The life cycle of the photon involves the life (creation) and death (disappearance) of the photon - a particle of light. The description of the photon can be applied to the entire electromagnetic spectrum from radio waves to gamma rays. Note that sound - vibration of air molecules - is not a photon.

The photon behaves as both a particle and a wave. The particle behavior is hard to describe without laboratory equipment, but you can see wave behavior. Hold your thumb and forefinger close together and look at a light source. As you bring your thumb and finger together you will see a series of dark lines - at least one dark line - between them. This is wave behavior.

Procedure

1. Cut out a square from the graph paper; for example a centimeter (cm) on the side in order to form an opening.
2. Cut out a portion of the graph paper from the opening portion and tape it to the ruler a unit distance (for example, 2 inches) from the end.
3. Remove the lens from the flashlight and put the bulb at the end of the ruler so it illuminates the opening in the graph paper.
4. Then take the other piece of graph paper and move it until the light from the flashlight illuminates 4 squares (you may need to turn out room lights).

Think about Superman. How could he visualize a scene with x-rays? The comics only show rays of x-rays from his eyes and the rays illuminating a person or an object. What would he need to "see" the x-rays?

To read more about photons, go to the Reading on The Life Cycle of the Photon