= Emission
{disambiguate=electromagnetic radiation}
= Emission
{synonym}
<Emission (electromagnetic radiation)> is the production of <electromagnetic radiation> by a physical system. Mechanisms include accelerated charges, transitions between <quantum states> and <thermal fluctuations>.
For an isolated <atomic transition>, a <photon> carries <energy> $h\nu=E_i-E_f$. In <thermal emission>, a macroscopic distribution of microscopic motions and states produces a spectrum controlled by <temperature> and material response. Emission must be distinguished from scattering of incident <radiation>, though a measured signal can contain both contributions. The process and <observation> <geometry> determine the relevant spectrum and <angular distribution>.
Back to article page
