http://www.bbc.co.uk/radio4/science/themat...rialworld.shtml
Should be on this coming thursday 16:30 - 17:00 GMT on BBC radio4, if you miss it though you can listen again to the recorded programme through that page I posted.
Its a very good programme normally, you can listen to the back programmes to get a feel. (Radio 4 and all the BBC radio channels can be listened to live through the net in whatever country your in)