On February 13th, Christopher Zeeman sadly passed away. Zeeman was a British mathematician who received a B.A. from the University of Cambridge and was awarded his Ph.D. in 1953 for his thesis on *Digomology*, which is an algebraic structure associated to a topological space that contains both homology and cohomology. It introduced what is now known as the Zeeman spectral sequence: a way to compute homology groups by taking successive approximations.

In 1964, he went to the University of Warwick, where he lead the setting up of the Department of Mathematics and the Mathematics Research Centre, both of which have established a large international reputation, which was largely due to Zeeman’s remarkable leadership. Zeeman’s leadership was an informal one, which allowed mathematical research to flourish. When Zeeman left Warwick in 1988, he was made an honorary professor.

Zeeman’s research has been in a wide array of areas such as topology, dynamical systems and mathematical applications to biology and the social sciences. His initial research was in topology and one of his theorems concerned the unknotting of spheres in 5 dimensions. Due to his groundbreaking work in topology he is considered one of the leading topologists of all time.

However, amongst the wider scientific community, he is most well known for his contribution to, and spreading awareness of catastrophe theory, which was due initially to René Thom. In particular, Zeeman was a pioneer in the application of catastrophe theory to the biological, behavioural and physical sciences. He invented the Zeeman Catastrophe machine which was a mechanical device to show how a small perturbation can give rise to a discontinuous consequence.

**Honours/Awards:**

- Senior Whitehead Prize of the London Mathematical Society (1982)
- Elected as a Fellow of the Royal Society of London (1975) and awarded the Society’s Faraday Medal (1988)
- 63rd President of the London Mathematical Society (1986-88)
- Knighted (1991)
- The Christopher Zeeman Medal for Communication of Mathematics of the London Mathematical Society and the Institute of Mathematics and its Applications is named in his honour. Its aim is
*“to honour mathematicians who have excelled in promoting mathematics and engaging with the general public”*, one of the great things that Zeeman accomplished.

When asked whether mathematics is an art or a science, Zeeman responded:

“Both. Sometimes you invent it; sometimes you discover it. You have to invent maths to get a solution to a problem but, in the process, I often discover a whole lot more which I didn’t expect.”

Christopher Zeeman will be greatly missed in the mathematical community, may he rest in peace.

M x