Interview with Gennady W. Potapenko on 21 August 1975
Description
Creator
Rights
Type
Interviewer
Interviewee
Location
Original Format of Digital Item
Duration
Interview Date
Interview Topics
Notes
The interview listed below was either transcribed as part of Sullivan's research for his book, Cosmic Noise: A History of Early Radio Astronomy (Cambridge University Press, 2009) or was transcribed in the NRAO Archives by Sierra Smith in 2012-2013. The transcription may have been read and edited for clarity by Sullivan, and may have also been read and edited by the interviewee. Any notes added in the reading/editing process by Sullivan, the interviewee, or others who read the transcript have been included in brackets. If the interview was transcribed for Sullivan, the original typescript of the interview is available in the NRAO Archives. Sullivan's notes about each interview are available on the individual interviewee's Web page. During processing, full names of institutions and people were added in brackets and if especially long the interview was split into parts reflecting the sides of the original audio cassette tapes. We are grateful for the 2011 Herbert C. Pollock Award from Dudley Observatory which funded digitization of the original cassette tapes, and for a 2012 grant from American Institute of Physics, Center for the History of Physics, which funded the work of posting these interviews to the Web.
In preparing Sullivan interviews for Web publication, the NRAO/AUI Archives has made a concerted effort to obtain release forms from interviewees or from their heirs or next of kin. In the case of this interview, we have been unable to find anyone to sign a release. In accordance with our open access policy, we are posting the interview. If you suspect alleged copyright infringement on our site, please email archivist@nrao.edu. Upon request, we will remove material from public view while we address a rights issue. Please contact us if you are able to supply any contact information for Potapenko's heirs/next of kin.
Please bear in mind that: 1) This material is a transcript of the spoken word rather than a literary product; 2) An interview must be read with the awareness that different people's memories about an event will often differ, and that memories can change with time for many reasons including subsequent experiences, interactions with others, and one's feelings about an event.
Series
Unit
Transcription
Transcribed for Sullivan by Bonnie Jacobs.
Sullivan
Ok, this is talking with Dr. Potapenko at his home in Pasadena on 21 August 1975. Can you tell me a little bit about your background before you did this radio astronomy experiment?
Potapenko
Well, let me tell you first that I came from Moscow, Russia, 45 years ago about. And then I was doing some research on short waves.
Sullivan
About what time was this?
Potapenko
About 1930. And I remember I measured some radiation which I could not explain and which was from certain direction over the time or about certain direction. And then we started studying it with Don [Donald F.] Folland. Don Folland was my student, very able boy which studied those noises.
Sullivan
This is in 1930 now?
Potapenko
1930. And more and more, next year and next year, there are several years I don't remember how many, but several years that was, and then finally we started being a special type of receivers to receive the noises. Then I made some photo-pictures of equipment and some curves of the observations.
Sullivan
Right, and you sent me one of those...
Potapenko
And I sent that to you. So that's about all.
Sullivan
But, in the middle of this [Karl] Jansky did his work, and did you know about Jansky's work?
Potapenko
I did not know before I started receiving those noises but certainly I learned about them and later reported at Caltech about them.
Sullivan
And so, was your main motivation to try to confirm what Jansky had first of all?
Potapenko
No, just to, I was not in doubt about his work but to confirm that what those noises are.
Sullivan
Extent perhaps?
Potapenko
The extent, maybe.
Sullivan
So, can you tell me a little bit about exactly what you built, what sort of equipment?
Potapenko
I built a frame for a rhombic, you know...
Sullivan
A rhombic?
Potapenko
A rhombic, or I think that it was a rhombic, not a square. I made several dishes of this type and repeated this noise around or near the frequency corresponding to 12 meters, where it...
End of Tape 38B
Sullivan Tape 39A
Sullivan
So you were saying it was at 12 meters wavelength?
Potapenko
Yes, about, giving better results. And then we built several similar receivers and then finally an antenna, one wire antenna. The picture of which I did send to you. And we did some measurements using that antenna, and then Folland, that was summer. And Folland went home, then he did summer measurements.
Sullivan
In Utah?
Potapenko
In Utah.
Sullivan
Now, were the receivers that you built, was there anything special about them, were they extremely high sensitivity?
Potapenko
No, nothing. They were sensitive alright, but not especially high sensitivity.
Sullivan
And also, you did some work on it at an ocean beach site, it looked like from the picture- some of it was in the Mojave Desert, right?
Potapenko
Yes.
Sullivan
And some of it was by the ocean, was it not?
Potapenko
Yes, by the ocean...
Sullivan
Where was that?
Potapenko
That is Balboa. No, I don't remember. It was Caltech’s station, oceanographic station.
Sullivan
What kind of station?
Potapenko
Oceanographic. And we made some measurements there but nothing, I did it just to be sure that our waves go around...
Sullivan
It just wasn't a function of some particular location?
Potapenko
Yes. So we found out that they go around.
Sullivan
But you had two different kinds of antennas also, you had the circular antenna which was in the picture by the ocean, as well as the mast antenna with the long wire.
Potapenko
Yes, in the desert.
Sullivan
Why did you have these two kinds?
Potapenko
One just, the other one was straight wire. One antenna was more sensitive because it was larger.
Sullivan
And, how many days total of observations did you take roughly?
Potapenko
Oh, several days, not much...
Sullivan
Just a several days, but not months or...
Potapenko
Yes, because after that I stopped to design new antenna and Mr. Porter, whose name you know, helped me in that, in designing the antenna, and I did show it to Dr. [Robert Andrews] Millikan.
Sullivan
Now, I want to ask you about this new antenna. He helped you with the mechanical engineering side of it, I guess, or the structural engineering?
Potapenko
Yes from the beginning.
Sullivan
Right, and you knew how you wanted, what kind of antenna you wanted to have. What kind of antenna was it?
Potapenko
All one wire.
Sullivan
All one wire?
Potapenko
One wire.
Sullivan
I see, and how did the wire go, can you?
Potapenko
Yes, the antenna was straight pole, and from one pole to the ground was antenna. That's all. And the man was rotating, going around with it and talking the antenna with him.
Sullivan
I see, so it was the same kind as the kind you had in the Mojave Desert?
Potapenko
Yes, that was Mojave Desert.
Sullivan
Oh right but I'm asking you about the one that you designed with Porter.
Potapenko
That was for the same antenna. I mean, for the same type of antenna.
Sullivan
Oh, the same type of antenna? Right. Except, it was going to be bigger or...
Potapenko
Bigger antenna and it could accommodate loop antenna.
Sullivan
What kind?
Potapenko
Loop.
Sullivan
A lobe antenna, I see.
Potapenko
A loop!
Sullivan
Oh, a loop, I see. So you could mount a loop antenna on it?
Potapenko
Yes, could mount one wire or a loop antenna.
Sullivan
So this antenna that you and Porter designed, was it going to be pushed around by a person also or have a motor on it?
Potapenko
No, no, we wanted to accommodate that later, but to start with just using the antenna with an observer.
Sullivan
I wish I had the drawing here, but it looked more complicated to me than just a support, a single wire.
Potapenko
Yes, that's right. I said loop, wire or loop.
Sullivan
Right, but was the loop going to be above the structure...
Potapenko
Above, above.
Sullivan
Oh, I see, you had a huge rhombus above it, I see what you're saying, yes. And what was the rough dimensions of it? Oh, I see you had a man in the picture, right, so I can get an idea from that. Right...
Potapenko
Right. I don’t remember. I’d hate to make a mistake.
Sullivan
And you estimated that it was going to cost how much?
Potapenko
$1,000.
Sullivan
$1,000, which was quite a bit.
Potapenko
Yes, impossible for Caltech.
Sullivan
Right, in the middle of the Depression, right. And you tried to get the money, you said, from Millikan.
Potapenko
Yes [?] my expenditure. That would be his department.
Sullivan
And what was his reason for turning it down?
Potapenko
Too much money!
Sullivan
Too much money. He didn't think that it was important enough to?
Potapenko
No.
Sullivan
Did he know about Jansky's results at all?
Potapenko
Yes, because I gave a talk.
Sullivan
I see but still. Did you talk to the optical astronomers at all at that time?
Potapenko
I believe, [Jesse L.] Greenstein. [Sullivan: But Greenstein did not arrive at Caltech until 1948]
Sullivan
Right, he was interested in these things. He wrote a paper with [Fred L.] Whipple, in fact, in ’37 trying to explain these observations. And what did Greenstein say at the time?
Potapenko
Oh he wanted to. Ok.
Sullivan
Was he encouraging you to...
Potapenko
Yes, and he knew Porter. In fact, they worked in the same building.
Sullivan
Were there any other optical astronomers that you tried to talk to?
Potapenko
No, I don't remember, maybe, casually.
Sullivan
The reason I'm asking this is I'm trying to get some idea of the attitude of the optical astronomers towards radio astronomy in its early days...
Potapenko
Oh, they said, that is very interesting, one pulse at the same time from the same direction...
Sullivan
But it seems like most of them really didn't understand.
Potapenko
No, nobody knew it, nobody...
Sullivan
Well, they didn't even understand the nature of the measurements and so forth, because this radio engineering was so different from using the Mt. Wilson telescope.
Potapenko
Yes, certainly.
Sullivan
What about your own astronomy, did you just get a couple of books to learn astronomy for yourself or...
Potapenko
Oh, I learned astronomy when I was young. So I talked their language and read at that time.
Sullivan
But this was the only time you had a chance to do some research in astronomy.
Potapenko
Yes, or close it was.
Sullivan
Why did you not publish your results?
Potapenko
Because if Millikan says it is not important, why should I submit my paper?
Sullivan
Well, Millikan was wrong.
Potapenko
Millikan was wrong, yes.
Sullivan
And Folland, I guess, was just a graduate student who was following your lead more or less?
Potapenko
Yes. You remember that antenna, that stand for the antenna, he designed it, that in order that it from the factory.
Sullivan
The one that was by the ocean? Do you remember where that was now? The name of the site?
Potapenko
No.
Sullivan
But it's somewhere right near here?
Potapenko
Right near here...
Sullivan
Were those the only two sites that you used in this region?
Potapenko
No, I tried that in the garden belonging to Caltech.
Sullivan
Where?
Potapenko
Garden, a vegetable...
Sullivan
Oh, a garden! And, this was right on the campus?
Potapenko
No, not on the campus, on the end of Pasadena [Sullivan: Avenue].
Sullivan
And you got similar results there, also?
Potapenko
I don't remember whether they completely identical or were just similar.
Sullivan
Yes, right.
Potapenko
But that was before I went to Mojave Desert.
Sullivan
And the idea of going to the desert was to avoid interference, I assume.
Potapenko
Yes.
Sullivan
Maybe you were getting too much in the garden, do you remember that?
Potapenko
No, I got less in the garden at Caltech…
Sullivan
Really?
Potapenko
But enough to disturb me.
Sullivan
Well, I don't think of anything else to ask you now. Maybe I will later on. Ok, thank you.