Speaker 1: Welcome to Brainstuff from house Stuff Works dot com where
Speaker 1: smart Happens. Hi Am Marshall Brain with today's question, why
Speaker 1: do win a green Life Savers spark in the dark? Actually,
Speaker 1: any hard sugar based candy will emit some amount of
Speaker 1: light when you bite on it, but most of the
Speaker 1: time that light is extremely faint. This effect is called
Speaker 1: tribo luminescence. It's the admission of light that happens when
Speaker 1: something is being smashed or torn. When you rip a
Speaker 1: piece of tape off the roll, it will produce a
Speaker 1: slight glow. For the same reason, tribo luminescence occurs when molecules,
Speaker 1: in this case crystalline sugars, are crushed. This forces some
Speaker 1: of the electrons out of their atomic fields. These free
Speaker 1: electrons bump into nitrogen molecules in the air, and when
Speaker 1: they collide, the elector drowns impart energy to the nitrogen molecules,
Speaker 1: causing them to vibrate. In this excited state, these nitrogen
Speaker 1: molecules emit light, mostly ultra violet light that's not visible,
Speaker 1: but they do emit a small amount of visible light
Speaker 1: as well. This is why all hard sugary candies will
Speaker 1: produce a faint glow when cracked, but when you bite
Speaker 1: into a winter Green lifesaver, a much greater amount of
Speaker 1: visible light can be seen. This brighter light is produced
Speaker 1: by the winter green flavoring itself. Methyl salicillate or oil
Speaker 1: of winter green, is fluorescent, meaning it absorbs light of
Speaker 1: a shorter wavelength and then emits it is light of
Speaker 1: a longer wavelength. Ultra Violet light has a shorter wavelength
Speaker 1: than visible light, so when a winter green lifesaver is
Speaker 1: crushed between your teeth, the methyl salicillate molecules absorb the
Speaker 1: ultra violet shorter wavelength light produced by the excited nitrogen
Speaker 1: and then re emit it as light in the visible spectrum,
Speaker 1: specifically as blue light. Thus you see blue sparks when
Speaker 1: you crunch on a winter green light saver. So you
Speaker 1: can try this out yourself. Grab some lifesavers, go to
Speaker 1: a pitch black room or closet with a friend and
Speaker 1: see what happens. Maybe some sparks will fly. Do you
Speaker 1: have any ideas or suggestions for this podcast? If so,
Speaker 1: please send me an email at podcast at how stuff
Speaker 1: works dot com. For more on this and thousands of
Speaker 1: other topics, go to how stuff works dot com and
Speaker 1: be sure to check out the brain Stuff blog on
Speaker 1: the how stuff works dot com home page