Interview with Professor Charles H. Townes by Joanna Rose, science writer, 7 December 2001.
Professor Townes discusses the development of masers, how success grew out of
failure (1:38), and the moment of the discovery (3:20). He explains why from time to time he
changes his field (9:22) – Townes is now doing astronomy – and also talks about his interest in languages and music (13:24), and how religion and science can converge (14:09).
Welcome to Stockholm and to the Nobel interview Professor Charles Townes.
Charles H. Townes: Thank you.
I would like to ask you about lasers that you are the inventor of and also that you got your Nobel Prize in, masers and lasers, you got your Nobel Prize for, I would say that the whole generation of people today were not even born when you did this invention and discovery, but how did you start thinking about masers?
Charles H. Townes: I was especially interested in trying to generate some short wavelengths to do spectroscopy, in other words the study of molecules and atoms. It was basic science I was interested in, I wasn’t worried about applications and so on, and so I tried very hard to find new ways of producing radiation, particularly radiation as small as a fraction of a millimetre, I wanted to get to shorter wavelengths. We could already get to wavelengths down to about three millimetres, centimetres and millimetres and so on, but I wanted to get to a fraction of a millimetre, so I worked at it very hard, I tried a lot of different … I tried several different ways and they didn’t work terribly well until I had the right idea finally.
Why did you need those shorter wavelengths? What was the need for the shorter wavelengths?
Charles H. Townes: I wanted those shorter wavelengths in order to do science, because we didn’t have those shorter wavelengths and I wanted to study molecules in particular, the structure of molecules and the structure of atoms and the characteristic of nuclei and so on within the molecules, that’s what I wanted.
And when you did your PhD you wanted to stay at the university but as I understand you were forced to leave and go to industry, to Bell Laboratories.
Charles H. Townes: Yes, I got my PhD at a time when there were very few jobs, the Great Depression before World War II and there were very few jobs in the universities, and I couldn’t find the right job but I was offered a job at Bell Laboratories so somewhat reluctantly I went into industry you see. But it turned out to be a great thing for me because I learned a lot, I learned a lot and even, then the war was coming along and I was … had to start doing engineering, engineering and radar systems, which wasn’t something I wanted to do particularly, I wanted to do new science. But in fact I learned a great deal from it and the maser really grew out of that.
So you were allowed to do basic science in the war?
Charles H. Townes: I was lucky in a way! It was a failure you see, a failure to get the right job, I had to take this job, but then I learned a lot from it and then that frequently happens, success grew out of failure. But Bell Lab was a good place, it was really a very good place.
Because you were also allowed to do some research that you were interested in?
Charles H. Townes: I was allowed to do some at first but then the war came along and I had to do completely engineering, but I learned a lot from it and there were a lot of intelligent people there, so the interaction was very important.
Do you remember the moment of this discovery of maser?
Charles H. Townes: I certainly do.
Yes, can you tell us about it.
Charles H. Townes: I certainly do, it was quite a moment. I had been working very hard and thinking of different ways, some ways of producing short waves, and I’d even been made a chairman of the department for the … chairman of a committee rather … for the country to try to examine how to produce short waves, and our committee travelled around and looked at what people were trying to do and so on, and we just didn’t come up with any good ideas, so we would have our last meeting in Washington DC and just before that last meeting I woke up early in the morning because I was worried about that we hadn’t been able to do anything.
I went out, I sat in the park, a beautiful day, and the flowers were blooming and it was sunny and I sat on the bench and now why haven’t we been able to do this, and I went through all the possibilities we had thought of, you see, and I had thought of, things I had tried and this didn’t work and this didn’t work very well, why can’t we do it now. Well, I thought, you know, if we could get radiation from molecules, molecules can produce very short wavelengths but how can we do that … Ah, wait a minute, wait a minute … I thought, yeah this is the way to do it. Oh yes, we can do it from molecules. We get molecules in the right kind of state and that can happen. Ah, and it was exciting.
It was exciting and I went back to my hotel room and I was in the same hotel room with Arthur [Schawlow] who was a post doc with me at the time, and I told him about it, he said Oh well, yeah, that sounds alright. Then I went back to Colombia and after a little while I got a student to work on it and we eventually made it work.
What did your colleagues say about your idea?
Charles H. Townes: It’s interesting, you see, many new ideas people won’t believe!
And they didn’t?
Charles H. Townes: When things are really new then it’s frequent with people going No, I don’t think that would work, but I started working on it with a student for his PhD thesis, we had worked on it for a couple of years and two of my very famous colleagues came in, one of them already had a Nobel Prize and he had been chairman of the department, the other was going to get a Nobel Prize later, and he was chairman at that time, and they came in my office and they said Charlie that’s not going to work, that’s not going to work, you’re really wasting the university’s money and you really have to stop.
Well, I was an associate professor then, and that means that they could not fire me, I had what we call tenure, they couldn’t fire me, even though the chairman of the department … I said No, I think it has a reasonable chance of working. Well, they walked out of my room angry and ah, that’s crazy. In about three months we had it working and one of them even then apologised to me, said Well, I guess you know more about what you’re doing than I do! But that’s not uncommon, a new idea that seems different and so on, other people in the field, if they didn’t think of it, they didn’t think it was likely to work.
So how did you manage they would say to be angry instead to be discouraged?
Charles H. Townes: Well, that’s part of science. If you’re going to do something original, you have to be prepared to differ with people. It’s very important to be able to differ with people. You listen to people, listen to other people’s ideas carefully, and examine your own ideas, to be sure you’re not wrong, you see, and let them criticise and thing about it, be sure you’re not wrong, but you’ve got to make your own decisions. If you’re going to do anything original then you carefully make your own decisions.
Could you ever imagine what will become of both masers and then lasers especially?
Charles H. Townes: I knew that masers and lasers would be important and I could see some applications for them, but I couldn’t possibly foresee all the applications, many of the things in fields that I weren’t familiar with for example. I wrote a paper with a doctor, a doctor wanted to see what lasers might do for medicine, and so we wrote a paper about it in the early days shortly after laser was invented, but I had never heard of a detached retina in the eye, and he didn’t mention it to me, so that was not one of the things we put down in this paper as a possibility you see.
But that was one of the first important applications in medicine to reattach detached retina, and I’m so pleased when people tell me their eyes have been cured that way. I realised it would be good in communications, but I didn’t think it would go on fibre optics, I didn’t think about fibre optics, I knew it would be very god for communication but fibre optics …
In what way? Communication …
Charles H. Townes: Communication just for transfer of information. Just telephones and information, computer information and so on, because it has a very wide band which you can put an enormous amount of information on one light beam. One light beam can carry all the information that is transmitted in the world on one light beam, in principle. But I realised that, I knew it would be of some importance, but I didn’t know it would be as important as it is.
It’s an enormous business now, enormous business, in a wide variety of applications. Of course my primary interest at the time was in science and laser had been very, very important for science in many, actually there are about ten or more Nobel Laureates who have used the laser in order to do their science for which they were awarded a Nobel Prize by now.
And you are still doing science and actually using lasers in astronomy?
Charles H. Townes: Yes, that’s right. I’m doing astronomy now. I frequently, I’ve changed my fields from time to time whenever a field becomes very popular and a lot of people doing it I think well, they don’t need me any more, I’d rather do something that’s being missed. I like to do things that I think are being missed and, so I’ve gone into astronomy particularly in infrared astronomy, which was not a well developed field, and now I’m trying to get a microscope on the sky in infrared wavelengths using two telescopes that are separated, now I have three telescopes, and for detection we use lasers for detection and then we also use lasers to control the telescopes very accurately. To do this for telescopes have to be very, very stationary, very accurately controlled, and lasers can do that, so lasers have made that work practical.
And you are looking at the black holes in the centre of the galaxy for example?
Charles H. Townes: Yes, that’s one thing I did, I looked for black holes in the centre of the galaxy and we discovered a black hole, it’s about three million times as heavy as the sun, a black hole in the centre of our own galaxy. But right now I’m looking at stars and watching their behaviour. We can see them in so much detail, we can see a lot of things that the stars are doing and all along see them change with time.
If we come back to the Nobel Prize, you share the prize with two Russian colleagues and I wondered did you have any contacts with Russians during this time, it was in the fifties, the Cold War was on.
Charles H. Townes: We had some contact but not a lot during the Cold War. Towards a lot of a part of that time I did make a number of trips to Russia after I got the Nobel Prize, and we tried to make contact, but I had, of course we read Russian scientific journals but I met these two Russians in a meeting in England.
You read Russian scientific journals in Russian?
Charles H. Townes: I studied Russian and I knew some Russian, but the Russian journals were frequently translated into English. So, we could read them in English too. But I met these two Russians at a meeting in England, an international meeting, on spectroscopy and microwave spectroscopy and so on, and they were there, and they gave a talk about the possibility of a maser. They hadn’t yet made one, but we’d already made one and apparently they didn’t realise it! And we had a good discussion, it was very … and particularly just walking on the streets we could talk, they couldn’t talk when other people were around very much, they had to be careful because it was a restriction by the Russian government I guess, but as we walked along the streets we could talk very freely and I’d had a very good time discussing the situation with them. That was the first time I met them.
When was it?
Charles H. Townes: This must have been, let’s see, it would have been 1961.
Charles H. Townes: Yeah. We had just made the first maser.
And then did you continue to have contacts with them?
Charles H. Townes: I continued to work, we continued to correspond, and we would send each other scientific papers, yes. So, the International communication in science is very important. Talking with other scientists is very important because you get ideas and trade ideas and help each other, and they didn’t have anything at that time which was new, later they had a new idea that made an improved maser for example, and discussion within international science and scientists is very, a very useful thing, and with colleagues back in your own university too.
So that’s why you studied French, German, Italian, Spanish and Russian?
Charles H. Townes: Yes, I studied languages. I like languages and so I’ve studied languages and I thought it was important to know Russian because very few people in the United States did know Russian and we were in contact with them. But I enjoy languages.
I see, and you’re also enjoying music?
Charles H. Townes: Yes, that’s right, I’ve studied some voice and studied some music and I like to try many things.
Are you still active in music?
Charles H. Townes: No, I’m not singing any more now. I think my voice has gotten a little rusty.
Okay. I have one final question. I have read in your biography that religion was a part of your upbringing, and I’m curious to hear about your thoughts about on the ways in which scientific and religious thinking can converge?
Charles H. Townes: Yes, well I am religiously oriented and I think it’s important, and furthermore I think science and religion will converge in the long run because both are trying to understand our universe. Science is trying to understand how our universe works, religion is basically trying to understand the purpose of the universe, the purpose and how it works must be related, and furthermore we really use all of our human talents to understand both of them. We have to make assumptions in science, they make assumptions or faith in religion and so on, and we use our religion, intuition and so on. So in the long run if we understand both well enough they are bound to converge.
They’ll come together I think.
Do you see any conflicts still, were they do not converge?
Charles H. Townes: Well, there are inconsistencies presently, there are certainly inconsistencies that we don’t understand, but even within science there are inconsistencies. We see inconsistencies within science, for example gravitational theory and quantum mechanics are not consistent with each other. But we know both are very good, and so we use them, we hope we’ll found out their inconsistencies, and so I think there’s the same thing with religion and science. There are inconsistencies, but we have to accept that, we don’t understand everything, but we hope we’ll understand it later.
This is really fascinating. Thank you very much for taking this time for the interview, thank you.
Charles H. Townes: Thank you.
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