Answer: Triboluminescence

The word might sound rather scientific, and maybe a little alien in nature (“triboluminescence” does sound a whole lot like a problem the crew of the Enterprise might run into, after all), but it’s a down-to-Earth phenomenon you may have even experienced yourself.

Triboluminescence is light created when crushing, tearing, or other mechanical action triggers the breakdown of chemical bonds in a material (or when peeling adhesive tapes). A popular classroom demonstration of this phenomenon, for example, is to give students rolls of Wint-O-Green Mint Lifesavers candy, enter a darkened room, and then have the students—much to their delight—throw tons of the candies into their mouths and chomp on them vigorously with their mouths open. Thanks to a double whammy of the shearing of the sugar structure of the candy generating triboluminescence and the crushing of the wintergreen oil fluorescing (which enhances the light), the students are treated to sparks of blue-white light.

Human fascination with the phenomenon isn’t thanks to recent scientific discovery, however. One of the earliest documented known examples of humans harnessing the phenomenon comes to us courtesy of the Uncompahgre Ute Indians, a tribe from what is now the U.S. state of Colorado. They crafted ceremonial rattles for use during night-time ceremonies that were made from buffalo rawhide and filled with clear quartz crystals. When shaken in the low light of a fire-lit ceremony, flashes of light could be seen from within thanks to the crystals impacting with each other and creating triboluminescent bursts of light.