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Lightning Fossils
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Back in medieval times in Europe, ringing a church bell was thought to protect the local village from a certain type of weather. In recognition of this purpose, it was common for church bells to be inscribed with the words "Fulgara frango," meaning "I break the lightning".

   
Photo: Greg Shirah, SVS

A commonly held but rather deleterious belief in those days was that the sound of church bells could divert lightning. Unfortunately, in one 33 year span, more than 100 bell-ringers lost their lives disproving this theory, so the bell inscriptions disappeared pretty quickly; but, the Latin word for lightning "fulgurate" survived and became the root of the English word fulgarite meaning lightning fused sand.

Like church bells, sand has no effect on lightning, but lightning has an effect on sand. A fulgurite is formed when lightning discharges between a cloud and the ground. The temperature from electrical resistance in the ground can get so high, that the sand melts in the ground, which later hardens into fragile tubes. These tubes are the fulgurites. They're kind of like lightning fossils. In fact, when excavating fulgurites, scientists use excavation techniques developed by paleontologists for removing dinosaur fossils.

The longest known fulgurite was found in Florida. It consisted of three branches totaling 38 feet. A beautiful sandy sculpture that formed...just like that, church bells ringing, or not.

For pictures of fulgurites, visit weathernotebook.org. Thanks to today's contributing writer, Bryan Yeaton. Our show's senior editor is Jay Allison. Thanks to Subaru, the beauty of all wheel drive, and the National Science Foundation.

 
Related Links

Photos of fulgurites

1997 Report of longest fulgurite found