|Postdoctoral researcher Carlos Camara and researchers have shown that simply peeling ordinary sticky tape in a vacuum can generate enough X-rays to take an image - of one of the scientists' own fingers.
"At some point we were a little bit scared," says Juan Escobar, a member of the research team. But he and his co-workers soon realized that the X-rays were only emitted when the kit was used in a vacuum. "We don't want to scare people from using Scotch tape in everyday life," Escobar adds.
This kind of energy release ¡ª known as triboluminescence and seen in the form of light ¡ª occurs whenever a solid (often a crystal) is crushed, rubbed or scratched. It is a long-known, if somewhat mysterious, phenomenon, seen by Francis Bacon in 1605. He noticed that scratching a lump of sugar caused it to give off light.
The leading explanation posits that when a crystal is crushed or split, the process separates opposite charges. When these charges are neutralized, they release a burst of energy in the form of light.
As long ago as 1953, a team of scientists based in Russia suggested that peeling sticky tape produced X-rays. But "we were very sceptical about the old results," says Escobar. His team decided to look into the phenomenon anyway, and found that X-rays were indeed given off, in high-energy pulses. " [ link ]