Bill and Julie observe the size of the opening of a laser and compare it with the size of a bright spot on the wall toward which it points. They discover that the spot on the wall is larger than the opening of the laser. Julie says that the spot on the wall is bigger than the laser opening because some light from the laser goes in all directions while most light travels straight to the wall. She suggests the following picture to illustrate her reasoning: Bill disagrees and says that light travels in a straight line and then "splashes" like water from a water hose when it hits the wall. He suggests the following picture to illustrate his reasoning: Describe the design of an experiment that you could perform to decide if one or both models should be rejected. Be sure to make a prediction of the outcome of your experiment based on both models (i.e., 2 predicted outcomes, one for each model).
