Interview with Professor John Tucker

John Tucker was born in February, 1952, in Cardiff. His father was a young police detective, with a rank of sergeant, and his mother was a housewife. The family were stationed at Aberdare, north of Cardiff, from which they moved across Glamorgan as his father was promoted. As a result, John changed schools frequently. Family life stabilised when they moved to Bridgend where the headquarters of the South Wales Criminal Investigation Department was located. Later, his father set up Wales’ Regional Crime Squad in Cardiff, and worked on the Investiture of the Prince of Wales and the Aberfan Disaster, as well as organised crime. His mother ensured the home was a very happy one.

John went to the Boys’ Grammar School in Bridgend where his favourite subjects were the sciences, especially physics. He says he was not particularly good at mathematics but later realised it was down to poor teaching, adding: “My memories were very much of enjoying most forms of school work, having quite an independent interest in the world and in different subjects. I remember coming home one day, and I discovered a new channel had appeared on my television at home, and it was called BBC2. In those years, and for many, many years, BBC2 was an enormous repository of cultural programmes, scientific programmes, advanced documentaries and that really was very interesting and quite influential.”

John chose to study physics, pure mathematics, and applied mathematics for his A-levels. His teacher of applied maths at Bridgend had created a new syllabus which combined computing with classical mechanics. John says: “So from ’68 to 1970, in my applied mathematics A-Level, instead of very advanced work on static mechanics, we were learning about Boolean Algebra, circuit design, algorithms, flow charts, and mechanical calculators of the classic wind-the-handle variety …. That had quite an effect because the Boolean Algebra and the circuitry was very, very abstract and it was taught axiomatically.”

John went to Warwick university to study mathematics in 1970. At Warwick, mathematics was exclusively pure mathematics: algebra, analysis and topology. Other kinds of maths had homes in other departments. His course allowed him to select subjects from different departments to make up the required number of elements and so in his first year John selected mechanics, philosophy of science and mathematics, and computing. In his computing course, he used an Elliot machine with punched cards to learn programming with Algol. In his second year, John added mathematical logic taught in philosophy by David Miller, and continued with computing with a course on the theory of computable functions taught by theoretical computer scientist David Park. By the third year, John says: “I had done courses on logic, the philosophy of logic, the history of science, the philosophy of science and computing. …  I enjoyed it. I simply did things that pleased me; it was absolutely great and at the end of my time at Warwick, I definitely had a huge appetite to learn more and focus on mathematical logic.”

John applied to and was accepted by Bristol and Oxford Universities to study mathematical logic. He chose Bristol University, having spent two weeks in Bristol at the European Meeting of the Association for Symbolic Logic in the summer of 1973. His supervisor was John Cleave who was a logician with very wide interests.  Cleave had experience of early computing from his time at Birkbeck working with Andrew and Kathleen Booth. John says: “He proposed that given that I knew an awful lot about algebra from the Warwick experience, I might want to examine a subject where you look at what can be computed in classical algebraic systems. I worked on algorithms and computability theory looking at the scope and limits and of what can and cannot be computed in the basic algebraic systems, groups, rings, and fields.”

John did this after he had immersed himself in universal algebra.  He adds: “Universal algebra was a world in which you didn’t know what the data was, you just knew that it satisfied certain laws and these laws were about the operations you could do on it and that was my PhD thesis.  … I learned a lot during that period of all sorts of subjects just to get this thesis written. I acquired a rather general appetite for absorbing things, sometimes very superficially I have to say, but it worked for me.”  While a research student he attended a logic conference at Leeds University where he met Stan Wainer (Leeds) and Jens Erik Fenstad (Oslo) both of whom would influence his development. 

In 1976, John applied for and received a Royal Society European Fellowship at the University of Oslo. Arriving in January 1977, he joined Jens Eric Fenstad’s logic group and began a lifelong collaboration with Viggo Stoltenberg-Hansen on computable algebra. John says of his time at Oslo: “It was very productive. I learned a lot. I learned that all sorts of things my colleagues were doing there, I didn’t like. They were far too arcane and conceptually exhausting and so that moved me in the direction of computing. There was a certain direction of travel in computing and logic at that time that meant that I was finding myself reading computer science papers more perhaps than papers in logic.”  He made good friends with colleagues and visitors, especially Jan Bergstra (Utrecht).

By the end of his two years in Oslo, John had moved from mathematics into computer science and was looking for a job. He wrote to Jaco de Bakker of the Mathematical Centre in Amsterdam, John explains: “I had vaguely been aware of the Mathematical Centre as a place for working on logical aspects of theoretical computer science, so I wrote him a letter and sent him some papers that I’d been working on, and I got a letter back offering me a job.”  He met de Bakker on his first day and they became friends.

He started his new role in January 1979. He adds: “I was formally, and I think completely psychologically now, a theoretical computer scientist. No longer a logician or a mathematician or of any other kind of tribe; I was in computer science and I loved it there too.  I loved Amsterdam and the work in the Mathematical Centre.” At Amsterdam, John began lifelong research collaborations with Jan Bergstra (then Leiden) on abstract data types and program semantics, and Jeff Zucker (then Mathematical Centre) on abstract computability models and their applications.

In 1981, John returned to the UK for family reasons and worked as a researcher at Bristol University. John says: “I felt an incredible sense of boredom returning to Bristol and I thought I really must start applying for lectureships fairly promptly. So, that year in Bristol was sort of productive but mainly productive because I had a massive legacy of work that I brought with me on returning from the Netherlands. I did get stuck into the new subject that I was going to work on, but my real focus was trying to get this scientific life on some sort of permanent basis.”

In 1981, John was appointed Lecturer in the Department of Computer Studies at Leeds University, then run by a demanding computational physicist, Professor Ken Smith. Here he learnt the art of teaching students. Among a number of initiatives, John went on to establish the University’s Centre for Theoretical Computer Science. The Centre came about following an initiative in the early 1980’s of Duncan Dowson, a mechanical engineer and historian of engineering, who suggested that Leeds needed to have inter-disciplinary research centres, and who having obtained funds, invited colleagues to apply.

John and Stan Wainer at Leeds, were already collaborating, along with colleagues studying logic in the Philosophy Department, and “so they decided to create an interdisciplinary centre for theorising about computing”. John adds: “It functioned rather well for some years, at a time when theoretical work and investment in computer science in the UK was growing.  The ‘80s was a very, very important period for the development of computer science in the UK and the university system. The creation of the Centre for Theoretical Computer Science at Leeds, staffed by mathematicians, computer scientists, and some philosophers, proved to be timely.” In 1985, the Centre started the annual British Colloquium on Theoretical Computer Science of which John was President until 1992. Its 38^th Meeting will be in Swansea in 2022.

At Leeds, John met and married his wife, the ancient historian Tracey Rihll.  His eight years at Leeds were deeply fulfilling.

Between 1982 and 1985, John was also a visiting professor at the University of Uppsala. John explains: “It came through my friend Viggo Stoltenberg-Hansen in the mathematics department at Uppsala. At that time, Uppsala had some miscellaneous small departments of computing: one devoted to numerical work, which was an extremely strong department; one department with a slight emphasis on hardware, digital technology of the electronics variety; and another one that was a little bit more like what you might call a computing department.  But they were small, and they had an important role in teaching but their research programmes were, at the time, extremely weak. So, there was an initiative at Uppsala to create a new degree. … Viggo organised for me to come and give a course on current trends in theoretical computer science. …  I went through lots of topics in order to showcase what theoretical computer science might be in order to feed the development of this new degree programme.”

As a result of the success of that initial lecture course, John was invited to continue as a visiting professor. John adds: “I went to Uppsala for seven years and performed those duties, wrote papers with Viggo and generally hung out with whoever was around and enjoyed what is a remarkable town and a remarkable university.”

He adds: “One of the things that is interesting is how small everything was in the 1980s in computer science in the UK, and in other countries. The older and the grander the university, with one or two exceptions, the more neglected and smaller was computing.  Places like Middlesex were thriving.  They simply saw the value and importance of the subject and taught it, and places like Leeds had the same attitude: there’s plenty of things that have got to be taught to people, let’s teach it!  So, they would set up departments and grow them and sometimes with little attention to research programmes. Research really started to take off as a kind of obsession in the British academic system through the research assessment programmes; that changed everything in the 1980s.”

In 1989, John became Professor of Computer Science at Swansea University, saying: “It was going home.” Ancestral families on both his mother’s and father’s side were Swansea and Gower people.

John’s role was to rebuild computer science at Swansea. His career at Swansea has seen him hold the following positions: Head of Computer Science (1994–2008), Head of Physical Sciences (2007–11) and Deputy Pro Vice Chancellor for high performance computing (2011–2019). His long-term research interests in data and the scope and limits of computing by machines, physical systems and people flourished.

In 1994, he also became the scholar of the history of computing. He says: “I’ve always been interested in historical things, both local history, and technical history. … I had done a huge amount of work with Peter Townsend on the new curriculum and I suddenly thought I want to do something about the history of computing in this university and I want to make sure I know a lot about this, it’s time for me to really study it. Of course, the best way to study something is to give a course on it, so I started to teach it in ’94.” John observes that students on the course are required to write about and present on an unfamiliar topic and the educational and training value goes well beyond learning about the history of computing.

In 2007, John founded the History of Computing Collection at Swansea University. He adds: “This is my most enthusiastic subject at the moment because I’d been teaching this subject for a long time and we had stored lots of bits and pieces.  For example, our department had been an Apple-based department from early on and there were other things there, all sorts of miscellaneous things. Our engineering department had been heavily into computing from the early 1960s so it was quite a kind of computing-oriented thing.  … The collection went in two directions. First of all, there is the natural equipment and software manuals which are lying around, then there is an archival operation because I have quite a lot of archives. Also, colleagues who were in Holland, for example, offered donations from their filing cabinets.  So, I started to collect the papers of various computer scientists who had retired and wanted to dispose of them in a way that was sound. … Suddenly, the archive started to grow and the space started to grow.”  The collection covers the whole of Wales though is stronger on south Wales.

To celebrate the Centenary of the University, he has recently written a history of computing at Swansea University up to 1989, the period before he returned: The Computer Revolution and Us: Computer Science at Swansea from the 1960s. https://collections.swansea.ac.uk/s/swansea-2020/page/computer-science

John offers the following advice for anyone thinking of a career in computer science. He says: “Never underestimate the power of an individual with an interest, and if that interest has got elements of passion about it –  and also ability –  never underestimate how important that is. The focus on the subject, for example, is the key thing.

“So, try to understand where you are in relation to those qualities, and that is all about this sense of inner confidence or belief, which needn’t be explicit but it’s simply in you and you trust it; even though you can’t rationally explain it, you trust it.

“Then be optimistic and hopeful that if you can satisfy yourself that you have these properties, things will work out for you through patience and persistence.

“My third point is never underestimate how many people around you don’t have these things and are yet doing very well, but are not doing particularly good things.  So, keep an eye on them, make sure they don’t get in your way, and keep the faith and be very cautious about the modern world’s mechanistic, transactional, bureaucratic tendencies.  If you keep all of those plates spinning, as long as the energy level – the real interest – is there, and the patience and persistence, it will all work out.”

Interviewed by Elisabetta Mori

Transcribed by T P Transcriptions

Abstracted by Lynda Feeley