Professor Cai Wen was invited to give a  lecture on Extentics in Guangzhou on  May 22nd, 2009. The title of the lecture is “Studying Smart Knowledge—Common  Lecture about Extentics”. About 200 people attended the lecture, mainly teachers  and students from Guangzhou Urban Technology  Academy and members of Popular Science Volunteer  Society Professor Cai introduced smart discipline, the basic theories of  Extentics, and the methods of becoming smart depending on lively stories in  understandable language. The lecture is warmly welcomed by the audience.