Thermal Radiation API

Stefan-Boltzmann thermal radiation and Wien's displacement law as an API, computed locally and deterministically. The power endpoint computes the radiant exitance of a surface, M = ε·σ·T⁴ — how much power a body radiates per unit area at a temperature, from its emissivity (1 for a black body) and absolute temperature — and, given the area, the total radiant power in watts and kilowatts; it also solves the temperature from a measured exitance. Temperatures may be entered in kelvin, Celsius or Fahrenheit. The exchange endpoint computes the net radiative heat transfer between an object and its surroundings, Q = ε·σ·A·(T_object⁴ − T_surroundings⁴), telling you whether the object is losing or gaining heat by radiation. The wien endpoint applies Wien's displacement law, λmax = b/T, to give the peak wavelength and frequency of the thermal spectrum and which band it falls in (the Sun at 5778 K peaks in visible green light, a room at 300 K in the infrared), and solves the temperature from a peak wavelength. The Stefan-Boltzmann constant 5.670×10⁻⁸ and Wien constant 2.898×10⁻³ are built in. Everything is computed locally and deterministically, so it is instant and private. Ideal for heat-transfer and building-physics tools, astronomy, infrared-thermography and solar apps, and physics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is thermal-radiation physics; for the RGB colour of a black body at a colour temperature use a colour-temperature API.