Mechanoluminescence

(from Wikipedia)

Each spring the Utes (Northern and Southern) hold their traditional Bear Dances. Origin of the Bear Dance can be traced back several centuries. Each year, a mid-summer fasting ceremony known as the Sun Dance is held; this ceremony has important spiritual significance to the Utes.

An Uncompaghre Ute Buffalo rawhide ceremonial rattle filled with quartz crystals. The rattle produces flashes of light (mechanoluminescence) created when quartz crystals are subjected to mechanical stress when the rattle is shaken in darkness.

The Uncompahgre Ute Indians from central Colorado are one of the first documented groups of people in the world known to utilize the effect of mechanoluminescence through the use of quartz crystals to generate light, likely hundreds of years before the modern world recognized the phenomenon. The Ute constructed special ceremonial rattles made from buffalo rawhide which they filled with clear quartz crystals collected from the mountains of Colorado and Utah. When the rattles were shaken at night during ceremonies, the friction and mechanical stress of the quartz crystals impacting together produced flashes of light which partly shone through the translucent buffalo hide. These rattles were believed to call spirits into Ute Ceremonies, and were considered extremely powerful religious objects.

Reading more about this phenomenon, I was reminded that if you break a Wint-O-Mint lifesaver apart with your teeth in the dark, your mouth lights up. This brings us to the old joke, of somebody thrashing around in the water calling for a lifesaver, to which Captain Bush smirking, tosses them a piece of candy instead of a real lifesaver. The story continues with the lifesaver slowing sinking to an Octopuses garden in the sea, where the creature curiously grabs it with one of his tentacles and then bites it apart with Ringo Starr singing in the background the reworked lyrics,

“I'd like to be under the sea

to see an octopus’s candy mouth sheen,
we would shout and swim about,

while his mechanoluminescence lights our dream"