Have your partner stand 50 feet away from you. Using your hand as an angle measuring device (see Figure 1.10), find the angular size of your partner. Calculate the height of your partner using the small angle equation (Equation 3.1). Have your partner make the same measurement and calculation for your height. Compare your calculated heights with your actual heights and discuss possible reasons for any differences.
Have your partner move an unknown distance (less than 100 feet) away from you. Using your hand, measure the angular size of your partner. With the known height of your partner, calculate the distance of your partner and then measure the actual distance (pacing it off is probably good enough). Have your partner make the same measurement and calculation for your distance. Discuss possible reasons for any differences between the calculated and actual distances.
Tie a ball to a piece of rope. Then, while walking in a circle about your partner, whirl the ball around your head. Walk as fast as you can and whirl the ball as slowly as you can. Be careful not to hit your partner with the ball! Ask your partner to verify that retrograde motion of the ball occurs for this combination of motion on the deferent (the path you walk) and epicycle (the path of the ball around your head). Switch places with your partner and repeat the experiment.
