Description Ever wonder why Italy's Leaning Tower of Pisa has been slowly toppling over for centuries? Stack books on a foundation of paper balls to learn about rickety building foundations and center of mass. How about the 15-foot-high tidal wave of molasses that tore through the streets of Boston in the Great Molasses Flood of 1919? Karate chop a full tube of toothpaste (outside!) to demonstrate the messy behavior of non-Newtonian fluids.