My Professorial Lecture has been postponed. The date, 30th November, was set months ago but now it clashes with possible nationwide industrial action. I feel this creates too many conflicts and complications so would prefer to find a different date. We are looking for an alternative some time in Spring 2012, and meanwhile I'd like to thank everyone who signed up and hope very much you'll be able to make it on the alternative date. I really appreciate your interest in the talk, and will announce the new date as soon as it's decided.