spectrum

spectre lumineux, spectre des couleurs

Ensemble des couleurs qui apparaissent quand on décompose la lumière.

En anglais simple : The range of colors seen when light is split into its different parts.

• A prism reveals the spectrum of sunlight.
• Red lies at one end of the visible spectrum.
• The rainbow shows colors across the spectrum.

Synonymes : range of colors

Expressions courantes : visible spectrum, color spectrum, spectrum of light

spectre radioélectrique

Ensemble des fréquences utilisées pour transmettre des signaux radio.

En anglais simple : A range of frequencies used to send radio signals.

• These signals use the radio spectrum.
• The company bought access to more spectrum.
• Different parts of the spectrum serve different wireless services.

Synonymes : frequency range

Expressions courantes : radio spectrum, spectrum allocation, available spectrum

spectre

Répartition montrant les types de lumière ou d'autres rayonnements qu'une substance émet ou absorbe.

En anglais simple : A pattern showing which kinds of light or other radiation a substance gives off or takes in.

• Each gas produces a different spectrum.
• Scientists measured the sample's absorption spectrum.
• Bright lines in the spectrum helped identify the element.

Expressions courantes : absorption spectrum, emission spectrum, spectrum of something