So-called non-Newtonian fluids are the stars of high school science demonstrations. In one example, an ooey-gooey batter made from corn starch and water oozes like a liquid when moved slowly. But punch it, or run across a giant puddle of it, and it becomes stiff like a solid. Pour it on top of a speaker cone, and the vibrations cause the fluid to stiffen and form strange tendril-like shapes. Now, a group of college students has figured out a new use for the strange stuff: filler for potholes.