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Oral History Transcript — Dr. Harold "Doc" Ewen

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Interview with Dr. Harold "Doc" Ewen
By Karl D. Stephan
At Millitech Corp., S. Deerfield, Mass.
January 28, 1998

 
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Harold "Doc" Ewen; January 28, 1998

ABSTRACT: Amherst College (1940-1942); professor of mathematics and astronomy at Amherst College (1942-1943); family background; Navy (1943-1944, 1952); discovery of the hydrogen radio emission, fate of the Ewen-Purcell horn; Harvard University Physics Department (1946-1949); interaction with Kenneth Bainbridge, Edward Mills Purcell, Norman Ramsey, Victor Weisskopf; work for the Navy on submarine detection (1952); Ewen-Knight Corporation (1952).

Transcript

Stephan:

The interview began at about 2:30 PM in Doc’s office in the northeast corner of the ground floor of Building 2 (the wall will shortly be torn down and he’ll move somewhere else, according to plan.) This is a direct transcription of the tape, edited only for clarity. I also took 7 pages of notes during the interview, which began with a question (not recorded) about Doc’s time at Amherst College. When the tape started, I had just asked Doc about a photo taken at Harvard showing him seated at his hydrogen-line setup holding a pipe.

Ewen:

… at Amherst for a year on mathematics, and Stan King, at the time, said, “If you’d just pause a minute and let me light up my pipe, because I want to talk to you about teaching here.” And he said, “And by the way, you should take up pipe smoking.” He said, “It’s extremely important. When you’re asked a question and it’s a little bit difficult to immediately grasp the important answer, you should take out your pipe,” he said, “like I’m taking this one out now, and you can find, where’d I put the tobacco well I put that in here,” stomp it just right, start it, get a little ash on it, stomp it a little bit more, and then say, “Ah, what was that question?” He said, “You’d get at least five minutes and you’ll come up with something.” That was Stan King.

Stephan:

You were teaching at Amherst College after you graduated.

Ewen:

That’s right. Well, it was a little… see, there was a war that started about then. And so Amherst in that year did something I don’t think it’s repeated since. And that was to accelerate their program.

Stephan:

So it was only a three-year degree or something?

Ewen:

Exactly. So I opted to take the summer course and the fall course in ‘42. And then in fall of ‘42, while I was still a senior and about to graduate, right at Christmas break, I was appointed to the faculty to teach math, and also of all things, astronomy, which I’d studied for one year.

Stephan:

Wow.

Ewen:

With John Hall. And John Hall, I guess, at one time recently was director of Kitt Peak. But he was called off to the Rad Lab as so many others were, and so Amherst had no choice but to appoint a senior to take over Professor…

Stephan:

So they were being just picked away.

Ewen:

Yeah. So he said, “Well, what you do…” I remember the day when Hall left. He said, “Well, this is a midyear exam that we just finished. So use your exam book as the answers and you can go ahead with the class. Just write yourself 100% on the exam and say “OK, let’s go.”

Stephan:

That was the end of the class.

Ewen:

That was it. So when the class finally did graduate the following spring, as most did, I went to my graduation as a member of the faculty, and said, “This is a new one.”

Stephan:

You were born in 1922? What’s your birthday?

Ewen:

March. March is always a good year.

Stephan:

What did your father do?

Ewen:

He was a carpetmaker, and went to Philly Tech and then came back to the Chicopee area and was a designer of carpets and rugs and all that sort of good stuff. That benefited a lot from the arrival of the PC. You would spend endless hours with paintbrushes and little graph paper.

Stephan:

Little dots and so forth?

Ewen:

Oh, yeah, all the way out, to make [inaudible] rugs.

Stephan:

So he was … a lot of attention to detail.

Ewen:

Yeah. Then he went on to, uh, he was in World War I. And he had taken a bayonet through his right shoulder. He was quite an athlete. But he came back and continued his baseball, which was his love, and pitched left-handed. And he was with the Chicopee Indians in basketball.

Stephan:

So he was quite athletic even after his injury.

Ewen:

Oh, yeah. Just stayed in with basketball and all that, the rugwork and that sort of stuff.

Stephan:

So did you live in one place pretty much the whole time?

Ewen:

Pretty much the whole time in East Springfield. I left there, let’s see, when I was about 16. 1 left that house and I went to Amherst.

Stephan:

I see, to go to Amherst College.

Ewen:

To go to Amherst College. And at that point, I never did come back and live at home, because I went from Amherst to World War II, and from World War II back to Harvard.

Stephan:

Did you have brothers or sisters?

Ewen:

One brother. He was a super machinist and draftsman. Most of my ancestry is in that arena, machinists and draftsmen. And they’re primarily in those days with Indian Motorcycle, Harley-Davidson, and the Smith and Wesson.

Stephan:

Even the Springfield Armory, you might have…

Ewen:

Springfield Armory, they spent some time in and out of there, so it’s like a peer group…

Stephan:

So your family’s been in the area.

Ewen:

Yeah, so they were all either machinists, draftsmen, and their hobbies were all the same, which was hunting. Oh, partridge, pheasant, rabbits, everything, Pelham Hills, motorcycle drivers all over the place. Hunters, fishers… [inaudible]. I was [inaudible] Model T. I remember driving those with the three pedals.

Stephan:

That’s great. So, let’s see. Were you interested in physics before you went to Amherst College? I mean, you had an interest in astronomy, did you have a hobby?

Ewen:

The interest in astronomy was really the math. The work I did there was on orbits of comets and asteroids.

Stephan:

Okay.

Ewen:

About all you need is Kepler’s Law, and there you go. And then I worked at the observatory with John Hall, which is on Snell Street. I heard recently that they moved that. It was an 18-inch refractor, and that was a pretty good-sized machine in those days for… I understand they’ve formed some sort of an amateur club, and relocated that telescope to a more appropriate place.

Stephan:

It used to be it was on a hill right behind U. Mass. [not sure this is correct — KDS]

Ewen:

It’s a Five-College thing. It was on Snell Street right near Johnson Chapel. Come down Johnson Chapel, Snell Street’s right across on 116. It was right off Pratt Field, so I’d have to bicycle down there all the time, get out the old Friden calculator. That’s the way I went through school, was with some sort of a fellowship that they dreamt up. And that was courtesy of Stan King, the president at the time.

Stephan:

So you got a fellowship to go to Amherst College?

Ewen:

Right. And the question was, you know, why do you want to go to Amherst? And I said, “Because I want to teach at Amherst. I think if you’re going to teach at Amherst, you ought to go there.”

Stephan:

So you wanted to…

Ewen:

He’d asked that question [inaudible] but he’d never had that answer. So when he hired me then, a couple of years later, he said, “Remember that day?” I said, “Yeah.” He said, “Well, it worked. You got the job!”

Stephan:

So you’re interested in teaching at that time, mathematics and so forth. So you must have done well in math at high school.

Ewen:

Right. I was a math major at high. Most of the… Well, I went to Tech High, which was on Elliott Street down there. And that, I guess, is just a hulk of emptiness right now. But it was a good school. And that, from there, was a short trip up to Amherst. Actually, what I did… there was a little stop along the way which got to be kind of exciting. Two of them, as a matter of fact. At Tech High, I received a full-tuition scholarship to Springfield College, because I was in the High Y group. [inaudible] High Y. They have a High Y thing, which is sort of a, get together once a week, talk about all the good things in life, seniors and so forth. My interests were primarily the Debating Club, the High Y club, and swimming. So a lot of that… I won a scholarship to Springfield College. So I went over there and said, “Okay, here I am, I know you fellows have gone out of your way to come up with all this money. I want to study math.” Well, they said, “How much math do you know?” Well, I’d taken first-year calculus and a few of those other things at Tech High. So I told ‘em that’s where I am. And they said, “Well, do you want to start teaching here?” (laughter). I said, “Well, gee, Pd hate to say good-bye to a four-year scholarship, but you fellows don’t teach math, and that’s it.” So I went across the street to AIC [American International College]. They had just been formed about a year prior, and the full tuition there I thought I could swing, because it was 220 bucks a term. And so I took a [jaunt?] to High Y, went to AIC. In about the middle of the first term, the English teacher at the time for freshmen had decided that she’d had it with how cold it was getting in this part of New England, and said, “Well, I’m going off to Florida. Why don’t you teach the class?”

Stephan:

Meaning you?

Ewen:

Yeah. Here I’m a freshman out of high school and I’m suddenly teaching English in my own class at AIC! “I’m through. This has gotta go.” So that’s how I went to Amherst, and caught up with them. AIC is not… The Dean at that time asked, “What’s AIC?” “American International College, it’s right…” “It’s a high school?” “No, it’s a college. I spent a whole year of my life there.” He said, “Well, well think about it, but we’ll take you on as a freshman and forget about AIC.” I said, “No way. I want to be a sophomore, and I want to get credit for that year at AIC.” So he said, “Well, that’s going to be hard,” because he wasn’t sure AIC was accredited. And so we cut a deal that if I could get the same level of grade average at Amherst in the first year I was there that I had at AIC, then he’d let me start as a sophomore. So I started out bite the bullet, sophomore, you get the grades, then we’ll agree. So I got to be a sophomore. Then I was a junior. Then that was about the time… You know, I hadn’t planned on doing all this. So I ended up commuting from Springfield and driving a Model A Ford up over the Notch all winter during that so-called sophomore year. So that’s then, let’s see, I graduated from Tech High in ‘39, entered AIC, so in ‘40, 1 was entering Amherst. And then by the time ‘41 rolls around at the end of the spring term, I had finished my commuting. So I spent one year at Amherst, which was the junior year, which was the ‘41 year over to ‘42, as a junior. And that, I ended up living at 8 Sunset Boulevard, up on the third floor, in a closet of sorts. And I understand that Robert Frost was there at one time. It wasn’t where…But this was my time because he, I had him for English. Hey, I’m tough! … So, then it was ‘42. Normally I would have graduated in ‘43, but by accelerating the class I got out in ‘42. As a result, I was only at Amherst for two and a half years. Okay.

Ewen:

Then I stayed on for a year to teach.

Stephan:

Then you joined the Navy.

Ewen:

Well, yes. And one of the reasons was, that during this process of teaching math, and then I was asked to teach meteorology, which I –- “What is meteorology?” — and found that that was because the Air Force — well, there was no Air Force at the time, Naval Air Corps and the Army, West Point, they sent a group of West Point cadets plus a whole bunch of V-5 cadets to Amherst to be trained in preparation for [inaudible]. In the process, they picked the so-called “baseball group” to go to Amherst. And I ended up then with students like Ted Williams, Pess Kogiash [?], and about three or four others that… In fact, my interest was basketball, swimming, and I’d gotten very interested when I went to Amherst in boxing. And so that had nothing in it at all for baseball. Suddenly these fellows show up, and they’re V-S cadets, and so I got to know Ted pretty well. He would have problems on occasion with some of the work, and my approach to teaching was if anyone fails to get a B, then I will spend all the time it takes to teach you what I failed to teach you to make sure you get at least a B. So I lectured usually from about 7 in the morning to 4 in the afternoon, on the regular shifts to handle both the cadets and to handle Amherst. But I was doing about 89 hour days. And then nights, I would start at 7 o’clock and go till about 11 trying to get our cadets…

Stephan:

Tutoring!

Ewen:

Tutor, you know. And I remember one time, when those air cadets… Williams came by and he said, “They locked Walker Hall.” Well, Walker Hall was one of the most beautiful buildings, in my estimation, that Amherst ever had. It was a brick building with gargoyles on it, real [?] stuff on it, just gorgeous. Some group of alumnis decided to strip that thing right down to the bottom twenty feet and turned it into the Frost Library. When you look at the Frost, you see the beginning of the base of at least three floors, with the gargoyles at the top, and that’s where I used to teach. Well, somebody’d locked the doors, and so I [said], “We’ll just have to skip it.” Well, we had an exam coming up in a couple of days, so the cadets went up there about 8 o’clock at night and took the doors off the hinges, off these huge oak doors, and [inaudible] went up to the third floor, lectured till the local police came… So if Williams didn’t get his B, then he’d take me down to the Cage, the baseball cage, and Johnny Seine [?], he was a pitcher for the Braves, but he would catch, and Williams, which I didn’t know at the time was a big deal, was a pitcher when he was in the lower leagues And he was a darn good pitcher. And Seine would say, “Look, don’t worry about it, he throws a pretty mean curve ball. But just stand there, believe it, he won’t hit you.” And Williams would wind up, you know, whi-i-i-i-ng! if you hit that professor, well, you can’t.

Stephan:

William Tell.

Ewen:

Oh, boy. So it was pretty entertaining. So I’d think twice before I’d slip him from B to C. So that was a fun old time. But as a result of getting to know these guys I decided to go on and join the Navy.

Stephan:

And that was in ‘43?

Ewen:

Well, I tried to do it actually during ‘42, but because the West Point cadets and the V-5, I was refused continuously.

Stephan:

Because they wanted you to stay there and teach?

Ewen:

Stay and teach because we’ve lost all our guys to Rad Lab, so we gotta do this, whatever. So, then, finally they said, “Okay, you can go.” I at that point had a [plan?] that I would go to pilot training, and then go off to Pensacola. Well, they said, “Fine, sure, we can do all that,” and all that stuff. Then my orders came through. I was ordered to, what the heck is the fort down on the East River, I remember a night.

Stephan:

New York City area?

Ewen:

New York City and the East River, there’s a fort. And I was protecting New York from attack on New Year’s Eve, 1943, marching on top of this building with a wooden gun!

Stephan:

‘43 or ‘44?

Ewen:

It was 43-44, there I am, marching with my wooden gun, watching for submarines in the East River. That was the fun beginning of a naval experience. From there they shipped me off to Princeton, and that’s when I learned that I was destined to become a naval tech observer, radar. So I went off to radar training.

Stephan:

Radar training at Princeton?

Ewen:

Princeton and MIT.

Stephan:

What was radar training at Princeton like?

Ewen:

It was mostly math. Most of the time we did other things, and…

Stephan:

Was there hardware involved?

Ewen:

No. There was no hardware, it was transmission-line theory, learning how to use your slide rule in a hurry, stuff like that. (I still have my slide rule, courtesy of the Navy.) Then this three months and suddenly you’re an expert, and then three months more at MIT. And at MIT, bingo. They said, “You gotta stay here and teach.” And I said, “Not me, I’ve been through that routine, I [want to join?] all those boys that are out there that are having all the fun, because I’m tired of teaching all these classes. So from there, MIT, I did finally get assigned to a squadron in Opa Locka, patrol boat squadron, torpedo bombers. So that was the first time I finally got attached…

Stephan:

So that was a plane that was for…?

Ewen:

Yeah, it’s a single-wing, single-engine, three in the crew, one with a standard [?] 50-millimeter out the back, one on the top, and a torpedo mounted directly underneath everything. Pilot up front.

Stephan:

And you went out looking for something to torpedo?

Ewen:

It just dropped on anything, with the torpedo, yes.

Stephan:

You actually saw some service.

Ewen:

Around the Caribbean. And then the word came that they actually weren’t having a war in the Caribbean, and so I was pushing the button, “Where are we gonna go?” The Pacific, the Atlantic? So I recall that all these opportunities suddenly opened up, and the one that I found most attractive, and everybody else did, was a Liberator squadron. Five squadrons had been assigned to Europe, to England. Now why the Navy would have five Liberator squadrons sitting on the ground in England was a mystery.

Stephan:

Big bombers, right?

Ewen:

Bombers, four-engine bombers, and they’re sitting right across the English Channel, and this turned out to be a deal cut between a couple of Navy types called Winston Churchill and the other, FDR And they said, “Hey, we gotta have one of our kind of air force, uh, navy, so Navy [made] Winnie and FDR happy and there are five squadrons sitting in England. Well, what we did, our job was to keep the U-boats down, and to spend most of our time chasing around out looking for them with this new gadget called radar, at night when they would surface to charge their batteries.

Stephan:

So you were out looking at radarscopes in World War II.

Ewen:

Oh, yeah, this got to be pretty serious stuff. So they would surface at night, we would try to keep them up, but Navy’s flights with Liberators were always about fifty feet off the water. So it was a pretty exciting game. A couple of our boys got the whole tail section blown off. And we had eighteen planes per squadron, five squadrons. Each squadron had one radar officer airborne, one radar officer on the ground. The ground fellow was to do the repair, the fellow in the air was to find out what the complaints were all about, pass the word on to the ground crew.

Stephan:

So which one were you?

Ewen:

I was airborne, Squadron 112.

Stephan:

So you would fly with one and then the other.

Ewen:

Well, I had eighteen planes I could fly with, so I got on the plane, I said if you want me to fly with you, I sit on the left seat, and I get flight time!

Stephan:

So you were flying.

Ewen:

So I was flying. I was flying PBM’s in the Caribbean, same argument. Radar officers were a scarce commodity. If you can find a flight radar officer, it’s like, wow. So he gets paid the normal flight pay, so you only get one per squadron, there are eighteen times three pilots, and one flight radar officer.

Stephan:

So you had kind of the picking of.

Ewen:

Oh, yeah. And I’d get my sonobuoys out there, and that was my great wireless link where I could just… The sonobuoys we were using in those days out of Hazeltine, you would drop them in the water with a parachute, microphone pops out the bottom, and then you play it back on a wire recorder.

Stephan:

So you were dropping those and then recording the signal back from them?

Ewen:

Yeah. What you do, you drop it in the water and you’re linked, it transmits directly back FM to the plane, you listen, you hear the guy’s motor. And you drop a pattern, and then you say, “Okay, given the pattern I know where this fellow’s going.”

Stephan:

So you got to use a lot of hardware.

Ewen:

Stuff that I learned about at MIT. Like sonobuoys.

Stephan:

Did you get into the details of it?

Ewen:

Yeah. It was…

Stephan:

If things broke, could you fix it?

Ewen:

In particular, both communication systems and the radars were — with the (patsu?) officer, in my time, just chatting with them, it got to be kind of a mutual effort. Occasionally I would work on it on the line as he got overloaded with other fellows.

Stephan:

The ground radar fellow.

Ewen:

So I got to be more of the superman for Stromberg-Carlson modulators, and he worried about the magnetrons and all that sort of thing.

Stephan:

So you specialized.

Ewen:

We set up, okay, we just focused on the modularity of this thing and we’ll knock it off. It worked well.

Stephan:

There was a lot of pressure to get things running and so forth.

Ewen:

Yeah, Well, that’s why I say the key was being able to talk to the patsu fellow while…

Stephan:

Patsu?

Ewen:

That’s the radar officer on the ground, maintenance for the patrol aircraft. For him, a heads-up was very critical as to what my appraisal had been flying with this particular crew. And so what I used for that was just a sonobuoy. I would just pull out the mike on the bottom that normally pops into the water and the whole thing was about yay long, about six inches in diameter, and I’d just get on the phone and talk into the sonobuoy. And he’d have one of these sitting up there, a receiver. That’s the way we chit-chatted as I came back into the field. He knew way ahead of time, I didn’t have to get on all this coded chit-chat.

Stephan:

So you had your own private way of communicating.

Ewen:

Our own communication link, which was a sonobuoy.

Stephan:

So you were making things do with what you had and so forth.

Ewen:

Well, there was one great moment there when we realized that the biggest problem we were having at that time with all five squadrons was the fact that somebody had let out the word that these sonobuoys cost one hundred dollars apiece. And in those days, that was quite a bit of change. We couldn’t get anyone to throw one overboard. So I set up a program with the skipper of 112 that I would take all of our techs out on one of these little — to show them how easy it was to throw a hundred dollars in the English Channel. So they’d just go out ten at a time, sit in the back of a Liberator and give ‘em a little speech, say, “See this? Now what you’re supposed to do is pull the antenna out, and release this catch on the bottom so the microphone will go in the water, and then the thing, when it hits the water, the parachute will drift off somewhere, and you’ll be able to tune in.” So I’d go through all of this and I’d throw one overboard, and then tune it in, and everybody could hear this on the amplifier in back, you know. And then I said, “Well, that’s not why we’re here today. We’re here today to just learn what it’s like to throw one of these over the side. So see this? I don’t pull the antenna, I don’t release the lock, I just throw it over. Gimme another one.” Then I’d just throw it out the window. “Just throw these things in the water, isn’t this fun, it’s a hundred dollars, there it goes, here’s to another taxpayer,” and I had ‘em stacked up like —. Then the pilot calls back and he says, “We’ve got a problem. You’ve been dropping this whole pattern, and we’re only a half mile off Cherbourg.” And he said, “They’re all drifting on the beach.” This is very highly classified stuff. So we come in, get everybody out to the machine guns, vroom-dddd, take the other planes and shoot these buggers down. They usually, finally there’s a little plug that dissolves and it fills water, but it’s good for an hour. And we figured these things would be on the beach before we’d get them.

So we were trying to shoot all this stuff down, and then about a week later, I had a call from one of the boys in Patson. [?] “You’re in trouble, they’ve sent a guy over here from Rad Lab, wants to know all about the sudden utilization rate, because they’re trying to figure out their production capability. “Let’s get behind these squadrons, they’re using sonobuoys like they’re going out of style!” See, nobody knew this was going on, this was just sort of a private little thing, and I’d mentioned it to the CEO, he said, “No, it sounds good.” So we were heavily depleted. They went to the CEO and said, “We got problems with MIT.” And he said, “Well, the colonel [?] knows the [report?] Nobody’s using them, they’re in the hangar. I said, “That’s not the problem. I modified all the radars that MIT sent in here, because, you know, you leave these guys alone at Tech, and they start getting fancy. And they had all these range mark things you could crank out the range marker and the PPI, you could do so much, there were so many dials and whistles, I would have spent the rest of my life trying to teach these techs what the new changes were every week. Every time another APD-5 came in, a new model designator, got all this sex in it, so I would just look up what the changes were, get inside, tear ‘em all out and make it the standard unit like we always had.

Stephan:

So you were modifying radars.

Ewen:

I was modifying radars which a violation of just about everything! (laughter) So I told the CEO, “I’m in big trouble here.” He said, “First, you gotta get some more sonobuoys over here right away.” So that was the one he was worried about. So I didn’t even have my regular supply. So I knew there was a truckload going from A to B, he told me where that was, he said, “Just go out there and get those and divert that and get them over here.” That’s all the 118 had, going somewhere. So I went out in my little jeep, stopped the truck, and told the couple of fellows, “Follow me, we’re going to 112.” [They said] “I got orders right here, and I don’t know who you are.”

Stephan:

What was your rank at the time?

Ewen:

I was a full-fledged enzyme. So I was way up above the truck driver. Your last commanding officer. So I said don’t give me any funny stuff, it could really happen, buddy. So follow. He said, “I’m going to report you.” “Fine. Go right ahead.” So we got back, be reported me, and the skipper of the 118 called my skipper and next thing I know, I’m on full report, captain’s mast, and I’m confined to quarters. They didn’t have a jail at that time. But I was ready to go to captain’s mast, they’re gonna have a court trial. Well, after a bit those two CEO’s went down to the bar down at the boat club. The word came up about three days later: “Let Doc out of the slammer.” So I got off that one. Then came the MIT guy and that was pretty exciting. Came in as one of these observers, it looks like he hopes nobody uses a 50-caliber in his range. “Well, guys, give him a quick chat, get him out of here.” So that wasn’t too bad, we just all about how we suspected they had some type submarine out there with a different pattern. “That’s great, at least, to have you fellows so interested in these things.”

Stephan:

What’s interesting to me, just looking at the details of the setup you put together, just looking at it I said to myself, “The person who put this together did not see radio equipment for the first time at Harvard.”

Ewen:

No! It was just fiddling, it was… I think the radar work helped out. Particularly how to build things when you can’t get the parts. That was very helpful.

Stephan:

Why don’t we talk a little bit about the parts of the setup? There were, in Buderi’s book, I’ve got a little chronology that unless you think there’s problems with it, I’ll leave it with you and you can tell me if there’s errors… I was interested to see how many war-surplus pieces of equipment were in your setup.

Ewen:

Very few.

Stephan:

Actually, there were two anyway. There was the local oscillator and the VHF transmitter.

Ewen:

Yes, the jammer. Part of the jammer. You’re right, that was critical. That was the most beautiful LO. That’s a free-running 3C22 lighthouse in a cavity. Warm it up for an hour, that thing would sit, if you would control the temperature in the room, you could hear an audio beat, the purest tone…I remember Weiss coming over from Lincoln Laboratories years later, had one sitting in the lab,… he borrowed it, took it out, looked at Mount Tom from somewhere, to — I don’t know how he looked over Pelham Hills, he was looking at some hill — anyway, it was the beginning of MTI, at Lincoln Lab.

Stephan:

Moving target indication?

Ewen:

This thing was so pure, and so solid, you could [inaudible — do Doppler with it?]

Stephan:

You think any of those are around, now?

Ewen:

Oh, I wish I could get my hands on one. I know where the tube is. I have the original tube out at the house.

Stephan:

Because phase noise was really not a concept that people had thought about that much. I mean it was stable or unstable, and it might almost be interesting to measure the phase noise of that thing.

Ewen:

It would be, it was just a golden tone. It was just like hitting a bell.

Stephan:

It wasn’t just the regular frequency stability of it, it was…

Parrish:

What frequency was this at?

Stephan:

1420 megahertz.

Ewen:

1420, cavity was about four and a half inches. And had big fat fins, the tube’s about yay high, and that would just shove into the cavity.

Parrish:

So you were just basically beating two of those together?

Ewen:

No. That’s what I was doing. Well, I wasn’t beating two together, I multiplied up. I would say 90% of the job for me on hydrogen, building the machine was nothing. Making sure you’re on the right frequency was everything.

Stephan:

That’s the impression I had. You had that long procedure in your thesis, in other words, particular…

Ewen:

A lot of General Radio hardware, which is stolen from Nuclear Lab. I would get that. Nuclear had all of the test equipment. They were like broadband wireless is today [at Millitech]. So I would go over there on the weekend, go over Friday, and fill up. Nuclear was where I was working with this external beam. So I knew where all the hardware was. And so I just literally put it in a wheelbarrow and drive it over to Jefferson Lab.

Parrish:

Did you work all weekend and take it back on Sunday?

Ewen:

Exactly. So the only time we could ever work hydrogen was on the weekend.

Stephan:

You weren’t married at the time?

Ewen:

No. It was really a nice setup. But you’d come in there on the weekend and you’d say, “Wow! This is golden.” You’d come in there Monday…!

Stephan:

The General Radio 620-A heterodyne frequency meter, do you remember any details about how that worked?

Ewen:

I don’t recall.

Stephan:

I have a fellow at GR who… But it was very interesting to me just how arduous it was to measure [frequency]. Now how far off was the actual signal that you eventually found from the laboratory measurement frequency?

Ewen:

150 kilohertz. And that was a big surprise. As a matter of fact, the surprise was because I knew the frequency that well, and we believed Prodell and [?] that well that I something was really, I completely overlooked the Doppler, the earth’s motion.

Stephan:

And that was the earth’s motion going around the sun?

Ewen:

That’s enough to swing it. And I remember when the light went on, it was the same night, and I called Harvard Observatory and asked some kid there, you know, who else is up at two o’clock except grad students, and asked him what the velocity of the earth was around the sun. I figured, “I’m not gonna sit here and figure out 365 days and all that jazz and astronomical units, you guys must have it at the tip of your finger.” He said, “Well, what are you doing?” I said, “Well, you know, I’m looking at interstellar hydrogen.” Bing! That phone goes on the hook.

Stephan:

He hung up on you?

Ewen:

Yeah! I’m in the physics department, I’m working on interstellar hydrogen. “Well good for you!” So much for astronomy!

Stephan:

Interesting story, the interaction between astronomy and… The fact that.

Ewen:

The diode was, of course, a product of World War II.

Stephan:

Well, a lot of things were.

Ewen:

It was a scaled-down S-band, it was right out of the book.

Stephan:

That’s great. The thing I was thinking about was the difference between the prediction and the measurement… Oh, I know what it was. In Buderi’s book you describe how initially you guys seemed a… it was two bumps.

Ewen:

Yeah, this is the thing, because we were doing switched frequency.

Stephan:

How did that come about, I wasn’t, I didn’t get the technical…

Ewen:

We didn’t initially have an adequate separation of the two frequencies.

Stephan:

What was the actual line that you were looking at shaped like? Was it kind of Gaussian?

Ewen:

Aw, it was just a mess. Because it was smeared by the fact that we had a very broad antenna beam. So…

Stephan:

You were getting stuff from all over the place.

Ewen:

All over the place. That’s why, you know, once it sort of sorted itself out, it was obvious that this machine was designed to detect something, but certainly wasn’t designed on the basis of what we learned. Initially, it was thought, I would say, probably eight to ten it was, it will not be detectable. Because there was no predictable mechanism for it to be observed. And as you review van der Hulst’s paper, it’s not really a prediction. He really says, “Wouldn’t this be nice?” Yeah, it would be nice, because then you’d have Doppler and you’d have. .. . So he was [favoring?] it and he was, and it was only because of Shklovsky saying, “This is so easy,” but he made a mistake in his math, and he had this thing at a thousand degrees! And he’s telling the Russians, “Do this! It’s so easy!” Well, he’s the one that got me excited, and I got to figuring, “I’m just gonna get blown out of the water because the Russians are going to do it first.” And I know the Dutch don’t give a damn. It was the Dutch who had been doing it and never told us! And they were working around the clock for five years. So we were just trying to do this to help out van der Hulst, he thought that this was another one of those numbers and it was buried in a paper that involves galactic, everything else. So it was…

Stephan:

It was a messy line.

Ewen:

Very messy line, but the thought, see, was initially, did a quick… well, let’s say it’s spontaneous emission. If it’s just the a-coefficient, the half-life of that bugger’s I don’t know how many million years.

Stephan:

Which means it’s very narrow.

Ewen:

So the other question is, “How do you detect something like that?” Particularly if you’re the radiometer type, you want to make a little money on bandwidth. Well, you don’t make a lot of money on bandwidth if the signal [?] is spontaneous. So then,…kicked it around for a while, I’d start to bring some of the great astronomy I’d learned at two months at Amherst, but we do have an average velocity distribution that would suggest a bandwidth of at least a kilohertz. So I said, “Okay, random motion, in space, five kilohertz. The line is five kilohertz.”

Stephan:

Okay. So that was your initial thought.

Ewen:

Where is it? Not knowing the mechanism, you can just hope it’s optically deep everywhere, and it’s right in the solar system. So you can start looking for it against the sun.

Stephan:

In absorption?

Ewen:

In absorption. Right. But that would mean you’d have to have some sort of steerable mount, unless you wanted to do it twice a year, something. So we said, “Okay, forget that. We’ll go for straight radiometric detection, and the philosophy of approach in designing the instrument will be that it’s ubiquitous, we don’t really know, [inaudible] the galaxy. However, it should be an effort that focuses on a negative thesis, in the sense that the design of the instrument must be adequate to defend a level of sensitivity so that you can at least finish off a thesis that says, “The next fellow has to jump this high.” This is not here at this level. That’s why I was so happy to have Mumford come through with the gas discharge.

Stephan:

So you knew what your noise figure was.

Ewen:

So I knew all about that machine. So I was able to start putting together [short gap between side 1 and side 2 of tape] … comment was,” Gee. Why is there so much hardware in this paper?” Well, because it’s a negative thesis. Well, ah, let’s see, what is the mechanism, we still don’t know. And then it’s all going to be known that it was certainly centered on the galactic plane. So it was part of our own Milky Way system. So that was, so a lot of surprises came up. I can remember a lot of discussions occurred after the detection with Purcell, with van der Hulst, trying to figure out what the devil is the mechanism? And it was only about three months later, at one of these afternoon seminars, that Purcell was describing some of his discussions with van der Hulst and how they were struggling with the physics of the, possibly the collision hypothesis, that Norm Ramsey and Weisskopf were sitting in the back of the room making so much noise talking to each other that finally Purcell said, “If you have something to say that you can share with us, we’d be happy to hear you.” And Ramsey says, “We think we’ve figured it out for you!” (laughter) “We’ve got it all figured.” So Weisskopf, in his usual style, says, “It’s obvious. You have two atoms approaching each other. You form a hydrogen molecule. At the moment of collision, the girl you brought to the dance is no more distinguishable than the other. And so when the collision is over, it’ll be just a quick collision, you might take the wrong partner home, and if you do...” That’s how it happened. When the molecule, it comes in with one of them antiparallel and parallel, whatever, and then they swap, and once they swap, bingo. He said, “Now, this is gonna take fifty years, but we’ve had enough time here.”

Stephan:

So they figured out while they were talking.

Ewen:

You’ll get a collision every fifty years that would be useful. And given fifteen billion years, it’s probably useful.

Stephan:

That’s great. We’re trying to get an idea of the two bumps you saw initially.

Ewen:

They were two different parts of the galaxy. Oh, no. Initially, the problem with this all along was…try to make it simple but also accommodate some reason. When you’re switching between two frequencies, then you’re looking, one of them is assigned a plus at the output, then the other a minus, so then, this one becomes what you’re passing across the spectrum. [drawing Fig. 1 on whiteboard, see notes]. The synchronous detector output will look something like this, a plus and a minus, if you were to go over one very narrow line. Okay, why are they so separated? Is it.

Ewen:

Because if I take this and I pass it over some monster line…

Stephan:

Because your IF bandwidth is narrower than the switching frequency.

Ewen:

Our first was… If we’d adhered to the Dicke philosophy of life, we should have switched the first LO. That was far too difficult in those days. So that said we’re gonna switch the second LO. So it says you don’t really have a radiometer because you’re… the mixer and preamp are in front of the switch. So we didn’t have a choice. One of those things. So the switching was done at the second LO. That’s why the preamp’s on a battery and is sitting on cotton and you inhale and exhale carefully near that, the heat settles down, that cascade was treated with such tender care.

Stephan:

Because any instability in it…

Ewen:

It was quite good. The thing about it, though, was it became part of the juggling factor because at 30 megahertz IF, and you’re trying to get something like a couple of megahertz or more of bandwidth in the IF, well, you have. You’d say, what the heck, you’re only looking at a couple of kilohertz. The shape of that line is so critical because this is now being differentiated by that second-LO switch. [Fig. 2 in notes]. So when you look at the line as detected, it looks like there’s a horrendous amount of drift. No drift at all in the machine, it’s just a question of whether you’re on this side or you catch the line on that side. So it was always jockeying the first LO to put the line as close as possible to the center so that when I scanned, I would scan right along the tip of the preamp bandpass. That was the juggling.

Stephan:

The real trick was getting the first LO in the right place to put the desired signal in the middle of your 30, okay.

Ewen:

Now you say, “Well, if you really want to detect this fellow, in that he’s broad, we gotta know what his bandwidth is. Suppose I have the situation in which, which was in fact the case, that I have a line that looks like so [Fig. 3], and I’ve got a separation like so. And I’m walking through this line. I don’t see the line. I see the derivative.

Stephan:

Just the slope, and you just won’t see it.

Ewen:

So it’s what you really want to do, you want to put a guy here, another guy here, and walk these through, and this fellow is plus and this fellow is minus, and the output is a plus followed by a minus.

Stephan:

You want the separation to be…

Ewen:

Much wider than the linewidth. [inaudible] antenna, and lines everywhere, and you can’t even get through it. That’s why you see all the screwball type things, when I get an overall line that looks something like this, the other guy climbed on top of somebody.

Stephan:

Same thing, just very messy.

Ewen:

And all I’m doing is plotting the synchronous detector output. We don’t know what’s going on out there. We don’t know at this point that it’s galactic rotation smearing the line, and the antenna is picking up everything.

Stephan:

Okay. So this clarifies things a lot.

Ewen:

So we immediately see radio astronomy, when it picks up everybody’s got a big antenna and it’s steerable. And you say, “Well, where’d they get that idea?”

Stephan:

Well, that’s great. So you suspected some of these at some point, when…

Ewen:

Oh, as soon as the thing came up and we started talking about it, you know, we said, “Oh, boy, guess what this is. If in fact we don’t have an optical depth that’s infinite or reasonable, and you can actually look through and now that you start thinking about galactic rotation, it modifies your optical depth because it dopplers out of the way. So you start looking at different parts of the galaxy.

Stephan:

So did this occur to you while you were using the 10-kilohertz or 15-kilohertz narrow bandwidth?

Ewen:

That one, no. The first one, the 10 kilohertz separation, first I used a separation of 10 kilohertz. That was — how can you get through this quick and dirty? So the way you do it is you peer in to the HRO, which is your second IF, and you see those big fat air capacitors with the tuning knobs. And you get yourself a propeller and a motor with a generator hooked to the back of the motor to drive your sync detector. And the propeller goes around, and that’s how you move it ten kilohertz. Well, it wasn’t quite enough. As far as I could tell, it was, “Hey. No line.” Well, I thought about it. If I know it’s five kilohertz, you know, due to velocity, could it possibly be ten?

Stephan:

So you saw nothing with the ten kilohertz?

Ewen:

Yeah. Then I went back to Purcell, that’s when I went for the 75, that’s when I had to buy…

Stephan:

So you had to buy a new radio?

Ewen:

The NBS-3. That was the baby. It got its full schematic in the thesis. I was impressed with that one.

Stephan:

You could work on that one.

Ewen:

Yep. That one I could go in.

Stephan:

Was the HRO borrowed?

Ewen:

Yes. That was from the nuke lab. All the General Radio gear, everything. All we had was the wood and copper and the horn.

Stephan:

The scope?

Ewen:

No, it was all borrowed from Nuclear.

Stephan:

Well, that must have made whoever paid for that happy. There’s one other thing, backtracking a little bit. From ‘46 to ‘49 you were in graduate school at Harvard.

Ewen:

Yeah.

Stephan:

And you…

Ewen:

That’s when I met Purcell, it was ‘49.

Stephan:

Oh, you met Purcell in ‘49.

Ewen:

In ‘49.

Stephan:

What were you going to do before you met Purcell?

Ewen:

Out of the Navy in the fall of ‘46. So I showed up at Harvard in my green naval aviator stuff, which drove some of the [upper crust?] crazy, I said, “Look, I haven’t been in civvies for three, I didn’t know what it was like to walk around except in one of these things.”

Stephan:

So you entered Harvard Physics?

Ewen:

I entered… That was because while I was in the Navy, I had decided with the GI Bill and all that good stuff, that what I’d do was go to Harvard Law. And failing that, probably Harvard Business School. But I was accepted at Harvard Law. And that’s just before the bomb was uncorked. And then, the head of the astronomy department at Amherst, Warren Green, got wind of the fact that I was going to go to Harvard Law, and thought that was a total waste of whatever. And he wrote me a letter that was very testy, “Don’t do that sort of thing.” And I at that time, because the bomb had been uncorked, they’d disbanded the squadron and they’d shipped me into Washington and I was with the Office of Research and Invention which became ONR, which owned NRL. So it was rubbing elbows with a lot of fellows. So I said to my CEO there, “Do you get a big thrill out of this? I notice you almost all have the DSC.”

Stephan:

Distinguished Service Cross?

Ewen:

“Died in the Swivel Chair.” (laughter) Was the way we referred to our Washington counterparts.

Stephan:

Okay.

Ewen:

That’s just the way he said it, “Okay-nnn” (laughter) These guys don’t take jokes very well. So anyway, we [inaudible] got used to living in Washington. Warren Green sent me this testy this little note… he was head of the Astronomy Department at Amherst.

Stephan:

He said you should stay in science?

Ewen:

Yeah, stay in science, all this other stuff, become an astronomer. He sent me at that time an application for an NRC [National Research Council] fellowship. I said, “Okay, keep Warren happy.” So I filled it out, dumped it in the mail, and a few months later, bang, I get an award, an NRC fellowship.

Stephan:

What did that amount to?

Ewen:

You can go anywhere you want, any university you want, anywhere in the world.

Stephan:

Wow. For how many years?

Ewen:

For whatever it takes to get your Ph. D. So I said, “Law school — you’re [invoked? –- unclear — meaning is “out”]. And I go toodling off to Harvard. I called my guy up in law school, I said, “Look, I want to go right across that green grass,” because at Harvard, the Physics Department’s about two hundred feet across from the law school. You know, I’ll take a few courses on the side to keep my hand in, but I want to go into physics. The question was, “Why would you ever want to study physics?” I said, “Hey, I was just about to go to Attu and bomb Japan, and they said, ‘We gotta find this guy Ho Chi Mirth because you can’t fly back to Attu in the fog, take your four-engine bomber, and the Navy was sending four-engine squadrons out. You take off, you bomb Japan, and you land either in Russia or in China and spend the rest of the war there. So that was the prospect.

Stephan:

Before the bomb went off.

Ewen:

Before the bomb went off. When the bomb went off they said, “Forget it, you guys don’t have to go to Attu.” So we were queued up ready to go off to Attu. So I was very happy to find out what the thing was they uncorked because it was a big deep secret, out there playing with radar. So that then seemed like, why not spend a couple of years and find out what this is all about. So that’s how I ended up in physics at Harvard. The unfortunate thing was that I bad not much of a background more than possibly one undergraduate to go on physics.

Stephan:

So did you take a lot of courses?

Ewen:

Yeah. That was the idea: cram in as many courses as you can so you suddenly know something about physics. And that was what I did between ‘46 and ‘49.

Stephan:

So you were mainly just taking courses.

Ewen:

Taking courses, finding what physics was all about. It’s kind of an interesting situation, if you had a math background and it was that time when quantum mechanics had just come out, and relativistic theory is beginning to get intertwined with all that, that it’s a lot easier to start there than to go back into classical physics. Now I was having a little problem trying to understand classical, than understanding quantum.

Stephan:

You know the mathematics…

Ewen:

Because I always looked at physics as, you know, somebody gives you some uniformity that some guy measured and the rest of it’s math for the next three months. It was kind of good fun. But I finally caught on to making the N-number large so it became classical.

Stephan:

So you worked from quantum to classical! So how’d you end up working for Norman Ramsey?

Ewen:

Norman, well, about ‘49, I’d decided… ‘48?... that an NRC Fellow is a wonderful thing except that they don’t pay you enough. And so I then decided to get a job, and I called the boys down at the National Science Foundation and said, “Okay, I’ll take a job so I can make ends meet.” Well, he said, “You cannot work and be an NRC Fellow.” So I said, “See ya.” So I gave up the fellowship in ‘48 to get a job at the nuclear lab. And that was to get the external beam. And it turned out at the nuclear lab, Bainbridge was the fellow in charge of the nuke shots at Bikini. And he also then was Purcell’s thesis advisor at Harvard. So when he came back, I got to know Ken [Bainbridge] pretty well. I wish I had a copy of that letter, I did for many many years. As a senior at Tech High, I sent Ken Bainbridge a letter at Harvard, and I asked him if he could define for me in a simple way what absolute zero was in degrees K.

Stephan:

How did you get his name?

Ewen:

A picture in a book, Wiley’s book in physics, I saw the guy’s picture in the book, I said, “Geez,” so I just wrote him a letter — tell me about it. And it was a picture of Ken standing in front of a spectrograph he had built. He was the spectrograph builder in those days. This had nothing to do with absolute zero but somebody had mentioned absolute zero and I said, “Gee, here’s a guy at Harvard, he builds machines, I’ll ask him what absolute zero is.”

Stephan:

So did you get an answer?

Ewen:

I got a brief note that was basically, “Drop by and see me.” So when I showed up there, about seven or eight years later, I went to see Ken, and gave him the letter, and said, “Here I am.” He said, “I also notice that you were in my class. So why don’t I explain it along the way… Well it turns out, since he was also Purcell’s adviser for his doctorate, it was natural to ask him who were the hot boys around I could work with, and he said, “Purcell.” Now at that time…

Stephan:

So the job with Ramsey was just…

Ewen:

He was sort of my mentor, Ken Bainbridge. He was the one I went to when I was thinking about working at the nuclear lab and giving up the fellowship. And he said, “Sure. I’ll get you the job.” And at the nuclear lab — the deal at nuclear was that Harvard gave its cyclotron to Los Alamos during the war. And in return, the Navy, through the Defense Department, whatever, funded the development of the 94-inch at Harvard after the war.

Stephan:

Okay.

Ewen:

That [brought?] on an influx of all the fellows that had come back from Los Alamos out of the woodwork, from the Manhattan Project. So I had the interesting challenge of suddenly showing up at Harvard in the grad school with all these super-physicists, all the grad students who had been out working on these machines. And 1 didn’t know how to spell hν. So that became the interesting little challenge for a couple of years. So I used to go and talk to Ken quite a bit because he was a hands-on type of guy, so he got me the job at Nuclear Lab and he said, “Purcell doesn’t work over there, he’s more of a theoretical than a hands-on guy but he’s going to stay at Cruft. So I’d suggest you work with Norm Ramsey. Ramsey’s in charge of putting the cyclotron together.” And so I met Ramsey. He said all he wanted was an external beam. “And as soon as we get this built, why don’t you build an external beam chain and get this out, because it’s not useful buzzing around chasing itself.”

Stephan:

Did you do a lot of instrumentation work in that?

Ewen:

Most of what I did on that was to build a computer which was a really Rube Goldberg effort, the last of the mechanical computers, all of the gears and things, clock making type things and cams, so that I could put in the various values of the beginning of the scattering, crank the machine, and the pen would actually draw out what the orbit would be. Because I’d done my orbit thing with astronomy, going back to doing orbits in the cyclotron.

Stephan:

[inaudible] how to build the thing.

Ewen:

I’d been thinking about this for a while from the work back at Amherst, how’d you do this without endless Friden calculations and plotting points.

Stephan:

So it was a mechanical analog computer.

Ewen:

Right, crank the thing and whee, there’s your orbit. And then building it, built the gadget that goes inside, in the channel and all that stuff. You’ll see it in all these pictures here. You look at that, that’s really what I was working on. Wasn’t working on hydrogen.

Stephan:

That was a weekend thing.

Ewen:

That was strictly a hobby on the side.

Stephan:

You weren’t really sure what, you weren’t doing Ramsey’s thing primarily to get a thesis, necessarily.

Ewen:

No, that was a job. And it was exciting because that’s where all the smarts were. All the fellows that were really exciting to be with were at the Nuclear Lab. Go over, well, Jefferson, Cruft, they had nuclear magnetic resonance.

Stephan:

That’s what Purcell got the Nobel Prize for.

Ewen:

Yeah, and they were doing things in a tin can. You know, the particle boys were across the street building the big ones. So it was two different worlds. It was very exciting.

Stephan:

Let me talk just a little bit about what you did after your Harvard time. You went back in the Navy a little bit?

Ewen:

Well, what had happened was, I was pretty sure… there was a crunch that came up, sort of toward the end of ‘50. I had worked on the machine and put it in its final form, again, the [inaudible] so I was ready to take data, but again that had to be scheduled for weekends and all this sort of thing, and I had Ramsey breathing down my neck because he wanted external beam, Because I had made the mistake of being quite convinced by the time ‘50 rolled around that this was going to be a super-negative thesis. And though I knew the machine quite well, I wanted to get very tidy of [sic] all the phenomenology and discussions of what possibly could mechanisms be that would have such a low threshold, because I was about to demonstrate that…

Stephan:

You were going to try to explain why it wasn’t there.

Ewen:

Yeah, I’m going to be writing a Sandy Weinreb mono [?] about this thick on deuterium. I’ve seen a few, [?]’s got one that’s about yay big. So I was feeling all these monsters coming down to land, and I was sort of like, “Gee, we had a great idea but it didn’t work, and so this is what I ended up doing.” So I knew I was in line for a big volume. So that to me, just sitting around the university and doing that, was like watching the grass grow. So I applied to Harvard Business School, figuring what I’d learned out of all this was that I didn’t want to be a lawyer, I wanted to be, know more of the Business School.

Stephan:

Were you thinking you’d finish the thesis?

Ewen:

Yeah, I would. I would definitely write the thesis. I’d do that the same way I’d participated in it, it’d be a weekend hobby. So I would rather get on with my life, which was never going to be science anyway, and…

Stephan:

Why wasn’t it, if you like…?

Ewen:

I don’t know (laughter). I like math and things like that, but they’re just fun things. But I thought, you know, I had to get serious, you can’t… It hadn’t occurred to me that you can have fun and be working at the same time. So, that was… just came much later. So out of this, I just sort of decided that what we’d do is go to B-school, finish the negative thesis. Might take two years.

Stephan:

By writing it up.

Ewen:

Yeah, get my MBA and my doctorate. So that I put in in the fall. And then that did get to some kind of a computer down in Washington, because that was then ‘52. I was accepted and entered the class of ‘52, no, it was ‘51. Fall of ‘51 was admitted to the Business School. And it was in that time period that the Navy got wind of this. And there was also a little motion underway called a Korean something-or-other. And because of that, they said, “Ah! Look what we’ve got here. We’ve got a guy that has two stripes now, instead of one. He’s got all this great education on how to build bombs (that’s a lot of garbage), and he’s available because the last thing you ever want to do with a guy like this is send him to a business school.”

Stephan:

And you were in the Reserves.

Ewen:

Right So I got a nice letter from the Navy: “We are going to need you for a little short additional period for this thing we call Korea. So you’ll be reporting for duty sometime in the spring.” That was all set up to occur. Like, you can see then that the pressure was on to get the line, to get the beam out for Ramsey or be shot dead in the water, take one last shot at hydrogen only to get final data as to the level below which you cannot detect it. I was almost disgusted for a minute, there, I tell you, particularly when it was a hundred and fifty kilohertz off. So out of that was, here’s sitting the Navy, not knowing I got a positive thesis overnight, you know, forty-eight pages of thesis or whatever it turned out to be, that’s too bad for the Navy because of all the stuff I had in the file, and then I’m on my way in the Navy. So that was a train I couldn’t stop. The Navy ordered me to active duty, sent me to Washington to get a Q-clearance, as they called it in those days. A Q-clearance was so they could tell you all about what atoms and molecules are all about…

Stephan:

Secret.

Ewen:

Yeah. And then you go doodling off to Los Alamos. Or at that time they wanted me to go first to Sandia. I was to go to Albuquerque. And, but to get the clearance, I had to go to Washington. What they overlooked was I’d spent my last year in Washington. Like, I knew how Washington was wired. So I just shot over to BuPers, got my jacket, sat on it, nobody could move me anywhere. I knew how to freeze that system cold!

Stephan:

So you had connections there to be able to stay there.

Ewen:

So then I … well, I was only actually on active duty for one month. I got down there, froze my jacket, wrote a proposal for the Navy on how to detect submarines using radiometric techniques, microwave radiometric techniques. And used as a reference [?] of mine. So I immediately got a contract with NRL to run back to the Boston area to get busy on this right away. And so I…

Stephan:

On an individual basis?

Ewen:

Well, see. What it was, it was my beginning of understanding how to get a job in a hurry. What you do is you write a proposal, get the contract, then you walk in and say, “I’d like to talk to you about a job. Here’s a contract. Would you like this backlog?” Fifty K in those days was, “boomp!” So I took it over to Tex Holt, who had formed a company called Scientific Specialties over in Brighton, and he was… there was another interesting thing about those years, ‘51 and 52. That was the time the Bell Lab came up with the transistor and told all the world, “If you want to build transistors, put twenty-five thousand down and you get a license and you’re in the transistor business.” And I remember the gold-mounted diode, the first one that came out from Bell Labs. So that was what was driving Tex Holt from director of nuclear research at… He had a nuclear lab…

Stephan:

Where was this?

Ewen:

At Harvard. Ramsey finished putting it all together and Tex Holt ran it. Then Tex was, between the two was another guy, oh shoot, he became president of GTE. Bumped into him a little later when we put a sixty-gigahertz radiometer up in ‘66, to get some mixers from GTE that were hard to get. Called the president, hers an old buddy of mine! That worked just fine. So anyway, that situation went about in there, was just coming up with an idea at the right time. The Navy’s always interested in finding subs. In the literature, there’s a publication that I did with a Walt Selloff called a DC comparison radiometer, which I think is probably what we need on this transconductance noise on MIMICS, which is something like… What it did was just take.

Stephan:

Where was it published? IRE?

Ewen:

Probably in the IRE, it was either IRE or Review of Scientific Instruments. It would just take a baseband, in other words, you’re building a spectrometer, just take a baseband against the narrowband filter to DC, just do a DC continuous subtraction. So that was 1952, published it, got a contract, built a few, rented a yacht, went out in Boston Harbor, threw sonobuoys in the water — how’d I know what a sonobuoy was? — listened to all this stuff, tweaked up, all the news of what was cruising around Boston Harbor.

Stephan:

So you started to look for submarines?

Ewen:

I would listen. And the big thing there was, Hazeltine built those sonobuoys, but didn’t know about how microphonic they were. And all I had to do was take their input tube, lift it up, just what I did with the preamp [of the hydrogen setup] put it on cotton, all the filaments through spring-type [?] nice and quiet, slip it back in the water, wow! You could hear all the way to England.

Stephan:

So you made it a lot quieter.

Ewen:

Oh yeah. DC comparison, just had to get rid of all the garbage up front.

Stephan:

Well, I’d like to spend more time, but I’m sure that…

Ewen:

Phase One!

Stephan:

Let me ask one or two questions about Ewen-Knight Corporation. That was to build radiometers for Harvard, was it?

Ewen:

No. Ewen-Knight, that was ‘52. What had happened with hydrogen was that, right after the detection, I had all of this flap with the Navy, and then with getting Scientific Specialties looking busy and staying out of Korea. As a result, I couldn’t stay that close to Harvard, and there was no interest at all in the astronomy department’s pursuit of 21 centimeters. As far as I was concerned, there was no point in proceeding further with what had been put together. It had been put together on the premise that it was a ubiquitous thing and it was going to be…

Stephan:

It was not really designed properly for.

Ewen:

No, no, not designed at all properly, and everyone… I had to take a lot of hits on this, they said, “Oh, you just left.” You know. Well, what can I do? The galaxy comes by twice a day, you’re pushing[?] your coffee break just so far. So it was an impossible thing. Anyway, the boys at the Department of Terrestrial Magnetism, Merle Tuve in particular and Vannevar [?] Bush. Van Bush had left Rad Lab and gone down back to the Department of Terrestrial Magnetism. And he decided to do something there about hydrogen. So he built himself a sixty-foot antenna…

Stephan:

This is Tuve?

Ewen:

This is Merle Tuve working for Van Bush.

Stephan:

Okay.

Ewen:

And he went… in Washington, D. C. they built a sixty-footer, right on their own premises, to work on hydrogen. So when I saw all of that interest in all of this, then they came up and in one of our little chats, Ed and I would get together, visiting firemen, want to come in and take a look at the machine [inaudible]… Well, I said, why don’t you just take the machine and [makes snapping noise]. You guys are going to do something with this, so go have fun with it. And it wasn’t until about two months later that they began to realize at Jefferson that the machine wasn’t there anymore. I still had [inaudible]. Because these fellows had the test equipment. I can’t get this to run half the time, after all, run over to Nuclear Lab, get the parts, check the frequency, do all this stuff.

Stephan:

So it moved to.

Ewen:

So it moved to Washington, D. C.

Stephan:

The operation did.

Ewen:

Nobody cared about the … the horn was sent out to Agassiz Station at Harvard. The mixer I had for a while and I used it as an ashtray, because it was just about the right, it would stand by itself. So that was a, and so that somehow found its way back and got married to the horn again. So I understand it’s in Green Bank. But while all of this is going on and Harvard’s showing no interest at all, then Purcell, who was of the same mind I was, it was sort of like, “It was an interesting physics experiment, it worked, wonderful, now what are we going to try?” There was no more physics there. So, other than trying to think about the mechanism, and so then, no interest at Harvard, we heard from Bart Bok, and this is late in ‘51. Bail Bok, at that point, is down in South Africa. Some station that Harvard likes to go to, particularly if you’re from the Netherlands, his ancestry goes back. So he was very upset about the fact that Harlow Shapley had done nothing about this. So he finally showed up in the late fall of ‘51, from South Africa, called a huge meeting over at the Harvard Faculty Club, and those attending were Menzel, Howard Menzel, who was the successor to Harlow Shapley about a year or so later, Harlow was there, Bail Bok was there, Fred Whipple was there, Purcell, myself, that was it. And we all, in memory of, always when you go to the Harvard Faculty Club and order something for lunch, if you don’t order horsemeat, you’re not one of the team. And so we all had horsemeat.

You can have monkey, you can have rattlesnake, and bear, but horsemeat is the preferred meat of the day for faculty members. So we, chewing on our horsemeat, the decision was, yeah, they should do something about this at Harvard. Bail gave a long speech on how important all this was to astronomy, and, you don’t want these Dutchmen knocking it off, because his professor for his doctorate was Oort. And of course Oort was the professor for van der Hulst. And so here’s the older student saying [crunching noise] “Damn the torpedoes, I’ll take van der Hulst on.” So it was Oort against van der Hulst for the [running play?] you know, let’s get the data, let’s figure out what the galaxy’s all about. So Bart sold his case, Harlow signed on, and then it went to the next round, was how do we implement this? Well, the issue was, “Why don’t we have Doc join the astronomy department, and he can teach the technology and Ban can mesmerize folks on the phenomenology?” Well, that was okay, we could do that. Next was, where do you get the telescope? Well, first, it had to be steerable, it had to have a multichannel, and it had to be a lot better than what we bad before, and [inaudible] what we’re thinking about. So we sort of sketched out the ground rules for this thing. And then the question was, “Well, what will it cost to build one of these things?” And knowing there is an escalation factor and it was a year later and the first one was five hundred bucks, I said, “Well, how about fifteen thousand?” Nice round number. Okay. Now, where are we going to get it built? I said, “Go to Cruft Lab.” Purcell then gave a speech that matched Dart’s speech. He said, “One. MIT won’t be part of this. I don’t want to get involved with those fellows. And if we let them in on this they’ll steal the whole show.”

Stephan:

That’s where the Cruft Lab is?

Ewen:

No, Cruft’s at Harvard, but what he’s concerned about is the Rad Lab is still reasonably active there, and Jerry Wiesner is his buddy down there, and Weisskopf, so all the American Academy buddies, when it comes down to cutting a piece of science out, he just, first thing is, “MIT’s out of this, don’t even talk to them.” I said, “Okay, get it built at Cruft.” He said, “Cruft? That’s Harvard engineering department Harvard doesn’t know anything about how to engineer anything. We don’t have an engineering department.” Well, I guess you could say that to Pierce and he’d turn over in his grave. Anyway, that was Purcell’s statement, Harvard doesn’t have an engineering department. He said, “They may have a galvanometer or two, but that’s about it. That’s about where Harvard is.” So, well, what are we going to do? Well, we can probably ask for some help from Raytheon. No, that would be expensive. There would be not enough control of the variables. Purcell, final statement “I got it. Doe forms a company. He builds the telescope, coordinates putting it all together, get it out to Agassiz, teaches the course, there’s no problem there because he understands what he’s built for sure, and then once it’s delivered and everything’s back and ready to go and he and Bail are teaching the course, he just dissolves the company.” So what’ll we call the company? Ewen-Knight. Where’s Knight come from? Knight’s a buddy of mine that’s got the thousand dollars you need to capitalize a company in Honda [?]. How do I get to build this thing? I gotta get the space, so Harlow Shapley’s there, I said, “I’m gonna need that check for fifteen thousand now.” He said, “Up front? Fifteen? Okay, I’ll get it to you next Monday.” So I get a check for fifteen thousand dollars from Harvard University, a thousand from my buddy to capitalize the company, and I found a furniture store in Central Square. “Central Square? You mean down there where all those people beat you up in the middle of the night? And the trolleys are still going by?” Well, the advantage was that I was strategically halfway between Harvard and MIT. So I would raid those two at night. And I says, “Half of why I’m calling it Ewen-Knight. We work only at night!” I don’t have any full-time employees. Everybody comes out and moonlights with me. So that’s what Ewen-Knight was all about.

Stephan:

So we really do have to wind up here.

Ewen:

Well, that’s how it got formed.

Stephan:

. And how long did it last?

Ewen:

Well, it was supposed to be three or four months. When we finished the machine, NRL called and said, “We gotta have one.” When I went down and [inaudible] that, the guy that accepted it was Arno Penzias, who was down there as a trainee at NRL from Bell Lab.

Stephan:

So it went into the 60’s?

Ewen:

It just kept going till about 1980.

Stephan:

And then you joined Millitech at some point.

Ewen:

‘88. In the interim, I was playing around with all the major companies.

Stephan:

Consulting kind of thing?

Ewen:

Yeah.

Stephan:

Well, this is great, Doc. I really appreciate this.

Ewen:

You didn’t even ask me what type of plywood, for that horn.

Stephan:

I’m sorry, maybe I’ll come back. What I plan to do is kind of do a first draft or something, and if you want to be co-author?

Ewen:

No

Stephan:

Okay.

Ewen:

Have fun with it.

Stephan:

I want you to look it over for errors and so forth. I want to go into more of the technical details than Buderi did, although it was a great story that Buderi wrote, I don’t want to step on his toes. But I think he helped a lot with the [inaudible] The Antennas and Propagation people will be able to…

Ewen:

Yeah. If you think of switched-frequency, you know, and plus and minus.

Stephan:

And I’ll get some copies of this [the binder he loaned me].

Ewen:

Have fun with this guy [the box with 3-D slides].

Stephan:

Thank you. Thanks, Allan, for being moral support here. [end of recording] The interview ended about 4 PM.