Interview with Merle A. Tuve
Description
Creator
Rights
Type
Interviewer
Interviewee
Location
Original Format of Digital Item
Duration
Interview Topics
Start Date
Notes
The interview listed below was either transcribed as part of Sullivan's research for his book, Cosmic Noise: A History of Early Radio Astronomy (Cambridge University Press, 2009) or was transcribed in the NRAO Archives by Sierra Smith in 2012-2013. The transcription may have been read and edited for clarity by Sullivan, and may have also been read and edited by the interviewee. Any notes added in the reading/editing process by Sullivan, the interviewee, or others who read the transcript have been included in brackets. If the interview was transcribed for Sullivan, the original typescript of the interview is available in the NRAO Archives. Sullivan's notes about each interview are available on the individual interviewee's Web page. During processing, full names of institutions and people were added in brackets and if especially long the interview was split into parts reflecting the sides of the original audio cassette tapes. We are grateful for the 2011 Herbert C. Pollock Award from Dudley Observatory which funded digitization of the original cassette tapes, and for a 2012 grant from American Institute of Physics, Center for the History of Physics, which funded the work of posting these interviews to the Web.
Please bear in mind that: 1) This material is a transcript of the spoken word rather than a literary product; 2) An interview must be read with the awareness that different people's memories about an event will often differ, and that memories can change with time for many reasons including subsequent experiences, interactions with others, and one's feelings about an event.
Series
Unit
Transcription
Sullivan
Ok, this is talking with Dr. Merle Tuve on 21 December ’73 at his home in Chevy Chase. Well, even before we get to Jansky, you worked in radio during the ‘20s, in radar, did you not?
Tuve
Yes, actually, I was a radio ham when I was a kid. Back in- in fact, I listened to OUI and POZ Hanover and now in Germany, back in 1915, ’16, and 17. My dad closed me up when- the President declared as we entered the War then they closed up all the amateurs. But I used to take the weather reports from Arlington and all that sort of thing when I was in knee britches. And this led me to be interested, well when I went to - when my father died in 1918 - one of the early victims of the flu - we didn't know what it was then. I went on to the University of Minnesota - this was just as I had finished prep school, a small Lutheran academy there in South Dakota. Went out to the University of Minnesota and got interested in physics and electrical engineering. Jansky, the one that you're going to interview here in Chevy Chase next week...
Sullivan
The brother of Karl [Janksy]?
Tuve
The brother of the radio astronomy Jansky, C. M. Jansky, was an Assistant Professor of Electrical Engineering, a young chap who had come up from Wisconsin. And he took up with us, those of us in the student body that were amateurs and when I was a sophomore, this would be early 1920, in the winter of 1919 - 1920, we had a whole lot of - well, not a whole lot, but maybe several dozen, E tubes and J tubes. These were the leftover tubes from World War I, vacuum tubes made by Bell Labs, oxide filaments, 5 watts, and two things happened. First, we made a broadcasting station under Jansky. We hooked up four of these J tubes in parallel and I guess those were the E tubes, the 5 watters, and we hooked a modulator, a couple of them, and we ran a broadcasting station there at the University for the farmers - weather reports, wheat futures, the market reports, and all that sort of thing. It was several hours a day. This, before KDKA was on the air.
Sullivan
I'll be darned. There were no regulations I suppose, either? You could just set up a station...
Tuve
Oh no, we were licensed.
Sullivan
Oh, you had to be licensed?
Tuve
9XAN, I think it was - that just came off the tongue - I don't remember just the numbers. I've had a number of call letters in my lifetime. Anyway, this was the University, Jansky had the license for the University and we broadcast all winter. I used to broadcast classical music. The rest of them were playing popular music and so on. So it was kind of interesting. Then I went on and finished in physics, and I took my degree in electrical engineering just to be sure that I had my feet on the ground. But I took all the physics they would let me while I was an undergraduate. Then I took a Master's Degree there at Minnesota. And one of the things I was doing in physics - one of the things I was doing was playing around with [?] wires, waves on wires - using an E tube which I'd taken off the base and fed it minimum capacity, trying to see how high a frequency I could get and measuring them on these [?] wires. Then I got to around 80 cm and I was fussing trying to get harmonics and so on, when Bright, Gregory Bright came, who was a graduate of Hopkins and he came as Assistant Professor of Physics, Associate Professor. And I was playing around there in the Lab that summer when - because I was going to Princeton to be an Instructor in the fall and be a graduate student under Carl Compton. And Bright discovered me in the Lab playing around with these tubes and so this was how we got acquainted. And, a couple of years later when I was teaching at the Hopkins and Bright called me up from down here, he had joined Carnegie, and says, "I want to talk to you about the possibility of receiving short wave." He did some of that while at Minnesota. We ought to investigate for terrestrial magnetism this conducting layer overhead. And the best way that I can think of is to reflect some waves off it. The upshot was I came down and talked about it and I'd had enough trouble getting these - receiving these waves on a separate detector just at the far end of a long room. The idea of getting them after they were diminished by reflection from the upper atmosphere, he wanted to build a parabola there at the DTM [Department of Terrestrial Magnetism] grounds, down in that bowl by the front of the building and have me receive it up there at the Hopkins. That scared me a little.
Sullivan
You mean it would be too difficult to receive at the same place? To have a transmitting and receiving...
Tuve
That wasn't discussed at the moment. This is continuous wave now - this wasn't chopped waves. So they had a meeting called by the Director, Dr. Bauer, to decide whether they should appropriate $2,000 to undertake this experiment. And I got up in the meeting and said, "By all means appropriate this $2,000, but please leave Bright and me the freedom of modifying the experiment as we go along - make some preliminary things first, because I'm scared about the intensity by the time it reaches Baltimore after reflection. And I think there might be another way of going at it - this business". Namely and this was an idea that I'd heard bandied around at Minnesota - Swan up there has proposed that you get the echoes, use the time delay - make a pulsed radio, send out 60 cycles and you ought to get not only the one wave but the other one slightly delayed. Something like that might work. And so, they appropriated the money and we then went off to supper...
Sullivan
What year was this?
Tuve
This was 1924. This was November 1924. And sitting at the dinner we remembered the terrible modulation that KDKA had for a region roughly 75 miles to 150 miles from the station- very good modulation in close, but when you get out there 55 miles to 75 miles it's just awful and then it gets better but sporadic when you get out to 150. So we sat and scribbled on...
[Tape problems here: Transcriber 's notes - what I could pick up here:]
Tuve
So we sat and scribbled on . and found that the , well sure the right in the middle of 1000 cycles, that order of magnitude and I wouldn't go for it - these things beating on each other. So then he said he thought maybe the best way right then - this chopping business may send out pulse rates - might be the way to do it. And I asked him how can we do it - how can we make a permanent record. [Tape problems] So that summer we borrowed the use of the transmitter station at NRL [Naval Research Laboratory]. We went down there and put on a chopper on the thing. I went back to teach at [Johns] Hopkins and I came down here for the summer. I was teaching in May finishing up the school year and Bright had worked up a chopping switch and he took it up to KDKA and he took it up to Jansky and ran this thing. And we got some delayed but couldn't be sure it was...
Sullivan translation of garbled tape:
They knew that between 75 and 150 miles radius from KDKA in Pittsburgh that you got this modulation and no one had ever quite understood what it was and why it was only at that radius. And it hit them that the modulation was about 1000 hertz and it hit them that this could be the beating between the direct transmission and that reflected off the ionosphere and that made good sense. So they decided that the way they needed to do this was to chop and to send out pulses - 60 hertz pulses to bounce off the ionosphere and then they had problems with what they should use for a permanent record and I couldn't quite get exactly what they finally did use. But finally in the summer of '25, they used, they borrowed the transmitter at NRL that was used for the [?], they put a chopper on it - Bright had designed the chopper apparently and they got delayed pulses, sure enough, sending from KDKA and somewhere else which I couldn't quite get. But they couldn't be sure that it was sparking.
End of Tape28B
Sullivan Tape 27A
Tuve
That summer we ran the sets down at Naval Research and as soon as we turned it on that afternoon in July - fine, we got good reflections and at the transmitter it was clearly in order. It was a clean sending. So, but it stayed the same height and it was this - if we just transmitted the waves through the Blue Ridge Mountains and back here it would have that delay. It just stayed the same way, one day after the other. But we would have the set only from 2 to 3 in the afternoon and then they had schedules in the Indian Ocean and all that sort of thing. It was in September before we got permission to use it one evening. And the minute we got that it started to go up, up, up, up, and then we knew it wasn't - it was the upper atmosphere, not the Blue Ridge Mountains. Well, this is a far cry from radio astronomy. But this is how I happened to be related to the proceedings of the Institute of Radio Engineers [IRE].
Sullivan
Well, it’s not so far. Was this a dish at NRL?
Tuve
Oh no, these were just short-wave code transmissions to the fleet. We used the fleet transmitter. And Gebhardt, Leo Gebhardt, was the engineer in charge and he would let us use it, you see, without chopper devices on it. And then he had to get it back in shape and test it for the afternoon communication from the Chief of Naval Operations to the fleet in the Indian Ocean. It was a little bit hairy at times. This is the way experiments are done when you, you know, you lash things up and you do the best you can. But this was short waves, I think, let's see 40 meters and 20 meters.
Sullivan
But the reason I ask is that I'm interested in knowing when the use of paraboloids started coming in. Do you know about that? The reason I'm interested is because [Grote] Reber built this backyard thing I think in '37...
Tuve
I'm trying to remember what Bell Labs did. Jansky himself had some kind of antenna in his later work. And that was, of course, just before Reber, but I think that Jansky had...
Sullivan
He had a paraboloid also?
Tuve
Not a paraboloid necessarily but an array which imitated a paraboloid in a way.
Sullivan
Yeah.
Tuve
Yeah, but nothing like Reber's. Reber made an honest to God paraboloid.
Sullivan
Right. And as far as you know that was the first even considering all of communications and everything, the first antenna?
Tuve
The first one that was actually fabricated. Our request to the Carnegie Director was for money for a paraboloid. This was in 1924. But we didn't build it.
Sullivan
Ah, yes.
Tuve
And the idea there was to have the wave short enough, even then there were problems that it would be an awful lot of spill-over - just haw deep to make the dish - what shape the paraboloid would be. It was obviously messy.
Sullivan
So, as far as you know then Reber was the first one?
Tuve
As far as I know Reber was the first one that fabricated an actual movable paraboloid.
Sullivan
And this ionospheric radar that you did was indeed- well, was this really the first radar of any kind?
Tuve
Yeah, sure. Yeah, that was the first pulsed radio. Before that everything was continuous. Except sparks, of course, but that was just the way you got the emission. No, as far as I know, this was the first pulsed radio. In fact, I'm sure that this was the first pulsed radio experiments.
Sullivan
And there had been experiments with objects, is that true?
Tuve
Oh well, later, a little later, we went on with these experiments but in 1927-28 we tried a number of things. First in 1925 we had the chance to use it in the evening and we found that it varied and so on. And then we tried it in some magnetic storms that we happen to be observing [?] so we ran continuously. A few things like that. In 1927-28 I had invented what I called the- well anyway, the Michaelson Interferometer [send out?] what we did was - by that time we had the receiver right at the transmitter right down there at NRL - and this was what the experiment was. And we let the crystal run all the time from the transmitter and picked up a little of that to give us a half deflection on our [?] and then we had the pulses come in from the sky and they would beat with it - first up, then down, then up, then down, to measure every time they change 40 meters in dimension or 20 meters actually in height of the layer, effective height of the layer, while we get a reversal, and so on. And counting these - the only time you can really work this was about the noon hour - it would slow down so that it was going up and down. But then pretty soon it would start going faster and faster and faster until we lost track of it. But this interference experiment - what did I call it - it's published in the IRE about 1928, that sort of thing was done. What was the question? I get to rambling here...
Sullivan
I was asking about if this was the first radar and you were saying that it was the first pulsed radio...
Tuve
Oh, yes, in that particular experiment we had a helluva lot of trouble with airplanes. Boeing field was just north of NRL, if you know, and these planes - they were little planes in those days - they were I guess students practicing landings or something like that - some days, you know our experiments at NRL were by special arrangement - we weren't there all the time and so it was a bit of a trip and you get down there and you try to run and during the noon hour especially when we could really count these fringes, then if an airplane came in and he'd bother us when he was miles away. And, we recognized the symptoms and we'd get this fluttering and a widening of the ground pulse and say, "Oh heck, here comes some more interference." Then we'd have to stand still till this airplane came in and settled on the field then we could make some more experiments and more counts. And I sputtered about this at lunch and around - I wouldn't care a damn about airplanes - we were trying to measure the upper atmosphere. Well, it was heard by a young Navy Lieutenant, Dick Parsons...
Sullivan
His mind clicked.
Tuve
His mind clicked and he wrote a letter to the Bureau of Ships up to Commander Rubble saying that this bothers these guys, they're interested in the sky but this is a fine way for keeping track of airplanes in the sky. I think we ought to push it. That's actually the origin of radar. This is how it happened. Now the British [Richard A.] Watson Watt and the others apparently claimed that they were first on radar and so on, well, we just haven't looked into it - it wasn't available to them - the secret things in the U. S. Navy files, because it was only - this was in 1931 - this was a couple of years afterwards. You see when we had finished the experiment and were no longer working down at NRL, that Dick Parsons - I'm not sure that I didn't know him then, although later we were great friends, worked together during World War II, a lot. But his letter - he had heard about this stuff, our experiment, second hand, then he wrote this letter. But by 3 years later they had mattresses on ships and were carrying out all kinds of experiments.
Sullivan
And Watson Watt work was when?
Tuve
As far as I know from '36 to '39.
Sullivan
Oh, it was that late, I see.
Tuve
Yeah, he was a developer rather than an originator. Down at NRL they had some other experiments going- Leo Young and so on, where essentially it was a CW radar. They found that when ships passed them nearby they would get the wobbles, the typical interference pattern. And later they were tempted to call that the origin of radar. I don't care what they say.
Sullivan
About when was that?
Tuve
Oh, Leo Young and company were working from 1923 to 1930, and it was only after radar began to be recognized, during the War and afterwards, during World War II, that they finally revived those old experiments and remembered how the troubles that they had had with interference patterns. But it doesn't make any difference - the thing developed - enough interested people pushed things to make it go. You've got to remember that in the early days working with - well 10 meters was the shortest wave that we used for our experiments - 10, 20, or 40 meters, the problem of definition was very different. On the other hand, if you were trying to warn a flight of a whole bunch of aircraft off of Europe approaching England it would be very useful for that, I quite agree.
Sullivan
Exactly.
Tuve
Well, this is kind of a far cry - the only reason for mentioning it I suppose is that it meant that we were reading the proceedings of the IRE. I had a subscription and I definitely remember noticing Jansky's experiments and thinking it would be nice to follow it. Follow-up on them, but I didn't have any real hopes because the definition problem was still fierce - he was working I think also at 10 meters. And I dimly remembered - remember the Australians first built a parabola out of wires?
Sullivan
Right.
Tuve
He built something like that up at Whippany, I think.
Sullivan
In the late ‘30s?
Tuve
No, middle ‘30s, before Reber built his dish. So, I think there was the kind of as I mentioned here a while back, the equivalent of the paraboloid early in wires hung from posts. The idea was at first he was studying static on the transmissions from here to Europe. This was his job. And then he got this hiss bothering him and traced it to the center of the Galaxy being overhead and then he, with some reluctance on the part of Bell Labs, was allowed to set up some special antennas to try to study the origin of this stuff in the sky. And at that point...
Sullivan
There was nothing published about that, was there? I've never heard about this.
Tuve
You'd have to look through the proceedings of the IRE. Jansky will tell you next week.
Sullivan
I'm certain I have all his published papers and there were a couple of follow-up papers but they were all working with this first year's data and was just more thoughts about them. There was no further data mentioned to do with the galactic hiss.
Tuve
Is that right? He wasn't really much encouraged by Bell Labs to monkey with the sky.
Sullivan
I’ve heard that but perhaps he did some things like this that never got published?
Tuve
Ask his brother. I may be doing people an injustice. But when you ask about the first paraboloid at least I would look to see. I know that his first antennas were directed toward the European circuits. They were directional for that.
Sullivan
They were highly directional in azimuth.
Tuve
Yes, but also somewhat directional for low angle too. And he wanted high angle so he did some monkey business with antennas. I dimly remember that.
Sullivan
I'm quite sure that's not published.
Tuve
Well, I think it's in the second one of those papers.
Sullivan
Well, ok, I'll check that.
Tuve
But he recognized the fact that his antennas that he started with were not suited particularly to identifying where the stuff was coming from.
Sullivan
Exactly, right. Was this radar work of yours a side line or was this your main effort at this time?
Tuve
No, it was the main effort as far as official department activities were concerned. This is why they hired me. But I wanted to go to Rutherford and work on proton-proton scattering actually. I was most impressed by the billiard ball scattering of alpha particles which Rutherford had done back about 1916. And I wanted to do this thing with hydrogen and I said that basically the thing I want to do is put a million volts on a vacuum tube because until we can get real sources of these things we aren't going to be able to do anything. This, mind you, is now in 1925 and 1926. They offered me a post to come back there after we had been successful in 1925. I guess the first time I proposed this was ‘24 actually to Carnegie. But when they wanted me to come back to the department and follow-up on these radio experiments and I said, "No, I want to go over to Rutherford and get a National Research Fellowship. And I'm applying" and so I asked them to support my application. They said, "Well, can you finish this in a year?" I said, "Oh, no, I should say not". Now, Fleming said, Fleming was Acting Director of the Department, he said, "Why don't you come here?" I said, "Well..." He said, "You can spend part of your time like that if you do some of it on the radio reflections, you can do some more on these vacuum tubes", he says, "You don't have to quit at the end of a year if you came here". I said, "You mean that that I can work here?" And he says, "You know Carnegie can't make a new department every time there's a new experiment that needs to be done." Within the given administrative framework, we're trying to do physics here, we've done a lot of physics, you've got to remember Swan introduced cosmic rays to this country in 1912 here at this Lab, 1911 and '12, and Barnett, S. J. Barnett, did the magnetization by rotation which led to- incidentally, a year later right about the time of these discussions- to the spinning electron. Barnett's work was physics. He said that, "I don't see but that you could do some vacuum tube work if that's what it for and get at these fundamental." I said, "I'm interested in the fundamental laws of electricity and magnetism. Obviously they fail in the nucleus- if you pack protons and electrons together something's crazy here". And for all these positive charges to be stuck together there's got to be a breakdown of Maxwell Laws as we know them. And that's what I'm interested in and the way to get at it is proton-proton scattering. He said, "Well, you'd better come here and you can have some years at it". I said, "It's a deal!" So I cancelled my request for an NRC Fellowship and came down here. And that was the basis of it. And, essentially I was on the same fellowship until I became Director. I always maintain it wasn't a job - it was a fellowship.
Sullivan
A long term fellowship?
Tuve
Yes. So this was - you asked if the radio was the main thing. In a way officially for Fleming whose problem was the Department of Terrestrial Magnetism to get at the upper atmosphere conducting layer. So we kind of split the time but meanwhile worked on vacuum tubes. We busted every vacuum tube. We made Tesla coils to just get voltage to start with. Then we punctured some very valuable tubes that I borrowed from Coolidge at the GE [General Electric] and we made all kinds of tubes and we could puncture every one of them till we learned how to divide the voltage, and by 1931 we actually got a prize for it, the EEE prize. It flabbergasted me. I had gone to Cleveland and forgot my pants. It was very snowy and misty like this and I drove up in a pair of overalls with some - I don't remember - work pants under it - and got up there and found that my suit missed the pants and I had to phone to Washington and my brother sent them up and I got them just in time to give the paper. Oh dear... But this way we showed artificial gamma rays and beta rays and alpha particles - all of them above a million volts. That Christmas of 1931, was it? It was a '31 prize. I don't know whether that was Christmas '30 or '31.
Sullivan
It is sort of unusual how many important things that were in nuclear physics right at '31-'32 and then Jansky also came along in that time. Not quite so obvious...
Tuve
It was a hot period, I'll tell you. Ernie Lawrence and I grew up together out there in South Dakota and he had finished at Yale doing some spinning things like Jess Beams does, has through all the years. And when he was headed for Berkeley he stopped by Washington to try to persuade me. He says, "Why don't you come with me. Come out to California. That's the real forward part of the nation. They are really forward looking out there". And I said, "Well, I'll give you something to put in your noggin." I said, "Why don't you go into nuclear physics", I said, "It's obvious that this is the next big challenge for physics and that's what you ought to do instead of just these mechanical experiments with tops." Well, so we traded friendly blows and he did finally go into nuclear physics.
Sullivan
Yes, he certainly did.
Tuve
But he came down while we were making - we had these oil filled tanks, and busting tubes, and we had hired a glass blower and we'd make tubes and he'd treat them and pop them out to beat the band and then bust them inside of 30 seconds- a lot of troubles. Radio astronomy then got started at DTM right after the War because of our ionosphere work. The ionosphere work went on. Actually in 1930 I advised Fleming to stop - it was late ‘29 and '30. I said, "As long as we're the old men in this field- we'd started this experiment and so on - and the Bureau of Standards is going to monkey around with their fading patterns forever, Delinger down there, doesn't want to touch the pulse method because we originated it and we're right here in town. And I've asked them to start things - get started down there but as long as we're doing it, I said, we're in his way. He'll stay with his fading patterns, which is a silly way. We know that 4 - 5 - 6 different wave packets come in and interfere. They come from different directions. You can see all these different echoes that are pronounced. And his method is only suited, just like Appleton's, when you've got simply two of roughly equal amplitude. So there's nothing but misleading results ever get into the Bureau of Standards, and that's a disgrace. If they get busy on the pulse method that could really find out what's going on." So I recommended to Fleming that we stop it and tell Delinger that we'll stay out, you pick it up. So Delinger immediately bit on that. He went downtown and got $500,000 with his next budget to go after pulse radio. This was in '31.
Sullivan
That's a lot of money.
Tuve
Yeah, it was then I’ll tell you because by that time it had tightened up. And then he got [Lloyd] Berkner hired from - Berkner had been a Minnesota man that we knew - and he'd been with the Byrd expedition and I had set a challenge to them - the Byrd expedition. They came around to our place because we were tied in with Arctic things and magnetism, so I said, "Listen, one of the really important things you could do is to go after fossils down there. If you can find that this was tropical it will prove the fact that with respect to the center, through the axis of rotation, the skin of the earth has moved." I said, "I have the picture that the slowing-up of the earth's rotation by the tides to the moon acts on the outside, but the inside keeps on spinning. Now if there is some paddle sticking down into that liquid, like the roots of the Rocky Mountains or the roots of the Alps or something, there's no reason why those shouldn't be diagonal which will make the skin skew." I called it the "brake-band theory". You've got a brake-band on the outside of the Earth and it will skew it around to shift the continents. This is how we got kind of tied in with the Byrd expedition, through some arguments. Well, Delinger hired Berkner...
Sullivan
Is this the same Berkner, by the way, that was important for NRAO?
Tuve
Yeah, same Berkner, Lloyd Berkner. I don't remember that we - no, we had not hired him. He came for a job to us and I said, "Listen, the thing for you to do is get into the Bureau of Standards. We're trying to get them to put in big money and follow-up on this pulse thing". So Delinger hired Berkner and Berkner went to work and made out a lot of orders and got everything started. This was in late 1931 and then the money clamped down. The Budget Bureau placed orders that they couldn't spend any more money, and so on and so on, and everything kind of stopped down there. So then Berkner's salary was even threatened because he was a fairly new appointment. So I went to Fleming and said, "Listen, that's too good to waste, let's get a hold of Berkner and bring him over here and tell him to keep going on the same job." Which Fleming did and we brought Berkner to DTM where he was for many years. Then Berkner carried on the experiments, set up- first he devised a system for continuous measurements of these radio pulses. Then varied the frequency from 4 to 30 megacycles or 4 to 20, something like that, with a continuous amps for sounder and then they installed it in Alaska, one in Waterloo, Australia, and one down in [?], Peru. And this was in the course of the ‘30s. During the War they ran into the trouble that the standard data receivers for the ships and for the artillery and for communications in the Army all went on the fritz because of the sunspot cycle. And, so they appealed to us at Carnegie. I was busying making proximity fuses, so I wasn't involved in this but Fleming was. They appealed to DTM and what could we do about - what should we have done? And Berkner was by that time down in the Bureau of Aeronautics and Electronics and in charge of all the electronics actually - and the answer was that we should have had ionosphere stations following the development here to know what it was. It should have been measured in the earlier sunspot cycle, but at least they ought to be warned that the density gets higher and higher so that they couldn't reach the frequencies with their sets. So the government gave a lot of money to Fleming to set up a world - we dealt with the British at the same time - half the world survey for ionosphere stations right during the War. Britain took over the eastern half, Europe and Asia, and we took over from Greenland to or thereabouts to China.
Sullivan
This is about what time during the War?
Tuve
Oh, year of ‘43, something like that.
Sullivan
Now when you say "go on the fritz," you mean sudden ionospheric...
Tuve
No, not sudden. It was just continuous. The density was so high that their frequencies - or was it too low - I forget which way the sun cycle went during the War.
Sullivan
It was a minimum?
Tuve
Yeah, it was a minimum. So what happened was that - well anyway their frequencies went right on through. They couldn't reach the frequencies that they needed.
Sullivan
So they couldn't bounce off the ionosphere?
Tuve
Yeah.
Sullivan
Well, that makes sense. There's less ionization.
Tuve
Yeah.
Sullivan
During a minimum?
Tuve
Yes. So they have to use lower frequencies.
Sullivan
So the electron density is lower.
Tuve
I didn't know whether they were messed up on the low side or the high side. But anyway, the crystals they furnished with all their sets and the coils wouldn't go to the frequencies you had to use during most hours of the day for communications, so they could get communication only two or three hours most days when they were lucky. It was a helluva situation for the Army and the Navy, and everybody. You see, everybody had started the standard frequencies that they had been specified without knowledge of the ionosphere. Well, that's what caused our department to have responsibility for something like nine stations, ionosphere stations, scattered all over the, more or less, Western Hemisphere. And following these things- I inherited that in 1946 when I became Director, we were still running all these stations.
Sullivan
These stations were radar stations?
Tuve
They were ionosphere sounding and recording, and then the analysis of them, which was a fairly big job too.
Sullivan
Let me just ask you before you start on the post-War. Do you remember any time during the War of reports of any solar interference that looking back can be said to be due to actual...
Tuve
I wasn't doing radio during the War, so I don't believe that I do. Of course...
Sullivan
You know the story about Hey and the British?
Tuve
Yes.
Sullivan
I was just wondering if there was an analogous thing?
Tuve
I don't know of it if there is. I'm a little surprised that this- in fact, I was trying to remember what did Jansky find with respect to the Sun?
Sullivan
He didn't find anything because he was at a solar minimum also. The maximum was about ’36-‘37. And indeed at that time there were many reports from amateurs connected with sudden ionospheric disturbances.
Tuve
Uh huh.
Sullivan
There was a lot of hiss in their receivers. No one ever put two and two together.
Tuve
Yeah, it kind of surprises me because the idea that the Sun was a source of radio noise is an old one to me, even when I heard about Hey. It didn't sound like anything new but, of course, the fact that it was so intense as to interfere with the whole operation, that's fairly new.
Sullivan
Well, at some times.
Tuve
Yes, but even that, we've all been blanked out on radio.
Sullivan
But in any case you don't know of...
Tuve
I don't know of any...
Sullivan
It's amazing to me. The whole U. S. military effort never got it picked up, apparently. At least I haven't been able to find it yet.
Tuve
Well, it didn't interfere with their actual operations.
Sullivan
Yeah, apparently not.
Tuve
I wouldn't be surprised if in QST you would find references to solar noise before the War.
Sullivan
What is QST?
Tuve
The amateur's magazine.
Sullivan
Oh, I'm sorry.
Tuve
QST.
Sullivan
I've never been a ham myself.
Tuve
Oh, I see. Well, I had it from Vol. 1, #1, which was about 1914 when it started. Hiram Maxim, the old Maxim inventor, was the beginner, originator of the American Radio Relay League. QST was their magazine. It's still being published. I think we have it on our library shelves at DTM.
Sullivan
So you became Director in 1946?
Tuve
Here we had all these 9 or 10 stations scattered over the Western Hemisphere that we were responsible for, for the Armed Force. So I said, "Well, how do I get unloaded from this?" We want to convert back to peace time - this was immediately what Carnegie said. We won't take government money, we'll go back to our small ordinary staff, and we will just try to convert to full peace status as fast as we can. So, I went down to the Bureau of Standards - to make a long story short - and I initiated the moves which ultimately created the CRPL - Central Radio Propagation Laboratory. I proposed to them that since all three services were interested and the Department of Commerce was also interested that the thing we ought to do was to make a central laboratory and give them responsibility for it, and serve all these interests. And I suggested, I think, that the Bureau of Standards be the place to have it. So they did combine. The first year or two was budget money from all the services and put into the Bureau of Standards and then later the Bureau budget was increased to cover this. Well, that meant that Harry Wells was - and Berkner for that matter, although he was in and out. He was advising so much for the government - he was on duty a good part of the time - but nominally he was running our radar things. He was back at Carnegie semi-officially and Wells was there and the problem was then how can we effectively make use of the background of these people. And I said, "Well, radio astronomy, if you look at this Hey business and the other things that we're beginning to find." This was 1946...
Sullivan
And Reber also?
Tuve
Yeah, I said, "I think that's the thing to do." This is how we got into radio astronomy, because we've had this long background of ionospheric work. And had people and the place, we had this observatory observing space out north of town, and Berkner wanting to expand and consolidate and do a lot of things at Carnegie, persuaded Fleming before I became Director to buy a new laboratory which is up at Derwood where I now work and that was all done in the hopes of doing something fruitful. Berkner wanted to go on and make automated ionosphere observations, but the trouble was he wanted to do all of everything by automation without being there to do anything himself. And this didn't work very well. But Wells didn't want to do too much of that automation business. He picked up the radio astronomy then, long waves - tried to make absolute measures of what the intensity was, coming from some of these longer wave sources. Well, that the way it got into Carnegie.
Sullivan
But was any of this published?
Tuve
Yes. That the reason I brought down these annual reports - there are at least references to all this work indulged- these are published.
Sullivan
I just don't remember in the late ‘40s any work done at DTM, so I'll be interested to see them.
Tuve
Well, I haven't looked at them for many years so I don't remember just how much...
Sullivan
But you say it was Wells?
Tuve
Wells, yes. He made a ground screen and then they calibrated height over it and he hung his wavelength - he hung these antennas in order to get something you could calculate the efficiency of and then he measured the intensities...
Sullivan
Yes, that was a problem because before it was only relative intensities.
Tuve
Yeah, then he went for a year - after they had put up the big dish - this was in the ‘50s then I guess - he went for a year over to Manchester to work with the 200 foot.
Sullivan
Yeah, in the late ‘50s. I know about that.
Tuve
I'd found difficulty frankly in trying to make Wells efforts really focused and fruitful. And it didn't go too well. So there may not be any large write-ups here but there is some mention of it. However, in 1952, was it, that the hydrogen line was first...
Sullivan
'51 actually.
Tuve
’51 was first talked about...
Sullivan
First discovered. It had been predicted in ‘44 during the War.
Tuve
Yes, I know. I was trying to remember which year I went to a Physical Society meeting.
Sullivan
Spring ‘51 it was discovered.
Tuve
Yeah, Ok. And I tried to persuade Doc [Harold Irving "Doc"] Ewen to join the staff. I offered him, a post and so on. Incidentally, his wife, who was his wife at that time, lives three doors down from the street here. She's married to somebody else now. But - and she says his answer was characteristic. He said, "No, I want to make money". I said, "I'm sorry, I can't promise you that at Carnegie. You'll be comfortable, that's about all I can say. You can have a living wage but then you quit worrying about it and go ahead and do what you want to." But I couldn't persuade him to come. However, parts of the original Harvard apparatus are still up in the attic at our Lab because we brought down his original Harvard equipment.
Sullivan
Why didn't they want it there?
Tuve
Well, they wondered if we were going to use it to measure the hydrogen line. Perhaps we did, I don't know. I don't remember.
Sullivan
I've always wondered why it wasn't followed-up more at Harvard those first couple of years. There was that first little paper...
Tuve
Well, it was just because Ewen was an electronics man- [Edward Mills] Purcell, Ed was intrigued by this astronomy thing and I think that kind of typical of Harvard's graduate studies. But then Ewen, instead of going back and pushing it himself, which he could have done at Harvard, went back and set up a company, as soon as he got his degree he set up a company. I guess it's still running.
Sullivan
Still going, sure.
Tuve
Yeah, sure.
Sullivan
Still going- Ewen Knight.
Tuve
So, then not getting Doc, I said, "Well this is interesting. Let's do it ourselves." So we had meanwhile started to build up a set and immediately Howard Tatel and I said, “Let's build a multichannel set.” It's obvious that most of the information is thrown away that you're receiving, so let's go right ahead instead of sweeping, we built a sweep receiver and we watched the hydrogen line. Incidentally, we got from the Bureau of Standards - they had half a dozen of the old Würzburg antennas down there…
End of Tape 27A
Sullivan Tape 27B
Sullivan
This is continuing with Merle Tuve on 21 December.
Tuve
So I wangled with the [National] Bureau of Standards [NBS] people to let us have on and we loan one of these Würzburg antennas and we would make the frame. So we - 2 or 3 technicians, Howard, and I designed an equatorial mount and scrounged some gears here and there- differential from an old Crosly or some other crazy kind of little car which we used for feeding we in the tracking motion and so on. And we set up this dish.
Sullivan
Was it equatorially mounted?
Tuve
Equatorially mounted.
Sullivan
I see.
Tuve
There are pictures of all this over at the Lab if you ever get interested. And we put it right there on the campus at the DTM right in the middle of town here. And we got pretty good with records. We built this 50 channel vacuum tube set. And, of course, vacuum tubes have troubles. They would run down, dying and so on keeping amplitudes under control was quite a problem. We got a lot of profiles. We, in fact, made a- with the Würzburg we made a complete study of all the sky that you can see from here. I think there's spaced 5° apart- 5 by 5, 5° grid, something like that. In parts of the sky I think it was a 10° grid, way high up there's nothing much interesting. And, some places closer and clearer. This was in the late 50s. This was Howard Tatel and I, and a couple of technicians. And then we had some fellows here for summer, George Field was one and another chap, what his name...
Sullivan
Was Bernie [Bernard F.] Burke involved in this?
Tuve
Bernie Burke, let's see. We brought Bernie down - it's a little later - when was Burke there? We had - yeah, he is the middle ‘50s. I had brought in [John] Firor, who's now head of NCAR meteorology. I brought Firor from the University of Chicago and one other chap. Bernie Burke - middle ‘50s.
Sullivan
Because ‘55 was the Jupiter discovery.
Tuve
Yes, you see in addition to the hydrogen thing I said we've got to have really all sides of radio astronomy if we're going to do any of it. We've got to know about interferometers too. So I arranged to rent flat bottom land, a farm out 20 miles west of here, along the Potomac and we put up some arrays first to look at the Sun and second a pretty good array about half a mile long - I've forgotten what frequency - 20 megacycles?
Sullivan
Yeah, 15 or 20, yeah.
Tuve
I think it was 20 megacycles. And which could be tilted - this had the crude parabolic reflector made of wires and then the whole thing could be tilted at a given angle with respect to the ground. It was an east-west array. And we phased it to look at the meridian overhead and we could cock the altitude to suit. This was the one on which Jupiter was found, kind of funny. Burke and Ken [Kenneth] Franklin who had come from California was an astronomer would set the job - Burke was a physicist - would set the job and get what we can out of this array. Firor was working on the solar array which was a T or an L and under different frequencies. So Firor was running one array out there and Burke was running and the other- and Franklin. And they - on Burke and Franklin's thing there would be certain interference. Now, we'd had quite a lot of trouble with tractors around there and some old cars, one thing and another. So we knew ignition noise comes in on the record every so often - you've got to keep track of what's happening. Then there was one thing that kept showing up around - well, this was August or September or something like that - it was showing up around 10 o'clock at night - it got later. And we said, "Oh, that's that crazy old Ford." There was an old Ford- Model T mind you. Maybe it was a Model A. I never saw it but the boys described it. One of the farm laborers had it out there - an old wreck of a thing. And they knew that - it would go by several times in the daytime and make a racket. And they'd see this fuss on at 10 o'clock at night. And they'd say this guy must be calling on his girl. Then it got later and then a couple of weeks later they said, "My God, it’s a quarter of 11," and so he must be - she's letting him stay. Then it got to be about a quarter after 11, and they said, "Oh, this is getting hot." So we were watching this romance. And then to our surprise this moved back - it got to 10:30, 10:00 and 9:30 and 9:00. Well, it didn't make any sense - there's something wrong with the romance theory. So Ken and Bernie looked all around to find out what the hell this could be due to. And then Ken, I believe, or both of them, discovered that the retrograde motion of Jupiter corresponded exactly to the meridian they were set on.
Sullivan
Oh, beautiful.
Tuve
But, we had - before we dreamed of Jupiter - you see we were all kind of watching this romance that we thought was that crazy old Ford. So this was an effort to qualify ourselves to be - to have some judgment about both interferometry and parabolic dishes work.
Sullivan
Let me ask you why you were particularly interested in the hydrogen line. Why did you - you apparently grabbed on to that when it came out.
Tuve
Well, it very intriguing and to me it's still very interesting because this is the stuff of which stars are made. And you're watching essentially the aggregates -the pulling together at a very early stage.
Sullivan
So was this your motivation at that time also?
Tuve
Oh sure. Yeah. Purely because it seemed more like astronomy than...
Sullivan
Than the previous radio astronomy?
Tuve
Yeah. More immediately associated with astronomical ideas, astrophysics ideas. It basic - you see protons had been both so it was kind of natural for me to be pushing the hydrogen...
Sullivan
Yeah, that's a very good tie-in. Right.
Tuve
And then we moved out to Derwood and improved some of our circuits. But when we lost Bernie, of course, that was the big, big blow.
Sullivan
That was ’64...
Tuve
Meanwhile, you see, I was functioning as Chairman for NSF on the Astronomy Committee and things like that. And this is part of the reason for making sure that you had some spurs, that you earned your own spurs and have firsthand knowledge in disappointments and so on. Otherwise you just can't understand why research people have so much trouble getting results, with each other, disagreeing and all that. You've got to have your hands dirty doing the same thing. So this is part of the reason why I have always spent time in the lab taking my own beatings and doing my own crazy dumb mistakes.
Sullivan
Just to stay in touch.
Tuve
Keeps you humble. Right. And this is why I was determined to have experience with making dishes and designing dishes and costs and tolerances and all the rest. And also keeping track of where the electronics was going so as to see what's important from the astrophysics standpoint, what was feasible from the electronics standpoint, and all that sort of thing. Otherwise you can't really function as an advisor.
Sullivan
No that’s right.
Tuve
And this is again half of it. I recognize that I was an older man, and an administrator, and my job was to try and make opportunities for others as best you could. But you can have some awfully bull-headed notions if you don't let yourself get trimmed down by firsthand experience with disappointments. So that's a good deal of the reason why I was doing this.
Sullivan
May I ask you - it seems to me for the 5 or 10 years after the War that the real lead in radio astronomy was held by England and Australia.
Tuve
Yeah, that's right.
Sullivan
Well, how did this happen? The U. S. had such a huge radar establishment, and yet the U.S. didn't seem to follow it like they did. Do you have any ideas on that?
Tuve
I wonder if I have.
Sullivan
Like the Radiation Lab, why didn't that become another CSIRO?
Tuve
Well, the Radiation Lab was for quite a specific purpose and the people that had been assembled there went back to where they came from, essentially and...
Sullivan
That's true. CSIRO did exist before the War.
Tuve
Yes, CSIRO was for a much wider purpose. Actually in part it was aided and abetted. I was one of the boosters of the Australians. In fact, when was it that they first wanted to get a big dish? Taffy [E. G. "Taffy"] Bowen came hunting for money and presented his ideas that they ought to get a big dish. I went to [Sullivan: Vannevar] Bush and made the case to him - I don't remember when- this was about 1950 I guess [Sullivan: later]. it And he presented it to the Trustee s and we got $.25 million for them to start on the dish, "priming money." I said, "Those people ought to be recognized in some solid way for the way they've gone ahead and done things - off quite a ways from the center of technical activities in the world. And they've done better than all the rest of us. If our Trustees pay that much attention to Taffy, it will help them get other support too. And he did. He raised that ante of $.25 million in cash from Carnegie to a $1.2 million or something like that and got his dish. So, I think a lot of us were boosting for the Australians. We were very pleased that this could happen. And it's best not to try to use money to beat them. At least that was my position- to use money to help them if you could but don't use the checkbook over here and the big resources of Armed Forces money, for example, to insure that we got something bigger and better than the Australians - that wasn't fair.
Sullivan
But of course in most scientific fields, I think this did happen that the U.S. was quite dominant.
Tuve
Yeah, yes.
Sullivan
I can't quite understand why radio astronomy was one exception during these first 10 years anyway.
Tuve
I don't like to put too much of it on Taffy Bowen, but certainly a good deal of it ought to rest on him. Taffy was part of the Rad Lab, but he went back to his home post and that's where the Rad Lab gave rise to radio astronomy. It was through Taffy Bowen in Australia, which was all right. It just as good as if he was in Texas - the subject was good. Now the British, I think they felt they had a lead and they'd better stay with it. Of course, there again...
Sullivan
Well, there were outstanding men, [Martin] Ryle and [A. C. Bernard] Lovell.
Tuve
Yes, Ryle and Lovell - both.
Sullivan
So perhaps that's it, that there happened to be these outstanding men in both countries.
Tuve
I think this is nearly always the thing that happens in the entrepreneurial status of a subject- this is what does it. Later, when you get to the technological phases- to make the biggest or the strongest or the most power- well, then, other factors enter. But strong men, really interested and competent, is the answer. [Jan Hendrik] Oort is the answer to Dutch astronomy, I suppose, in large measure. They’ve had a whole lot of them but they were associates of Oort- no doubt they interacted and made it strong. Blaauw is a good man - a lot of others. They aren't all Oort’s students, I don't think, but...
Sullivan
Well indeed, he's the guiding force.
Tuve
Yeah. Well, it's the pilot light that just keeps going- every time there's a chance, it stays on fire.
Sullivan
Exactly. He's still going strong, by the way.
Tuve
I think it just fabulous. I'm so pleased, because he's always had big, broad-gauge ideas too.
Sullivan
Well, then Westerbork itself was his - I mean he saw what Ryle was doing and he was very impressed with it and he said that we need to do this.
Tuve
I've watched the Benelux Cross and all those other things go through so many gyrations I'm awfully pleased that Westerbork has worked out as well as it has. That represented a great compromise and a considerable I think disappointment, I think, to Oort because they couldn't get the money for a big international activity.
Sullivan
But it's still a fantastic instrument.
Tuve
Just doing everything the other one would have done. It's fantastic. Well, these are a few highlights of things. I don't know exactly what you are interested in.
Sullivan
Thank you very much. That ends the interview with Merle Tuve on 21 December ’73.