This activity illustrates how crunching on a wintergreen LifeSaver® makes a miniature lightning storm in your mouth. When you crush sugar crystals, the stress in the crystal creates electric fields. These electric fields rip the outer electrons from molecules. When the molecules recombine with their electrons, they emit light. In addition to blue and violet light, the crunched crystals produce ultraviolet light, which you can't see. Wintergreen oil converts ultraviolet light into visible blue light, making the light you can see brighter.