## string theory

There are many theories in particle physics that cannot be tested in experiments. Does this make it unscientific? This debate, featuring one of our favourite theoretical physicists, David Tong, explores the question.

Interalia is a show by Turner Prize winning artist Grenville Davey and theoretical physicist David Berman.

How many dimensions are there? In the latest online poll of our *Science fiction, science fact* project you told us that you'd like an answer to this question. So we went to see theoretical physicist David Berman to find out more.

A bizarre set of of 8-dimensional numbers could explain how to handle string-theory's extra dimensions, why elementary particles come in families of three... and maybe even how spacetime emerges in four dimensions.

String theory has one very unique consequence that no other theory of physics before has had: it predicts the number of dimensions of space-time. But where are these other dimensions hiding and will we ever observe them?

On the face of it, an artist and a theoretical physicist might seem an unlikely pairing. But Turner Prize-winning sculptor Grenville Davey and string theorist David Berman's collaboration is producing beautiful, thought-provoking work inspired by the fundamental structure of the Universe. Julia Hawkins interviewed them to find out more about how the Higgs boson and T-duality are giving rise to art.

*Strong Fields, Integrability and Strings*programme, which took place at the Isaac Newton Institute in 2007, explored an area that would have been close to Isaac Newton's heart: how to unify Einstein's theory of gravity, a continuation of Newton's own work on gravitation, with quantum field theory, which describes the atomic and sub-atomic world, but cannot account for the force of gravity.