[Doc Ewen]
Ewen and Edward Purcell with the 60 foot antenna. (Photo courtesy of Doc Ewen)


[Ewen and the horn antenna, Harvard, 1951]
Ewen and the horn antenna, Harvard, 1951. (Photo courtesy of Doc Ewen)


NATIONAL RADIO ASTRONOMY OBSERVATORY ARCHIVES

Papers of Woodruff T. Sullivan III: Tapes Series

Interview with Harold Irving "Doc" Ewen
At Weston, Massachusetts
August 12, 1979
Interview Time: 2 hours, 10 minutes
Partially transcribed for Sullivan by an employee of Ewen-Knight. Transcript completed by Sierra Smith in 2013

Note: 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.

Part 1 | Part 3

Sullivan

With Doc Ewen on 12th August 1979. So what range was the L.O. turned over?

Ewen

I believe it was about Ī 150 kHz and that was accomplished by cavity-tuning a 3C22 lighthouse tube in a radar jammer cavity. It was a surplus World War II device. It was very stable.

Sullivan

What was your form of output?

Ewen

The method of determining the frequency was quite linear with just a manual drive on the cavity for that small of range and the method of measuring frequency was by that very complex, in those days, synthesizing harmonics with General Radio equipment that was strewn all most over the laboratory. Most of what I had in there in that laboratory was frequency measuring equipment, and we would count up, then down, and check, and check. And this was then evaluated independently for me by... [Ewen: Most of that equipment was provided on "weekend loan" by the Nuclear Lab. I would bring it over to Jefferson in a wheel barrel on Friday afternoon, and then back to Nuclear the first thing on Monday morning. Weekend holidays were cherished. Our payoff weekend was Easter. [Sullivan: not on tape. 25 Mar 51 = Easter Sunday]]

Sullivan

And your signal output was just a strip chart?

Ewen

That's right. Just an Esterline-Angus strip chart, crank it up with a crank.

Sullivan

I've seen pictures, where you are there with headphones on. Was that just testing equipment, or were you actually doing observations that way?

Ewen

Well, occasionally I would put on headphones when observing in the evening just to listen to the heterodyne beat as that oscillator was being tuned and I had an old comfort chair brought in and put in the lab. And I would just close my eyes, and snooze a little, and I would listen to that thing whistle and if it gurgled or popped, it was almost like babysitting. Iíd be able to come to. And I would also tell the night janitor what times to definitely wake me up. But I could tell that gadget when it was running correctly, it had, because of the number of gears and motors, peculiar little noises coming out of it. I could walk into the room and Iíd just listen and I could tell you whether the receiver was working or something had happened.

Sullivan

Let's go back to your attempts to detect the line. So 10 kHz did not work. So, what time are we talking relative to final detection?

Ewen

It was probably in the late summer, fall of í49 or '50. No, we didnít really get it together until early í50. [Ewen: late Ď50s, just before Christmas]. Then the next step was to separate the frequencies further. No other changes were made and to accomplish that, it then became necessary to introduce two oscillators in the communications receiver. That was not a large modification. I also at that time did by just simple interchange in the communications receiver, change the bandwidth to 15 kHz, to improve sensitivity a little, wondering if I was really improving the signal-to-noise, so I didnít know whether Iíd gone out of the line for sure. So, then we tried both a 5 and a 15...

Sullivan

But since you had been switching to 10 kHz anyway, that probably told you that you were inside the line.

Ewen

No, I was still working on [Sullivan: the assumption of] the negative thesis.

Sullivan

Thatís what Iím saying but, by broadening the bandwidth, you couldnít be sure that you didn't have a super narrow line.

Ewen

The whole focus of attention was to separate the frequencies, but that would be the only thing which would be of any value in searching for the totally negative thesis.

Sullivan

But now in fact, you just said you were not worrying about Earth Doppler motion. But if there had been a very narrow line, you would have missed it, would you not?

Ewen

Absolutely. [Ewen: narrowing the bandwidth by a significant amount would degrade sensitivity and have an adverse impact on frequency stability and tuning rate.]

Sullivan

It was by luck it had been right at the line.

Ewen

As a matter of fact, it was detected by luck and Iíll tell you how.

Sullivan

Well, we are getting there.

Ewen

We are getting there. I then put the two oscillator system together but it was fixed. I was unable to adjust it, do it quickly. Switching then was something like 25 kHz when it was on square wave, a little neater job than this wheel. And nothing that I could really say was a detection. Some little gurgles and burbles but they could have been noises that the machine was generating for itself.

So then, we had a summit meeting with Ed. As I recall it was in the late fall of '50 and it was, "Are we ready to go for the negative thesis?"

And Purcell was just a giant at those meetings. Rather than discuss whether it was time to go for a negative result, he was more upbeat on, "Is there was anything else that you would like to buy or try before you let it go down the drain?" And I said, "Well, it would be very expensive?" And there was just one other thing I could try in order to separate the frequencies even further but to do it I would have to buy a new receiver. There was a new one which National Company had just come out with and it cost $300. I would modify that and if that didnít work, nothing would work. But we donít have that kind of money because we only had $500 for the program, and weíd spent the $500 on the horn. So he said, "Well, if that is your decision, come on back tomorrow and weíll finalize it."

So I came in the next day and Iíd mentioned it to him occasionally, and this is one of the things that he has never given me an answer as to how this happened. But he said: "Now youĎre sure. $300 and you buy that receiver and thatís going to be it?" He reached and pulled out his wallet and took out $300. I don't know where the $300 came from. It was cash.

Sullivan

Laundered.

Ewen

So there it was. I said, "Yes sir. Iíll do my thing." And I bought and modified the receiver and did that with loving care, working with that receiver. And the very first night I turned it on, put that thing on, the line was detected, very peculiar way.

Sullivan

What was your switching now? How far away?

Ewen

75 kHz. And I knew that everything sounded good. The machine was really running beautifully. I was scanning the Ī 150. And I started scanning through the rest frequency and that was just a big nothing. All the way to the end and I thought, "Oh well, just let it run because maybe Columbia goofed [Sullivan: in the lab measurement of rest frequency]. "And at the very end, and that's probably the record I should have kept- at the very end of that strip chart record and this was about 6 feet long and at the right angles, you see this things go up and just again it went off scale. I said, "My god, what could that be? That is too resonant for anything Iíve got in this machine." So my feeling was 100% that it was an equipment error that I was unfamiliar with, some sort of resonance.

Sullivan

This was 75 kHz off the rest frequency?

Ewen

No, 75 kHz switching and 150 kHz tuning.

Sullivan

Oh, 150 kHz off.

Ewen

I was at the end of the scan. I couldn't go any further. The oscillator wouldn't scan any further. The motor boom, hits the limit and thatís it. So I just moved everything back 150 kHz, cut the gain a little, and the then goes off the chart.

Sullivan

But you had enough confidence in your receiver though?

Ewen

Oh, yeah. I didn't think it was the line, but I knew that...

Sullivan

That you could investigate it anyway...

Ewen

That I could quickly investigate it by shifting over here and scan that part. But had I stopped at, say, 100 kHz instead of 150 kHz, I never would have seen it.

Sullivan

You would have had your negative thesis.

Ewen

That's right. But the minute I saw that- what the devil could be 150 kHz. And thatís what I was thinking sketching this thing out. And that's when I called the Harvard Observatory. It was about 2 o'clock in the morning. And I said: "Physics Department at Harvard and weíre performing an experiment here."

Sullivan

You got someone at 2am?

Ewen

Yeah, at 2am, some grad student on the phone. And I said, "Weíre over here in the Physics Department and we are performing an experiment that involves astronomical coordinates. And I can tell you that we are now looking almost directly south at a declination of -5į. But what Iíd like to know is, can you tell me the component of the velocity vector in that direction as a function of hour angle, say from midnight to three in the morning because I'm trying to measure a Doppler shift?" There was a big pause, "Who are you?""Physics Department - Harvard." "What are you looking at?" "Interstellar gas. I'm looking at a resonance in interstellar gas and I need a Doppler component from you fellows." "Well you better call us some other time. Doppler, what are you guys doing over there? Is this a prank call?" So I said, "Iíll get in touch with you later." Just zip. After that I didnít call the observatory. I just got the books and looked it up and computed it myself.

Sullivan

There had been work done on that sort of thing before.

Ewen

Oh, sure. It isnít that complicated but at 2 in the morning, you figure-heck, Iím sitting right here at Cambridge, why can't I just call the Harvard Observatory and have a fellow just spew that to me over the phone. Why should I go to all the details of looking it up?

Sullivan

In fact, did you worry at all...

Ewen

See, I hadnít worried about anything.

Sullivan

No, but about where you were looking in the sky or were you just tune on when you got things working?

Ewen

The only thing that I was concerned about was to pay attention when the Milky Way went by.

Sullivan

OK, so you did do that?

Ewen

Right. That was the only thing I worried about. I knew I was looking south, I knew when the Milky Way went by and line came in just about ballpark.

Sullivan

But you didnít care whether it was daytime or nighttime, for instance?

Ewen

No. The only thing that made nighttime observing attractive was thatís when I wasnít working at the Nuclear Lab. So in the daytime the machine ran by itself. I had it set it up so that at noon I would go over, crank it on because itíd be just 12 hours later and the Milky Way was going by around 2 oíclock. So, I was just sketching the negative side and Iíd just crank around and let her do her scan.

And then, it would automatically stop at the end of the scan. Then at night I'd take a look at it and I remember after I got this detection, I was picking up that one on the backside of the Galaxy. See, the thought was that the whole astronomical input at that time was that if you're going to see anything, you're going to see it near Sagittarius. You need a big, dense cloud and that fellow is right in the middle of the galaxy. This idea of looking around and casually seeing hydrogen all over the place hadn't occurred to anyone. When I saw it in the anti-center, that thing came in really strong and narrow. And I just dismissed that. I was too busy getting it over here at night where it belonged at night when I was there. If it wanted to do it in the afternoon on its own time, I would just take those and pile them up, and forget that.

Sullivan

This is now a few months later?

Ewen

No, this is in the same time as the line was being detected because it was picking it up in the afternoon for me automatically. But I wouldnít believe it because I would figure that was the day of "MITís on the air," somebody is goofing me up, the car...

Sullivan

No mention about that in your thesis at all?

Ewen

No, I never mentioned- I never mentioned it to Purcell until much later, that I had the anti-center, that it showed up over there That was even neater and clearer but I wouldnít believe it if I wasnít there.

Sullivan

This brings up a related question. How was the angle of the horn chosen? In other words, declination -5į?

Ewen

It was chosen on the basis of the waveguide bend that was commercially available at L Band, that would allow me to bring the waveguide horizontally out the window and then up. That comes out at -5į.

Sullivan

Did you pick a room that was facing south purposely?

Ewen

Yes, I did. I did do that, definitely wanted to look south. I wanted to be on the local meridian. I did check out the road that we were within 10į or something. But that reminds me of one that Friis taught me because I asked him at one time, "Why were all antennas that Kennedy was building and were being used in tropo-scatter, why were those 28 feet? And why werenít they 30 or some number of meters?" And he said, "It turns out that plywood is 14 feet long," and he built the first one as a model in wood and then fellows came along with their aluminum- 28 feet.

Sullivan

Well, thatís how Grote Reberís- his was a 30 foot dish for the same reason, the length of wood he could get at the local lumber store.

Ewen

And thatís what Friis was doing at Bell.

Sullivan

It may be the same lumber standards that made that 20 feet the same as Reberís 30 foot dish.

Ewen

But somebody put a vertex in the middle for Reber.

Sullivan

Ok, I wanted to ask, frequency switching. Where did the idea of frequency switching come for that?

Ewen

The idea was at that initial meeting with Purcell and I think was just a natural for nuclear resonance. And Purcell said, "Just frequency switch."

Sullivan

Was it a standard technique at that time?

Ewen

All of the other grad students at that time were doing nuclear resonance type work, and at that was fairly standard. As a matter of fact, trying to decide what we would call a thesis and what discipline was the thesis- my final doctorate sheepskin says "Microwave Spectroscopy," so trying to decide what hill we were going to be on. We are going to be in microwave spectroscopy and that is the standard technique.

Well, it was Purcell who suggested it and I think it was unfortunate that he didn't get greater recognition, particularly that that idea wasn't recognized as a rather significant thought because Dickeís contribution was really "switched load". The "switched frequency" mode is not really a true Dicke. So that was a whole new radiometer type, much the same as the [Whiteoak?] machine or whatever. But it has always been called the Dicke radiometer.

Sullivan

But was he the one who developed frequency switching for NMR [nuclear magnetic resonance].

Ewen

Purcell, I can say without question was the one who suggested it for the radio astronomy application.

Sullivan

And for NMR also, is that correct?

I believe so.

Sullivan

You were working all the time on the accelerator? So, this was really, like you said, a hobby?

Ewen

This was nighttimes and weekends. I was putting in 40 hours at Nuclear.

Sullivan

And Purcell, also, you said he was away a lot of the time.

Ewen

He was tied into those committee meetings for the Korean War and he was fairly high up with the Defense Department. So most of the fellows were shuttle-hopping to Washington, most of the key scientific types in those days. And I think he was essentially assigned almost on a sabbatical for about a year assignment in Washington. But at the times I needed him he was there. He participated in all major decisions. And certainly while weíre hacking wood and putting things together- in many ways I benefited possibly by the fact that he wasn't always there, because I could get some things done at the Nuclear Lab and I wouldn't have to say: "I haven't done anything for two weeks." But I knew what the schedule was, and they were all put together and he was a very good advisor in the sense that he never really bugged me. He wouldnít even call and I would wonder...

Sullivan

Whether he cared at all.

Ewen

No. I would look at the phone and say: "Boy, if he calls, what will I say?"

Sullivan

So, having this initial detection which looked pretty good, you said you now thought about the whole business of Doppler and within a few days...

Ewen

Oh yes. Almost immediately. As a matter of fact when I first discussed it with Ed, I recall the night it was first detected. It was 25 March and within 2 or 3 days right around there, I had it really nailed down and understood the frequency shift. And then I just picked a morning when I was confident that that was it and everything appeared reasonable, that I recall taking the Esterline-Angus roll of about 30 feet and I knew where Ed would be coming in in the morning, he usually came down a long hall in Cruft. And I had my old, bloodshot, red eyes and I took the roll and zipped it about 30 feet, right at his feet and said: "There it is." And he saw me, "Really?" There it is. It was just beautiful. So from there on it, it was, "Well, come on in the office and we will find out what had been detected."

Sullivan

Well now, there still was there not some luck involved because you calculated the orbit of the earth and got that motion and so forth.

Ewen

Well, I got Hercules too. I knew the Sun, the Solar System...

Sullivan

You got that, the whole Galaxy. But, if the line had been at -100 [Sullivan: Km/s] with respect to the local standard of rest, you still could have been way off.

Ewen

No. I was strictly assuming hydrogen at rest and the Solar System was the only one moving in the whole show.

Sullivan

So now, what did you do at this stage? Did you follow this up or confirm further?

Ewen

No. At this point, it was treated as an experiment to be performed in physics. It had been performed. Itís complete. If it had been performed by the Astronomy Department, it would have been a different thing. But in the Physics Department it was strictly an experiment in Microwave Spectroscopy, very convenient laboratory. It worked and there was obviously some significance that would be drawn by astronomers. So it was in that context that we wrapped it all up. It was at about that time that Purcell then said, "For the publication of this, in the field of radio astronomy, who are the people, because Iíd done that literature search, who are the people and who do we get in touch with?" And then he sent a wire to [Joseph L.] Pawsey in Australia and one off to- well, it was going to be the Netherlands. I don't know the details of how he discovered that van de Hulst was at the [Harvard] Observatory. He may have met him, I don't know. It was not my opinion that he had. I have no recollection of any thought that he had met him. He certainly never discussed it with me other than it was coincidental that van de Hulst was there. And now that we had gone through the two months [Ewen: more likely weeks] of assuring ourselves that we had detected the line, he said, "Why donít you go and see van de Hulst." That was very much like Purcell, who though a very important cog in the whole wheel, it was typically of Purcell to say, "Hey kid, you did it, you tell him." And which to me, I looked at it that way, my eyes cloud a little, thatís my father saying that, you know, "Hey kid, be a big guy. Go tell him." So, I went up to the Observatory looking for Hank van de Hulst, located him, and just very quietly told him my name and what I had done with Ed Purcell. And he was quite shocked, to say the least.

Sullivan

He had known nothing about this operation at all?

Ewen

No. I had never talked to him before. He was quite taken aback about all this having happened. And so then he asked me for details of where we were looking and how it was done. I had brought along some strip charts, but I hadn't brought schematic drawings and those details. But he then placed a call immediately to [Jan Hendrik] Oort, and when he got Oort and [Christiaan Alexander "Lex"] Muller on the phone.

Sullivan

While you were still in the office?

Ewen

Immediately. And he then described to them where the detection had occurred and what the intensity was. And then they asked that I get on the phone and describe how it had been done, how "switch frequency" worked, what the noise figure that had been measured, what the signal/noise ratio was and how the overall machine was calibrated and the use of this noise source- things like that, that apparently were new to the Dutch. And so I went through quite a discussion in some detail and agreed then that I would then send schematic drawings and any parts, like 6AK5 low noise preamp tubes, that weren't available conveniently to the Dutch, to get all of these to van de Hulst so that he could expedite the shipment to Holland. And then the understanding was that we would appreciate confirmation, since they had proposed the detection. I did not then meet again with van de Hulst until the time of my doctorate oral. He was on the committee with Purcell of course and some others.

Sullivan

When was that?

Ewen

That was probably a couple months later and the interim was occupied by the fact that I had completed then the thesis and I wrote it up. I got up to 47 pages and then take the oral. But I had one other thing that I had not completed and that was my German qualification. So I packed a bag and went to Vassar, where I knew a friend who spoke German, and I spent, right after the detection, right after speaking to van de Hulst, 2 or 3 weeks out at Vassar studying German. And that got to be pretty well known by Bok, who was in South Africa at the time. He said Oort was furious. How could anyone detect an interstellar line and then be studying German? Because thatís what I was doing, because otherwise I wouldnít get my Ph.D. And I remember getting the German out of the way. The professor in charge of the German exam was Oldenberg, atomic physics, and Oldenberg selected a chapter out of [Oppenheimer?] and Becker on magnetic theory. And he told me about the chapter. He said, "Hereís the book. Itís in German so Iím sure you are familiar with the text. Just translate this chapter." And he left me in a room, all by myself, and through the door came [?] and if you know [?], who is the seat of the chair of Einstein, heís quite a speaker and a mother of grad student or possible undergrad student at Trent, [?] was right there at the door of the room where I was trying to get my German out of the way. Iíd spent three weeks at Vassar. And [?] was going, with his hands going up and down, telling about this poor kid was going to have to be kicked out of school for awhile. So I just picked up everything and went up stairs to another room and then Oldenberg found me up there. He said, "My god, thank heavens Iíve found you." "You know what youíve done," he said. "Youíve violated this and that. I should notify the Dean." So I told him about [?] and I said, "You can ask him. He was blowing my mind down there. I just went to another empty classroom." And thatís all that happened. So then he quickly looked at what Iíd written and he said, "Thatís a beautiful job of the chapter but itís not the edition you reading." But he said, "I think you know German anyway, know a few words." And that was it. So thatís that aside. And then as I said, I didnít see van de Hulst again until we got down to oral time.

Sullivan

Now just let me check on dates here, because the Dutch detection was in late April around April 20th. [Sullivan: Wrong, 11 May] So, you must have spent only a week or two in your confirmatory observations before you went and told van de Hulst.

Ewen

We told van del Hulst... I guess we... I may have that wrong. I see what you mean. My feeling at the time- I had wrapped it up in three days- was that I had it. The great concern of Purcell was that I the MTA or a high line... [Sullivan: like the MTA!] [Ewen: Last note in lab notebooks re observations is April 22- then it begins again in the fall (í51).]

Sullivan

Thatís right, you haven't said that for the record. There were some interference possibilities.

Ewen

When I showed Ed the chart and said, "There it is," he said, "Come to the office. Weíll see what you detected." And I was a little concerned when he got on the phone and called [Sullivan: MIT] Tech and wanted to know what they were doing. He was interested that there was something on the paper but he was then going to search out what it was. And I was quite confident because everything checked, but it had only been 2 or 3 days that Iíd worked it. And it may have been at that time and that was certainly the motivation for confirmation with Ed, to not only how to you join the radio astronomy club but how do you approximately make certain that this has been detected because though you can try a lot of things individual- he did recognize the significance of the measurement as an interesting experiment in physics...

Sullivan

He wanted independent...

Ewen

So he may have been motivated very early on then to say, "Go find van de Hulst." Because I know even at those early meeting, he was discussing who should we get in touch with and settled on the Dutch and the Australians. And though the English were quite active at the time, we did not contact them.

Sullivan

Do you remember any advice from van de Hulst on how you might- from an astrophysical point of view - improve your technique or follow it up or specifically if you might go to a more extended frequency switching?

Ewen

No. The first discussion that I had with van de HuIst was the original one after the line was detected and then at the time of the doctorate oral, when after I had been asked a couple of relatively simple questions in physics, the meeting broke up with Purcell and van de Hulst at the blackboard for about two hours to discuss what this all meant from the physics and astronomy standpoint. And I can recall sitting there, dozing, and listening to those giants with my feet up on the chair until at some point in time Purcell looked around and said: "Oh, you're all set Doc, you can run along."

Sullivan

You thought this was still part of your exam?

Ewen

Right. I was waiting for them to turn around and say, "Now that youíve listened to us, what do you think?" But fortunately, he said I could leave and so that was the only other time. And the next time that I met van de Hulst was at Leiden. I took a trip over there sometime.

Sullivan

It has always interested me that those two papers in Nature that came out are so different in their approach. Your paper with Purcell is physics of the line, while their paper is entirely galactic structure. Just an different approach.

Ewen

And the telegram from Australia - detection!

Sullivan

Right, weíve slapped together a receiver. Weíve got it.

Ewen

It works.

Sullivan

So, you got your degree right only three months after the line detection and then was there no more follow-up in the Physics Department? Purcell said, "The experiment is done."

Ewen

None. The experiment was done and we notified the Harvard Observatory, of course, because I had been there with van de Hulst. Harlow Shapley was the Director at the time and there was no real interest to pursue it further. No interest at all at Harvard. So we just packed up shop. There were some visiting firemen who would drop by occasionally. [Sullivan: Taffy Bowen was one of these (letter 10/22/51 from Purcell to Kerr)] And Iíd be over at the Nuclear Lab and Ed would call and say, "So and so is coming into town and he wanted to see the machine." So we would converge there for a couple of hours, turn it on, make it do itís little Rube Goldberg audio thing, and if he happened to be there when the Galaxy was around, weíd get a line that he could take home. So that was about it. It was a little pony show. And I was then at that time very involved with this Korean War thing and being called back to active duty and problems with whether I was going to be in the Navy and finish up. There was a lot of confusion in that area so that as far as operating the equipment any further, no.

Sullivan

So basically you were working on the accelerator during those years?

Ewen

Right, getting the proton beam out of the cyclotron and that occurred just three weeks prior to the detection of the line.

Sullivan

Oh. I see.

Ewen

It was just bang-bang and everything was over. Weíll just wrap up and decide what comes next and try not to have another war.

[Ewen: The time period between the detection of the line on March 25th and graduation in June was a bit hectic. First, came the oral followed by two weeks of studying German and my qualifications exam in that subject. One week to write the thesis. Then, "Greetings" the Navy ordered me back to duty. Apparently, they felt I would be more useful as an officer in the Korean War than a graduate student at the Harvard Business School that fall. I had applied and had been accepted just a few weeks earlier. I was ordered by the Navy to report to Washington, D.C. for a two week period during which my "Q clearance" was being processed. Following the receipt of the "Q clearance", I was scheduled for assignment to the Navy Nuclear Group at Sandia, New Mexico. During my two-week stay in Washington, I submitted an unsolicited proposal to ONR describing a unique technique for the passive underwater detection of submarines. I was awarded a $50K contract, released from active duty and returned to Boston to act as principal investigator on the underwater warfare contract, which I had arranged would be awarded to the Scientific Specialties Corporation. At that time it was headed by a former director of the Nuclear Laboratory. The kick-off meeting for that contract was scheduled the same day as commencement, as a result I missed the opportunity to wear the doctorate robe. During the summer of '51, I spent most of the time on a 65 foot yacht cruising around Boston Harbor and the adjacent islands experimenting with my underwater detection scheme. Other than occasional visits to Harvard, most of my time was fully occupied for the rest of that year with the underwater warfare technique (which was quite successful, by the way). [Sullivan: Not on tape]]

Sullivan

You were in a race on the accelerator too.

Ewen

Yes. That was with [Enrico] Fermi at Chicago which I felt was the great accomplishment. If I were asked at that time, "What is the greatest thing you did in í51?" And certainly for the next two or three years, I would have answered, "The external beam from the Harvard cyclotron. [???] the cyclotron, get the external beam, and beat the boys in Chicago." And that was it, thatís where I spent all my time.

Sullivan

It would be interesting- Let me ask you, at what stage did you feel that detection of the 21 cm line was more important?

Ewen

Well, it started about a year later when Bart Bok came back from South Africa and hat was also the beginning of Ewen-Knight. It started with Bok and when he looked me up when in hours of when he got back into town. And at that time, I was working on the underwater warfare problem, which was more important than my being in Korea and I was working for a company called Scientific Specialties, which was an outgrowth of the Nuclear Lab. And Bart looked me up and asked what the status of the machine was. I believed prior to his return- this is the part that Ed and I havenít quite resolved how it happened- but that machine filled a room about the size of this room, just giant, and in that period about the early summer, during the summer...

Sullivan

Of í52?

Ewen

Of í51.

Sullivan

Oh, í51. Thatís right. But Bok came back when now?

Ewen

Bok came back, I believe, early í52 or something like that, somewhere in there. About a year, it was probably spring on í52. It was in between those two times when I was working during the summer, I remember a call to go to Washington to talk to Vannevar Bush, and we walked in a park in Washington. He told me the great virtues of being a fellow at Carnegie and that they had decided that I should come to Carnegie and be a fellow and I wouldnít have to worry about anything the rest of my life, which immediately convinced me I didnít want to go to Carnegie. He said the wrong thing. So Merle Tuve I guess had sort of put him up to it, the head of the Department of Terrestrial Magnetism. But Van Bush and the boys at MIT- I think the president of MIT went to Caltech, who was he? I got to know him...

Sullivan

At that time?

Ewen

Right, but he was a buddy of Conantís and I believe he was president of Caltech.

Sullivan

DuBridge?

Ewen

DuBridge, right. DuBridge and Van Bush were buddies and of course, DuBridge...

Sullivan

He had been head of Rad Lab?

Ewen

Right, with Purcell and everyone- It was a real tight club. So between DuBridge and Van Bush and all, I donít know what part Purcell played in all of those because in those months, he was back in Washington and I really didnít get to see that much of him other that an occasional call of, "When are you coming down?" But I remember describing this whole thing, how to operate the machine to Merle Tuve. Itís my understanding that an arrangement had been made to ship all of it to Washington and I was on my way back to my submarines. So a truck arrived one day and we put everything in the truck and it went to Washington. They didnít want the horn. That went to the Smithsonian and then went down to Green Bank. And so, Merle Tuve and Carnegie had the original machine. And it was much later, I think it was in the late fall of í51, about in there, I had a call from Carnegie. Theyíd put it all together, dusted it off, and it didnít work.

Sullivan

Of course.

Ewen

This is what I call a confirmation. So I buzzed down to Washington and fiddled with the machine and theyíd put it all together, there wasnít much fiddling. And they had a big 60 foot antenna I believe, right there in downtown Washington and pointed it off toward the local cloud and in it came. And Tuve made an interesting comment at the time. He said, "When you sit it down,"- part of it Iíd built out of 2x4s because we couldnít afford relay racks, things were sitting on little shelves there, so they had all these little wooden things and I had a placed to hand my jacket, a little hat hook on a 2x4, he said, "You know Doc, we saw that and we put all that together and we put your hat hook up." He said, "We didnít realize the things doesnít work unless your hatís hanging up." I said, "Thatís it. Stick the hat on and see if it works." It was one of the those things. Then, with Bok when he came back, he looked me and he apparently raised the roof with the Harvard Observatory, with Menzel and Shapley and how ridiculous this all was.

Sullivan

Letting this all slip away?

Ewen

Oh yes, just absolutely ridiculous. Not only letting the equipment go, but letting this team fall apart. Well if you know Bart, you know he really put it to them.

Sullivan

Iíve talked to him.

Ewen

He did it all. At that point, he just said: "End of nonsense". He pulled the team together. Got hold of Purcell and myself, Shapley and Menzel and we all went over to the Harvard Faculty Club, [???]. We had a little summit meeting to decide what Harvard was going to do about this, to pacify Bok because Bok was going to do something about it. Very quickly it became apparent that Bok had convinced Shapley, and Shapley was ready to go and Harvard was going to move into the field of 21 centimeter research. It would be a major effort. We would immediately go for NSF [National Science Foundation] funding and put Harvard on the map. This was the chance which all U.S. radio astronomy had been waiting for, to get something going here, rather than it running only in England and Australia and so forth. This would be the focus. And so, of course, with Bok, you just nod your head. So we nodded and then Shapley said, "Well, now we have to figure out how to do it." And so he turned to Purcell, "How are we going to do it? Can Doc build a machine for the Observatory?" I said, "The only problem is that Iím working and Iíve got this thing with Scientific Specialties. How about getting the Engineering Department to do it?" And Purcell said, "Engineering Department? Did you have anyone in mind? Harvard or MIT?" "Well, weíre talking about a Harvard program here." "We donít have an Engineering Department so that is out of the question." "How about MIT?" "No, not them either, itís Harvard"- because while MIT and Harvard are close, they arenít all that close when it comes to something like this. I was picking up all these little niceties at the table. Finally Purcell, and this strictly a Purecellism. He said, "Iíll tell you what we will do." He said, "Doc, you know how to build it. We canít build it in the university. Why donít you form a company, build it, and then liquidate the company and that way we will have the machine." And he said, "Now all I got to do it figure out how much it will cost and Harlow, you just pay Bok. So it will be his corporation. So it will be Harvard University, some corporation, build it." And this was Purcell, my business school manager, and Shapely said, "Well, it sounds great to me." Casually Bok said, "As long as we get the job done." So here I was sitting with these fellows and they all start looking at my end of the table saying, "Well, whatís the name of the company and when are you going to have it ready and how much is it going to cost?" And I said, "Wait a minute." Purcell throws an idea on the table and suddenly everybody is jumping me for answers. So I said, "Iíll be back. Iíll get in touch with you. See whether we can do something." So I got in touch with my buddy Bill Pritchard and we spent an evening going over- Bill is at Raytheon- what it would take. And maybe could Raytheon build it, let me go back to my submarines and what we came up with probably cost around $100,000 in those days.

Sullivan

Right, thatís a lot.

Ewen

And no way we were going to get that kind of money for hardware into a company out of NSF. We could get couple grad students on it but not that. So we fiddled and fiddled with it and finally just the bare pieces for the receiver were going to cost somewhere around $10 or $15,000 and Raytheon wouldnít touch it. Pritchard told me, "They wouldnít let it in the door." So then, the problem was looks like I have to form the company and I had just about wrapped up my project and the Korean situation had cooled enough so I thought I could afford to go into astronomy without making it look like I wasnít needed at Sandia or something, it keep clearance- because thatís what I wanted to be thought, to live out my life at Sandia making bombs. So then the decision was made and I got back with Shapley to proceed, form a company- Purcell, at that time, said he was not going to, I had to work with the Astronomy department- and that it would cost $15,000, take about six to nine months. Iíd form a company. Iíd need a $1,000 to capitalize the company so I borrowed that from a guy by the name of Knight, who was an MIT graduate and was also an Amherst graduate- an old buddy of mine. And Geoff Knight, who did a thesis on [quadripolar?] moments at Tech, put up $1,000. So we didnít waste time figuring out what we would call it, we called it Ewen-Knight. Heíd go back and do his thing because he wasnít in radio astronomy, he was in having a lot more money available instantly than I did. And two years later, I paid him back his $1,000 but retained his name as Ewen-Knight, which is spelled with a K. Thatís why we spelled dae, dae, because we didnít spell Knight right. In other words, Harlow Shapleyís best statement, he said, "When you meet Doc Ewen, youíll find out heís keeping everybody in dark about Knight." Yeah, thatís Harlow. And so, we formed a company and located it at 698 Massachusetts Avenue, which is right at Central Avenue, in a furniture store, second floor, short term lease, build it and get out.

Sullivan

That was going to be it?

Ewen

That was going to be it. Didnít hire any full time people, just moonlight Harvard, MIT fellows at night, the best technicians they had, mostly pulling fellows out of the lab down on [?] Street, the Instrumentation Lab.

Sullivan

The Instrumentation Lab.

Ewen

Right, thatís where I got most of the shop stuff. So we go to work at 6 oíclock at night. Weíd work until 3 in the morning and, then Iíd go back to work, sort of red-eyed, which is kind of the way we do it now with the troops.

Sullivan

But let me ask though. Undoubtedly you could have had a position at the Observatory yourself, if you wanted it? Obviously you chose to go this route.

Ewen

I did. That was one of Bokís- I failed to mention it. At that meeting, Bok insisted that not only would we implement this engineering wise, as Purcell suggested, but that additionally I would join the staff and teach the engineering...

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Modified on Tuesday, 16-Dec-2014 15:52:54 EST by Ellen Bouton, Archivist (Questions or feedback)