Welcome to Brainstuff from house Stuff Works dot com where smart Happens. Hi Am Marshall Brain with today's question, why do win a green Life Savers spark in the dark? Actually, any hard sugar based candy will emit some amount of light when you bite on it, but most of the time that light is extremely faint. This effect is called tribo luminescence. It's the admission of light that happens when something is being smashed or torn. When you rip a piece of tape off the roll, it will produce a
slight glow. For the same reason, tribo luminescence occurs when molecules, in this case crystalline sugars, are crushed. This forces some of the electrons out of their atomic fields. These free electrons bump into nitrogen molecules in the air, and when they collide, the elector drowns impart energy to the nitrogen molecules,
causing them to vibrate. In this excited state, these nitrogen molecules emit light, mostly ultra violet light that's not visible, but they do emit a small amount of visible light as well. This is why all hard sugary candies will produce a faint glow when cracked, but when you bite into a winter Green lifesaver, a much greater amount of visible light can be seen. This brighter light is produced
by the winter green flavoring itself. Methyl salicillate or oil of winter green, is fluorescent, meaning it absorbs light of a shorter wavelength and then emits it is light of a longer wavelength. Ultra Violet light has a shorter wavelength than visible light, so when a winter green lifesaver is crushed between your teeth, the methyl salicillate molecules absorb the ultra violet shorter wavelength light produced by the excited nitrogen and then re emit it as light in the visible spectrum,
specifically as blue light. Thus you see blue sparks when you crunch on a winter green light saver. So you can try this out yourself. Grab some lifesavers, go to a pitch black room or closet with a friend and see what happens. Maybe some sparks will fly. Do you have any ideas or suggestions for this podcast? If so, please send me an email at podcast at how stuff
works dot com. For more on this and thousands of other topics, go to how stuff works dot com and be sure to check out the brain Stuff blog on the how stuff works dot com home page