HAROLD UREY
Interview with Harold Urey VINCENT J. LANDIS Son Diego S s t e Unirerrify
Son Diego, California 921 1 5
Dr. Urey, those of us from the relalively small colleges and universities take special note of your own background at Montana University and also that your major was zoology. There must be a story here. Urey: My early life was spent in lndiana, my lather's death playing a very decisive role when I was but six years old. He asked that the money from his life insurance be used for the education of his children. Without it there would have been no high school. As I often remark, I passed out 01 grade schook at lndiana with s grade of 76. Passing was 75. In other words I just got through. I went to high school with dillerent results. I immediately became a leader in my class in high school at Kendallville. I was much interested in Latin. I thought Latin was very, very interesting to the point of looking forward to a career as a Latin teacher. My Latin teacher, Mr. E. E. Kling, a person whom I admired, was the reason for it. Actually, I liked all my subjects as I struggled along with them. I taught country school one year in Indiana and two years in Montana. My mother and stepfather moved to Montana. I taught in the upper Yellowstone Valley. One of my schools was close to the Absaroka Mountains and the other up in the Gallalin Mountains. Landis: That is beautiful country, but still, why the University of Montana? Urey: There I ran across a friend, whom I see even today, who decided that he was going to go to college so I thought "well, maybe I had better go to college too." That was how f decided to go to college. Life's turning points are mostly small incidents. I went to the University of Montana. I thought I would be a psychologist. For the basic reason that the psychology department didn't take freshman students, I took chemistry and biology. In the biology department I benefited from a remarkable teacher. A. W. L. Bray, who was English (Cambridge, England). He was visiting the United States, and he was "bumming" his way on the Vain. When he got to Missoula, a guard saw some lee1 sticking out from under a car. The guard thought they didn't belong there so he told him to get out. He found that there was a University in town. He got a job as a janitor. The administration, to their credit, soon found Landis;
by Vincent J. Landis out they had a very intelligent janitor. He was made an Assistant Professor of Zoology. So, in a way he gave me a Cambridge education. He took a great deal of interest in young people. In the true Cambridge sense, he was sort 01 my tutor. I owe an enormous amount to Bray. 1 took about as much chemistry as biology. 1 managed to graduate i n three years. World War I came on and there was a need for chemists, not biologists. I went to work in Philadelphia for the Barret Chemical Company. When the war ended, I was invited back to Montana as an Instructor in Chemistry. This accounts for the change from biology to chemistry even though the latter was a minor subject. Landis: I have always tell many of the smaller schools very oiten have some real gems. A great strength of our educational system would be lost without their schools and their teachers Do you have leelings on this subject? Urey: Thai's right. I owe an enormous amount to my prolesSOTS there. Professor Bateman and Professor Richard Jeggie. People who devote themselves principally to teaching, as they did there. Well, alter being there for a couple of years, f decided I had better get a Ph.D. degree, and so, I went to the University of California a1 Berkeley. There G. N. Lewis, Professor Joel Hildebrand, and others were very important in my getting an education. Landis: This was essentially your first contact with what we would call "big name s c i e n t i s k in a leading University? Urey: Thai's right. After I gained my doctoral degree, I went to Copenhagen lor a year with Niels Bohr. There I met Krammers. Prolessor Krammers played a very important part in my professional development. He and Professor Bohr remained awfully good friends the rest of their lives. Landis: Did your Copenhagen experience suggest the work on the deuterium problem? Urey: NO, it was later work on basic atomic structure. As a matter of lact, I went from Copenhagen to Baltimore, to Johns Hopkins University. I was there quite a number of years. I didn't do any research there that I Volume 51, Number 9. September 1974
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thought was very important. There were certain ideas that I think were quite wrong. I had an idea about the structure of the hydrogen molecule ion, but the old mechanics were no good. The new mechanics came out about that time and, of course, that ditched everything about the old model. I then went to Columbia. There we got busy on spectroscopy and things which really worked into the discovery of heavy hydrogen. Of course, there is no doubt but what that is the most important thing that I have done in my lifelime. The world agrees, but the thought occurred to me that you may have gotten equal or greater enjoyment out of other pieces of work. Is thispossible? Nothing has matched my enthusiasm for deuterium and allied projects. I worked on heavy hydrogen and the methods of separating isotopes by chemical methods, which were later developed during the war into very good methods for getting heavy hydrogen. The work was done mostly by Jerome Spivak, who has a company working on this problem. I often think that he saved the United States government a couple ot billion dollars. Later I had to take over the direction of the separation of the uranium isotopes. It was a job that I didn't like very much, but I did it as well as possible. Heavy hydrogen, of course, has developed into an enormous project. If fusion can really be developed, its importance will reach new heights. I recently worked out that there are about 9 g of deuterium per square centimeter of the Earth's surface average. The energy in this is equivalent to the burning layer of coal over the earth 400 km thick to carbon dioxide. If'N last a long time-if it can be worked out, and of course, a great many people have worked on it since. One's greatest success comes from doing things that inspire other people lo do a lot of work, and that has certainly been true in this case. Your early isotope studies musl have suggested oxygen paleo-temperalure measurements. The problem is not physico-chemical, really; it's very different. In Chicago we got into paleo-temperatures. This concepl depends upon difference in chemical properlies of the oxygen isotopes, and of course, other isotopes as well, but we applied it to oxygen isotopes. Several young men participated. One is at Miami, Professor Emiliani. He has been able to relate the temperatures in the Carribbean for the last 400 thousand years showing that the ice ages cycled in a regular fashion. He also suggests thaf we are at a peak of the temperature cycle at the present time. His data show that the temperature will now go down, leading inla another ice age. He has been able to get very good results. Professor Clayton, in Chicago, has applied the same principle to the temperatures of crystallization using rocks, through distribution af oxygen isotopes between the different crystals. What is the currenf state of your isotope research here a t La JoUa? W e have refined the data on the abundance of elements. Professor Hans Seuss, a colleague, got me into this and we feel we have an "abundance of the elements" table that is a classic. It has been worked on by quite a number of people since. Even so we still don't know the abondances of some important elements. For example, iron. Professor Sol Penner here has students working on the abundance of iron, and trying to decide what the proper abundance of the element is in the sun. I n my opinion, his results indicate lhal iron is less abundant than many people currently think. Possibly the composition of the moon is approximately the same as primitive solar rocky material, not the earth and some 01 the meteorites as people think. These data on the elements have catalyzed new ideas about the origin of life.
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Do you have any current projects in this area-lhe origin of life? I have a former student Professor Stanley Miner who is working on this project. f have done everything I can to boost him instead of myself in this field. He has kept in touch with this field over the years and is doing excellent work, in fact, writing a book on the subject of the origin of life now. Part of the "History of the E a r t h includes your concept of reducing methane, ammonia, and hydrogen atmosphere. How did this concept originate? It started with the abundance of the elements because hydrogen is so much more abundant than oxygen thaf everything looks as though it should be reducing. It seems lhaf no matter how the Earth formed during early years it would be surprising if the atmosphere were not a reducing atmosphere. I don't think there is any doubt but that the atmosphere of the Earth was reducing with no oxygen up to about 2 million years ago. A very interesting thing. Of course, if was steadily becoming oxidizing. A man from South Africa, ProhsSOI Pretorius, a consuflanf for the gold interest in Africa, pointed out in a meeting recently lhal the gold is deposited in fossils that are known as slromaloliles. They appear to be fossil algae. This deposition continued until about 1.9 billion years ago and stopped. This phenomenon is not at afl clear or understood. It looks as though gold were washed out of the hills, in a s d u ble form flowed down to lakes or seas where these algae existed. The algae finally must have precipitated the gold. It looks to me as though the gold dissolved as the complex gold cyanide, and the algae oxidized the cyanide and precipitated the gold. This process would only be possible in a world of a reducing atmosphere? Yes, only in a reducing world. As soon as oxygen became important, of course, there could be no cyanide around in any important amounts, and gold would not be soluble and hence the whole process stops. I think that is a very interesting chemical consideration. Does your theory extend to other metals? Yes. The great iron deposits of the Earth date to about the same time. Now, in the reducing atmosphere, you would gel ferrous hydrogencarbonale which is soluble in water like calcium hydrogencarbonate and would be carried by streams to a body of water where algae would oxidize the iron to insoluble iron oxide. This would eventually form a deposit of the ferric oxide. These all deposited around the same time. You see, just as soon as oxygen became prevalant in the atmosphere, ferrous oxide in the streams could not exist. It would immediately oxidize to ferric oxide and not dissolve, again indication that about 2 billion years ago the atmosphere of the Earth became oxidizing. I s this consistent with most of our sub-surface geology, that is a reducing environment with many sulfides? 01 course. It is curious that ferroic oxide exists in so many rocks in the earth and apparently rocks that are coming from the mantle of the earth. One wonders how you got both metallic iron in the core and ferroic oxide in the manlle. There's an inconsistence .I don't know why lhis is true. I think the geologists are very puzzled by this. It partially answers the question of how I happened lo gel interested in the origins of life. It all seems to reflect a steady, almost inevitable progression. Actually, to look for major impact or turning points, outwardly it seems like you've had four or live phases of interest Getting into the abundance of the elements was an important business for me. I think that this was an important thing to do. In part if was due to my good friend Hans Seuss. It was his idea to refine our data
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on the abundance of the elements. I think we did pretty well as a team. The abundance of iron has, however, been a continuing problem. You see, the astronomers said that abundance of iron was low in the sun as compared lo the meteorites in the earth. Then I devised a method for producing objects with large amounts of iron. Later lhey cut the ground out from under me by saying that this was all wrong. More recenlly it looks as though I was not so wrong about some of these things. The Priestley Address will include some thoughts on this. [Ed. Note: See C&E News. H. C. Urey, Priestley Award Address, Dallas Meeling, ACS, Spring 19733. Landis:
Deuterium has many ramifications; the benefits of deuterium to the organic chemists and biochemists is certainly one, and, as you have menlioned, the enormous energy potential is another.
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The enormous use of deuterium as a tracer is something I foresaw. I thought it would be useful in this way. I confess I did not foresee the use of the hydrogen bomb or i b use as a source of power. I remember Fermi slopping me one lime on the Columbia campus explaining to me lhat he thought lhat we might combine the deuterium atoms into helium and get energy out of it. I was very much surprised and didn't appreciate its importance at all at the time. He was working on the atomic bomb while I was working on the separation of uranium isotopes by diffusion as well as the separation of hydrogen isotopes. This was the time that Jerome Spivak succeeded in inventing the process. He has been trying to get the governmenl to give him royalties on his patents ever since. He is very persislent-I just wouldn't have time to argue with the governmenl lor that long, even for a million dollars. I rather think he will gel some reward for this.
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You remarked how clever Fermi is. So you have thoughts now on the science and engineering that has been involved in such places as Hanford and the AEC installations? Yes, 1 do. My, what work we did together! And now we make the damn bombs, stack them away, and what for? We mustn't use them. We just must not use them! The damage to people generally would be simply unbelievable. It must not be done. And, 01 course, there are these power plants that produce plutonium-plutonium is exceedingly poisonous. One pound divided uniformly among all the people of the earth would kill us all. One pound! The breeder power plan& would produce plulonium and it would have to be stored. The hall life of plutonium 239 is about 25,000 years. That means it would have to be looked after for hundreds of thousands of years. For example, you can't take down a plutonium power plant for thousands of years because of the activity. You would have lo do it by remote mechanical means and then store and take care of the radioactive material lor long periods of time.
To return to factors that were important in bringing you to your unique position in science. Is there a secret to your breadth 01 interest? Urey: I had a straight A record in everything except in physical education in college. I maintain thal an inlelfigent person can learn all sorts of things besides his specialty if he works a1 it. You may not be able to be a musician if you do no1 have the knack to do it, but you can learn a lo1 about music if you try, regardless of whether you are good at it or not. There are many people who could have done everything thal I have done. But there is a moral for young people-they first should try to be right also. Landis: There is a related question-Do you think if should be research and teaching or research versus teaching? Is /his even a valid question? Perhaps it is something
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like science versus religion when lhey should be complementary? I think, myself, that people should leach and do research both. One of the things that one should always try lo do is keep up to date on the subject he or she is teaching. I kept teaching until I was 77. Finally I let it be known that I was bored with keeping up with the subject; therefore, they should retire me. They told me lhat lhey had intended to retire me anyhow. As soon as I found lhat I wasn't trying to keep up with the subject, right then it was time to quit. I n college teaching, keeping up with the subject is exceedingly important and many people don't appreciate this. It lakes a great deal of work to do it-work and study outside the classroom, to keep up with the developing subjects. Research is a catalyst to this process. You should try to carry your own research on about the same lines as your teaching. Try to match the two logether to a certain extent. Somelimes people don't do it, but almost always trying to keep up with research in some field requires following what's happening in related fields as well. Have there been major activities outside your professional sphere which you think have enriched your life and balanced the scientist part? Has your involvement in atomic energy lead to polilical concerns? Actually I'm always concerned about political problems. I have a way of celebrating the 4th of July thal is a little different lrom some people. I get down the Encyclopedia Britannica and /urn to the Constitution of the United States and read some fraction of it on the 4th of July. I read something of the Constifution and to me it is one of the most remarkable documents I have ever seen-to lhink that a group of men on the seaboard of a strange continent with savages behind them and enemies in front of them would write a documenl of this kind and put in the Bill of Rights. I just wonder if people of the United States would approve of /his Constitution today if it were put before them. I am ferribly concerned about some things lhal happen from time lo lime. This sort of concern I have always had to a certain extent-and I still have. Where do you see science going lrom here? Do you think there are bypassed areas into which people should be encouraged to go? That's not easily answered but 1'11 tell you what I find about scientific development. I had no idea that heavy hydrogen would be useful in a practical way. I don't believe anybody around me did. In studying the moon. I wasn't interested in magnetic fields at all. I didn't think they were very important, but other people worked on magnetic lields. Now here I am preparing a lecture lo give tomorrow, and I'm working on a paper with a friend, in which I think magnetic fields perhaps are decisive about how the moon was made. I didn't expect it at all. You see, science has for its purpose understanding n a m e . You don't know whether it's useful or whether i l will lead to important developments; so for this reason, I think that all fields of science should be pushed. None of us knows ahead 01 time where the exciting, important fields are. This is also true of practical applications. You don't know where the practical applications will come from. I don't believe that studying the moon is going to help us in any practical way, but you can never be sure. You are prepared, then, to be wrong on thal point? The spin off should no1 be ignored; side things are very important. It is very imporlanf to get very small and eflecfive computers in order to go to the moon. I believe it took 84 minutes for the compulers (when Apollo 13 went wrong) to outline what they should do next. If 200 people had worked on this in long hand, it would have taken 47 years to do this same job. That Volume 51, Number 9.September 1974
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would have been a "tittle" too late to help. So, it may mean that computers received a very important push lrom the space program. Activity 01 these kinds, of this sort of thing can be surprisingly important. I think people make a mistake in thinking that lhey can see ahead 01 time what we should work on and what we shouldn't. This is a mistake that is being made by the administration at the present time. I am in lavor of research and development on subjects related lo the environment, but also that's no reason for terminating something as important as the space program. Landis:
You would like "also space" rather than "instead 01 space"?
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I think that going to the moon, quite aside lrom science and all related factors, was immensely exciting. We are bordering in this discussion on still another important area-it seems that research is always gelling more expensive. Prices are going up on a# fronts including research. Many scientists feel that they must be and are almost totally dependent on lederat grant support for their research. In grant support the agencies almost demand an objective or conclusions stated in advance 01 doing the research, or, as it seems, when one applies for lunds.
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That in itsetl, do you not feet, represents an inhibition 01 research in the pure form at least? Urey: ll's very dilficull to explain to a non-scientist exactly just what we are trying to do, what the importance is, and why we are interested in it. Naturally we should have thought ahead concerning support for science. Certainty we could not expect to go on and on with exponential increase in support for science. It had to level 011 some day. A more reasonable federal attitude would have been based on what fraction of the gross national product should be put into scientific research? What is the limit we should aim for? Maybe we can't answer these questions exactly, but we oughl to have thought about it. Landis: It is too late now to think about it? Urey: I say that support shouldn't be just chopped olf. It should very likely be leveled oft. We certainty must study the options, but now we should flatten 011 and then judge whether we should go up or down from where we are. As scientists it's partly our own fault. We simply haven't given it proper thought as to the totat importance. We could also ask, how much should be put into music? How much should we put into education? Certainty science is not the only place lor our investment. Landis:
