radiative heat transfer

Blackbody

An idealized physical body that absorbs all incident radiation, regardless of frequency or angle.

Emissivity

A measure of how effectively a surface emits energy as thermal radiation, compared to a blackbody.

Stefan-Boltzmann Law

A law that states the total energy radiated per unit surface area of a blackbody per unit time is proportional to the fourth power of the blackbody's absolute temperature.

Planck's Law

Describes how the intensity of radiation emitted by a blackbody is related to the wavelength of the radiation and the temperature.

Rayleigh-Jeans Distribution

An early model that describes the spectral energy density of electromagnetic radiation at thermal equilibrium.

Displacement Law

Describes the wavelength at which the emission of a blackbody spectrum is maximized, which shifts to shorter wavelengths as temperature increases.

Radiative Heat Transfer

The transfer of heat through electromagnetic waves, as opposed to conduction or convection.

Radiation Isotropy

The property of radiation within a cavity where all directions have equal intensity.

Solid Angle (dΩ)

A measure of how large an object appears to a given point, measured in steradians.

Thermal Equilibrium

The state in which two bodies or systems exchange energy at the same rate, resulting in stable temperatures.

Blackbody Radiation

The electromagnetic radiation emitted by a blackbody in thermal equilibrium.

Hohlraum

An evacuated cavity that simulates blackbody radiation; it emits radiation uniformly in all directions.