They have proven to be useful examples of gravitational wave dynamics. By developing the affine geometry of projection tensor fields, I am finding a single set of insights and identities which apply to a wide variety of different situations. For example, the geometrical theory of surface embedding due to Gauss and Weingarten, fluid dynamics, spacetime perturbation theory, and the dynamics of cosmic strings and membranes are all included in this framework. The course is taught from a home-page on the Web. The large lecture sections now focus on familiarizing students with the web site, commenting on the material and illustrating it with demonstrations, and testing for comprehension after every main point by using the questions embedded in the web site.
Every lecture is a quiz and every quiz counts towards the student's final grade.
In this model of instruction, the lecture ceases to be the main information transmitting device. Instead, it becomes a device for motivating students to use the web site which is then the main teaching engine of the course.