Retirement of Professor Bill Jackson

23 October 2024

When did you first join QMUL and what was your academic journey before that?

I came to QMUL in 2003. I was a maths undergrad at Imperial College from 1971-74 and then moved to Canada to do my postgraduate studies on a Commonwealth Scholarship. I did my MSc at Queen's University with Norm Pullman and my PhD at the University of Waterloo with Adrian Bondy. I returned to the UK as an EPSRC Postdoctoral Fellow at the University of Reading with Crispin Nash-Williams in 1978. I joined Goldsmiths College as a maths lecturer in 1980 and stayed there until 2003.

You have been at QMUL for a long time then! What kept you here?

I enjoyed being part of a large and active group of mathematicians with interests in combinatorics. In particular the weekly meetings of the combinatorics group which encouraged lively discussions both during and after the seminars. I also enjoyed interacting with the many PhD students working in combinatorics and related areas, not just academically but also on the squash court.

Your main research area is graph theory; could you tell us a bit about that?

A graph is an elementary mathematical structure consisting of vertices and edges in which every edge joins a pair of vertices. Graphs first appeared in puzzles from recreational mathematics ,(such as Euler's problem of finding a walk around the seven bridges of Königsberg or Hamilton's game of constructing a cycle on the dodecahedron which includes every vertex exactly once). Graph Theory has become increasingly important in the last 80 years because of its applications in operational research and computer science. Indeed the original puzzles of Euler and Hamilton have important real life applications in the field of network routing.

And what about some specific problems you have worked on?

My PhD was on cycles in graphs - I obtained a sufficient condition for a regular graph to have a Hamilton cycle which extended previous results of Erdős and Hobbs, and Bollobás and Hobbs.

I wrote several papers with Tibor Jordán from ELTE in Budapest in the 1990's and early 2000's on the optimisation problem of determining a minimum set of edges we can add to a graph to satisfy a given connectivity requirement.

Tibor got me interested in graph rigidity in one of my extended visits to Budapest in 2003 and I have been working mostly in this area since about 2005. As is true for most of the best problems in graph theory, the fundamental problem is simple to state but extremely difficult to solve: we are given a graph whose vertices lie in 3-dimensional space and we would like to know when the positions of its points are uniquely determined by the lengths of its edges.

I have been collaborating with a consultant for Siemens in Cambridge, John Owen, on applications of rigidity theory to CAD since 2014. One of our publications determines when a 2-dimensional CAD drawing consisting of points and lines is uniquely determined by its point-point distances, point-line distances and line-line angles.

What are you hoping to get up to in your retirement?

I plan to stay research active for as long as possible. I visited Tibor Jordán at ELTE for 2 weeks in May this year and will spend 2 months at the University of Tokyo with Shin-Ichi Tanigawa from September. I will be attending a 3 month research programme on graph rigidity at ICERM in Rhode Island from February 2025. After that I am open to offers.

Thank you Bill! We also asked for memories from a selection of Bill's current and former colleagues:

RA Bailey: I have known Bill Jackson since at least 1987, when I participated in the 11th British Combinatorial Conference, which was held at Goldsmiths College, London. I was his colleague in the Department of Mathematical Studies at Goldsmiths from 1991 to 1994, when I left to join what was then Queen Mary and Westfield College.

At some later date, Goldsmiths decided to close the Maths Department. I heard about this when I was Head of the School of Mathematical Sciences at Queen Mary. At that time, the number of undergraduate entrants in each subject, as well as the money paid to the university for their teaching, were strictly controlled by some government body. I had the idea of trying to see whether, if we took on staff from Goldsmiths, this body would allow us to recruit more undergraduates. They approved of my plan, and so Bill Jackson as well as statisticians Lawrence Pettit and Roger Sugden, analyst Cho-Ho Chu, and astronomer Richard Donnison moved to QMUL.

From then on (until I retired from QMUL in 2012), I regularly saw Bill in the weekly Combinatorics Study Group, as well as chatting to him about various aspects of teaching Combinatorics. He was a great colleague.

Viresh Patel: As a postdoc at Queen Mary about 10 years ago, I had several research discussions with Bill and worked in a group with him during a research retreat. We didn't end up writing any papers together, but he offered a lot of encouragement at the time and some of my research since then has been inspired by his work and conjectures.

Katie Clinch: Bill has been a wonderful mentor to me since I first started my PhD with him 10 years ago and in my career since. Beyond maths, Bill is keen on many sports. It felt like at every conference he attended, his enthusiasm would somehow convince a ragtag group to join an impromptu football game. The image of everyone from fresh PhD students, to shuffling professors, all playing on the pitch together, is one that sticks with me. I also have fond memories of hiking in the Rocky Mountains with Bill after a conference in Banff. Whenever one of our fellow hikers got anxious about bears, Bill would start singing to scare the bears away, whether or not he remembered the lyrics.

Dudley Stark: At Bill's Inaugural Lecture he showed a long list of papers recently published and the convener said something like "that's the kind of research output we like to see". It made an impression on me.

Peter Cameron: After Bill came to Queen Mary, we went out running from time to time along the canal and river towpaths. One day when Bill and I were running, we passed two young boys, one of whom called out, "Look, it's 118 and 118!"

[For readers under the age of 40, at the time there was a company providing a telephone directory enquiries service on the number 118118. Their marketing (to quote Wikipedia) "featured two men with droopy moustaches, wearing items of clothing with 118" and "was originally launched using the two men dressed as athletic runners" -- the resemblance to the two protagonists here is indeed uncanny!]

Robert Johnson: Bill was a great colleague. I found him full of support, encouragement and sensible advice, especially in my early years at QMUL and later when I took over from him as Head of the Combinatorics Research Group. He was collaboratively minded, and generous with his time and expertise. Over the years he gave great leadership in his research area and the school, always doing this in a quiet, modest and unpretentious way.