From a chemistry andor physics point of view. How do you explain pepper repelling from dish soap?

The answer is on this site:
http://www.newton.dep.anl.gov/askasci/gen06/gen06174.htm

The "simple" answer is that the surface tension of the pepper particles is less than "pure" water (about 72 ergs/cm^2), so the pepper particles tend to float on the water's surface. When you add a drop of soap, you greatly reduce the surface tension of the water near the point at which you add the soap. Initially, this causes a repulsion of the pepper particles and the particles tend to follow the high surface  tension areas. If you shake the solution, you will find that the pepper particles get "wetted" by the soap solution and the pepper  will disperse in the soap solution.