20:32DiscoveryExchanges At The FrontierEpisode 3 - Patricia ChurchlandBBC World Service Duration: 27 minutes Wed 16th Dec 2009, 20:32 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 & NatureFormatsDiscussion & TalkBrandDiscoverySeriesDiscovery: Exchanges At The Frontier Source: BBC Online