What causes an object to glow in the dark is the characteristic of flouresence.

What exactly is florescence?

Florescence is when something stores the energy from light when it is exposed to it. It later emits that energy as a glow when it is removed from the light source.

What causes this to occur?

This occurs because a substance in the object, called phosphur, is exposed to light. This exposure causes some of the electrons in its atoms to become excited. While they are excited they are trapped in a lower energy state that takes them a long time to escape. In order to return to their original state they must emit light. There are two main phosphurs used today to make objects glow in the dark. They are zinc sulfide and strontium aluminate.

What determines how long the glow will last?

How long the glow will last is determined by how long the object has been exposed to light and how much visible light the object has actually been exposed to.

Interesting Facts

Radium was used to make glow in the dark objects until it was determined to cause cancer.

Glow in the dark gloves are now being made so that the deaf will be able to sign to each other in the dark.

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