Convert Pica (pica) to Electron Radius (re) instantly.
About these units
Pica (pica)
A pica is another typographic unit, equal to 12 points, or 1/6 of an inch, making it larger and more suited to structural layout than to fine detail. Picas are commonly used to measure text blocks, column widths, margins, and line lengths in print and digital page design. The pica originated alongside the point in printing traditions stretching back to the 18th and 19th centuries. It offered a convenient intermediate scale—small enough for precise adjustments but large enough for practical page design. When newspapers became widespread, picas helped designers rapidly calculate column grids and organize dense printed pages. Even as publishing tools evolved into software like Adobe InDesign and LaTeX, picas remain deeply integrated into the workflow of book designers, typographers, and professional printers. They are part of a system that allows page elements to be arranged with precision, ensuring that every visual aspect of a document aligns harmoniously.
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.