Light sticks are one example of chemical light. Light sticks such as this one will emit light with a gradually decreasing intensity for more than 24 hours. Although the chemicals used in light sticks are different than the chemicals made by bioluminescent creatures, the basic principle is the same. The image to the right demonstrates how light producing chemicals are isolated from a bioluminescent organism.




HOW THEY MAKE LIGHT

All light in the universe comes from the same basic process. When an electron absorbs energy, it moves to a higher orbit. When the electron falls back down to a lower energy state, a packet of energy, known as a photon, is released. Electrons can get excited in a number of different ways. In the sun, a candle flame or an incandescent light bulb, the electrons are thermally excited, which is why we tend to associate heat and light. In bioluminescence the electrons are excited by a very efficient chemical reaction that generates no heat at all. This is why bioluminescence is sometimes called cold light.

 


D. Smith



Different chemicals make different colors, as you see with these different light sticks. Bioluminescence comes in all colors: red, orange, yellow, green, blue and violet. The color of bioluminescence most often found in the ocean is blue. Since blue is the color that penetrates farthest through water, it is not surprising that this is the color that evolution has selected most often for communication in the oceans.




 




 


DR. WIDDER WELCOMES YOU TO COME ALONG WITH HER AS SHE EXPLORES THE GLOWING, SPARKLING, LUMINOUS WORLD OF BIOLUMINESCENCE.