In 1953, two physicists showed that an electron beam skimming past a grating emits light whose color depends only on the electron's speed and the grating's spacing. Known as Smith-Purcell radiation, this phenomenon has become a useful tool for building compact, tunable light sources and tracking...
Source: [Phys.org](https://phys.org/news/2026-10-plain-silicon-reveals-hidden-electron.html)