Katherine MacAlister talks to Marcus du Sautoy, about his new play X&Y, and finds out what makes him tick

Interviewing Marcus du Sautoy, the Simonyi Professor for the Public Understanding of Science and Professor of Mathematics at Oxford University, is a daunting prospect for someone as hopeless with figures as me.

But then I remember that it’s the man himself I’m interested in, what makes him tick, how he got where he is, how he spreads himself around the globe so efficiently, this inherent need to spread the word, the lure of TV and radio, and why, more importantly, he is acting in his own play at the Oxford Playhouse

In fact I had nothing to worry about, Marcus being as charismatic and alluring to talk to as he is to his students, audiences and TV fans no doubt.

But it’s still a fascinating diversion for one of the world’s most famous academics.

“I’ve loved doing theatre since I was a student here and despite being an academic, part of being a scientist is imparting that knowledge, whether during a lecture or seminar, it’s still a theatrical role - to bring your subject alive and to perform it, to get people excited by the same things that you find exciting," he tells me.

Some might say it's rather unfair that he’s been given two gifts, at which he throws back his head and laughs out loud. “I am passionate about both,” he accedes. "But I grew up in Oxford and went to university here, and while I did choose maths, I did a lot of theatre and mixed with all sorts of wonderful people doing all sorts of different subjects and things. I don’t enjoy being compartmentalised.

Which is what made him such an ideal choice to take on Dawkins mantel of Simonyi Professor, a role he takes incredibly seriously. Anyone who has heard the speakers he poaches from around the world talking about their scientific breaktheoughs will know how enlightening they are.

"I can sit type up a paper on the quasi split of algebraic groups, as I'm doing now, and still get excited by my own subject, making new discoveries, but it does make me want to go out and tell as many people about it as possible, to engage the world in your work.

“And theatre is another way of doing that though,” he insists, "to get people to look at the world of science in a different way, whether in stage, radio or TV, aiming to fire up the imaginations of the next generation. I see it as an obligation."

Which is all well and good as an advisor or visiting speaker, but parading around the Oxford Playhouse stage dressed up as a cube is quite another. “I know, I have rather put my head above the parapet,” he laughs.

X&Y grew out of a collaboration with Complicite Theatre so when he hooked up with fellow science thespian Victoria Gould the seeds were sown.

"I wanted to bring the maths alive through a story, because I think maths and theatre have a lot in common, a set of rules and constraints and what grows from that, but performing X&Y also plunges me deeply into a fantasy I have had since I was a student and my PHD was stalling, that I could run away with a theatre company instead.

"Realising I can do both – performing and doing maths at the same time is the most exciting thing for me. So yes it is a big risk. and right out of my comfort zone, but I like pushing myself and my boundaries."

And the plot? "I play X who lives in a cube and is comfortable there unaware there is a universe going on outside it, escaping through his own mind. And then Y literally crashes into his cube, having been searching for a human in the endless cubes she has come across, never giving up that there is something or someone else out there. So this is about the realisation that there is something more. It's about the big questions about the universe, whether there is anything else out there, whether the world is infinite, all explored on the microcosm of the stage.

"It sounds big and philosophical but it's also very playful with lots of humour in it," he promises.

But why insist on starring in it himself. Why not put some other mug in the cube? “Because X is who I am and has the same conflicts and questions that I do. So it's basically about what I’ve been thinking about for the past three years. Its basically me at heart.

"And there is something so exciting about the buzz of performing, of creating something. It’s a bit of a drug, just like proving theorems. Its very powerful.And i want to keep trying new things. I enjoy new challenges and that includes bringing up my children.

Oh yes, amongst the plays, travelling and theorem solving, Marcus has three children at home in London.

“My wife thinks I’m slightly Aspergic,” he grins, “But whatever I focus on, takes up all of my attention whether I’m playing with my children or trying to solve a mathematical problem. But I can switch between the two quite easily as well.

Put it this way, I’m not still doing this because of the maths problems I’ve solved, but because of the ones I haven’t, and in the same way people really want to know about science and they have a real appetite for it. The BBC does not make TV science shows to be worthy but because people watch them. It's my job to bring the maths alive."