I found this learned Mans' lectures to be very interesting. Dr. Michio Kaku is asked to make many speeches by very important organizations. There is an introduction the first little bit of the video you could skip to get to the actual Doctors' lecture. That too takes a little time to listen to but I find it worth it. It makes me wish I was an expert in physics.
So grab a cup of coffee sit back and enjoy. Have a great day:)