Brainspace – July 2019

brainspace SUMMER 2019 13

When all four chemicals combine, they produce the flashing green-yellow light that we all

are familiar with. The chemical reaction produces oxyluciferin in its excited state. This occurs

when oxygen is available in the lantern. As oxyluciferin returns to its normal state, it releases a

burst of light. The scientific term for this is bioluminescence. Bioluminescence is cold light and

is 100% efficient. Unlike a light bulb where much of the energy is lost as heat. Bioluminescence

does not produce any heat.

The Science of the Magic

Are fireflies the only

creatures that can glow?

In fact, bioluminescence is a very

common phenomenon in nature.

Almost all deep sea creatures glow.

Some bacteria and algae also show

bioluminescence. Each creature may

have different luciferins, the light-

emitting compound, and a different

luciferase enzyme that catalyzes the

bioluminescent reaction.

How does bioluminesence

help the firefly?

A firefly can glow even when it is in

its larval stage as a glow-worm. The

glow helps it to scare off predators.

When the larvae matures to become

a firefly, it uses bioluminescence

to communicate, attract mates or

discourage prey. There are more than

2,000 species of fireflies and most of

them have a different flashing pattern

of light. Not all fireflies can glow!

Unfortunately, with rapid urbanization and loss

of habitat, fireflies are fast disappearing from our

landscape, and a day may come when they may

not be there to bring a sense of magic to warm

summer nights.