By the next Olympic Games,almost all of the competing of high jumpers had adopted what came to be known as the Fosbury Flop.What's the secret behind the technique?It lies in a physics concept called the center of mass.For every object,we can locate the average position of all of its mass by taking into account how the mass is spread around the object.For instance, the center of mass of a flat, rectangular object of uniform density will be in the intersection of both diagonals,in equal distance from each corner.We can find the center of mass for other objects by similar calculations,or by finding the object's balancing point,which lies right underneath its center of mass.