How Do Things Glow in the Dark?

Watches, stickers, toys-- all of these can glow in the dark. Most glow-in-the-dark products employ phosphors, a type of chemical. Glow-in-the-dark seems like magic, but is really a matter of simple chemistry.

Many marine animals are bioluminescent.

Phosphors

Phosphors are chemicals that emit light after being energized. Glow-in-the-dark products made with phosphors need to be exposed to light to charge.

Other Uses

Phosphors are also used in TV screens, computer monitors and fluorescent lights.

Chemiluminescence

A different way to create glow-in-the-dark objects is chemiluminescence, a chemical reaction that emits light. Chemiluminescence is used to produce glow sticks.

Bioluminescence

Many animals are bioluminescent, or able to produce light. Deep sea worms, bacteria, fungus and fireflies can all glow. In 2006, scientists in Taiwan created glowing pigs by adding jellyfish DNA to pig embryos.

Fun Fact

Glow sticks were developed by the U.S. Navy as an inconspicuous source of light for forces operating behind enemy lines. Divers searching in muddy water also use glow sticks for illumination.

References

• The Bioluminescence Web Page
• Chemistry Explained: Chemiluminescence
• BBC: Taiwan Breeds Green-Glowing Pigs