Planck's law is a fundamental law of physics that explains the distribution of energy emitted by a perfect black body at a given temperature.
The units of Planck's law in terms of wavelength are typically expressed as energy per unit wavelength per unit area per unit solid angle (e.g. J⋅s−1⋅m−1⋅sr−1).
Planck's law is used in various fields of science, such as astrophysics, cosmology, and thermodynamics, to understand the distribution of energy emitted by objects at different temperatures.
Planck's constant, denoted by h, is a fundamental constant in quantum mechanics that relates the energy of a photon to its frequency. It is used in Planck's law to calculate the energy of electromagnetic radiation at a given wavelength.
Planck's law is derived from the concept of black bodies, which are theoretical objects that absorb all incident electromagnetic radiation and emit radiation at a specific temperature. Planck's law helps to explain the spectral distribution of energy emitted by black bodies at different temperatures.