Convert Foot (US Survey) (ft (US)) to Electron Radius (re) instantly.
About these units
Foot (US Survey) (ft (US))
The US Survey Foot is a standardized version of the foot, defined as exactly 1200/3937 meters (~0.30480061 m). It was adopted to maintain continuity with older surveying records when converting to the metric system. Surveyors, engineers, and geographers in the United States used this unit for mapping, cadastral surveys, and infrastructure projects. Its slight difference from the international foot allows historical survey data to align accurately with modern geodetic coordinates. Although the international foot is now more common, the US survey foot remains relevant for interpreting historical survey data and legal property boundaries.
Electron Radius (re)
The classical electron radius, approximately 2.818 × 10⁻¹⁵ meters, is a theoretical value derived from classical electromagnetic theory rather than an actual measured size. It represents the radius a charged sphere would need to have in order for its electrostatic self-energy to equal the electron's rest energy. Although electrons are now understood to be point-like or extremely small compared to this radius, the classical electron radius remains useful in scattering theory, especially in calculations involving Thomson scattering — the elastic scattering of electromagnetic radiation by free electrons. Thus, while not a physical dimension of the electron, the classical radius serves as a meaningful parameter in specific areas of physics and retains importance in radiation modeling and plasma physics.