The greatest cataclysm ever to effect the Earth was how our Moon was born. The gravitational interaction between the Earth and Moon can be seen by the action of the tides. This tidal friction has slowed the Earth's rotation gradually over the years. Back in the Paleozoic there used to be over 400 days per year. In this discovery we will be describing the geometry of the Earth, Moon, and Sun as they gravitationally interact.
People First determine the direction that the Earth rotates.
If you look down on the north pole of our globe which way would it spin. It is easy to figure out relative times around the globe. Start in the position that you have determined to be representative of a Full Moon. As you spin around watch the shadows change on the ping-pong ball. Make a sketch of the shadows that you observe at twelve equal intervals.