John Kelleher recommends the "In Our Time" podcast series. The Science Archive is available online at: http://www.bbc.co.uk/radio4/features/in-our-time/archive/science
Highly recommeded are:
Baconian Science http://www.bbc.co.uk/programmes/b00jdb6c Karl Popper http://www.bbc.co.uk/programmes/b00773y4 The Scientific Method http://www.bbc.co.uk/programmes/b01b1ljm The Scientist http://www.bbc.co.uk/programmes/p00548jq