Cherenkov Radiation Key Ring

Features a blue-toned, fractal representation of Cherenkov radiation in water. Customise by adding your own text on the reverse side. The blue glow in the water surrounding nuclear reactors is Cherenkov radiation. When a charged particle does move through a medium at a speed higher than the speed of light in that medium, a faint radiation is produced by the medium. In water charged particles excite water molecules, which then return to their normal state by emitting photons of blue light. Because the particle is moving faster than the speed of light in water, it can trigger a cascade of photons that are in phase with each other and can interfere constructively to form a visible blue glow. This is somewhat analogous to a sonic boom in the atmosphere. This effect was observed by Russian scientist Pavel Cherenkov in 1934 when he was asked to look at the effects of radioactivity in liquids. Cherenkov won a Nobel prize in 1958.