Notice: We are in the process of migrating Oral History Interview metadata to this new version of our website.
During this migration, the following fields associated with interviews may be incomplete: Institutions, Additional Persons, and Subjects. Our Browse Subjects feature is also affected by this migration.
Please contact [email protected] with any feedback.
This transcript may not be quoted, reproduced or redistributed in whole or in part by any means except with the written permission of the American Institute of Physics.
This transcript is based on a tape-recorded interview deposited at the Center for History of Physics of the American Institute of Physics. The AIP's interviews have generally been transcribed from tape, edited by the interviewer for clarity, and then further edited by the interviewee. If this interview is important to you, you should consult earlier versions of the transcript or listen to the original tape. For many interviews, the AIP retains substantial files with further information about the interviewee and the interview itself. Please contact us for information about accessing these materials.
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. Disclaimer: This transcript was scanned from a typescript, introducing occasional spelling errors. The original typescript is available.
In footnotes or endnotes please cite AIP interviews like this:
Interview of Edward Ney by David DeVorkin on 1984 February 29, Niels Bohr Library & Archives, American Institute of Physics, College Park, MD USA, www.aip.org/history-programs/niels-bohr-library/oral-histories/28322
For multiple citations, "AIP" is the preferred abbreviation for the location.
After discussing his upbringing, undergraduate education in physics at the University of Minnesota, and postgraduate education and work at the University of Virginia during World War II, Ney describes returning to Minnesota in 1946 and his contributions in the cloud chambers field for the balloon research then being conducted with Jean Piccard and others. He then reviews relations with the Rochester group conducting similar experiments, reasons for using balloons instead of rockets, involvement in the Orbiting Satellite observatory program, and training the Mercury and Gemini astronauts. Ney concludes by discussing his move to the area of infrared astronomy, relations with infrared astronomers, work in Australia in 1962 with Brown and Twiss, and overall thoughts of the military's balloon program in the early 1950s.
I am very glad that you are able to talk with me for awhile on short notice like this. Could we start by finding out where you were born, what the names of your father and mother were, their occupations, and what your family was like?
I was actually born in Minneapolis because I was Caesarean; but I grew up down in Iowa, called Waukou, Iowa. So my early years were spent in a small Iowa town.
You said your birth was Caesarean; that's why your mother had to come here for the medical?
Yes, right, to Minneapolis.
So, formally, I was born in Minneapolis, but I really grew up in Waukou, Iowa. My father was a salesman. My mother was a housewife who had infantile paralysis, so she did the things other people do, but with considerable difficulty. I came to the University of Minnesota in 1938, after graduating from high school in this town of about 2,000 population.
Let me ask you two quick questions: First of all, were you the first in your family to go to college, and was that something very new for your family? And second of all, were you interested in science before you came to college?
Yes, I was. I was really interested in chemistry, because I happened to find some books I could read on chemistry in this small town. And I was challenged to do science because (chuckles) the principal of the high school said nobody in Waukou had ever been a successful scientist, and I wouldn't be, either.
That is a good way to get started.
What about going to college? Were you first in your family?
Well, I was the first and only son. Going to college was not something that was done, I would say, by more than three or four out of 50 in my high school class — a different kind of life than now. My sister also went to college, but at Luther College in Decorah, Iowa. Fortunately for me, very soon after I started to college, I realized that chemical engineering wasn't for me and changed to physics. And I was lucky enough to get a job working for Al Nier in his lab.
What was it that brought you away from chemical engineering to physics? Can you recall?
I think I was just more challenged by the courses. By the time I was a sophomore there hadn't been any real courses in chemical engineering, which wasn't fair to that discipline. But physics certainly seemed to me to be more fundamental than the other courses I was taking in electrical engineering.
Did you like the mathematics part of it?
I liked the back of the envelope kind of stuff more than the math, and I realized that there was a better use of math in physics than in engineering studies at that time. I guess it is not so true now.
What was it that interested you most about physics? Was there something particular happening about that time? I know that nuclear physics was really making some tremendous discoveries about that time.
Well, in my mind the four outstanding people at Minnesota were Jack Tate; John Bardeen (who subsequently left and got a couple of Nobel Prizes); John Williams (in nuclear physics); and Al Nier (in mass spectroscopy). I actually got to work with Nier at a young age, and I felt I learned a lot and owe him a lot for teaching me early how to approach problems in physics.
How did that happen? How did you get to work with him?
Well, I just asked him one day if I could play with an oscilloscope, because he had used one in demonstrations. He said: "Sure, come down to the lab." I did, and subsequently was one of three undergraduates who helped him on his various activities. These included: separating carbon isotopes in a thermal diffusion column; the age of the earth (which was done mostly by Nier himself, and by Bob Thompson who was a year ahead of me in school); and separating uranium 235 with a small mass spectrometer that we ran most of the summer of 1940. We separated five micrograms of uranium 235. This was used to confirm and get more details on the slow neutron fission produced in uranium 235, which had been previously shown in a much smaller sample that Nier collected himself the year before.
So we are talking about 1940?
Right, because it was 1942 that I graduated from Minnesota and went to Virginia to work with Jesse Beams and Leland Snoddy.
Who was the second name?
Leland Snoddy. We worked on the centrifuge method for separating uranium isotopes.
Was this part of the Manhattan project? Were you officially involved?
Well, it wasn't the Manhattan Project then. Al Nier left to go to New York to work in the Kellex Corporation, which I guess was officially part of the Manhattan Project.
At that time, while I was at Virginia, I also was a consultant to the Naval Research Lab and worked with Phil Abelson, who developed another method for separating uranium isotopes. NRL had a pilot plant ultimately in the Philadelphia Navy Yard. So I ultimately spent about a quarter of my time going to Abelson's activity, and the rest at Virginia.
Was that at the University of Virginia, where Jesse Beams was?
During this time — certainly these were the war years — I would imagine that you saw your activity as war-related. Were you engaged in any other kinds of research, or did you have any plans for the future?
Yes, I did start to do some cosmic ray research towards the end of the time I got my Ph.D. from Virginia, which was in 1946. At that time they asked me to stay on with the staff, which I did. We began doing some underground experiments with counter telescopes in a cavern — in endless caverns — near Newmarket, Virginia. I had just barely got started on that when I had the opportunity to come back to Minnesota and join Frank Oppenheimer and Ed Lofgren in their balloon experiments.
Let me ask about the cosmic ray work of Virginia: this was putting counters underground, so you were looking for a very different type of particle. What were you looking for exactly?
We were actually doing what came to be standard stuff in those days — looking at the absorption of mu mesons in matter — it was just there was a cave handy and available. I also had one of Scott Forbush's ion chambers, which we ran in the cavern. But the records from that were never over a long enough period of time to be useful.
Your interest clearly was in particle physics at that point?
Now, you left Virginia in '46 to come back to the University of Minnesota?
Yes. In 1946 I came here to teach a summer school class and got involved with Frank Oppenheimer and Ed Lofgren, who were building up a balloon project in Minnesota.
They were the ones who started that?
They were the ones who started it. Joe Weinberg also came at that same time. I shared an office with Joe originally when I came here. Charlie Crichfield, whom I had known in the East, was also on the faculty, and I think maybe even was an associate professor at that time.
Was Piccard here yet?
Jean Piccard was definitely here. It was just after the time that Piccard had built a cellophane balloon with his students, and launched it from Memorial Stadium, to show that you could reach high altitudes with plastic balloons. His concept was that he would make a cluster of these things and fly himself to high altitude. It never came to pass.
What do you know about the origins of that? It's always been fascinating to me that General Mills had a research group here that provided the balloons and was so actively involved in that. Do you know who started that — did Piccard start that? And do you know when, possibly?
I'm not sure of the exact details, but I think the General Mills interest was because of an employee they had, Otto Winzen, who himself was very committed to the idea of making plastic balloons for any purpose — science or manned flight. He was a balloonist, and he was the one that drove the effort at General Mills. Subsequently, of course, when General Mills did lose their interest in it, Raven Industries in Sioux Falls, South Dakota, formed out of a number of the people that were in the General Mills group. Also Otto and Vera Winzen started their own company — Winzen Industries — which is still a balloon manufacturing company today, as is Raven.
Do you know if Frank Oppenheimer or Ed Lofgren had any contact with Piccard or with Winzen in deciding to do balloon research?
I doubt it. I think that Jack Tate found out about Piccard's interest and decided that it would be good to start a group in Minnesota, trying to use the balloons for scientific purposes — Piccard was more of a balloon flyer, not so much of a scientist. Nier told me that the department first tried to get an outstanding cosmic ray guy with a reputation — actually Tom Johnson (did the east-west effect and got the wrong answer) — but he finally decided not to come. As a consequence, they hired Frank and Ed and me instead of one real professor.
You all came pretty much at the same time?
They came almost an academic year before I did.
How did you feel about coming back here? Did you look at it as home?
Well, yes primarily because of my connection with Al Nier; but our work was a separate thing. I didn't see Nier that much in those days, because we were primarily concerned with making cloud chambers which would work at high altitudes under extreme conditions.
Okay, this is something I would like to straighten out. I know that your group here generally used plate stacks and cloud chambers. I thought it was broken up and that you were in the plate stack group more than the cloud chamber group. Is that right?
Not really. Ed and I worked almost entirely on the cloud chambers. In fact, I did work with Phyllis Freier in the emulsion business.
She lead the emulsion?
She really was the person that was primarily in emulsions, along with Bernard Peters and Helmut Bradt at the University of Rochester. In that connection the cloud chambers played an important secondary role, in that when we discovered heavy nuclei, the statistics were all in the photographic emulsions. Some of the emulsions were in the stack above the cloud chamber, and the others were in the stack below. The cloud chamber had four or five lead plates which almost completely absorbed the heavy nuclei so that the stack below didn't show any while the stack above did. So you wouldn't have needed a cloud chamber for that. But even so, a lot of people like Blackett believed that cloud chambers were the way to see elementary particles. At the time Powell and Lattes and those guys thought the emulsions were equally good. I believe the emulsions probably contributed many, many times as much physics — as much information — as the cloud chambers did. But the cloud chambers showed heavy nuclei in a way that the cloud chamber people were used to seeing.
Isn't it ironic, though, that you were using Illford plates which are British and yet the British people weren't using the plates themselves? Is that a correct statement?
No, I don't think so. I think the British always used Illford. The decay was seen in Illford C2 plates.
Were those the earlier plates?
Yes. Eastman Kodak was making some photographic emulsions dedicated to nuclear physics, but the Illford ones had had much more testing. They finally showed minimum ionization tracks first. We did fly some Eastman plates, too; but the Illford at that time were the best emulsions.
Let me ask you to back up to that famous 1948 project which all of you were involved in, where you found the first hard evidence of heavy nuclei among protons; and if I can, maybe to even back up a little further than that. Had you been aware of problems in cosmic ray physics and of these issues before you came back to Minneapolis? Were you aware of them in Virginia?
Only in a casual way. I think our point of view was that we wanted to get cloud chambers and emulsions to a high altitude, where whatever was there as primary particles could be seen. We all felt that probably the primary particles were protons, with an admixture of electrons. And I, at least, didn't have any feeling that there would be heavier nuclei in the beam. That is kind of stupid, because it is obvious that, if they are a sample of some part of the universe, then they should have some sort of representation of the composition.
Were you interested in them primarily, though, as probes of nuclear structure?
No. We always wrote proposals that said things like "looking for the nature of the nuclear force" and all that junk, but that was just because people bought that sort of thing. We were really interested in phenomenological cosmic rays: the east-west effect, latitude effect, composition.
So the geophysics as well?
Could you reconstruct all of the major steps that led up to the 1948 flight, including: how the group was put together, who was responsible for what, when the flight actually was, and how the data was reduced, and how you felt when you first realized that you had a heavy particle event there?
Well, I'm not sure I could detail everything.
What stands out in your mind that would be important to me?
One thing that stands out was that we weren't the first people to get emulsions at a high altitude. The Brookhaven group was. They had priority for an earlier flight; but they didn't recognize heavy nuclei in their plates until after we had found them.
The flight was one in which the cloud chamber probably had the highest priority. I'm not sure that cloud chamber worked. The emulsions were above and below the cloud chamber, so they used the absorbing power of the lead in the cloud chamber. Half of the emulsions were ours, and half of the emulsions were Bradt's and Peters'. I think independently and almost exactly at the same time, we (primarily Phyllis, and Bradt and Peters) realized that you could follow these tracks through large numbers of plates. In those days the plates were backed with glass, so that when a heavy nucleus went through one emulsion, there was a large gap before you found it in the next one. There were several things that we felt had to be shown if the particles really were primaries. One is that if they were nuclei, they should have nuclear interactions. We scanned something like 3 mean-free paths before we found nuclear interaction. That's three sigma.
Who found the track?
I think Phyllis found the first interaction.
She was doing her own scanning?
Yes. What we finally did in the emulsion work was to try to put the nuclei in classes by ionization. To do that we had to establish something about the range of the particles, because the ionization was simply Z2/B2 (beta) times a constant, a logarithm, and if beta approaches 1, then you can see the Z2 dependence of the particles. But you have to establish in a given case that the range of the particle is long enough so that it will be near the speed of light or set a limit on the speed. So in the emulsion work we were trying to get the charge distribution of carbon nuclei and Z greater than 10 (neon). In the cloud chamber we tried to develop a better ration of alpha particles to protons, because you couldn't see protons at minimum ionization in the C2 emulsions in the early flights. So they complimented each other pretty well. The cloud chamber made it possible to see that the proton to alpha ratio was like we believed it should be in astrophysical matter, 10 to 1, or so. Then the heavy nuclei was relatively less abundant, like carbon nitrogen and oxygen down by a factor of 100 from protons. So the emulsions were better for the heavier particles and the cloud chamber was useful for the lightest nuclei. In fact, I must say that the most convincing thing to me was seeing a quarter of an inch lead plate with a heavily ionizing particle on both sides of it in a cloud chamber.
That record came through on that flight?
I believe it was that flight. If it wasn't, it was one of the very early ones. I think it is one of the pictures in the first paper that we published. A theorist (I won't say who it was) told us that they were just fission fragments. But to have fission fragments with a range of a quarter inch of lead is pretty far out. In fact, I believe that the Brookhaven people, who knew more about fission fragments by far than we did, interpreted the tracks they saw as fission fragments and didn't try to follow on into further emulsions.
Was that a typical thing then for a lab physicist to do?
No. I think normally ranges of particles with the energy of machines in those days, with glass backed plates, would not produce particles which could be followed from one to another. One of the exciting things about primary heavy nuclei was that their ranges were quite large when you got up to 80-90,000 feet. When you go down as low as 60,000 feet or so at the Pftozen-Maximum you hardly saw any, but when you saw them in their glory as they come into the atmosphere, they have long ranges. I started to say that the three things we knew we had to prove were: that they were nuclei that interacted with nuclei; that they ionized like highly charged stripped particles; and that when they slowed down, they finally acted like nuclei in that they captured electrons and finally ended up as atoms. So the end of such a heavy particle track is a kind of a taper where, as the particle reaches the velocity corresponding to the atomic velocity of an electron, it captures an electron. So Z is reduced until it finally becomes neutral; you see a taper track.
How was the work broken up among a good number of members? Did you think of yourselves as a team, as a working group? Did different people have specific responsibilities?
Yes, pretty much. Phyllis was more or less in charge of the emulsion work; and we — although I think, I probably did more than Ed and Frank — would all look a bit at the emulsions. Frank, Ed and I were concerned with the cloud chambers and the balloons, because even though we didn't have direct control over the balloons at that time, they weren't a very reliable delivery system.
These were the new plastic balloons, Skyhook?
Right. The first Skyhook was flown for an experiment by Vern Suomi at the University of Wisconsin in a meteorological experiment. When the balloon took off his equipment hit the ground and it quit working. That's typical. Many balloons would break a ceiling. A lot of them would suck air, so they wouldn't get to ceiling. Then it was difficult to organize a way of retrieving the equipment after flight. We used to hang a radio on and follow it with automobiles and beachcraft airplanes supplied by the Navy.
Let me at this point still ask you a little more about the dynamics of the group, and about the rationale. First of all, was the group pretty smooth running? Did everybody know their place, or was there any friction within the group that is worth talking about?
Not really. Ultimately, some friction developed between the Rochester group and ours. I think everybody saw that this was a good thing. Originally we started publishing together, but very soon after that we worked separately. There was no internal friction in our own crew, I think.
Why did the Rochester and the Minnesota groups come together in the first place?
Well, that's complicated, and I probably don't know how to answer that. Bernard Peters was a protégé of Robert Oppenheimer. Bernard and Frank had a long-standing friendship, so that since we had the packages to fly and the capability of getting them on the balloons, they came out and added their photographic stuff to our balloon gondolas. They were then, of course, able to take advantage of all the stuff we had developed for recovering packages and measuring time altitude curves and all that. Now it is trivial, but in those days it was important, of course, to know that you were really at a high altitude for a certain length of time.
That's right. Could you also amplify that marvelous statement you made about what your true interests were within the group? When I mentioned nuclear processes you stated that it was easier to get money let's say, from ONR if you were interested in nuclear processes. Was this in terms of what appears now at least to be the obvious applications to weaponry, to ordnance and that sort of thing? How did people here feel about that?
I guess it isn't fair to say that everybody's interests were phenomenological cosmic rays. Mine were. It was obvious, when you started looking at heavy nuclei and interactions in emulsions that there were some very high energy events that you wouldn't ever be able to reproduce on the ground. So, for example, John Naugle's Ph.D. thesis was on high energy interactions of heavy nuclei. And Phyllis spent a good deal of time looking at the morphology of the kinds of interactions that heavy nuclei make with nuclei in emulsion, which, in the last few years, has gotten to be a big thing with the machines at Berkeley. Accelerating very heavy nuclei and looking at the same things that we looked at in 1947. Nobody was very interested in that aspect of it then.
You were still looking at particles that were at energies far beyond what the bevatron could produce at that time?
When did that change? When did the ground-based bevatrons or high energy accelerators match cosmic ray energies?
The bevatron didn't exist at that time, because that was when Ed Lofgren left here to go to California to build the bevatron. Ernest Lawrence got him away from here, so that Ed was the shortest lived member of the group. But we had interactions many, many times more energetic than any data produced with the bevatron after it was built but I wouldn't be able to give a date of when this changed.
I know that it is in that book that I showed you. There is one whole chapter on that. Of course, cosmic ray meetings were exciting, because there were people like Rochester who were studying V particles.
V particles is what they were called then. Now, they are just a member of a large group of unstable nucleonic decaying particles — hadronic decaying particles. At the meetings would be people interested in both things. Jim Van Allen was always sort of a morphological cosmic ray guy, not interested in nuclear physics at all; whereas, Peter Fowler at Bristol would be equally interested in the nuclear physics aspect and the phenomenology of the cosmic rays. Scott Forbush was completely phenomenological cosmic ray, while Blackett was interested in the nuclear physics aspect, as was Powell's group, Lattes and Fowler.
What about Neher and Phyllis Freier?
Neher was very much interested in phenomenological cosmic rays, and I think he was completely uninterested in using cosmic rays for high energy nuclear physics.
Was there a major accelerator here?
There was a Van de Graff.
There is a man who came to your group in the early '50s, — Gilbert Perlow, who worked with Ernst Krause at NRL in the V-2 cosmic ray experiments that they did. What were your relationships with the NRL group doing cosmic ray work, or with Van Allen, during the earliest period (1946 to 1950)?
Gil Perlow came here quite a bit after the cosmic ray heavy particle period.
Yes, he came in '52.
Charlie Critchfield got him to come, because we had gotten our balloon study funded, to find out about the physics of balloons, and to try to improve the reliability of balloons. Gil came to help us work on that.
So he didn't come to do cosmic ray physics?
Not primarily. In fact, I don't think he did any cosmic ray physics at that time. He was here earlier than that when I took a lab course from him, Modern Experimental Physics, where he encouraged me to measure the zenith angle dependence of cosmic ray intensity, which is cosine squared. That was when I was a student back in the ‘38 to ‘40 period. Gil was here then as a visiting professor or an assistant professor. He told me at that time that cosmic rays was the field where if you just got into it and learned about it, you could be the biggest expert in the world.
That's very interesting. I haven't had a chance to meet or talk with him. I heard he was down at Oak Ridge. Do you know where he is?
He's at Argonne now. He was one of these pioneers in the Mossbauer Effect. He's one of the best experimentalists I know. After Ed left and after Frank lost his job because of this communist McCarthy Committee stuff, Jack Winckler came, who had made a latitude survey at high altitude. He used the Norton Sound as the vessel to launch balloons from, and produced the first high altitude and latitude survey in that.
Wasn't Van Allen doing similar things with his Rockoons?
That was afterwards. The rockoons came quite a bit later. I couldn't give an exact date. Winckler's latitude survey was long before that, and Van only flew rockoons from Fort Churchill. It's a little hard to hang a rocket on a balloon out of Minneapolis. Although after he tried it — after he showed you could do it — I ordered some Mickey Mouse rockets and Minnie Mouse, or some damn thing, from the ONR. They were out on the loading platform, and somebody in the administration building saw that there was a package out there marked "Dangerous." They discovered that they were rockets, and now they are buried out at Rosemont. I suppose they are still there! (laughs)
You never flew them?
Did you, or anyone in the group, have any early interest in doing cosmic ray work from rockets, and from the V-2s in particular? Did anyone ever, like the NRL or APL people, offer your group a berth on a V-2? Did anyone here ever request to work on a V-2 or on an Aerobee during the early years?
I don't believe so; certainly I didn't. The only thing that we got exposed from rockets was a package that John Naugle attached to an Atlas Missile, which didn't even go into orbit; it was suborbital.
That was a launch. Those were in the mid-50s.
We were quite good friends at that time with Herb Friedman and Van. We had a friendly competition going, I think, on studying such things as solar cosmic rays. They would try to do it from rockets. We would use balloons to try to measure solar injected cosmic rays shortly after solar flares. We had a kind of monitoring program going where we could run out and launch a balloon as soon as we heard there was polar cap absorption going on due to particles arriving. We got some extremely heavily exposed plates, which left no doubt that the sun was injecting particles at times in enough intensity to be dangerous to astronauts.
Was this prior to Sputnik? This was in the '50s, or even earlier?
It was during the '50s that we started the balloon project, during IGY, really, 25 years ago.
Yes, that's right.
IGY was 18 months. In fact, the first day of IGY Winckler discovered x-rays from aurorae. He wasn't looking for them. He was flying the standard flight. He and one of the students went out looking, and every time they would see an increase in the aurora in counting rate. At that the time it wasn't obvious that the aurora had in it electrons of high enough energy to make x-rays, which would reach down to balloon altitudes.
Yes. I'm interested in getting your recollections of the worth of the V-2 cosmic ray work prior to IGY. So, did you know and were you aware of what the NRL and the APL people were interested in doing?
Did you think it was a good thing? Or did you feel balloons were a better way to go?
I, at least at that time thought balloons were a better way to go. Gil Perlow was, I think, at NRL at the time and flew a little cloud chamber on a rocket.
I believe, looking back over it, that he identified at least on primary alpha particle in those exposures. But the thing about cosmic rays is that it takes so long to get a decent exposure that the balloons under a finite amount of atmosphere could beat the hell out of the rockets. Even though the rockets were above all the observing matter, the main thing was to get area and time. The rockets just didn't have it. The rockets were terribly useful for extending the cosmic ray altitude, for example. Van Allen showed that if you extend the cosmic ray rate which we see at the top of the atmosphere to very, very high latitudes — yet still before the radiation belt — then you just see the cosmic ray intensity constant for a long period of time.
So you are talking about the plateau?
I think that the rockets in their primitive state were, however, ideal for some kinds of experiments, which Herb Friedman and Dick Tousey were very expert at doing. Highly absorbed radiation that we would never see at balloon altitudes was one of the best results. The understanding of x and shorter wavelength radiation, which came from the NRL work, was probably the most outstanding contribution, in my opinion. Balloons could produce so much better statistics than rockets, that I didn't feel attracted to rockets at that time. In fact, I never was.
Yes. Were you ever asked to participate in the rocket panel, the UARRP, as it was later called?
No, I don't think so. I was a member of the cosmic ray panel for IGY. I don't believe, for that period, any of us or the Rochester group got involved in the V-2s.
Unless Winckler did. I know from correspondence I've heard about, that Marcel Shein of Chicago was very skeptical of the use of the rockets. This caused Van Allen, Perlow and others, when they wrote review papers, to defend the use of rockets somewhat. I also know there was always a constant competition for money and that sort of a thing. But I realize that the rocketry was moving so fast, that it possibly was hard for outside groups to participate, too. I would love to have your sense of that. Did you know of other groups that would have liked to have participated, but for one reason or another couldn't? Or did you know of any stronger negative feelings about rockets?
I think it was a matter of a limited number of opportunities. The people who were close to the rocket program, like Herb Friedman, had a great advantage over anybody else trying to get in the business. The balloons have always been a vehicle which gave you a chance to develop equipment with high reliability. You could put things on a balloon that wouldn't survive high g but would not freeze and keep working for long periods of time. I don't believe that there were people trying to get in on the act. There just wasn't that much opportunity. People were doing the thing they thought they could do best. I didn't feel any competitive business. I probably should have, because Van did so well with his Explorer I. But in those days we were all sort of equal. We tried to understand cosmic rays, and some people tried to understand high energy physics, using cosmic rays. Rockets and balloons were equal opportunities. But until you got satellites up, rockets weren't nearly as attractive as balloons. You couldn't, for example, monitor heavy nuclei to see what sort of solar flares they were associated with, and what kinds of configurations in the solar system were required in order for particles to reach the earth. The early data on solar accelerated high energy particles almost all came from balloons just because we could get them up fast, or keep them up for a long time.
Waiting for a flare.
Rockets contributed nothing to that phenomenology, until satellites made a bad case for the balloons, because they were up all the time (laughs)!
What satellites projects have you been involved in?
I've been involved in two unmanned satellite projects using OSO, the Orbiting Solar Observatory satellite. I worked for two years with early astronauts, getting pictures above the earth's atmosphere of the zodiacal light and the airglow, and atmospheric phenomena.
You mentioned they were John Young and …?
Well, all of the early ones, except for Glenn.
Why except for Glenn?
He just happened to have gotten out of it. Glenn was out of the flying astronaut mode by the time I got into it. Carpenter, in fact, was the earliest one that I worked with.
You had to train them to do the observations you wanted to be done?
Yes. To know what star fields we wanted, how to use the cameras to photograph the things we wanted to see. So we would take them down to the Morehead Planetarium in Chapel Hill, North Carolina and show them in the planetarium what we wanted them to do.
Yes. How trainable were they? How agreeable were they as research assistants?
Well, they looked on space as an engineering and jet pilot business. They did the science because they were told to do it. All the early guys, with the possible exception of Pete Conrad, were really test pilots. I don't know Glenn, so I can't say about him. But of all those other guys, of which I probably met 80%, Conrad was the only one that I saw that had a real interest in science.
Hmm. That's very interesting. We're going to be celebrating the 21st anniversary of Apollo 11 in July, and we have invited a number of Apollo era astronauts to speak about "the astronaut as scientist." Pete Conrad was the first one to accept! (laugh) I wonder why that is? If he was more amenable than the others?
He was more of an intellectual than any any of the others, by quite a good deal, with the possible exception of Mike Collins.
Harrison Schmitt was?
Well, Harrison Schmitt was sort of after my time, again, so I couldn't say.
You are talking about the original Mercury astronauts, pretty much?
Right, and the second group.
The Gemini people?
Yes. I never had much to do with Apollo, but I saw Mercury and Gemini guys.
How did you get onto OSOs? What OSOs did you fly on? Did you simply answer an RFP, or did you have any closer connections with the Goddard group?
Well, in those days there weren't RFPs. I think John Naugle started that RFP stuff (chuckles). When we got on the OSOs, there just weren't that many people that wanted to do the experiment. In fact, we had done the astronaut stuff on dim light phenomena. We had some ideas about what to do to study zodiacal light from an orbiting spacecraft. The concept of OSO was well developed so we just applied for one of those individual sectors on the wheel. And I believe that on the first OSO, at least, they weren't even all filled up. The equipment was all built downstairs.
Here in the physics building?
Yes. Quality control and all that garbage was nonexistent.
Did you talk or work directly with John Lindsay?
Yes, John Lindsay was surely the father of the OSO concept. He was the guy whose drive made it go. But our equipment worked on both of these OSOs. I forget, the number of the OSOs was complicated.
Yes, because one blew up. Another one died in orbit because of star fish and that kind of thing.
Yes. We weren't on either of those. We were on what would have been OSO E and OSO F.
Not OSO I?
No. In fact, I have an OSO package.
What is it, an artifact?
The Ney Ball.
The Ney Ball, University of Minnesota Zodiacal Light Experiment. It's a beautiful little plaque with a red bloodshot eye. Then you have some zodiacal figures on there. This is a telescope unit. It's got a plug here, I guess, and then some potted electronics in it. Is this the device?
I think that was a prototype exactly like the one that flew.
Let's see, what is this?
That's where the photomultiplier and telescope went.
It went in the hole in the center?
Right. There's a picture of it out in the hall. You can look at it and see what the geometry was. But this is the real thing.
I'm sitting here holding this, which is a laboratory prototype that you have right here. I assume that you are not going to let this out of your sight. If ever you find you have to, however, we would certainly like to know that it is properly presented. It's beautiful.
You notice the generation of the electronics —. It could be considered primitive today?
Oh yes. That's the torus of copper windings there?
That's the fly back oscillator that makes the high voltage supply for the photomultiplier, which took a voltage divider over there. I'd forgotten how primitive it actually does look.
How long did it take you to design and build?
Less than a year; about six months.
Things have changed. What about this second plaque?
That was the plaque that went on the second one.
Ney Ball 2. Dark light, University of Minnesota, OSO-F.
In the Space Science Center they have one display which has the cameras that we built which the astronauts used. It also has, I think, one of these complete outfits.
Marvelous. Is that an aluminum or magnesium …?
It's magnesium obviously, it's so terrible.
You mean that greenish corrosion?
The corrosion was always green. Aluminum won't corrode like that.
As long as there is no beryllium in it to worry about.
So there is one of these at the center.
That's just marvelous. I want to make sure it's going to remain safe with you, however. You're not going to chuck that out someday, I hope?
No, I don't think so. It's small enough. All the old balloon stuff and the cloud chambers and all that, I think, are long gone, though.
Yes. I was going to ask you about early artifacts, especially about the original plates. You said they are all gone?
No, the plates aren't. Phyllis has got all of those filed away. I don't know whether the emulsion is still stuck on them.
I hope so. Those are gelatin-free nuclear emulsions. Maybe they don't last for very long?
No, I think they probably last as long as emulsions last. I haven't looked at any of the early ones.
Let me ask: in addition to artifacts, have you kept all of your correspondence and project files from back in the '40s?
Phyllis has done a better job than I have.
I see you have green folders there?
These are all notebooks. They are chronological, and they cover certain lengths of time. But none of them go back to the really exciting times.
See, those look like 1969. By the really exciting times, do you mean back in the '40s?
Well, some of the exciting times are in those, because when Nick Woolf was here we discovered the silicate business in super giant stars, and comets. But I don't have any of the original stuff. I would be hard pressed to find a picture of Frank Oppenheimer, I think.
But Phyllis has records, of course, of all the emulsions. And they are in good shape.
Let me also ask: What caused you to migrate from cosmic ray into infrared and other areas?
Well, to be honest, you would have to say it is more like random walking. Every 10 years or so I got so I wanted to do something different. The first real change when we were trying to decide where the electrons were in the cosmic rays — we knew that the electron flux was way down. We wanted to try to find out where the electrons were coming from, and where they were. That led us to try to look for synchrotron radiation in the solar corona to see if there were any electrons being accelerated that we could detect with an eclipse experiment. And that turned out to be wrong. The emission of light by the solar corona is all scattered sunlight; Thompson scattering by free electrons. There is no synchrotron component, which we had hoped to see. In the course of doing that experiment we got interested in the zodiacal cloud. That is what led us to the astronauts.
That's a marvelous story. But could the dust, there, lead you into infrared as well?
Not really. That was more a change of plan because it seemed that the kinds of things a physicist could do that might be useful in astronomy.
Is that a decision you made yourself?
Yes. Frank Low had already done some successful infrared astronomy when we got into that game.
Was this his lear jet bolometer?
Prior to the lear jet. It was ground-based stuff, the 28-inch and the 21-inch telescopes on Mount Lemon. How did I get into that? Well, I've always had an interest in atmospheric physics. I had a graduate student who did a Ph.D. thesis on the infrared radiation of the atmosphere, so I knew a little bit about infrared. It seemed like one of the new frontiers in astronomy, to get into. We built a telescope — we got a 30-inch telescope — not knowing whether we would be able to build detectors and dewars. We knew Frank Low had done it, though, and the biggest secret is always whether you can do it or not (chuckles).
That's an interesting statement.
True of the bomb, too.
Oh sure. But what is your philosophy of doing science? Do you want to strike out on new paths where no one else has built a machine? Or do you feel more comfortable exploiting something that somebody else has really broken?
The new areas always appeal to me, because they are more of a challenge. Maybe, in this case, you did know you could do it. But maybe not well enough. The only competition was Frank Low and Gerry Neugebauer at Caltech. And Gerry didn't have very good detectors and dewars. He had a lot of telescope aperture. Frank had really good detectors but limited telescopes.
Why didn't they get together?
Business is competitive. And Gerry had good graduate students. I remember Frank saying at one time that he would trade him a dewar for a graduate student! (laugh together)
Yes. It was a challenge. The telescope was small by current standards, very small. The stuff that Frank and Gerry and we did when Nick Woolf was here, starting about '68, is what made it clear that infrared had so many new things in it that it would be easy to get support to build that telescope in Mauna Kea. The Wyoming people with their infrared telescopes were all students of ours. A student is more valuable than a dewar.
That's a great statement! We saw an early attempt to make a helium dewar for an Aerobee flight that Martin Harwit had produced. They finally had to go back to nitrogen. The design of this original dewar wouldn't hold the helium because it was not critically enough done. But that design of dewars seemed to be a really demanding problem. Did you get into that yourself?
Yes, very much. We spent almost two years on dewars and detectors (mostly on dewars). I must say that, of the people who spent a lot of time with small helium dewars, I think I may be the only one who hasn't blown one up. Frank has blown one up. George Rieke has blown one up. Even Bob Goerz has blown one up. Liquid helium below the lambda point is like dynamite sort of, in the sense that if the neck of the dewar freezes up, and if the helium builds up pressure, it will blow out the dewar and expand by a factor of 700.
Were you in contact with Martin Harwit when he was trying to design it?
Yes. Well, that's competition again. I never really did talk with Martin very much. (This is off the record.) I didn't have that much respect for him. I thought Frank Low and Gary Neugebauer were really the soul of infrared astronomy as it started. And I was wrong, because Harwit has done some quite good things. But he does them in a different way. Instead of going out and trying to find out just what's there, he thinks up what lines he might like to see, and then designs a piece of equipment to look for those. He finally succeeded with the ionized carbon shells with the Kuiper airplane observatory.
Yes. Did you follow his early apparent detection of an infrared sky background; the cosmological problem?
I was interested in that problem, but I didn't know that Martin had really done anything on it.
Well, the story as I understand it was that he thought he found it. But it wasn't what it was supposed to be, because it was completely off the black body curve for the 3° background. Did you follow that in the literature?
No. But I was interested in the general subject. When I went to Australia in 1962 to work with Hanbury-Brown and Richard Twiss on the intensity interferometer, Fred Foyle was there, too, and we developed a friendship that was very strong. I was flying balloons myself to try to take pictures of the zodiacal light from the Southern Hemisphere; I had balloon cameras which were attached underneath the balloon and rotated to take panoramic views of the sky. Fred said to me one time then: "That's all interesting solar system stuff, but it's not real science." He says (chuckles): "If there really is any leftover stuff — if there was a big bang and anything left over — then you ought to be looking at longer wavelengths." And I kind of chuckled; that was before Penzias Wilson did actually do it a couple of years later.
That's very interesting.
But there, I apparently was not using the right equipment: it's a radio problem. It would have been exciting to try to figure out how to do it. It's interesting, also, that Fred at that time still believed in the steady state.
This is the early '60s?
Yes, 1962. He still was thinking of all the options. I think he did believe at that time that helium was the problem. So the big bang which produces the helium was in his mind. In thinking about nature, he wasn't as narrow minded as people thought he was about steady state cosmology, and as he appears to be now about the origins of intelligent life from space.
Wichramasinghe? I've been following that a little bit. I'm really fascinated with something that seems to be a pattern in your life. You seem to be a technical problem solver. You went down to help Hanbury-Brown and Twiss with the technology of their intensity interferometer; did you actually build it, or what?
Well, that's not really the reason I went. It happened to be what I did. I went because I thought there was something fundamental about this stuck-together photon business. I thought it was fundamental physics.
Stuck-together photon business?
Well, that's the way the intensity interferometer works. It works because if the photons are within a coherence length they will be stuck together; because Bosons will stick together. If they were Fermions they would repel each other. If you just split a beam of light into two beams and take the square root of N, look at correlations. When they are photons, you will get more than you should. If they are Fermions, you get fewer. At that time people, including Dick Feynman, were not so sure that this was an absolute consequence of quantum mechanics. But it is. So I went down because I thought maybe there was some fundamental physics involved.
I say I went down to get my merit badge in astronomy. But I got down and found out that there wasn't anybody down there that knew any astronomy; certainly not Hanbury-Brown.
Yes. Was that a transition for you then? You went down to give yourself a chance to, as you thought, get some active training in astronomy?
Yes, and to see whether there was some experiment that you could do that was fundamental, which depended on this Hanbury-Brown Twiss effect. Nowadays it isn't obvious that there was a controversy. Janossy was a big cosmic ray guy who got it wrong.
Janossy was one of the people who were trying to prove that there was no Hanbury-Brown Twiss effect. He just didn't know what to calculate. And there were many others that thought it was unreasonable that you should get more coincidences than just the statistical number. So partly it is trying to get into a new field. We were invited to the Pontifical Academy meeting that year on cosmic rays and interplanetary space. I talked about what we found out about solar protons; solar particles. I have never done any cosmic ray work since that time.
When was that meeting?
That must have been a real transition for you.
Yes. Then in Australia, I essentially just marked time while doing engineering on the interferometer, of course, and flying these little balloons. It was when I came back, then, that I was looking around for something to do. Infrared seemed like a good thing to try.
What contact did you have with (Willem) Luyten?
As little as he could arrange. Luyten felt that physicists had no business getting involved in astronomy. He's a Dutch "Herr Professor" type. The contacts I had with him, unfortunately, have not been too good. I'm sorry about it because I certainly respect the work he's done. He would do things like locking up the astronomy library so the physicists wouldn't get in there and learn astronomy.
He locked it up?
Yes, and we couldn't get in the library. I guess the time my stick was really broken up with him was when I got the dean to say he had to let us have the key to the astronomy library. He really hasn't spoken to me since.
Amazing. That's really too bad.
Well, there are a few people in astronomy like that.
Well, I always thought that Luyten, from what I've heard, fits that description. But he seemed to be an extreme example.
He's a current legend, if there ever was one. He must have a sense of humor, though. I remember we had a cosmic ray data center here. Bill Weber was in charge of it, and he had a great big poster on his door that said: Cosmic Ray Data Center A: Knock then enter." Then a typed card appeared on Luyten's door, which was up the hall from Weber, which said: "Data Center of the Universe: Don't knock, just get the hell away"!
(laugh) Yes, that must be a sense of humor, all right! Is there any part of your experience in the early balloon period that you think is important for me to understand or know about when I come to writing up that period that we haven't discussed? Something that would put it into proper perspective vis-a-vis the cosmic ray work that was done on rockets?
In terms of cosmic ray work in general and atmospheric physics, too, with balloons, everybody knows about NCAR. NCAR is sort of a consequence of this balloon project that we had in Minnesota, which was originally classified and supported by the three services.
Which balloon project was this?
No, you never heard about it. Winckler and I decided that the balloons were so unreliable at one point — this was after the easy stuff, like finding heavy nuclei ions and particles — that we would really have to have a scientific engineering project to understand how balloons work, and make them better. That was called the Minnesota Balloon Project. Charlie Critchfield was the director of this thing. And Charlie Critchfield got Gil Perlow to come. I'm looking at a final report which I'll lend you overnight.
But it's the only copy we still have left. It tells what kinds of things we did. There was a period in there from '51 to '55 when we didn't publish anything, because we were writing classified documents.
Okay. This is "Final Progress Report, Volume 16, Research and Development in the Field of High Altitude Plastic Balloons." "Sponsored jointly by the Army, Navy and Air Force under contract ONOR-710 (01) with the Office of Naval Research, December 15, 1951 to August 31, 1956. Prepared by the Department of Physics, University of Minnesota; Minneapolis Minnesota." So you have an NACA Standard Atmosphere Nomogram here?
It was originally a classified document, downgraded to unclassified? And you've got some nice photographs.
Yes. It's a summary of the things we worked out on this project that we considered fundamental, like the natural shape that balloons have, and how you build them so they don't get circumferential stress. It was really engineering. The reason I now know — and probably knew then — was that the Air Force wanted to get pictures to spy on Russia. It was before satellites and so the Air Force support came because they wanted to use whatever we learned to build balloon systems that they could fly across Russia. And they did. They used these airplanes that recover parachutes over Japan — they'd knock the payloads off the balloons and catch them. Then Gary Powers. In fact, there is a picture in the newspaper of Khrushchev that I wish I still had holding one of these balloon packages, thus recognizing them. Gary Powers was shot down shortly after that, and he was much better — propaganda.
He was a better thing for Khruschev to hold.
This document includes such things as the Minnesota launching method, and some very interesting cartoons. That's a marvelous thing. What I would like to do is Xerox this thing as well.
We can do some of this here.
Yes, it shouldn't travel.
Yes. This is our only copy.
Great. Well, we're at a good place to stop right now. So I thank you very much for this.