15:32DiscoveryExchanges At The FrontierEpisode 2 - Lawrence KraussBBC World Service Duration: 27 minutes Wed 9th Dec 2009, 15:32 on BBC World Service OnlineAvailable for over a yearListen nowLeading scientists are tested over the social impact of their discoveries by philosopher Anthony Grayling and the public.GenresFactualScience & NatureBrandDiscoverySeriesDiscovery: Exchanges At The Frontier Source: BBC Online