Lively and diverse conversation with Libby Purves and guests Seth Shostak, Fergus Anckorn, Guy Masterson and Vyvyen Brendon. Seth Shostak is senior astronomer of SETI - Search for Extraterrestrial Intelligence - based in California. He is currently in the UK taking part in Exchanges at the Frontier, a unique series of events created by the BBC World Service and the Wellcome Collection, in which the world's leading scientists are tested over the social impact of their discoveries by philosopher Anthony Grayling and members of the public. Fergus Anckorn was held as a PoW by the Japanese for over three years during the Second World War, helping build the infamous 'Bridge over the River Kwai'. Now aged 91, he is the longest serving active member of the Magic Circle. Having performed as a magician since he was a small boy, little did he know that his performing skills would save his life. During his time as a PoW, he sometimes did magic tricks for the guards and soon found that if he used their food as part of the trick, they let him eat it afterwards. A book about his life, Surviving By Magic is written by Monty Parkin. Guy Masterson is an actor, theatre director and writer. He was inspired to go into the theatre by his uncle, the late Richard Burton. Guy himself is probably best known for his stage adaptation of Dylan Thomas' Under Milk Wood, a work with which his uncle will be forever associated. His latest project, Morecambe, is the first biographical play about comic genius Eric Morecambe - which comes to London's Duchess Theatre in the 25th anniversary of the comic's death. Vyvyen Brendon is a former teacher. Her latest book Prep School Children - A Class Apart over Two Centuries looks at the history of prep school children, featuring boys' and girls' experiences from 1800 to the present day. Prep School Children - A Class Apart over Two Centuries is published by Continuum.