X-rays by triboluminescence?

Headnote

A recent discovery shows that more thon just light can be produced by rubbing.

The phenomenon of triboluminescence, the emission of light during rubbing, is well known and was first recorded by Francis Bacon in 1 620 where he noted that, "It is well known that all sugar, whether candied or plain, if it be hard, will sparkle when broken or scraped in the dark." Also, the emission of other particles such as electrons to produce a "triboplasma" at sliding interfaces is well documented.

One might expect that this phenomenon would relate to the strength of the chemical bonds that are broken. However, it was found as early as 1 939 that an adhesive tape affixed to a surface, which is thought to be held together by rather weak van der Waals forces, provided, upon peeling apart, an example of a triboluminescent system and generated light emission that could also be detected by the naked eye.

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