Kirsty Young's castaway is the physicist Professor Jim Al-Khalili.

He's spent his adult life studying sub-atomic particles - and trying to explain them to the rest of us. He fell in love with physics when he was a teenager growing up in Iraq. With an Iraqi father and English mother, the Baghdad he spent his early years in was cosmopolitan and vibrant but, once Saddam Hussein came to power, his parents realised the family would have to flee, and he has lived and worked in Britain for the past 30 years.

Record: She's Not There by Santana Book: The Road to Reality by Roger Penrose Luxury: Acoustic guitar.