Unexpected sources of X-rays
Stories from Physics for 11-14 14-16
- Though the emission of X-rays from lightning had been predicted several decades ago, it is only in recent years that the high-energy radiation has been detected. However, the mechanism by which lightning produces X-rays is currently poorly understood.
- Peeling Sellotape generates X-rays and a team at the University of California have produced enough X-rays to take an image of one scientist’s fingers by uncoiling tape in a vacuum. The phenomenon is a form of triboluminescence, the release of energy from the breaking of chemical bonds when mechanical energy is applied to a material.
- Triboluminescence was first reported in 1605 when Francis Bacon observed that lumps of sugar released light when scraped. Many common sweets will display the effect and a paper reports the spectra of radiation given off by an American Wint-O-Green Lifesaver TM. Diamonds are both triboluminescent and thermoluminescent: a thirteenth century bishop, Albertus Magnus, noted that the precious stones emitted light when placed in warm water and Robert Boyle observed that a diamond fluoresced when struck with a bodkin.