Why Does Phosphorescence Glow?

Sydney Morning Herald

Wednesday January 7, 2009

PAT SHEIL

PHOSPHORESCENCE is caused by materials in the bodies of microscopic marine organisms known as dinoflagellates. They glow when they are disturbed or attacked and, if there are enough of them about, can be made to fire up just by sweeping your hand through the water.

Inside the body of a dinoflagellate are the substances luciferase and luciferin, which chemically react with oxygen in the air above the water to produce light with minimal heat levels. Propellers of large ships can generate quite a light show in the right waters.

Jellyfish and various species of worms, shrimp and squid produce their own light through phosphorescence. This is particularly useful for creatures living in the mesopelagic zone, a range of depth from about 200-1000 metres below the ocean surface, where little light can penetrate.

Phosphorescence is different to fluorescence (think electric lighting) and luminescence, which can be created in all sorts of ways, including simply putting stress on crystals. It gets weird: it's possible to generate X-rays by pulling sticky tape off a reel but you have to do it in a vacuum, which is tricky.

© 2009 Sydney Morning Herald

Back to News Index | Back to Home