I've only just found this thread, but those who can listen to or download from the BBC website (not sure whether it's UK only), look out for the radio program series "In Our Time" with Melvyn Bragg. Although Melvyn is an author and playwright a fair proportion of these programs embrace science and are delivered with very high quality (in terms of the treatment of the topics and the expertise of the participants). Although an "arts" person Melvyn is extremely open minded about science and doesn't fall into the frequent trap of dumbing down.
It's carried by BBC Radio 4. The website archive goes back literally years.