00:00:00 Looking at you, am I doing all right?

00:00:04 Oh yeah, you're fine. You're looking a bit here, you're looking at me.

00:00:08 It's comfortable, that's the way you talk to people. Are you comfortable with me?

00:00:12 Oh yes, yes, very comfortable. We're fine here.

00:00:16 All right, so you began attending the McMahon Committee,

00:00:20 the McMahon Committee

00:00:24 hearings, where it was being decided whether

00:00:28 atomic energy should be under civilian or military rules.

00:00:32 Yes, and at the time, as I mentioned,

00:00:36 pardon me, I'll start over again,

00:00:40 I was interested in hearing, going to these hearings

00:00:44 because I was very eager that the

00:00:48 control of the atomic bomb be taken away from the Army.

00:00:52 And of course I went there in uniform as a representative of this office,

00:00:56 so I had to figure out a function. And I decided that the way

00:01:00 I would try to participate there was by

00:01:04 transmitting all my notes that I considered to be useful

00:01:08 for the hearings to my superior officers,

00:01:12 emphasizing the fact that the situation as it was excluded

00:01:16 the Navy. And I was pressing hard on the

00:01:20 theme that the Navy should have just as much access to this

00:01:24 as the Army, and if it went the Army way, why they wouldn't.

00:01:28 I pointed out that propulsion was one of the

00:01:32 most important uses of atomic energy, and that was all Navy.

00:01:36 Well, I would give these reports every day

00:01:40 to my lieutenant commander, for whom I worked, he'd read them,

00:01:44 he'd pass them on to the captain who was in charge of the office,

00:01:48 a man named Captain Conrad, a very enlightened naval officer,

00:01:52 and Conrad read these things and he'd pass them on to the Admiral.

00:01:56 And so pretty soon, I didn't realize this

00:02:00 at first, you know, but there were a lot of people reading these reports.

00:02:04 And so that got me a certain

00:02:08 attention there. The other person who was

00:02:12 head of office naval research with a civilian counterpart to Conrad

00:02:16 was Alan T. Waterman. And between

00:02:20 Waterman and Conrad, they worked out a modus operandi

00:02:24 for the support of fundamental research in peacetime

00:02:28 with DoD money. And that became

00:02:32 the cornerstone of federal support of research, and

00:02:36 Alan T. Waterman, after a few years, became the

00:02:40 first director of National Science Foundation, and he took all these principles

00:02:44 that we'd been developing in office of naval research over

00:02:48 into the National Science Foundation. So it was

00:02:52 an exciting time to be there. Incidentally,

00:02:56 one of the themes that I began trying to sell

00:03:00 on this line that the Navy's being excluded from

00:03:04 all these activities was that

00:03:08 the Bikini Test was under plan.

00:03:12 Of course, that was the first attempt to use atomic weapons against naval

00:03:16 vessels. And I contended

00:03:20 that the Navy should have a more important role in just putting the sitting ducks

00:03:24 out there. But the Army wasn't about to let them in on anything.

00:03:28 And so I proposed a whole list of

00:03:32 possible remote detection experiments that the Navy could do and the Army couldn't

00:03:36 stop them from doing. And I suggested seismic and flying planes

00:03:40 with filters and quite a variety of things.

00:03:44 This, again, got a lot of attention. And so that brought

00:03:48 me to one of the important decision points in my life. They were sufficiently

00:03:52 impressed with all these things I'd been doing

00:03:56 that they tried to get me to stay in the Navy. And

00:04:00 the lure was that they'd send me out to Bikini to watch the test.

00:04:04 But the Bikini Test corresponded with the beginning of graduate

00:04:08 school. And I decided, no, I'm going back to graduate

00:04:12 school. And if I get out there in Bikini and this test is

00:04:16 delayed a couple months, I won't be able to start on time.

00:04:20 So I told them no.

00:04:22 Why did you want to go to graduate school?

00:04:24 Well, it just was the natural next development

00:04:28 in my professional career. As you probably

00:04:32 will understand, fundamental research was

00:04:36 a very exciting thing to me. And the locus of fundamental research was in

00:04:40 public universities. And, of course, I had the notion that among the

00:04:44 public universities, Berkeley was number one.

00:04:48 And I really wanted to be in a public university.

00:04:52 Why a public university rather than MIT?

00:04:56 Well, I felt very, very strongly

00:05:00 the fact that if there had not been

00:05:04 a public university, UCLA, at the time, I wouldn't have any

00:05:08 college education at all. And I felt I had a debt

00:05:12 to repay there. I've always felt that. I've never wanted to

00:05:16 transfer to a private institution. I always felt

00:05:20 Berkeley was the place for me.

00:05:22 Okay, so you came back to Berkeley to start your Ph.D.?

00:05:26 Right, in 1946.

00:05:30 And I went to work with Kenneth Pitzer,

00:05:34 whom I consider to be the brightest in the chemistry department at the time.

00:05:38 He was a young fellow, and recognized by Latimer

00:05:42 and all the faculty as the leader of the department.

00:05:46 And so I started to work with him, and got my Ph.D.

00:05:50 in three years in 1949, and they gave me a job

00:05:54 as an instructor then. And I've been there ever since, except for the three-year

00:05:58 interlude in Washington.

00:06:01 Who were some of your classmates?

00:06:05 Well, let me see. Bill Waltner is

00:06:09 an individual who shared a lab with me, who now is a prof at

00:06:13 Florida State. And Mike Kasha, who

00:06:17 is a prof at Florida.

00:06:21 And Don McClure, who's a prof at Princeton.

00:06:25 Mike Kasha and Don McClure were the last two graduate students

00:06:29 who worked with G.N. Lewis.

00:06:33 So we had a clique going there.

00:06:37 All these people that you mentioned went into teaching,

00:06:41 did any of the others go into industry, or was that

00:06:45 you went with a chemistry Ph.D.?

00:06:49 No, another one of the people I was very close to, Alan Webb,

00:06:53 he went into one of the oil industries.

00:06:57 About a 50-50 split.

00:07:01 But you didn't want to go into industry.

00:07:05 You wanted to stay in pure research?

00:07:09 I wanted to stay in a research teaching type situation.

00:07:13 And when I started looking for a job, of course there was all these G.I.'s

00:07:17 just finishing school and flooding the markets.

00:07:21 Academic jobs were hard to come by.

00:07:25 I offered a job at General Electric Company at what seemed an enormous

00:07:29 salary at the time.

00:07:33 They had a very good, very fine research lab.

00:07:37 So that was very enticing to me.

00:07:41 However, Lattimer felt that I should get an academic job.

00:07:45 To give me a holding pattern

00:07:49 while I continued to look for an academic job, they hired me as

00:07:53 an instructor. Incidentally, specifically at a time

00:07:57 when Joel Hildebrand was the dean

00:08:01 while Lattimer was away or something.

00:08:05 Joel Hildebrand is one of the profs who had a tremendous influence on me.

00:08:09 He was a bona fide researcher,

00:08:13 very interested in his own fundamental research.

00:08:17 But he, more than anybody else in the faculty, was devoted to undergraduate

00:08:21 teaching. He taught freshman chemistry.

00:08:25 I really got my beginning in

00:08:29 teaching undergraduates with Joel Hildebrand.

00:08:33 So in a sense you decided that you would prefer having an academic career

00:08:37 and a career in industry where you might eventually

00:08:41 make a great deal more money.

00:08:45 I was strongly tempted because the General Electric lab had such a good reputation

00:08:49 as a research lab. And, of course, there was more money.

00:08:53 But in the last analysis, the

00:08:57 instructorship at Berkeley was very appealing to me.

00:09:01 And after two years they put me in a tenure-track assistant prof

00:09:05 job. Generally speaking,

00:09:09 during this period, my first decade or something like that,

00:09:13 I was continually being offered jobs in industry at about

00:09:17 somewhere between two and four times the salary I was getting as an academic.

00:09:21 But so you preferred the teaching and the research

00:09:25 end of it. Right. Well, you were quite

00:09:29 well known for two areas of research during the fifties at Berkeley, studies

00:09:33 on the hydrogen bond and the development of the matrix

00:09:37 isolation methods in infrared spectroscopy.

00:09:41 See, I never took chemistry.

00:09:45 Okay. Let's take a short break.

00:09:57 If I make a blunder,

00:10:01 is it okay if I just stop the sentence and start it all over?

00:10:05 Well, you were quite well known

00:10:09 for several areas, two in particular, of research in Berkeley

00:10:13 in the 1950s. Do you want to first talk a little bit about the hydrogen bond?

00:10:17 Yes. Hydrogen bond. Bond. Yes.

00:10:21 I was

00:10:25 engaged in the use of infrared spectroscopy,

00:10:29 which Pitzer had recognized as one of the important techniques

00:10:33 that chemists were not using then, an important way to learn about molecular

00:10:37 structure. And in the course of this, I discovered that

00:10:41 the hydrogen bond

00:10:45 caused very large perturbations in the infrared spectrum of molecules

00:10:49 that formed hydrogen bonds. And so it became

00:10:53 an interesting thing for me to study, to

00:10:57 see what one could learn from infrared about the hydrogen bond. And I became

00:11:01 very interested in it. And the upshot of this was that in the second half of

00:11:05 the fifties, I and a colleague,

00:11:09 Albrey McClellan, decided to write a book about the hydrogen bond.

00:11:13 It turned out that this was a landmark book in the sense that

00:11:17 we tried to include everything that was in the literature

00:11:21 at the time, and finally had to

00:11:25 put a cut-off date on the literature because it was growing exponentially

00:11:29 and we couldn't keep up with it. But the hydrogen bond turns out to be

00:11:33 one of the most important bonds in biological

00:11:37 systems of any, including the carbon-carbon bond.

00:11:41 And so this has been a very important field. At the same time

00:11:45 I was studying flames.

00:11:49 Pitzer's work had tended to

00:11:53 lead me to think about molecules that had unusual chemical bonding.

00:11:57 They didn't fall into the normal pattern of chemical bonding.

00:12:01 And one finds this sort of species, so-called

00:12:05 free radicals, abundant in flames. So I started

00:12:09 trying to do infrared spectroscopy of flames. This was very

00:12:13 frustrating because we couldn't get the concentrations

00:12:17 high enough to get characteristic

00:12:21 absorptions of them. And one day, with a post-doctoral

00:12:25 student of mine, Eric Whittle, sitting at a bag lunch

00:12:29 at my office, I came up with this idea that maybe

00:12:33 the thing for us to do was try to trap these transient species

00:12:37 very short lifetime, microsecond lifetime

00:12:41 in solid inert gas at cryogenic

00:12:45 temperatures. If we could trap them, then they'd have an environment

00:12:49 that was totally inert and we could do leisurely spectroscopic

00:12:53 study. That was the so-called matrix isolation technique.

00:12:57 That was the early 50s and

00:13:01 there was no experience in the field, no cell design

00:13:05 or anything, so we had to do everything from scratch. But I was used to

00:13:09 working with cryogenic liquids like liquid helium and liquid hydrogen

00:13:13 and so that didn't bother me a bit.

00:13:17 We proceeded to develop techniques and

00:13:21 equipment with which we could do this cryogenic spectroscopy.

00:13:25 But that was a nice test of stubbornness

00:13:29 because it took us about six years before we had our first

00:13:33 real success. And of course we made progress all along

00:13:37 the line, getting better and better at it, finding out what the variables were.

00:13:41 But finally we had our first success

00:13:45 and from then on things have blossomed.

00:13:49 A group down at Rice University recently compiled

00:13:53 a bibliography of all of the papers they could

00:13:57 find on using the matrix isolation technique

00:14:01 and there were thousands of papers in that bibliography.

00:14:05 So it was a very successful technique.

00:14:13 For a high school student who's taking a

00:14:17 chemistry course, what would this mean

00:14:21 to that person? Well one might think of the technique

00:14:25 of matrix isolation as analogous to

00:14:29 what one pictures and hears about in science fiction

00:14:33 of organisms being trapped in solid ice

00:14:37 and by reason of the cold low temperatures

00:14:41 all chemistry being stopped, you see.

00:14:45 And then one can come back in this

00:14:49 fictional line years later and warm it up and you'd have your

00:14:53 species back again. That's the general idea except instead

00:14:57 of ice, it's the

00:15:01 environment, which is what we call the matrix, is solid

00:15:05 argon or solid krypton and in order

00:15:09 to keep it solid you have to have the temperature at 20 degrees kelvin or

00:15:13 even lower, 4 degrees kelvin with liquid helium.

00:15:17 But then if we can get these very reactive molecules

00:15:21 embedded in the material then it's like

00:15:25 the dinosaur in the ice. It's at such a low temperature

00:15:29 chemistry stopped and you have all the time you want to study it.

00:15:33 But if nothing happens while it's in this frozen

00:15:37 state, what can you study? Well you study

00:15:41 its characteristic absorptions and that's the valuable part of the

00:15:45 infrared spectrum as far as a chemist is concerned.

00:15:49 Every molecule has characteristic vibrational motions

00:15:53 and those characteristic vibrational motions are manifested in

00:15:57 characteristic frequencies that act like a fingerprint and you can

00:16:01 identify the species that's there by its fingerprint

00:16:05 and decide things about its molecular structure.

00:16:09 Another key research of your

00:16:13 the key area of your research dealt with chemical lasers.

00:16:17 Do you want to talk about that? Yes.

00:16:21 The chemical laser idea was a natural follow on

00:16:25 thought to lasers in general and physicists

00:16:29 were coming up with quite a variety of lasers in which

00:16:33 the light is taken out in the form of laser light

00:16:37 that's a form of energy and you never get any free lunch

00:16:41 so somehow you have to put energy in and

00:16:45 all of the lasers that were being

00:16:49 developed by the physicists, mainly by the physicists, were

00:16:53 either initiated by putting in light of ordinary

00:16:57 type, that is not laser light, so light in, light out, or energy

00:17:01 in, energy out, or electrical as for instance in a fluorescent

00:17:05 tube we put in electrical energy. But of course

00:17:09 the idea of drawing energy from a system by use of

00:17:13 chemical reactions is a very familiar one. It's like comparing

00:17:17 an electric car to a normal automobile

00:17:21 in an electric car you have electrical energy that is converted

00:17:25 into mechanical energy. In an automobile you

00:17:29 take a chemical reaction and from the heat release in the chemical

00:17:33 reaction you're able to convert it into mechanical energy.

00:17:37 So the question was whether one could find chemical reactions that

00:17:41 allow you to tap the energy release in the

00:17:45 form of light and consequently develop a laser system

00:17:49 from that with no electrical cord associated with it.

00:17:53 As I say this was a natural thought

00:17:57 and all of the big labs in the laser field were working

00:18:01 on it like Bell, IBM, and

00:18:05 people who were very conversant with

00:18:09 chemiluminescent reactions, that is chemical reactions that release

00:18:13 light, like Schuller down at

00:18:17 UC San Diego and Broida and

00:18:21 so on. All the big names were in this. Polanyi who later got the

00:18:25 Nobel Prize and Dudley Hirschbach who got the Nobel Prize

00:18:29 they were trying. So lots of people were trying

00:18:33 and what we did was make a shot

00:18:37 at it by a technique that was just off the beaten track

00:18:41 and that people felt didn't have much chance. That was to

00:18:45 look for chemical lasing, chemically

00:18:49 pumped lasing in the infrared region. Of course we were geared up to do

00:18:53 infrared spectroscopy and also we were geared up to do it on a short

00:18:57 time scale. So we did an experiment nobody else was doing

00:19:01 and after about maybe

00:19:05 nine months to a year of very frustrating

00:19:09 failures, we finally recognized that we were

00:19:13 getting lasing action and that was the birth of the first chemical laser.

00:19:17 And we went on from that and discovered about the first twenty or so

00:19:21 chemical lasers, all in the infrared.

00:19:25 Would you describe the origins of your studies with Casper and the iodine

00:19:29 atom?