(uncountable, engineering, acoustics) A phenomenon wherein external stimuli such as mechanical loading generate physical vibrations.

plural of emission line

(physics) A discredited scientific theory, once considered an alternative to special relativity, proposing that light is emitted at speed c relative to its source instead of applying the invariance postulate.

(astronomy) A nebula composed of ionized gases which produce visible light (as distinct from a reflection nebula, which reflects the light produced by neighboring stars).

plural of emission nebula

plural of emission nebula

The permit to emit carbon dioxide and other greenhouse gases during a specified period.

plural of emission allowance

(physics) A nuclear reaction in which one or more neutrons are emitted. / A form of radioactive decay, where a nucleus with a severe excess of neutrons, emits a neutron.

superlative form of low-emission: most low-emission