Sometimes it needs a physicist to make things clearer. After months of luminescence dating (OSL) and still struggling with the "so, electrons in a grain of quartz, energy goes in, electrons get trapped, more energy and then they jump out, releasing photons..." arm-waving explanation of what luminescence dating is actually measuring, it was nice to see Prof. Brian Cox doing a better job of it, whilst explaining time itself, in this clip from BBC2's Horizon 'How Do We Know What Time It Is?'.
Brian will be giving a lecture at the University of Manchester this week, discussing the universe. His brand of rockstar-physicist (TM) astronomy has proved so popular that all the tickets were snapped up in 12 hours, but a live webcast of the lecture can be viewed online.