or seven sources. The Centaurus A was the other. [inaudible] discovered a southern one.  That list undoubtedly included Cygnus and Virgo. Not sure which else.

Sullivan: 44:08

You mentioned, this 100 megahertz map they did that they talked about the local spiral arm and all that seems to me they must have been really brushing up on their astronomy to know about such things were.

Kerr: 44:21

Yes, during those years, we all are gradually got interested in astronomy. In the solar the period especially Pawsey and McCready went down to Mount Stromlo to start interrogating the astronomers something about astronomy. And the person that they got interested in astronomy was Clae Allen, a C.W. Allen, at least the person that they got interested in radio astronomy, C.W. Allen. And he was a solar specialist. So he was especially good at telling them all about the sun and the whole background to a way in which the sun radiated as a source, and the role of the chromosphere and the corona and the different levels for different wavelengths and so on. That was developed through the cooperation between Pawsey and Allen and D.F Martyn, who by this time was also at Stromlo. At that time the director of the Stromlo was Woolley and he, of course, was not interested in radio astronomy, quite the opposite. But Clae Allen was so interested that he started a program himself, and he and Colin Gum set up a yagi and receiver at 150 megacycles at Stromlo. That was all from radar surplus equipment that Pawsey got for them, I'm sure. And that was at least-- no, sorry, this was 200 megacycles. It was 200. And that was one of the first really worthwhile surveys of a hemisphere of sky and it lasted as a valuable survey for quite a long time. In fact, it [surpassed?] the northern survey a few years later by Priester in Germany is widely published as one of the first complete surveys of the sky.

Sullivan: 47:10

What sort of resolution did they have?

Kerr: 47:11

That was, say, 15 degrees again. And in modern times it’s not that good. In those days was almost [inaudible].

Sullivan: 47:25

What is the reference for that survey?

Kerr: 47:27

That also was published in the Australian Journal of Scientific Research.

Sullivan: 47:32

By?

Kerr: 47:33

By Allen and Gavin.

Sullivan: 47:35

But what about this other 100 megahertz survey you mentioned [again?]?

Kerr: 47:42

That was Bolton and Westfold.

Sullivan: 47:44

Why was that 200 one better?

Kerr: 47:48

Well, it had a bit more resolution than the 100 megacycle, I guess, because of the high frequency, that’s probably the reason. The choice of these frequencies was almost entirely a question of what receivers were available. And it wasn't until a few years later that people started making receivers specially for radio astronomy. In the early days, they just use existing ones or else built improved bits for existing ones.

Sullivan: 48:27

All right. What about this German survey you mentioned? I've never heard of that.

Kerr: 48:31

That was by Priester about 1955.

Sullivan: 48:35

Oh, that late.

Kerr: 48:37

It was still, well about '53 maybe. But it was still true that at that time, there was no overall survey of whole sky. And putting those two together was a useful piece of work. At a frequency as high as that anyway.

Sullivan: 48:56

Now where is the Priester and survey published?

Kerr: 49:03

I'm not quite sure, I'm afraid. I've mostly seen it in the form Priester [inaudible].  It came out in a German publication first of all, perhaps in the German Zeitschrift [Zeitschrift für Astrophysik] but it is quoted in various places. Sorry, I can't help out my memory. Well, I'm still following this particular thread, though, I haven't yet said anything about what I've been doing, what I was doing. Following this thread through the Bolton and Westfold, they completed their survey about 1948 or so. Or '49. And in 1950, they both went traveling. Then Westfold actually went to spend a year or two in England, but Bolton went just to establish contacts with the rest of the world on this interesting new subject. In particular, the two of them together spent a while at Leiden. And they spent a lot of time with Oort. And there's a paper in the BAN or somewhere by Oort and Westerhout, that was interpreting the Bolton-Westfold survey in terms of thermal or nonthermal sources.

Sullivan: 50:58

So where's this?

Kerr: 51:01

That's about 1950.  It’s is all wrong now, in terms of their interpretation, but that was because the angular resolution had smeared everything out. So they were working in a hopeless cause really. Those were the days when people are all optimistic, about correcting for antenna broadening and so on. Beam smoothing effects, or beam smearing effects. And in Bolton and Westfold’s paper, there's a complete story of how you can correct the beam smearing and get back all the information that you'd ever lost through using a 15-degree beam instead of an infinitely [inaudible]. Then at that time people, they will have probably realized that you're not going to get information back, and you don’t even get some of it back, but it was a few years later when the theory of this gradually developed led by Bracewell. So that time, people were optimistically trying to restore all the information in the maps. Another funny story, or a funny story about that visit to Leiden that this astronomical innocence of Bolton and Westfold, to come to the fountainhead of all wisdom in astronomy. And in the course of some of their work, there are some results that have to be corrected for the precession from one year to another, and the great Oort carried out the correction. And then it turned out later he made the correction in the wrong direction. But this is the sort of way that people acquired astronomy. It started very much at first of getting in touch with knowledgeable people that's Allen in Australia and the people like Oort and so on overseas.

Sullivan: 53:33

It's maybe Greenstein in this country.

Kerr: 53:36

I don't think Greenstein was terribly much involved, he was to some extent, I guess he must have, because he was the one who eventually got Caltech interested in doing some work. But make the perhaps had a bit of the attitude of once bitten twice shy about [inaudible]. They didn't throw themselves into it immediately.

Sullivan: 54:08

Which bite are you referring to?

Kerr: 54:10

Well, interpreting Jansky. That he was one of the few people that took Jansky seriously, but probably because nothing came of it that time and nobody else was interested. That perhaps [inaudible] away too.

Sullivan: 54:36

I see. But anyway, we digress.

Kerr: 54:41

Yeah. I forgot to do all the other people [inaudible] were not involved at the astronomers as such on the whole did not get very much interested in it [inaudible] and then Bok in the early '50s was one of the first people in this country to get interested in radio astronomy. There still at that time, there's not much interest at all.

Sullivan: 55:13

What did Bolton learn from his around-the-world tour?

Kerr: 55:17

Well, I suppose that he, and also Pawsey did some touring at that time. They learned something about what were the interesting problems in astronomy generally. Then acquiring some of the attitude of astronomers towards astronomy instead of just electrical engineers and physicists’ attitude towards astronomy. So that this literally got them interested in the future possibilities, that the whole subject, that it became clear that it was worthwhile trying to develop the quite high-resolution systems and pushing the subject as far as it would go because it was clear that there must be lots of interesting things. And there are undoubtedly many interesting studies in the Radiophysics files at that time that discuss the future possibilities of radio astronomy. I've got copies of a few of those that probably [inaudible] many studies and so on have been thrown out, I regret to say, as far as I was concerned. But I did it partly because I knew the full set of all that stuff was on file in the Lab, that they've carefully kept records of everything as far as I know.

Sullivan: 56:58

We won't take your amateur historian [inaudible] responsibility.

Kerr: 57:05

I kept a lot of it. And a lot of stuff there.

Sullivan: 57:12

Now, did they bring back ideas for new experiments to do, I imagine also? I mean, I'm wondering, for instance, the 21-centimeter effort began around this time.

Kerr: 57:24

Yes. I heard about the 21-centimeter line at that time, that the interesting, that's the time when Oort was very interested in it. They had started work on it at Holland. However, nothing was specifically started in Australia after this news got back, after Bolton got back. And Pawsey had heard of it, too. This was because they were pressing forward with other things. And in fact, no work started om the 21 centimeter line until after Ewen and Purcell’s discovery. Until the news got back, they hurriedly whipped up a 31-centimeter line receiver in about six week and confirmed the discovery. This was only possible of course because by that time there was quite a pool of equipment around, the people who were pretty skilled at putting things together into a system.

Sullivan: 58:48

Was there any fundamental difficulty in doing this line receiver?

Kerr: 58:55

[inaudible] from doing it to me?

Sullivan: 58:57

Yeah. I mean, I guess could have been if they put together six weeks.

Kerr: 59:04

Oh, no, it’s just that they were so busy with what they were doing that that was just put on the shelf or something, but they laid it out.

Sullivan: 59:12

So you mentioned that you and, you haven't been talking about what you were doing. Was this in a different line, I guess, in this low-frequency continuous--

Kerr: 59:23

Yes. I came into it a little bit later. I was in the closing stages of the war I was involved in the study, the performance of radar equipment, in particular, a connection with weather and the radio propagation factors, and the propagation in the troposphere, and so on. And we had a program set up for collecting effective performance data from all the Air Force radar stations all around Australia and New Guinea. And we did a quite large statistical study. And that was before the days of computers, too. We had many girls instead of a computer.

Sullivan: 01:00:16

That's calculators?

Kerr: 01:00:17

Yes. And that really kept on, or the study of that stuff, kept on for about a year after the end of the War. So I was involved in that until sometime in 1946, or perhaps early '46. And there's a publication on that in Australian Journal of Scientific Research that was called “Super Refraction for the Performance of Radar Stations at Coastal Environment.” So I got involved in the astronomy game a bit later. And did it in a slightly different way although actually, the flying radar itself, as also using wartime equipment was still lying around. And to begin with we're following up on other phase discoveries. Hey, of course, got involved in radar echoes of meteor trails. So we set up a radar system at a very long wavelength. There's something a lot of tech leaders, I was there looking at meteor trails. And the other things were getting so--

[silence]

Sullivan: 01:02:19

Continuing with Frank Kerr October 3rd, 1971. And we're talking about the first radar-

Sullivan: 00:03

[inaudible] had a [inaudible] bigger than what?

Kerr: 00:04

Continue where you left off. It was always jokingly said that the diameter had to be 255 feet to be bigger than Jodrell and the great disappointment of Taffy and others when the diameter had to be cut down to 210 for cost reasons.

Sullivan: 00:23

These other people have other things they want to do with the same amount of money? Like what?

Kerr: 00:32

Well, people like Christianson and Mills were strongly opposed to the idea of going on for a big dish because they thought of it in part as a white elephant that would eat up all the money, and it would change the character of the Lab from a Lab which was innovative and built its strength on innovation and new ideas to one that became just like any old astronomic observatory that would do things just because they had the telescope there and you had to observe with it. So there were very good [inaudible] other people wanted to develop things like big arrays. If they had their way, it would have gone eventually to [inaudible]. Would have gone on eventually to something like VLA maybe, I don't know. And certainly, Mills had plans after he'd got his first cross working and [inaudible]. And he had plans for bigger cross to be built inside CSIRO, and it could not be built the same time as the Parkes dish. So that's why he left and went to Sydney University. And Christianson really left for a similar sort of reason. And so in the mid-50s, there was quite a battle going on really, and Pawsey was a brilliant scientist but he was somewhat weak as a character-- weak in character in taking on seasoned veterans like Bowen or Bolton, who were sort of [inaudible] par excellence. And so Pawsey’s influence was sort of declining through this great battle.

Sullivan: 03:02

Now was Pawsey with Bowen in wanting a big dish?

Kerr: 03:05

Pawsey could never quite make up his mind. That was very difficult. He was keen on both. He could see the sense in the big dish, but he was also terribly interested in developing high-resolution instruments. And if he'd been left to himself, I think he would have done the high-resolution work [inaudible]. But he did join in the interest in the Parkes telescope, although in a slightly lukewarm sort of way. But he did take on the scientific planning of it very much, just because he was that kind of chap. If there's a problem to be tackled, he'd certainly tackle it to do the best he could. I was one who was very keen on the big dish because I got involved in 21-centimeter work. And in that case, the big dish was very suitable. And so I was one of those greatly in favor of it. And so I, in a way, became Taffy's assistant in getting the project through.

Waitress: 04:26

Would you all like anything else?

Kerr: 04:29

How about a cup of tea, please?

Waitress: 04:31

Oh, yeah. Your hot tea. Okay.

Kerr: 04:32

Yes. Thanks.

Sullivan: 04:35

Do you want to take a break to have a few bites? Okay.

[break]

Sullivan: 04:42

Continuing with the Parke's dish development.

Kerr: 04:47

So the project started, at least in Taffy Bowen’s mind, somewhere about '54, I suppose. It really got going, in let's see. Begin '57. Yes in '57, we've already had somebody in London working with the engineers. So the contract for a design study had been let about '56 or '57. And there's a quite interesting booklet. I should have shown it to you, that was put out. It's something around '55 called “The Case for a Giant Radio Telescope.” But it was put out for publicity purposes inside CSIRO. And also copies were given to members of parliament and so on. And I essentially wrote that, although my name isn't actually in it. It's as if it's written by Bowen. And at the back of it, it contains about seven or eight sketches of the possible ways of making a giant radio telescope including a hole in the ground, all sorts of curious structures like that.

Sullivan: 06:14

Let's see how [inaudible]. [inaudible]. [inaudible] Now they’s eliminated the vacuum cleaner.

Kerr: 06:22

I guess that was about '55 or so. And then Taffy is quiet way, he kept on poking away the sources of money and eventually sold the idea, and at least got approval for a design study to begin with, and a pretty good understanding that the project would go ahead. In the meantime, Christiansen and Mills-- no, Mills was still there. Christensen had left, and Mills was unhappy. But there was a committee set up to plan the thing from our end and work out the very detailed specification from the user's point of view. And one of our people, a person called Minnett, Harry Minnett, M-I-N-N-E-T-T. He became the engineer in charge. He had been at the Lab for quite a long time, since 1940 or so, and been working in radar and civil aviation and on the outskirts of radio astronomy. So he was not an astronomer at all. He came in as the engineer. Actually, he's still connected with the project in Sydney at present, I didn't actually meet him. At least, no, sorry. He's working on the optical telescope mainly in the same sort of capacity.

Sullivan: 08:11

[inaudible]

Kerr: 08:12

Yeah. He's essentially the chief liaison officer between users and contractors. He’s got a strong engineering bias and understands what the users want and tries to interpret that into engineering terms and liaises with the actual design people.

Sullivan: 08:42

Is that a verb, liaises? I never heard that one before. [laughter]

Kerr: 08:46

Well, it's the sort of jargonistic verb anyway. I don't know if it's in Webster. Then I see you know what it means. It isn't new to me. As it turned out he himself I think carried out a lot of the survey system design personally just because the contracted people were not very good at that. So he was in London in 1957 when I was there briefly. I was spending a few months in Leiden and I visited London two or three times in the second half of December. And he had been there for about a year at that stage. He was working hard with the engineers, Freeman Fox and Partner in London. In fact, I had been corresponding with him from Sydney in quite enormous detail and did a lot more of it after I got back. As our user's committee, it was not the NRAO type of user's committee, it was a committee of potential users of the telescope. We worked from what we thought we wanted in a telescope, and we produced some of the first ideas on digitizing telescopes things like that. And Harry Minnett at the London end tried to turn all their sort of stuff into actual design hardware, for designs for hardware. And that worked out pretty well. Their final design is very well suited to the easy operation, or certainly more so than any telescope before that, and probably more than for most since, because a great deal of thought went into the planning of its detail. Well, as would be said now, the interface between the user and the telescope. So I suppose around about 1958 or towards the end of '58, the design study ended and the firm contract was let. It was let with MAN in Germany, as you probably know. They built a telescope in about 18 months at the price of, what was it, 500,000 pounds or, no, 700,000 pounds Australian, thereabouts.

Sullivan: 11:53

[inaudible]

Kerr: 11:56

Right. Yes, they started off in this business with the Parkes telescope, and they did a pretty good job because there's almost nothing in what they did that anybody's ever found any [inaudible] with, any criticisms that have been-- it's usually been somebody else's part of it, troublesome relays and things like that. So at about 1958, there was great activity in trying to decide on the site. It first perhaps started in 57, and it really came to a pitch in 58. And the principal site hunter, it was McCready, Lindsey McCready, and in the early stages, the hope was to try and get it to somewhere on the coastal plain, somewhere close to Sydney. In fact, he started off hunting around the possible sites within 100 miles of Sydney on the coastal plain. And there were two or three slightly possible sites, but it was realized eventually that these were all a bit risky, that there was too much development going on that might last long.

Kerr: 13:29

So sometime in 58, we decided to move across the mountains and find something on the other side of the mountains, and three or four of us went around then in a group. We found several possible sites, a site near Cowra, C-O-W-R-A, which looked good for a while, this side in the [Macquarrie?] river, and the site near Parkes, which is not the present site. That one's slightly closer to the town. And the Cowra one was eventually given up because it looked as though a company was interested in canning peas, and so on, was gradually spreading its activities in this direction. It looked a bit unsafe. Also to Cowra, the council, a town council was not specially interested in as. On the other hand, the Parkes people who could see exactly what this thing would do for Parkes, and they fell over backwards, trying to offer us all sorts of assistance with roads and so on. And so it looked much more friendly atmosphere there. So one fateful day, we went back again to show Taffy Bowen the we’d selected near Parkes, and he was quite taken with it. And we all were again, but then we decided to go looking a bit further. And we started driving northwards from the site we had chosen as the first one. And about three or four miles further north, we found an even better site, and so on that day, essentially, we decided to go there.

Sullivan: 15:41

Where in [inaudible]?

Kerr: 15:43

Well, a greater area of flat ground and somewhat more isolated, and somewhat more distant from Parkes, and so more clear of electrical interference. The idea of flat ground was always very important in site selection, I'm sure to a greater extent than any other countries, the selection of the site, this is because of the great interest in crosses and other sorts of arrays. And so, as a compromise with the people who have been so interested in arrays, it was always stated that the site must be something with a quite large area of flat ground around it. So that an array could be built centered on the Parkes dish, or including the 210 foot dish. So we chose that site as a very likely one. And on that same day, started making inquiries about who owned the place. It turned out to be somebody called Austie Helm, H-E-L-M. And the Austie stands for Australia. Australia James Helm, it was because he born on the day the Australian Federation came into effect on January 1st, 1901. The we started to interview the town council people and, at that time, the mayor of Parkes was a funny character called [Sess?] Moon. And was typical country town in those days, it’s become slightly more civilized since. All transactions were carried out [inaudible] Hotel and [Sess?] Moon used to tell us his story. His special personal story. He'd been a soldier, of course, in World War II, I suppose. World War II, yes. And came back with a decoration of BSO. BSO is Balls Shot Off. He used to tell us how he envied you chaps with two because I've [inaudible] with one. So those days, in that period, we visited Parkes quite a lot to establish contact with people and survey the site and so on. Of course, we lived at the pub and spent a lot of time establishing contact with the locals, which meant drinking in the bar more than anything else.

Sullivan: 18:56

It's a real chummy sort of situation.

Kerr: 18:57

Yeah. It was there that we learned that in that very dry atmosphere, you can drink beer forever and you don't notice, which is quite good. But on this first trip, as a matter of fact, it was one slightly dark note, but I think it was the first trip. But the snake was seen on the site and was duly killed. It's rather strange because almost no other snakes have been seen ever since, but.

Sullivan: 19:40

[inaudible].

Kerr: 19:42

Yeah. So during that next year, as I say, some of us visited Parkes quite a lot going up to establish contacts and so on. And one interesting story at that stage is that the actual selection of the very precise spot where the center of the telescope was going to be was surveyed by around three of us. Pawsey and McCready and myself I think. And I've got a picture in my slide collection of Pawsey actually measuring off the last bit with his tape and driving a post in to show where it was. But the interesting point is, that a few weeks later, Taffy Bowen went up to the site very quietly with McCready and got McCready to take a picture of him driving the post in to show where the site was. And that picture has been published in various propaganda journals.

Sullivan: 21:04

So you would prefer if I chose a picture like that to--

Kerr: 21:07

Yeah.

Sullivan: 21:08

--use yours.

Kerr: 21:10

But at about that time, as I sort of implied earlier, Pawsey was dropping down in importance, unfortunately. And sometime after the building started, which was in '59, we had a visit from John Bolton, who was then at Caltech. He came out to see us for a while. Went up to Parkes. In fact, I actually drove him up. And it dawned on us eventually that this was a deep, dark plot of Taffy's. Taffy was going to bring Bolton back again from Caltech and put him in charge of the whole Parkes project, over Pawsey's head. And that's what in fact happened. Although I saw the public meeting of the whole research staff was held at one stage to ask Taffy if this was in fact so and that he did the kind of wriggling-- attempting to wriggle out of things that you'd expect the president to do. And he would not admit to having invited anybody to come back. And that if a post as Officer in Charge was to be set up, it would be properly advertised and anybody could apply for it and so on, in the normal way. However, a few months later, we heard that John Bolton was coming back to be Officer in Charge and it and was all done in a very underhand way.

Sullivan: 23:13

Had there been someone else in this place before or was it just created?

Kerr: 23:16

It was created to come into effect. Well, actually, Bolton came out after the building process had gone about one third through, and he spent most of his time at Parkes during the final two thirds watching over it and getting a pretty good acquaintanceship with detailed construction and so on. Of course, that's what he enjoys more than anything else, poking around with bits of cable and digging holes and so on. That's his kind of astronomy. And so shortly afterwards, Pawsey accepted the position of Director of NRAO, because he regarded himself as having been pushed out of Radiophysics. And that was after Otto Struve died, they had no director. And the place was in somewhat of a mess. Had not yet established itself as the leading organization in this country and there were feuds in all directions as to how much strength would be given to it and so on.

[Editorial note 2025: Otto Struve resigned as NRAO Director effective 1 December 1961, and died in 1963.  David S. Heeschen was appointed Acting Director after Struve’s resignation.  On 17 December 1961 Pawsey was appointed NRAO Director, with the appointment to be effective 1 October 1962.  In March 1962 Pawsey visited NRAO, and it was during this visit that the first symptoms of his illness appeared.]

Sullivan: 24:39

This is around' 60, or this all true with that?

Kerr: 24:43

It might have been '59, perhaps. Well, perhaps it was '60 year, because Pawsey was certainly present at the time when the telescope was commissioned, as we call it. We don't use the word dedicated, in '61.

Sullivan: 25:11

Well, I just want to get it approximately.

Kerr: 25:13

Yes. He must have come over in '62.

Sullivan: 25:15

He accepted the post, but he never did take it?

Kerr: 25:19

Well, he thought it would be quite a challenge, and it was put to him that he was the only person who could bring all these rather dissident and competitive American radio astronomers together and make them into a group. And so he accepted that challenge and he came over, it might have been late '61 or early '62, ‘62 probably. He came over intending to spend a few weeks looking around, surveying a scene and forming a policy. And then he was going back to Sydney for a few months before actually coming over to the job. However he started to feel rather sick about a week before he left Sydney, but he still came over here and got very ill and was operated on. It was clear it was a brain tumor and that he had no possibility of recovering really. But he came back to Australia for a few months before he died, finally, in late '62. But this was a very heart-rending thing in the whole history of the whole business because all those others had been on Pawsey’s side, and these arguments felt that he had been very badly treated in our whole business, and that even his brain tumor might've been due to an emotional reaction to his bad treatment. Pawsey was great man, he's one of the greatest men in the history of radio astronomy. Any history of him should pull out a lot of Pawsey’s character in this. He was weak as an administrator, but he was extraordinary as a producer of ideas and as a wonderful critic of ideas too. He had enormous physical insight and he could really pick the holes in the proposal or an argument very quickly.

Sullivan: 27:57

Let me ask just one quick question now. Who did become Director at that time for NRAO?

Kerr: 28:03

Well, Heeschen became Acting Director, or at least he was Acting Director. And he was slightly more positively confirmed as Acting Director and then I suppose about a year later he was made Director.

Sullivan: 28:22

Now, back to Pawsey. Can you just briefly describe which ideas-- I mean, what he did scientifically? I'm not very familiar with what he did scientifically.

Kerr: 28:34

Well, his stuff is, rather in the way-- well, he didn't publish a great deal himself. In fact, one of his very strong points has always been said to be that he had the ability to develop the latent powers in other people. That all of people who came out of that group, the Christiansen, Mills, Wild, and so on, count myself in it, that all of these people that sort of made independent and the skillful in their subject, and experienced and self-reliant, and so on, quite largely because of Pawsey’s way of drawing people out. Pawsey was not the kind of research leader that insist on claiming everything himself. But he fed the ideas that other people developed.

Sullivan: 29:48

He was really a teacher then.

Kerr: 29:49

Yes. He was a teacher as much as anything. And in the written record, you don't find his name on many papers, but he was the inspiration behind an awful lot. And, well, in a way, I suppose his work was done at the time when his influence dropped down, because his main work was in bringing other people up to this sort of equivalent status. And there was time for him to start in some other way.

Sullivan: 30:23

Right. Do these other people that you mentioned-- do they acknowledge this influence?

Kerr: 30:30

I'm sure Bolton didn’t, Bolton would never acknowledge Pawsey. But all the others did so.

[Brief pause on tape.]

Sullivan: 30:41

Okay, continuing with the Parkes dish story. Bolton took over as Officer in Charge about one third way through the construction.

Kerr: 30:59

Yes, that would have been early 1960 I suppose.

Kerr: 31:02

And then the completion date was in '61. Let's see. It was probably about in May, was it? Anyway, there's an article in, it’s an article, not in a letter, that reported the opening really. I actually wrote it. It was unsigned. It's one of the pseudo-editorial reports. And then this describes the day when everything was officially commissioned. As I said we don't use the word dedicated, which is only used religiously.

Sullivan: 31:54

And this was what date now?

Kerr: 31:55

It was in '61. I'm just trying to think exactly when it was. In the first half of the year. And it was commissioned by the Governor General.

Sullivan: 32:15

And [inaudible] Governor General was it?

Kerr: 32:21

Well anyway, his name's in that article if you want it.

Sullivan: 32:26

And this was the [second letter issued?] at the time of the general [inaudible].

Kerr: 32:29

Yes, but it could easily be claimed it was the best because its surface accuracy was much higher. So by that time, nobody worried too much about the drop in size. Incidentally, the drop in size is an amusing story in itself because the first design was worked out for a size, oh, for something about 255 or 260 feet. The design study also was supposed to include the rate of change of the cost with the diameter. And they worked out that the cost would go up as something rather power of the diameter over a certain range. And the cost estimates for a 260 foot each came out to be too high. So it was scaled down to a two tenth of the size. As it turned out the cost of redesigning it for a smaller size, the first variance the slightly erroneous concept in the scaling, finally resulted in the 210 foot one costing just about as much as the 260 one would have.

Sullivan: 33:52

The same sort of service accuracy?

Kerr: 33:54

Yeah. However, maybe if the 260 had actually been built it might have cost more. But this was commissioned on some day early '61 And this was a special day and all sorts of preparations were made on expecting great crowds of people and there were display boards put up all over the paddock and so on. And the grand tours of people and parliamentarians and town councilors and all sorts of people, plus hoi polloi and so on. Great crowds of people were expected, the special reserve school kids and citizens of Parkes and so on. As it turned out, the day dawned with a very high wind on a supposedly windless site, and the whole ceremony went through. It was an open-air ceremony. And it was a 50-mile wind blowing the whole time. 50-mile-an-hour wind blowing dust all around us. And so that the crowd that turned up was rather less than expected because it was such an awful day, and the ceremony didn't go too well because everybody was sort of just wishing it would be over. And you couldn't hear the speakers too well, because the wind blowing into the microphone produced such a terrific noise.

Kerr: 35:45

And I know at the end of the day, I've never seen such a dirty shirt as the one I took off because there was so much dust attached to it by the sweat and so on. Then afterwards, there was a special entertainment or a reception rather. And this is another funny story. There were two classes of tickets to this opening day. The pink tickets and the blue tickets. And if you got a pink ticket, you could come to the reception at the present residence at which the Governor General was present and all his entourage. If you had blue tickets, you went to a reception in a tent. And that's where the ordinary crowd went to, of course. The important people such as Bart Bok and all the senior Radiophysics staff at various university people and town councilors and so on were all asked to the high-class reception. However, Harry Messel, the professor of physics at Sydney University, and Bernie Mills, the famous radio astronomer, were given blue tickets. And they had theirs in the tent because of Taffy's hostility to them.

Sullivan: 37:24

Oh, it was purposeful.

Kerr: 37:25

Oh, yes, very purposeful. And the Daily Telegraph, the slightly second rates in the daily newspaper as in the morning newspaper, carried a photograph the next day, which was also rather purposeful. The only photograph shown was one of Harry Messel and Bart Bok and Bernie Mills. They're seen together with the telescope in the background as if they owned it. That was also purposefully done by Harry Messel as part of his long argument between those two.

Sullivan: 38:16

Where did Messel fit in? You haven't mentioned him before.

Kerr: 38:21

Yes. Well, Messel is another character. If you don't know Messel you haven't lived, sort of thing. Now he's an ex-Canadian. He's got a very flamboyant red beard and never stops talking. I suppose he knows some physics, or he used to 10 or 20 years ago, but he's mostly an operator and a collector of money. And he's done pretty well at bringing money into physics. But he's formerly a cosmic ray person. And he's a character in Sydney to the extent that if a newspaper cartoonist wants to show a scientist going to the moon, they show Harry Messel, and so on. And he's got strong friends and strong enemies, of course, as you'd expect from this type of person. And Taffy Bowen and he are great enemies, although I suspect most of the enmity is on Bowen's side, really. Well, the place where he comes into the story is that when Bernie Mills could not get support at Radiophysics for his big cross project, Harry Messel took him in. And Mills is a professor in the physics department, which is run by Harry Messel.

Sullivan: 39:51

At the University of Sydney?

Kerr: 39:53

At the University of Sydney. So that's where he comes in.

Sullivan: 39:55

Now, after the commissioning of the telescope, was it a shake down trials, or had they already taken place? Observations began right away?

Kerr: 40:04

Some trials had taken place before. And it was already a sort of working system. But the things you could call shake down trials went on for a few months after that, really, before it really got going in a proper way.

Sullivan: 40:24

And just to finish up, when were the first observations that were-- true observations that were done on it?

Kerr: 40:31

Oh dear. It's hard to pick the exact moment. The first observation I ever did, I think I-- I was looking at the moon as a calibration source, but all I could get was radar pulses. That was on 408 megahertz. And from the time that they cut off, we worked out that the transmitter responsible must have been in Hawaii or thereabouts. And that was a period when there were various military projects going on in this country, about using the moon for spying on bomb explosions and all that sort of thing. So these projects were all secret and you couldn't find out where the pulses were coming from.

Sullivan: 41:44

But you don't remember specifically which program was first scheduled on the dish?

Kerr: 41:51

I don't really, because things came in rather gradually. The first observations were purely of a test nature. There were some nice records of things like [inaudible] showing it resolved, and showing it as a double source, which hadn't been seen before. Observations of Jupiter.

Sullivan: 42:30

That's all right. I mean, that's something that can be checked.

Kerr: 42:33

I'm sure there'll be something in the written records somewhere about. There's one of-- the first really new scientific observations coming out of it was the polarization of Centaurus A. And this was rather a heart burning thing for Taffy Bowen, too, because this happened at a time when Ron Bracewell was visiting and was at the telescope. And Bracewell was actually visiting the University of Sydney, and so he had no connection with CSIRO, but he was-- he and Cooper were responsible for this great new discovery and there was terrible arguing between Bowen and Messel as to how this should be published, because Bowen tried his hardest to exclude Bracewell completely from it.

Sullivan: 43:40

And what was the end result?

Kerr: 43:42

It ended up as a paper by Cooper and Bracewell, or Bracewell and Cooper.

Sullivan: 43:48

And where is this?

Kerr: 43:49

I think it's Nature, probably. There'd been a long tradition of first discoveries being in Nature, as you know.

Sullivan: 00:01

Well, thank you very much. I think it's obvious we're going to have to have another session sometime, but I think that's enough for now.

And you say this report was written in '57 by--

Kerr: 00:13

In '57, Yardley Veers. That's V-E-E-R-S. From somewhere in this country, I'm not sure where he came from, but I came across his name again recently here somewhere. And he was visiting Sydney for a few months on some scheme or other. It was partly with he’s, I think, a physical chemist or something like that, or chemical physicist, whichever's which. And he was partly with similar types in our national standards laboratory, and partly working with us, and he produced a very interesting report, which I came across in the end just last year, and it struck home to me what an opportunity was missed, really, because he set out quite a few interesting lines worth looking at that have been found since, others that haven’t. And suggesting further possible studies, laboratory and otherwise, and I suppose, really, it wasn't followed up because that was a time when there was big pressure for the big dish. And the people were putting all their efforts into antenna development at that time, telescope developments. And also, as I said, Pawsey’s influence was sort of dropping down, and if he had wanted to-- he probably didn't feel so free to push things.

Sullivan: 01:55

Yeah. Thank you.

Kerr: 01:58

I think, perhaps, '58 it would have been, not '57.

Sullivan: 02:00

I'd like to have a copy of that.

Sullivan: 00:06

Continuing with Frank Kerr, October 3rd, 1971. We were talking about the first radar astronomy in Australia, and you decided not to work with meteors because that would be too much of an effort you said.

Kerr: 00:24

Well, it didn't sound especially interesting as compared with the other more astronomical things that were going on. They thought they wanted to get outside the earth. But however, we did do a bit of looking around, and when I say we, the other person involved in that was Alex Shain, C.A. Shain. And we did some looking for various mysterious echoes that had been reported, either, during the war or before the war. The famous long-delay echoes that were supposed to [have been?] coming out after 27 seconds-- or 32 seconds, that sort of thing, studied by Van der Pol about 1932, that were and still are a complete mystery.

Sullivan: 01:20

Still are?

Kerr: 01:21

Yeah.

Sullivan: 01:22

Are they still observed?

Kerr: 01:24

No. Well, they're not still observed. That is not quite clear whether they didn't exist or whether it's because there's just too much clutter in the radio spectrum now so you don't have any chance of getting them. There are few possibilities there. However, the fact that we didn't see them-- and also somebody else at Cambridge, England was doing a study about that time, and he systematically [didn’t find them?], and that also suggests that perhaps they were something spurious.

Kerr: 02:02

But they were reported by Van der Pol in Holland and somebody in Sweden and also somebody in Indochina. And there were theories that these things were perhaps something connected with the ionosphere and that in some way they collected a very low-grid velocity and low attenuation or some funny mode of propagation in the upper ionosphere or alternatively, that they might be connected with the [inaudible] ring of particles. That was a favorite thing at that time [inaudible], but we didn't ever see anything. We also have looked at the [inaudible] without any success. But then we decided to have a go at the moon. Especially, it's just about that time, at first, because those were obtained by this country by the US Army Signal Corps people at-- what's the place called in New Jersey?

Sullivan: 03:26

Fort Monmouth.

Kerr: 03:27

Fort Monmouth, New Jersey. Project Diana. They were working at [inaudible] or something like that. And the interesting thing that came out of there with this was really an engineering-type study, and they didn't follow it up that systematically.

Sullivan: 03:49

Was it published in any form?

Kerr: 03:51

Well, Sky & Telescope is the main publication I can recall. I think it was probably in the-- yes, in the IRE Proceedings at that time too. That's about 1947, and they got a [inaudible]. And the interesting thing to us was that the echoes were recorded in varying strengths and to be consistently lower than they are in strength than they anticipated, and so we thought that seemed interesting to study. And because it was quite likely that the variations [were?] at least in class, in the ionosphere, we weren't thinking of long wavelengths. Also by doing it in long wavelengths, when you get a free transmitter and it's much stronger than ours, we made arrangements with Radio Australia - that's the short-wave broadcasting service - and borrowed one of their transmitters, [inaudible] Victoria in the small hours of the morning when they happen to be not using it. And I said, "The small hours of the morning is a good time to get through the ionosphere at low angle." Of course, the broadcast station transmits at low angle because that's where it wants to go. And so we keyed this broadcast transmitter by landline from a station that we specially set up near Sydney. At least, this was the place where we had been doing this radar work anyway, in a valley near Sydney, about 20 miles north of Sydney, a place called Hornsby.

Kerr: 05:49

This incidentally, perhaps answers your earlier question about places which were set up for radio astronomy. This was one of the two or three places specially set up for radio astronomy to work. And it was basically for this radar work. We didn't want to be in the same place as any receiving station. It was an enclosed valley. It was quite a good place. And we set up a rhombic antenna there that we used for receiving, and we pointed that towards San Francisco. This was because we used the-- if I think about the transmitting antenna with the broadcast station, that was also directed towards San Francisco.

Sullivan: 06:37

And what frequency was this, now?

Kerr: 06:39

This was at either 18 point something or, 18.7 or 21.5 megahertz. They operated on one or both of those frequencies, sometimes simultaneously, sometimes only one. And we only worked at particular times. That's the one way in which we learned about astronomy. We learned about orbits. We learned all about the motions of the moon in that state. We demonstrated to ourselves that this particular system could only work about three or four days per month, such that the moon would be [inaudible] in the early morning hours, in which the transmitter was not being used, and that's when that particular transmitter and antenna system was not being used, right? So it took about 20 days of the year I think just to learn using the system, and so we're studying echoes from the moon.

Sullivan: 07:54

You had no trouble obtaining them?

Kerr: 07:56

Well, yes, we've had trouble, and the first night we were doing it, we didn't succeed. This was a very disappointment for the representative of the Australian Broadcasting Commission. He was also doing us a very small favor, [laughter] and he gave up. He didn't come the second night to do us a favor, and then he phoned us and asked us about it. We told him. And then, we said, "Sure, let me tell you his story." He came out later, recorded some of the sounds, so. But that was sort of fun.

Sullivan: 08:36

And that might be the first radio astronomical recording.

Kerr: 08:39

Yes, it probably was one of the first.

Kerr: 08:42

I still got a copy of it. And we showed that the signals were almost always much less than expected, often about 10 dB less.

Sullivan: 08:56

Now, what were you using this to sort of [inaudible] composition for the lunar surface? [inaudible].

Kerr: 09:04

Well, we said they're about 15% perfection [inaudible]. That was sort of reasonable [inaudible], yeah. And we didn't know much at that time as to whether it was a rough or a smooth reflector, either. It was another thing, and that’s got much better understood since. But we studied the variations with time, and we showed that there were short-term variations, a few seconds up to a minute or so, well, after that 30 seconds perhaps. But the short-term variations were connected with the moon's vibration. That's how we had to understand all about vibration. And there was longer periods fading the order of minutes that correlated with the critical frequency of the F2 region of the ionosphere. And so we separated those two out and the--

Sullivan: 10:10

The vibration was just a difference in distance. It was causing a change, or?

Kerr: 10:14

No. It was interference between reflection from different paths.

Sullivan: 10:18

Oh, I see, different aspects of the phases of the moon, yeah.

Kerr: 10:21

But the moon was to some extent, at least, the rough reflector, and we're getting interference between reflections at the different points of the moon.

Sullivan: 10:32

Different [sub-earth?] points, yeah.

Kerr: 10:35

And the moon was, in effect, rotating relative to us, the first vibration plus our motion, [inaudible] rotation of the moon, part of it. And this rotation of the moon gave varying interference, and so this produced a fading.

Sullivan: 10:59

And where was this published?

Kerr: 11:00

That's also in the Proceedings of the IRE, about 1949 or early '50s.

Sullivan: 11:10

Had other people, meanwhile, been bouncing stuff off the moon too, or is this the second [time?]?

Kerr: 11:16

That was the second one that was well known, but there's a mysterious project by somebody called Bay. Z. [Zoltan] Bay.

Sullivan: 11:34

B-A-Y?

Kerr: 11:35

B-A-Y in Hungary. And this has probably never been published anywhere, probably, nobody ever noticed, so. And they may never find out much about it. In fact, the only reporter that we ever knew [inaudible] Soviet publication. And then this was a terribly [marginal?] experiment. They had no proper receiver and had some electrochemical sort of gadgets that said the moon echoes appeared as a slightly increased production of hydrogen or something and then changing color and everything. But at least, this man always gets mentioned in any historical and statements. I found it interesting that one of the Project Diana people, a man called Webb -- I met him and by chance at '67 at Arecibo when I visited there for a week. And he was just visiting temporarily. But he's now at the University of Illinois, and I met him again last year there.

Sullivan: 12:46

Did he mention, at all, the radio astronomy?

Kerr: 12:48

[inaudible]. He has come back again in the radio astronomy just the last few years. He's been in electrical engineering ever since, and he's still really in their electrical engineering department, and so that sort of carried over on the coattails of George Swenson in astronomy.

Sullivan: 13:11

So you didn't really feel any great competition, then, while you were doing this?

Kerr: 13:14

No. It was sort of isolated project really. And it wasn't until some years afterwards, that they started-- well, almost a year or so afterwards that they started some at Jodrell Bank. And by that time, transmitters were starting to be developed, especially, for this radar work. And so that worked out, eventually, became more powerful.

Sullivan: 13:42

And what year was this for Jodrell Bank?

Kerr: 13:45

Let's see. I guess probably about '54 or so that they really got into it. The first person really involved was Jack Evans and was leader for Lincoln Labs for a long time, J.V. Evans. And he was there first at Jodrell Bank.

Sullivan: 14:10

So now, your moon radar experiments, then, were in '52, '53?

Kerr: 14:15

Yeah. In '46, I started-- the end of '46, I went through all of '47.

Sullivan: 14:23

That's what I thought. You said Jodrell was a year or so after?

Kerr: 14:27

I think I was wrong. I don't think it started till the '50s.

Sullivan: 14:34

I thought we were earlier.

Kerr: 14:36

Yes. I think I must have been wrong there. And then, yes, it was later. That's why they were able to start getting more powerful transmitters, well, technical advances in the transmitting in the meantime. And after our moon work, I spent the next year studying, writing up all the moon work and also thinking about the possibilities of echoes from the Sun and planets. And we worked out the theory of all of that, and as classical paper, that formed on the possibility of radar echoes from the Sun and planets, that's also in Proc. IRE. And around that time, 1950, it would be, I’d say, labelled by me. And that's the sort of pressing of label on this. We, ourselves, eventually decided not to get into a business because it was quite clear that it involved building a pretty expensive transmitter and antenna system that we decided to stay on the passive side, but concentrate on the receiving stuff because in the meantime, it'll be going ahead so far.

Kerr: 16:09

Then, at that stage, I personally went to Harvard for a year and probably again with the idea of getting into astronomy, [inaudible] astronomy. And I happened to be there when Ewen and Purcell detected the 21-centimeter line. And van de Hulst was there at that time too, and he was on a visiting professorship for a semester, and we were both called across to Professor Purcell’s office on the morning after Ewen had detected the lines in the small hours of the morning, that same day. And Purcell was very keen on having this discovery confirmed before he published it. He was the cautious physicist type. So van de Hulst sent a cable to Oort, and I sent a cable to Pawsey recording this, and the Dutch, of course, were very disappointed that somebody had beaten him to it because they'd been working on it for longer and they really deserved to get there first. And they would have, but some of their equipment was destroyed by fire apparently. And this spurred them on to even greater efforts and then a couple of weeks later, they succeeded in detecting it too. The cable I sent to Sydney, apparently, they stirred them all up and Pawsey decided the line had to be found instantly. And Christensen and Hindman got onto it and they lashed up this receiver pretty quickly in a trailer out at a station called Potts Hill, which I'll come back to some other time because it had already been working as a radio astronomy set up for two or three years by then.

Sullivan: 18:16

This is the one with the [inaudible].

Kerr: 18:18

Right. Yeah. Right.

Kerr: 18:21

And they set up this 21-centimeter line equipment in a trailer, a single channel go to, of course, at that stage. And they found the line after about six weeks. But of course, they had already equipment working at somewhere near that wavelength. And they had the expertise to do it all, and they got it going pretty quickly.

Sullivan: 18:50

And Purcell held off until there was confirmation from both men.

Kerr: 18:53

Well, he held off until there was confirmation from Holland. And then those two groups prepared their papers and sent them in. And in the publication in Nature, it's got these two papers plus the cable from Pawsey as reports the further confirmation in Sydney.

Sullivan: 19:15

Did you know about the project before they found it?

Kerr: 19:18

Well, I didn't know about it until I got to Harvard, but I knew about it a few months before. Yes.

Sullivan: 19:22

I see.

Kerr: 19:23

And I was in on-- but there's gossip. I guess you've heard this story of Ewen’s negative report first, haven't you?

Sullivan: 19:30

No. I don't think I have. But do tell.

Kerr: 19:34

It was his PhD project, of course, this project. And after a certain time, he came back to the Purcell and reported failure, that he could not detect the line. Asked him what to do. Could he turn in the-- turn in this negative result as a thesis? And Purcell was a very wise physicist. And he said, "Yes. I'll accept the negative thesis, but it must be 10 times as good as a positive result." He said, "Go back and check. Check hard." And so Ewen went back and checked, checked, checked, checked. And sure enough, in due course, he improved his sensitivity and he found the line.

Sullivan: 20:29

Well, he actually did improve the equipment. It was a sensitivity problem.

Kerr: 20:37

Or stability or something. This was done with a horn that was piped down out a window of the Lyman lab at Harvard. A good name, of course, Lyman for this.

Sullivan: 20:49

Yeah.

Kerr: 20:51

But the sky drifted past and the Milky Way, as you saw, somewhere. It came past 3 or 4 o'clock in the morning on that famous day in March of 1951.

Sullivan: 21:07

So now what were you doing at Harvard? Were you getting a master's degree, or?

Kerr: 21:11

No, I just went for a year to get involved in astronomy. I did get a master's degree, but I didn't go there really with the intention of getting it. I went there with the idea of spending a while in contact with astronomy. Menzel talked me into acting as a graduate student and actually taking courses and signing up. Actually, when I went, I hadn't really intended to do that but as it turned out, I ended up with a master's degree. And this was partly because I thought I'd passed the Ph.D. qualifying at the end of the year, so. I really gave it, I guess. So then when I came back, I ended up at Harvard in the northern summer of 1951. Then came back by Europe, and then I looked in at Cambridge, Jodrell Bank, and Leiden, and so on, on the way, getting more contact with any other radio astronomers. And we got back, I suppose, at the end of September '51, and at that stage, Christensen and Hindman had just completed their first rough survey of the 21-centimeter line region of the southern sky, which was published in the Australian Journal of Scientific Research. And Christensen wanted to get back to his solar work and I took over the interest in the 21-centimeter work. And I guess I've more or less been there ever since in one form or another. So that's the early period as far as I was concerned. But you probably want to hear some other time about the setting up of the other stations near Sydney.

Sullivan: 23:30

Yeah, particularly Parkes, of course.

Kerr: 23:33

The early work at Potts Hill and Dapto, Fleurs, and then the other one later on Parkes. Yes.

Sullivan: 23:51

Who were the people that were working at these other stations between '45 and '50? I assume they haven't been mentioned yet.

Kerr: 24:03

Well, McCready.

Kerr: 24:05

Where's the entrance to the [inaudible]?

Sullivan: 24:06

Just right here? Yeah.

Kerr: 24:16

Yes, McCready and Ruby Payne-Scott and [inaudible] for a while, and Fred Lehany, and Yabsley. They were both involved in early solar work in particular.

Sullivan: 24:36

And Christensen, I guess.

Kerr: 24:37

Although Christensen actually came in sometime later, Christensen was not in it in the very early time. He did not join the Lab until about 1948 or '49. He was at AWA, Amalgamated Wireless Australasia.

Sullivan: 24:58

I know them. They're the contractors that run [inaudible].

Kerr: 25:01

Oh, yeah. Yes, they're still the biggest radio company, I guess. I don't think they're doing as much research work now as they used to. Although no problem, it's so difficult to compete with the bigger RCA and Bell Labs and so on. They tend to adopt things from other places rather than take it themselves. At least at that time, they had a fairly big concern. And they were connected with radar too because they made all these highly mobile warning sets.

Sullivan: 25:39

And they still do do a lot of radar work. Well, like I said, that was-- all the people in [inaudible] were employees for AWA.

Kerr: 25:47

Oh, yes. I see. They were the contractor.

Sullivan: 25:49

Right. Well, I think that's a good, good breaking point unless there's something else to say.

Kerr: 25:54

A few are things we could do some other time.

Sullivan: 25:57

We have arrived at Hojo's [Howard Johnson’s]. We're ready to check-in. Well, thank you.

Kerr: 26:02

All right.

Sullivan: 26:07

Okay, we're now continuing over martini and clams.

Kerr: 26:12

All right. As you're going to be a Dutchman shortly you should know that the present day is a very famous day in Leiden.

Sullivan: 26:21

Was this the day they had the big festival out there?

Kerr: 26:23

Yes. 3 October. It's the anniversary of the relief of-- the seige of the city by the Spaniards.

Sullivan: 26:32

Yeah. [inaudible].

Kerr: 26:34

This famous holiday. You want to try and get the one-day--

Sullivan: 26:36

Celebration event.

Kerr: 26:37

--in a year. I suppose every city's got something like it. It's a special one. Well, let's see. The [inaudible] token.

Sullivan: 26:54

Faxed it.

Waitress: 26:58

[inaudible].

Kerr: 27:01

Okay. It's worth prefacing any story of the Parkes dish by saying that the history of radio astronomy in Australia in the early days were very much connected with the development of ideas in electrical engineering and physics, but that's especially in the early days. The principal contribution was in developing new antenna systems. And so generally in the form of arrays and, of course, the cross and the various things connected with that are an example of it. And the Wild spectrum analyzer and so on. Great deal of inspiration for all this goes back to Pawsey and his history. And it's worth saying this because there was great opposition to the idea of developing a big dish inside the Lab. It was Taffy Bowen who was very keen on the idea of a big dish. This has often unkindly said as being in the sense that he wanted it as a status symbol for the Lab and himself. In particular, in the early days, it was always [inaudible]. He said that the diameter….

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