The following is a lecture on string theory by Edward Witten upon receiving the Newton Medal.
Note: Use the little screen icon -- second from right on bottom -- to flow up the image to full screen size.
Halfway through the second part, Witten talks about M-Theory.
In watching these videos it becomes very clear that the skills of the creator are not the skills of the expositor. For a generalist such as myself, I need an expositor with the ability to draw appropriate pictures and connections to make this material come alive. With Witten I find hints of something very interesting, but he doesn't know how to describe it in ways that makes it truly meaningful for me.