The Swinging Wonder

the Swinging Wonder Recently, an American manufacturer developed a scientific demonstrator named « the Swinging Wonder ». Intended for use in schools as an aid in understanding certain principles of Physics or in the home as an educational toy, this small demonstrator quickly became an object of fascination for both the science teacher and the layman. The purpose of this device is to demonstrate Sir Isaac Newton’s law of motion, in which action and reaction are equal and opposite. In its appearance, the swinging wonder is a boxlike open wooden framework approximately ten inches square. Five lenghts of strong string are attached to both the front and top rails of the framework. Each piece of string hangs downward in a « V » shape, with a small steel ball attached at the base of the « V ». At rest, the five steel ball hang in an even row in which each ball touches the one beside it. The steel balls are suspended about two inches above the base of the framework. Much of the effectiveness of the demonstrator comes from its simplicity. To operate it, an experimenter may begin by lifting the steel ball at the extreme left of the row of balls, raising it out beyond the side of the framework, and then releasing it so that it returns to strike the remaining four balls still hanging motionless in a row. When this happens, the released steel ball will stop in its original place at the left end of the row, and the corresponding ball at the extreme right end of the row will automatically swing out and up for a distance aqual to that to which the first ball had risen. Next, the experimenter may grasp the two steel balls atthe left end of the row, lift them out to the side as he has done the first time, and release them together. Now, they will return to place,striking the row of balls and causing the two corresponding steel balls on the right end side to swing out because of the transfer of momentum. If three or four balls are raised on