After five and a half years Colm-cille Caulfield is stepping down as Head of the Department of Applied Mathematics and Theoretical Physics (DAMTP). He talks about major challenges and proud achievements, why DAMTP is a great place to work and study, and what his advice is for the next Head.
What is the role of a Head of Department?
"I think the word that immediately occurs to me is 'responsibility,'" says Caulfield. There is the responsibility to ensure the good running of the Department, so that it succeeds in its joint missions of producing research and providing teaching, both of the highest international quality. This involves leadership of academic as well as professional support staff, but also looking after finances, ensuring a safe working environment, and allocating resources to the various activities the Department is engaged in.
"There's also a strategic component — looking towards the future and how to improve the provision of research and teaching. This means you have to engage with all your colleagues in the Department, recruit new ones, and also decide how to run the professional support administration."
A HoD also needs to be a figurehead. They need to engage with stakeholders, with alumni, with possible industrial collaborators, and with possible donors to gain the resources that ensure the Department can continue to flourish and thrive.
Navigating the COVID-19 pandemic
It's a long list of responsibilities that would be demanding at the best of times — let alone at a time of international crisis. Caulfield became HoD in January 2020. By the end of March 2020 the country had entered the first full lockdown of the COVID-19 pandemic.
At the beginning of the year the imminent threat was a faint rumour to most of us, but thanks to in-house expertise Caulfield was forewarned. "We are very fortunate in DAMTP to have Professor Julia Gog, who is a world authority on the mathematical modelling of infectious diseases," he says. "She was very much involved with the British government's COVID-19 response for example contributing to the Scientific Advisory Committee for Emergencies (SAGE). So as this strange disease was being heard of from China I talked to her about what was happening — from as early as February we were very concerned."
Caulfield was keen that staff should be able to work from home, and encouraged them to do so even before the University followed suit. "I have a very clear memory of walking around the Centre for Mathematical Sciences after it had been closed down with my skeleton key. Going around into deserted offices, closing windows and so on — that's my memory of the very beginning."
There was still some Easter Term teaching to be done and this required improvisation bashed out during days of online meetings with staff as well as the other two members of what Caulfield calls the "triumvirate": James Norris, at the time Head of the Department of Pure Mathematics and Mathematical Statistics (DPMMS) and Andrew Thomason, also of DPMMS and then Chair of the Faculty Board.
"It was a very stressful time but also a wonderful aspect of teamwork, really trying to ensure that our students had as good an education as possible and also the best possible examinations," Caulfield recalls. As a result of this huge joint effort the Faculty (DAMTP and DPMMS together) was able to offer in-person exams to those who wanted them as early as September 2020. "It was so important to us to retain credible and rigorous credentials for our students, proving that they had done well in a trustable exam."
Teaching continued — in zoom sessions, with filmed lectures given to an empty lecture theatre, and notes written on tablets — until the Centre for Mathematical Sciences could open once more, albeit with precautions such as mask wearing, limited office occupancy, and rules regarding ventilation. This gave DAMTP a chance to apply its maths. In order to understand the air flow in the various lecture halls, Stuart Dalziel, Director of the GK Bachelor Fluid Dynamics Laboratory, together with some postdoctoral research associates, conducted smoke tests in the different rooms.
"We connected with the DAMTP attitude: we got to the heart of things, we understood the air flow in the building to identify for ourselves a trustable level of ventilation rates," says Caulfield. "I was really happy that when we came back we were able to say 'this is a safe place to work'. Because it's so important for mathematics that there is interaction — for teaching as well as research."
Getting DAMTP through the pandemic is one of Caulifield's proudest achievements. "The way our priorities emerged to be focused on the students, that wasn't a conscious decision. There certainly wasn't a stick in any sense, or a carrot. It was just clear that it was the right thing to do."
Smart people and smart connections
In terms of more usual academic activity Caulfield is pleased with a number of new educational initiatives. A new undergraduate sequence of courses in the Natural Sciences Tripos on quantitative environmental science, as well as three new interdisciplinary Masters programmes: joint with Physics and the Institute of Astronomy; joint with Earth Sciences, and joint with the Genetics department.
At DAMTP there is a real focus on getting to the fundamental 'why' of whatever the system is, using rigorous mathematics, to be able to trust our conclusions. Professor Colm-cille Caulfield
"Through that, and for other reasons too, we've had the opportunity to recruit a large number of outstanding new colleagues at different career stages," he says. "This injection of new blood from diverse backgrounds, working on incredibly exciting new fields is something that I'm really pleased about. These researchers are likely to feed into the Department's future success. We followed the advice of my father who once told me, 'always hire somebody smarter than you'. Thank goodness I wasn't looking for a job at the same time as our new recruits!"
Smart staff and students also require smart new funding directions and this leads to one of Caulfield's most enjoyable experiences as HoD: working with Cambridge University Development and Alumni Relations (CUDAR). "The funding landscape is changing for universities all over the world and particularly in the UK, so funding streams have to become more diverse," he says. Funding for PhD students and for the highly effective summer internship programme for students are particularly important. "Going out and talking to alumni, to foundations, and to companies about the great education and research we do here, and also asking for the support that we need to continue to do it, is certainly the thing I've most enjoyed."
If you want to learn, teach
Teaching, Caulfield emphasises, is at the heart of DAMTP's mission. "It is incredibly enriching to the academic that, through the process of teaching, they themselves learn," he says. "There is also the fantastic aspect that we are in the fortunate position to attract incredible PhD students and postdocs to come and study here. There is such positive feedback between our research and our teaching, for sharing knowledge, generating new knowledge, and also training the next generation of colleagues and collaborators."
Research culture at DAMTP, says Caulfield, is based on a unifying philosophy that spans across all research areas, from theoretical cosmology to the mathematics of health and life. "Mathematics has an incredible power to identify the dominant fundamental aspect of the complex system you're looking at. At DAMTP there is a real focus on getting to the fundamental 'why' of whatever the system is, using rigorous mathematics, to be able to trust our conclusions."
While the mathematics is rigorous and can be highly theoretical, applications remain a crucial driving force, whether it is to understand the potential of quantum computers, the transport of heat by the oceans (one of Caulfield's own research interests), and even rescuing old artworks. "Researchers here use sophisticated mathematical imaging techniques to improve the way you restore art — that's a beautiful example of the kind of philosophical approach we have here at DAMTP."
Handing over the baton
Caulfield will hand over the role of HoD to Nicholas Dorey in September 2025. A major piece of advice he would like to pass on to his successor is to delegate — not in order to reduce the workload but to be able to actively engage and include other members of staff and to benefit from their wisdom. Indeed, during his period as HoD Caulfield re-introduced the role of Deputy Head of Department, and introduced the new roles of Director of Applied Mathematics and Director of Theoretical Physics. "Not to create an extra layer of management, but rather to have another wise head for me to talk to and develop some consensus about the decisions to be made."
Caulfield also stresses the important role of the non-academic professional support staff without whom the entire operation of DAMTP and its sister department DPMMS would grind to an agonising halt. "As HoD you spend a very large amount of time working with and relying on the professional and support staff at all levels." he says. "They are so vitally important to the success of the core missions of research and teaching. You really appreciate this when you are responsible for things."
The role of a HoD comes with plenty of hard deadlines and issues that need to be seen to immediately. But within all this urgency, Caulfiled advises, it's vital to listen carefully to all the other people working in the Department with you. "The really important part is to understand and communicate with your colleagues about what their concerns are and what their new ideas are. That's what really helps the Department to continue to thrive."