The HLF Portraits: Dana S. Scott

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The HLF Portraits: Dana S. Scott
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The Heidelberg Laureate Forum Foundation presents the HLF Portraits: Dana S. Scott; ACM A.M. Turing Award, 1976 Recipients of the ACM A.M. Turing Award and the Abel Prize in discussion with Marc Pachter, Director Emeritus National Portrait Gallery, Smithsonian Institute, about their lives, their research, their careers and the circumstances that led to the awards. Video interviews produced for the Heidelberg Laureate Forum Foundation by the Berlin photographer Peter Badge. The opinions expressed in this video do not necessarily reflect the views of the Heidelberg Laureate Forum Foundation or any other person or associated institution involved in the making and distribution of the video. Background: The Heidelberg Laureate Forum Foundation (HLFF) annually organizes the Heidelberg Laureate Forum (HLF), which is a networking event for mathematicians and computer scientists from all over the world. The HLFF was established and is funded by the German foundation the Klaus Tschira Stiftung (KTS), which promotes natural sciences, mathematics and computer science. The HLF is strongly supported by the award-granting institutions, the Association for Computing Machinery (ACM: ACM A.M. Turing Award, ACM Prize in Computing), the International Mathematical Union (IMU: Fields Medal, Nevanlinna Prize), and the Norwegian Academy of Science and Letters (DNVA: Abel Prize). The Scientific Partners of the HLFF are the Heidelberg Institute for Theoretical Studies (HITS) and Heidelberg University.

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I'd like to begin these interviews at the beginning you're the only person who is sitting in the same town in which it was born so can you tell me a little bit about your childhood did you grow up here in Berkeley no I didn't grow up here in Berkeley the reason that I was born here for my parents were then living in San Francisco was there was no bridge there was no bridge in 1932 on either the Golden Gate or the Oakland Bay Bridge everyone could commuted back and forth across the bay by ferry boats so my pants were invited to supper and drove on the automobile ferry over to Oakland and then during supper my mother said oh oh and she absolutely refused to go back on the ferry boat across the bay so I was born in Alta Bates Hospital here where subsequently both of our grandchildren were born as well but I wasn't really a Berkeley resident until I came to college in 1950 you grew up in that system know all over Northern California huh what of various reasons first of all my father Caves are was his work was to be in the logging industry equipment things and so he was very much a traveler and so we lived in several places but then my parents were divorced and my mother moved to where some relatives were and then we moved again after my grandmother died and so we moved around so put on and Northern California to focus on the school that the high school press that you went to can you put on searching for as offensive as an intellectual back your home or school that may have begun your intellectual progress or one one quick fact is that my father's older brother went to college who became a dentist but aside to that either in my father's family or my mother's family no one had gone to college really so and until until my time but I want to tell you something about school yeah so my first junior high at high was in Chico California and I want to particularly mention things about detective stories do you know these interviews with David Suchet who has portrayed Ricky Lupo role one wonderfully well done things of course ITV has the advantage of hundreds and hundreds of hours of TV to make regulate interviews but it's really very charming and I recently bought the whole collection of pearl stories say they were able to film everything that Agatha Christie wrote and I loved Agatha Christie in my middle school junior high school time and so in chico one saturday i went to the city library and checked out three Agatha Christie books and as I was taking them out the library and looked at me and said you know we have other books in this library as well but that had a big influence on leaves that kind of storytelling and history furniture but the thing that had the biggest influence on me at that time and beginning of high school or in Chico was my fans teacher I played the clarinet after time and he was very very supportive of young people in fact he told me one day the reason I like teaching is that the students never get any older and he was really great in getting kids to realize their their talents so he saw that I was interested in how it is that instruments produce their sounds so he gave me to loan his copy of this book it's by Dayton Clarence Miller the science of musical sounds and not so long ago I was able to get a very nice used copy of it one thing that Miller did was to make sounds visible of course he didn't have the kind of electronic equipment that we have today but he was very clever as a experimental physicist to do that and it was absolutely fascinating to learn where sound comes from but in order to understand the explanations you have to know the math behind it and so one of the main things of course are trigonometric functions as periodic vibrations and so I had to teach myself a lot of math in order to do that and then as a subsequent from the references in that book when the and the second half of my high school time we moved to Sacramento in the library of the state legislature there was a very very quiet place hardly anyone use it I discovered Helmholtz's book on musical sounds and that had an incredible influence on me and later life I read about helmets one of the most tiring biographies because he did so much in his life on so many so many fields but in the question of music and acoustics he explained all kinds of things about tunings and temperaments on on instruments and in order to understand a tuning you have to understand logarithms because the scale on the piano or any musical instrument is a logarithmic scale or when you just go there CDE just go through the scale it's really logarithmic as you go to higher and higher Sciences or so to understand that and to understand why temperament works out I had to learn a lot more mathematics to do it and so that maybe is a lesson that curiosity will lead you to places where you have to look at things in ways that you wouldn't have thought you would have until you found that you had to know the reason why something happens but I need to tell you a story about Chico that was my first or my first high school because many many years later when my wife and I were living in San Francisco it turned out that our the husband was our next door neighbor had also had his schooling in Chico maybe about 10 years earlier than when I was there and I asked him did you ever did you ever have ping mr. ill off as a math teacher and he said let me tell you about mr. Hill off then I had become a lawyer and will for many years in San Francisco and once his firm sent him up to Chico to take part in a trial there and he was there in the courtroom when
one of the first things that happened with Carl was that an expert witness was brought in it was an expert witness a retired math teacher mr. ille off and the first thing that happened was that they asked him do you recognize anyone in this room so he looked around and then he saw Danny said oh I remember him I taught him algebra and he didn't do very well so that's the Revenge of your math teacher you had him as I had him oh yes and it was a meal in the way he was a very very good teacher but he made you work right that's all right it was was there a salient mentor an expert about the music group was there a salient mentor that saw in you the talent that he has to guide you with a good an idea of what your next stage would be not really I mean both in Chico and in Sacramento the high schools will very very good and it was very lucky to move to Sacramento because it was closer to to advanced society I mean and Chico I probably would have gone to Chico State and become a high school teacher but in Sacramento and the high school there if people had come from all over and so I had the idea that it's possible to go to university and of course in those days if you got a B+ or so average you could go to Cal UCLA everyone was was admitted and the costs were credibly low because the state state supported things it's no longer cool I'm afraid and so we wondered what will happen to our grandchildren we were getting close to college age anyway it was really the combination of the teachers but then also that I taught myself a lot of math the math teachers were good in both places but I taught myself a lot of math so I got a taste for it and so when it came time to to the University I had already decided that that would be a good major what are the ambitions of this 18 year old at this point musics beginning to go to university I think just to get on with life but what was completely that changed my life with Berkeley I don't know whether you experienced it all herself was that coming from Northern California you know it was a very homogeneous population I had no concept of European culture as a Northern Californian and then all of a sudden here at the university there were people from all over and you know I met so many different kinds of people and also as I'll explain later the European influence was was very strong so that completely changed things to have that University experience in the university but as one comes to choose a major what comes to choose certain professors follow how was that developing in your in your intellectual progress well at the beginning I really didn't know what higher mathematics was going to be like and so it it it turned out that certain of the teachers and professors that I met turned me then to the subject that I was going to to really concentrate him so the first thing was that I had to earn some money to go to university so I was working in the library and the periodical swing this was a period before the publishers tried to bankrupt the libraries by having so many periodicals so there was just one room in the dole library where all the periodicals came they were held for about two years and then bundled up and sent to the boundary to the bindery to put in their in the stacks so while I was filing their journals that he come in I came across the Journal of symbolic logic and I opened it and it was all completely nonsense to me I couldn't understand that there was one article I just happened to see you know I was doing this when I was supposed to be working but I was looking at the things back in the stacks where we kept the journals and there was one article that I could understand and so I checked that out and read it and then it turned out that the next semester the author of that article was teaching an elementary bats course here he was a Polish man who had escaped from a Poland just after the war in between the time the war ended before the Communists took over he was just able to get out of the country on a forged Passport and he went to South America but because of the work he had done in the underground university he had contacted contacted alfred tarski the professor in logic here at berkeley and so after some correspondence tarski arranged for him to be invited into a junior position here in berkeley and so he was completely amazed that i had read his article because he didn't expect that a sophomore would know anything about her what he had been doing there so that started a very fine relationship and he had some problems that he was working on and he got me interested in the problems and I came up with some answers here and rewrote some joint papers together Lee Badgett as an undergraduate yes that was between sophomore and junior junior years and so that was very key of course it was very close to tarski and introduce me to tarski and then that late that led on alas he was a very bad driver and he was taking tarski mrs. Starsky and another graduate student off to a mass meeting in Southern California and he had a very bad automobile accident and the car rammed what rolled over on him and he was killed that way so that was that was a terrible upset but are they connection with tarski and the the tarski school boys survey is very already established and and so I then joined that school and so how problems being framed through your contact McCarthy huh what is he doing in the shaping of your perspective okay well it was already two things I mean through the other teacher I didn't name him his name was kolinsky Jung torski he had already studied tuskys work and so then I read starsky's papers there but the key thing about tarski was uh he was an absolutely masterful lecturer just an incredibly good lecturer and so I was friends with single the students and we always went to his classes and so it was his example of his teaching that was extremely extremely influential I want to tell you a story about tarski so then just before the war was declared he came to Harvard
for an International Congress and then war was declared and he couldn't return to Warsaw his wife and the two children were able to stay in the countryside they survived and he got them out to start look at the end of the war but then he was caught here in America and so he tried to find some jobs it was very difficult than any refugees and then very luckily because Griffith C Evans who was terrible Department Department's building is named after Evans now he had wanted to build up the department here in Berkeley and he was taking advantage of various refugees that came there and so torski was invited to come here well he spent the rest of his academic career on the East Coast he had made good friends with a fellow named McKinsey was very interested in his work there did some collaboration together and Mackenzie had been his PA didn't on his PhD at Berkeley and so when tarski moved here but Kinzie also moved to the west coast and in the first year that our ski was here the summer time was coming in and it was announced that there would be a departmental picnic and everyone had to bring something to the picnic out in Tilden Park and so McKenzie and another friend in power we're in the car driving up to the park and darky said oh my gosh the napkins the napkins I forgot the napkins stop the car and so he rushed into a drugstore and up to the counter and said to the boy behind the counter napkins napkins do you have napkins and the poison sanitary napkins sanitary of course sanitary how many pots four boxes please fortunately at the picnic it was noticed what they were and they were hidden away before anyone else saw them but tarski was always extremely and patek in getting things right and making sure and that it was understood and our that's a good example of his and here's her personality was he as a teacher of yours determined to set you in any direction I was interested in mentoring the extent to which he's thinking about you your career expectations perhaps of working with him in the university oh yes yes and he had many and he had many students he was extremely good in finding problems to work on but he also had standards and kept students working for years some of them took seven eight years to get a PhD because he just wouldn't sign off on their on the work so there are two sides to that I mean lots of interests knowing where to look for problems but also then insisting that you do more and more and more start doing you decided not to do graduate working perfectly that was because of my own fault tarski colleague in England or translating the papers in German and French from before the before the war and the page proofs came to tarski - correct and it turned out that professor would Jerry who is a biologist was very very good at languages but he wasn't so good at the mathematics and so several things were misunderstood in doing the translation so tarski hire those people to read the page proofs so I did very good job for about two three months and then I got sick of the whole job and I neglected my work very badly I wouldn't even answer the telephone sometimes when he phoned and he got very angry at me for neglecting the work so he fired me this was my first year as a graduate student so he fired me from that and was was was very mad at me and it was my own fault I mean he had hired me he was paying me to do the work which which I didn't do fortunately that your Foreman Steen rod from Princeton the famous topologist was visiting Berkeley and so I went to him and asked him if there was any chance to be a graduate student at Princeton and he gave me a very very good recommendation and so that's how I got to to Princeton oh this kind of accident like this shape so their yard Princeton you're you're already set on a career as a mathematician oh definitely yeah see I I had done the BA in mathematics I'm Gary and was the first year graduate read what did you expect of your career at Princeton where did you think you were going well Princeton had a very well-known logician Alonzo Church answer on the faculty there and so it was just obvious I only become his PhD students there in whatever logic and I'll enlarge it because that was tar skis area and we all knew Church whose name he was a he was very well-known as a editor and promoter of logic and so I just continued there actually for the work on the thesis that were questions that had come to me through tarski that I wrote about and I say about Alonzo Church he was very good in correcting the spelling in my thesis but he didn't really contribute to the subject matter well is that well he didn't need to I mean I got some results because you look yeah you and so good at one well it was lucky I was lucky to find some answers to some problems and so that could develop into a thesis and he didn't of course with any business students insist that they do absolutely what he wanted them to do but what they thought that they could do so what was the problem that you were seeking an answer to at this point that's a little hard to explain here in the sitting room but tar skis early work had shown that the logic of real numbers and the logic that you need for Euclidean geometry can be done in a very constructive way so that all problems can be solved when formulated in a certain way and so I did some work on it to expand that in a certain sense to higher dimensions and to relate the possible interpretations of geometry at higher dimensions to ordinary Euclidean geometry and so that was that was what about what sector you're taking an academic career and although it's yes by that time yes I mean because all my examples were professors so I just assumed that I would want to become a professor I'm just assuming that your thesis was accepted with some claim I wouldn't say a claim but it was regarded as as satisfactory as accurate but I want to tell you more about Princeton because Princeton is such a center for mathematics all kinds of people came through there in the Institute for Advanced Study is extremely important in Princeton I had me that's where our
fellowman was and that he did his first computing machine there that I had the opportunity to work on and of course one of the key things for logic was girdle also names court girdle being something to you have you heard about him okay he was a brilliant as an Austrian in his twenties and so some outstanding problems and then at earth through the war he wasn't Jewish but he had a number of problems in Vienna and he emigrated to the to the States just at the beginning of the war there and Philemon arranged for him to be appointed to the Institute for Advanced Study where he spent the rest of his career but he was a very I mean he had this great fame for his work in logic but also he was a rather a difficult personality and I want to tell you a couple of stories about him throughout his life he had some questions at some problems of being too worried about things maybe some almost sometimes in his life uh paranoid about difficulties and things like that but he was very brilliant and he also mented lots and lots of people who came on visiting times for that at the Institute for Advanced Study and so there was really a school of logic that was there in Princeton combined with the University and Institute so professor churches secretary who was the wife of a graduate student cold graduate student from the bank was on the city bus one day when mrs. gurgle got on the bus mrs. Cavour his release also and she was greeted by a friend and she been to the hospital where her husband had been there with the others and the friend said how was your husband doing and mrs. g?del said oh that man is nothing but a brain on two legs which sounds are they bad coming from the life but I know what she meant girdle was Oh clever you could never win an argument with him no matter what you suggested he would find if the answered books to confuse and refute things so that that's I'm sure and he drove his doctors crazy because he objected to everything they wanted to do he always had the worries about it another statement of mrs. girdle that I particularly cherish or as the times if the writer monsters came from Europe had been friends in Europe and they came to visit Princeton and it was decided on something we should have a drive in the country but then a girdle himself decided that no he would stay home and bake a goal they could go on the drive so there they were in the car and all of a sudden mrs. girdle said almost wonderful to be out for a drive and not to have a genius in the back seat so maybe that gives you a little bit of a feeling of his personality but I want you in the next hour I wanted to know and this is rather baldly at how clever did you think you were in this amazing circle of logicians well there were lots of other mathematicians too like John Nash had just gotten his sort of PhD there and he was regarded as as a super super genius at the time and there were many other extremely successful mathematicians there so I just felt myself as kind of middle middle level I wasn't I wasn't thinking of myself as as very exceptional like many people there but I was lucky that a mathematician from the University of Chicago spent a sabbatical at Institute for Advanced Study Paul Hamels and so I was getting my PhD in 58 and so he said welcome as an instructor in those days you had instructors before you became assistant professor I come to the University of Chicago so that was a lucky thing to meet someone that way and then you know I didn't have to search for a job but this other perfect mom and where is Chicago in your intellectual development so you could you go to Chicago as an instructor well the University of Chicago also was an amazing Center for mathematics and many other things - of course when it's a major university and and also in my life had the advantage that I met and married my wife there too so it was it was a lucky move to be there again you don't know these boos what's going to happen to you right there and so I developed more of my research went forward there and it's set the tone for continuing when Chicago was very very competitive and so I wasn't hired after to continue after two years but I had an offer from Berkeley from the tarski School to come back to Berkeley and so in 1960 we moved back to back to California when do I find the individual interested in computation in the logician about matter competition where is that how does that evolving as an interest okay well I came through an area of logic called recursive function theory so here at Berkeley there were two excellent people the one was a professor Raphael Robinson and his wife Julia Robinson oh did her thesis under tarski but and those days because of despotism Wars you couldn't have both a husband and a wife as professor in the same same Department and so Julia never had position here until much later in life she was elected and finally to the National Academy and she became president of the American Mathematical Society and so then Berkeley R with embarrassment almost appointed her as a professor but she and her husband worked together very very much and her workers very very much should buy it and so they were they were quite role models so for me to because of their interest in recursive function theory and I want to tell you a story about Julia but her sister told this so during the war there were a number of warm projects on campus and so Julia was hired on this project and the requirement on the project was you had to write a report on what you did every week so Julia's first week's report was as follows Monday tried to prove the theorem Tuesday tried to prove the theorem Wednesday tried to prove a theorem Thursday tried to prove a theorem Friday theorem false she was never asked to write a report after that they felt that she would just
continue on with her work all right but they were they were great role models for me and so that interested me a lot in recursive function theory and then at Princeton two of church's thesis students in the 1930s for quite a quite important in the development of regressive function theory and particularly Stephen clay me who was a longtime professor at Wisconsin University of Wisconsin and wrote very influential books there and he came as a he came as a visiting professor to Princeton while I was there graduate student there and I got to know him very well and of course all of us had been studying his books and his work tool and so that was a very very strong influence and then one of the professors in electrical engineering at that time was working on computers and he got for me and another graduate student the chance to work on the phenomen computer at Princeton and so I had some introduction to actually trying to make a computer do something and so thought that was strongly motivating experience getting to see how computers actually could do things of course the problem I did was a very simple one but still for me it took a lot of thinking to to make it work then when I came to Berkeley after being in Chicago for two years the computer idea was just beginning to take on in that's 1960 you know we didn't have a lot of computers we depended on mainframes and other things like that and so and also that was just the point where the alcohol language became popular and there was a professor here in the medical analysis was very keen on that and so he and I became friends and he introduced me to that and so that was the next influence was to to have that connection with people actually working with computers here at Berkeley I was then a through various combination of personal influences convinced to change from Berkeley to Stanford in 63 and so when I went to Stanford there was also a big development there though it took some time for the computer science departments to actually be formed they were they began in sparks of electrical engineering usually but I got to meet interesting people there like Don Knuth whose name I'm sure you know and said actually been interviewed I also like period here set and what point are you beginning to feel you are making a contribution advancing the idea of logic and the computer or complexity and the computer where are you beginning to get excited about what you might add to the field okay well as I say the computer science department really hadn't been formed there yet in the mid 60s but there were a number of people working with ideas of computers and using computers and there were several good students there in fact some of them and one of my seminars are blocking on her name what are the recent Turing Award winners who's now been a long term professor at MIT she was in my seminar that I had there and in Stanford and I think I influenced her of it.where with her very successful career just as when she was a beginner they then so I had connections there and were doing some teaching and so that was part of the development but we really the crucial thing that happened was that in 68 69 when I was on sabbatical first and after them I met some people in the computer area there that I later had a contact with but in the summer of 1969 Patrick soubise who was my mentor and friend at Stanford had recommended me to go to an i-strip International Federation of information processing workshop during the summer and where I met a lot of people trying to talk about the connections of [Music] understanding computer programming and the logic that should go along with it and many of them I really didn't think had good enough ideas there but there was one person whom I really related to and understood what he was saying that was Christopher stretchy who was in Oxford the back arm previously had been in Cambridge and was very influential in early developments with computer languages later your names were linked yes because I felt the state she had the best possible ideas so I arranged to go for an extra term of leave that some of them in the in the fall of 69 to Oxford to work with stretchy and so that was that was the key the key thing there what inside I know it's simplifying a very complex process but what an insight emerge from your your work together you must I was he yes I can tell you I don't know how I can explain it to you but straight she was trying to use a certain kind of mathematical technique that has been developed by church it's a technique for giving abstract definitions of functions it's called technically lambda calculus because a Greek letter lambda is using it but of course that doesn't mean anything it's just a Greek letter but Church developed it in very formalistic way without any mathematical models and so I told Strachey you can't just use this formalism you have to have something that has a real mathematical interpretation to relate this kind of logic of definition to the computations that you have to do and so from experience that I've had with colleagues at Stanford I wanted to and also going back to work of cleany earlier that I knew about I wanted to explain to him that he could adapt some of the things that had been done in logic and recursive function theory on a more theoretical frame he could adapt those to his problems that he wanted to to do to relate to computer languages and so I wrote out a report on that about how I thought it should be done and in doing that I had to develop certain mathematical structures to explain of what what was going on with it and then one Saturday in November I
was lying on there and our rented flat I was lying on the bed in the guest room and I thought to myself oh no if these mathematical structures can be expanded in this way there must be an expansion that provides a mathematical model for church's system for years I've said the Church of system made no sense because it didn't have any mathematical models but once you tried to expand certain kind of structures to do things similar to what church's formal systems it then church's system did have mathematical models and so that was the key Philander the thing and that was then developed by a number of students about student and colleagues over Christopher stage here of course night later students as well what was that called as an insight there yes in a warrant and the name name o- and make any sense I called it domain theory because the structures were good domains on which to do your to do your definitions and that has stuck but but the the idea is really to you see a recursive function theory focused in its development going back to clean events to on functions from integers to integers but now an integer is a very discrete thing and you get a very discrete value there and the place lots to say about what kind of computations are possible but you should also think of operators that operate not just on the integers that operate on functions or operate on operators operate on operators that operate on average and so on and so the question was how to build up a structure that explains the coherence of this hierarchy of operators and so so that's that's what our unit if you look made a discovery that there was a good one to to look at that word give me interpret the missing interpretation for churches and calculus was Oxford of sounds like a very salient important point in your intellectual development because of this relationship I suppose it's a cheat before absolutely yes yes and then so I mean we had that big cloud racing over one one term there in the fall of 69 and then I took over a job in Princeton I changed from Stanford to Princeton and our Strachey came to visit me in Princeton and we did some collaboration but it was difficult at long distance to do too much collaboration and then completely out of the blue I had an offer to become the first professor of mathematical logic in Oxford not awesome and so that was that was quite a difficult decision but I especially hope to be able to start a new strong collaboration with stray sheep what happened I mean it it there there there was a good good start there but it turned out that over the years perhaps space she'd had too many cherries before supper that his liver gave up and he died very quickly after the liver liver shut down just a few years that did you guess not yes and in the intervening time when I went to alter it in his very unfortunate death you see Oxford is completely governed by the faculty not by the administrators they don't really have the same kind of creative things we have so it's committees committees committees committees and I was on two faculties ferocity and mathematics and state she was starting up the program in computer science there wasn't a degree in computer science right away it started under him and so there are lots more committees to do it and then of course the whole is an exam based system and so you have to write exams you have to write all the syllabus for the exams and then you have to collect the exams so it's committee those hundred committees so there was no time for collaboration before he died so levels so but the big advantage of Oxford was I had a whole number of really excellent students there and so it was it was a very good atmosphere of course what ruined it in the end was mrs. Thatcher because when she came in in the end of 70s the whole financial picture changed you know for example the Thatcher government insisted their overseas students had to pay full fees okay so around the country many a programs shut down because they weren't getting half of their students from overseas and things like that so then when out of the blue I had an offer from Carnegie Mellon in 1980 the financial situation I hadn't ever intended the leaving Oxford but the financial situation I was very discouraging very wonderful young colleague after he got his degree he interviewed 12 times at least and always came in second and had to go and be a schoolteacher for a period eventually got a university position but was very bad times for academic position so that was very discouraging the university went to Carnegie Mellon what was its situation to computation as a field by now it's establish well yeah so they just had their 50th anniversary two years ago I think and so they were well established by 1980 so Stanford started about at the same time the very computer science department and Carnegie Mellon also had made a very big name and artificial intelligence through there's people there some of them are Turing Award winners as you know so it was a very well established program Oxford was still at the beginning of its computer science program and so a Carnegie Mellon had much more to offer in the way of computer science so that was part of it attraction was there a distinction made between theoretical computation inquiry and applied and practical so of course all the time is right then sometimes they don't talk to each other not if you were invited as a theorist yes yes and the department was really had happy to have it here there with theory developed particularly well there are lots of aspects to theory a lot of it has to do with combinatoric so all of it is much more like Baum Knuth for example I think dr. booth partly would be called a theorist I mean he's got fantastic actual computations amazing ones in his life but also there is there are other aspects to that that is really regarded
as theoretical and so our Carnegie Mellon was a glad to try to develop that kind of programming so that you continue have a very active reproductive intellectual life and we can't get to all of it but is there a next stage we might spend some time with where the questions you're asking and perhaps the solutions you're finding or something that RT in your career oh well again at Carnegie Mellon I mean with that starting in the 80s and then I retired in 2003 are they were it was very attractive for students so there were a lot of good students that came through that and so that was that was also very lucky for me surprisingly enough to of my in the later years still my best students came from Slovenia the difference between the Western countries and the Eastern European countries is that at the college level the ecrv countries had much more traditional programs and so because computer science is sometimes a very mixed environment there the Eastern Europeans had better boss from their basic college education very mathematical of the American students did and so as I say to my students I'm still in close contact with them in Slovenia were extremely good to have it but there are also several other ones too and so I've been really lucky in and having your students another group came from Scandinavia especially from Denmark and so one of my last students is head of a department in in Denmark now anger during this turbulence and in the present both in terms of your interest but also that you speak to the next generations of researchers whether the interesting problem and directions and perspectives that you would convey yes--that's I don't quite know how what to put into words here I mean they're just lots and lots of problems available but one thing that I see in the present time is knowing what has been done in the past and what you should build on and so my experience in the last last five years here is that the Internet has absolutely completely changed research for one thing there are things like keys that is at Cornell University which is a repository and so it was really started by physicists because I think physicists are always under a lot of pressure it's kind of one-upmanship who has the next big idea and so journal publication was too slow so they put things in electronic form in in our keys so they are available me tomorrow right that's been fantastic to have a preprint things available there but the other thing that I use absolute everyday is Google Scholar because if you if you say Google Scholar then a new search page comes up there and then if you put in the right names in the right keywords you find decades of references to books and journal articles on subject area and so I think a problem that we have to solve is with this incredible richness of available materials how do you get an idea as to what's important for your work what's been done in the past what to do how to keep your bibliography you know sufficiently detailed enough and all of that I think we need more tools that will come with the Internet to help with research the other kind of thing that is completely changing is the cloud what does the cloud mean it means you can have just your iPhone say and communicate with the cloud and find all kinds of materials data pictures articles that sort of thing in other words you don't have to have your own big computer you just have to have a connection in the cloud to find things that's about your reason is a phenomenal opportunity can also perhaps a confusion yes lots of confusion as to how really to organize your thoughts to make the best use of all of those knowledge any young man you are facing a world of limited information as I sense it I mean at the beginning of a field like to think fundamental insights to be to be found and this feels like an era where there is so much out there to be sorted is that a oh yes excellent that's been the big change because I mean in 50s or the 60s when you were in college there there are only certain journals where you would look to find the things but now there's just an incredible worldwide connected Walter Walter of information and it really takes a lot of effort to keep track of what's going on this is question what might have worked would you enter into as a young computational addition SM okay I think yes I think I can answer that because I have a very big a colleague in Bruin I've been working with and that's using the computer to prove theorems and there have been several great successes with that but it needs lots more development because it's hard to communicate with computers to get them to do things and the question is how to be able to say questions which are you can understand which you can then give to a mechanical device to do something to and then to get answers out of it that you can also understand there so there's been a lot of excellent development and I know many people around the world working on those things but in a way it hasn't had an impact on mathematics the same as say for example John Nash was able to do with pencil and paper when he proved his theorems are but but there's a big opportunity to get the computers to do scientific deduction and I think that's going to be the next big breakthrough it's it's it's not it's not solving questions in jeopardy or doing or doing you know games of chess winning chess games but proving theorems will be a big a big development and I would recommend someone to go into that thank you so much thank you for being here [Music]