# Review: X&Y, Science Museum

*Published in the Telegraph, 12.10.2013*

Two variables walk into a cube. That’s not the set up for a boffin’s bad joke, but the actual start of *X&Y* – a maths lesson masquerading as theatre from Oxford’s current Simonyi Professor Marcus du Sautoy and actor-cum-academic Victoria Gould. “Identify,” says one, as if kicking off some conceptual Hamlet. “Qualify. Factorise.” And that, dear readers, is when this critic and his rusty, 12 year-old Maths GCSE began to lose track.

X&Y is a look at conceptual numbers, specifically zero and infinity. Du Sautoy and Gould play two Beckettian figures stood in a single white cube that’s part of an apparently infinite series of similar, but not identical, white cubes. There must, they theorise, be some way out. Mustn’t there? What if it’s a loop like a bagel’s surface or a Mobius Strip? Gould exits stage left and, some time later, re-enters stage right.

Essentially, the question is whether we can talk in such abstracts even though they can’t actually exist in reality. Theoretically, you can keep halving an orange into an infinite series of tasty, increasingly tiny half-time snacks, but reality – clearly – doesn’t work like that. So can we really base our maths – the building blocks by which we understand our universe – on such impossible ideas?

What Du Sautoy and Gould eventually propose is that maths, just like theatre, relies on models and metaphors, whereby something real stands in for something unattainable. There’s a sense that maths is itself a form of performance, that we’re all complicit in accepting its base terms; the blackboard is the same as the stage.

However, quadratic equations and shape theory are few people’s idea of good entertainment. Maths can make great theatre – think of Complicite’s gorgeously ethereal *A Disappearing Number* (on which, incidentally, du Sautoy and Gould first met) – but it needs some human interest to do so. Served up this neat, it’s just unpalatably dry. What’s more, the show’s thought process follows such logical steps that it can’t really ever spring a surprise.

I’m not convinced it works as a maths lesson, either. Once du Sautoy and Gould get going, there’s no stopping them. Either you keep up – in which case, you probably had some grasp of its ideas already – or else, like the remainder at the end of long division, you get left behind. These days, there are plenty of theatrical forms that allow a genuine two-way dialogue between actors and audience, but by opting to lecture, du Sautoy and Gould are content to let whatever sticks, stick.

*Photograph: the Science Museum*