Light

Try it: Phosphorescence

You will need an object that glows in the dark (for example, the luminous dial of an alarm clock) and colored filters, particularly red.
Charge your object with white light, then turn off the light an observe how the glow decays. Next, charge your object with light of various colors by covering it with a filter before reexposing. Explain, why some colors can evoke phosphorescence and dome can not.

Your TV screen is somewhat phosphorescent, decaying rather quickly, but just slowly enough to make successive scans of the picture blend into each other.
You can excite the phosphorescence with your camera's electronic flash unit. Have the TV turned off in a completely dark room. Hold some object, maybe your hand, on the screen. Then close your eyes, and fire off the flash toward the screen at close range. Immediately open your eyes and remove your hand from the screen to see a fleeting shadow of your hand on the TV screen.

Try replacing your hand with filters of various colors. Why do some filters seem to throw good shadows and others hardly any?