Mariella Frostrup meets Ruby Wax; mathematician Marcus du Sautoy; writer Wendy Law-Yone and Ian Martin of the D'Oyly Carte Opera Company.

Marcus du Sautoy is the Charles Simonyi Professor for the Public Understanding of Science and a Professor of Mathematics at the University of Oxford. He presents a new series on BBC4, Precision: The Measure of All Things, which explores the history of numerical exactness in our world and how precision has come to rule our lives. Precision: The Measure of All Things is on BBC4 at 9pm.

Ruby Wax is a comedian, actress and mental health campaigner. In her book, Sane New World: Taming the Mind, she demonstrates how our minds can send us mad and how we can rewire our thinking to cope with a frenetic world. Sane New World: Taming the Mind is published by Hodder & Stoughton.

Author Wendy Law-Yone was born and brought up in Burma before fleeing the country at the age of twenty. Her book Golden Parasol: A Daughter's Memoir Of Burma tells the story of her father, the proprietor of The Nation newspaper, who spent five years as a political prisoner. Golden Parasol: A Daughter's Memoir of Burma is published by Chatto & Windus.

Ian Martin is general manager of the D'Oyly Carte Opera Company. D'Oyly Carte has returned to the stage after lack of funds forced it to stop performances in 2003. Following a rebate from the taxman, the company has made its triumphant return with Gilbert and Sullivan's operetta, The Pirates of Penzance. The show, produced in association with Scottish Opera, is on tour.

Producer: Paula McGinley. Show less