Convert Vara Castellana (vara castellana) to Electron Radius (re) instantly.
About these units
Vara Castellana (vara castellana)
The Vara Castellana is the traditional Castilian vara, approximately 0.8359 meters in length, and was widely used throughout Spain for centuries. Its application extended to construction, tailoring, agriculture, and property measurement, serving as a versatile unit bridging everyday tasks and formal documentation. The vara's influence reached Spain's colonies, where regional variations arose, adapting the unit to local measurement conventions. In architecture, artisans used the Vara Castellana to proportion buildings, plan streets, and ensure symmetry, making it central to civil and domestic design. Although no longer in practical use, the Vara Castellana remains crucial for historians, architects, and legal researchers examining pre-metric Spain and Latin America.
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.