Chemical Action, What's Your Reaction?

What Makes the Flash of Light?
What do you think causes the light on a firefly? A French physiologist Raphael Dubois studied the light producing cells of the firefly in the late 19th century (1887), and observed that there are two chemicals that interact to produce the bioluminescence. He discovered that fireflies have a chemical called luciferin (meaning "lucifer" or "light bearing" in Latin), which reacts with another enzyme called luciferase to create the bioluminescence, when air comes through holes in the firefly's abdomen.

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Say's firefly (Pyractomena angulata
Credit: Arwin Provonsha,
Purdue Department of Entomology


Thanks to the Firefly
Today, these chemicals are used in research for cancer, multiple sclerosis, cystic fibrosis and heart disease, and they have also led to new technology for flashlights and flares and glow sticks, according to scientists at Purdue and Ohio State.

Did You Know?
The light that the firefly emits is extremely energy efficient. Whereas light bulbs give off only 10% of their energy as light (and 90% as heat), the firefly gives off almost 100% of its energy as light.

It is sometimes called a cold light, since it does not give off much heat.