Convert Square Mile (mi²) to Electron Cross Section (σₑ) instantly.
About these units
Square Mile (mi²)
A square mile equals 640 acres or about 2.58999 km². It is the primary unit for describing large areas in the United States and the UK, particularly in geography and land-use planning. City sizes, county boundaries, national park dimensions, and lake surfaces are often expressed in square miles. Because of its large scale, it is ideal for measuring political subdivisions, conservation zones, and territorial claims. The square mile also appears in demographic statistics—such as population density—and in historical surveys of American frontiers, where square-mile sections formed the backbone of land distribution policies.
Electron Cross Section (σₑ)
The electron cross section, often denoted σₑ, is not a fixed unit but rather a physical area representing the effective interaction size of an electron in scattering experiments. It is typically expressed in barns or submultiples such as square femtometers (fm²). Electron cross sections are vital in quantum electrodynamics (QED), X-ray scattering, atomic physics, and materials science. These values describe how electrons interact with photons, atoms, or other electrons, determining phenomena such as absorption, conductivity, and radiation shielding. Because electron interactions are probabilistic, σₑ provides a statistical measure of likelihood rather than a physical surface, illustrating how area units are used conceptually at quantum scales.