Al Walters age 9. of Seattle. Wash..
How does a firefly light up?
Al’s question was chosen from many just like it. If you were one of those smart enough to wonder and ask about fireflies. you are smart enough to have other questions. So please use one or more of them to try again. It's too bad but. as you knows Andy can only choose one of these popular questions.
This is midsummer. The first fireflies have arrived to decorate the dusky evening. Some flash their fairy lights as they flit through the air. Others like the glow worms signal from the ground. Soon the marshes and the damp grass will be aglow with thousands of them. For the fireflies are waking up for summer.
It’s easy to catch a firefly for he is a slow moving fellow. He may be half an inch long ‑ which is big enough for study with or without a magnifying glass. The four wings are neat and gauzy. the lower body is divided in segments. Actually the fireflies are classed as beetles. our beetle is a drab brown color. But the tail segments of the firefly body are paler and more yellowish.
This is where he keeps his flashlight. The special tissue there is soft and fatty. It is riddled with the tiniest of tubes. Two magic substances operate in this fatty tissue. We are right to call them magic for only the fireflies and glow worms know how to make them. These substances use the air in the tiny tubes to make the firefly’s special kind of light.
Naturally. magic materials must have fancy names. One of these is called luciferin the other luciferawe. Both names are coined from an older word for light. Luciferase is one of those enzymes Andy wrote about. It can make other stuff work without seeming to work itself. It prods the luciferin to work with oxygen to make light. But the luciferin does not burn away. It is there ready when the firefly wants to flash another signal.
The firefly's light is still very much a mystery to human beings. For it is a cold light. Your firefly will flash as you hold him cupped in your hands. You can feel no heat from the light. And as you know. there is quite a bit of heat even from an electric light bulbs. So far. mankind has been unable to make a light that does not give off some heat.
The heat from our lamps is wasted energy. We don't need warm lamps. It is better to use that energy to make more light. But only the little fireflies and glow worms know the trick. They flash on their magic light as they choose. True. it i s only a small lamp. but it is a better lamp than we have yet been able to make. It is cold light ‑ light without heat.