http://mediasite.com/

Learning how and when and by whom ideas were developed and discoveries made is critical to understanding them colossal edifice that is human knowledge, especially if you aspire to make a lasting contribution to building upon it. (This is part of the reason a good university degree includes a huge amount of reading.) The BBC’s In Our Time series is a great place to start dipping a toe into the history of science and philosophy, whether to expand your general knowledge or seek out interesting areas for further research.

BBC Radio 4: In Our Time

It’s available online and by podcast, so you no longer need to be in the UK to take advantage of Radio 4’s thoughtful but accessible programming.

Further to the history comment, there's also http://globetrotter.berkeley.edu/conversations/ and http://www.talkinghistory.org/index.html

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