The result of any process where in the energy transmitted toa system via electromagnetic radiation is added to the internal energy of that system. Each material has a unique absorptionspectrum, which makes it possible to identify that material using a device called aspectrometer. (Compare absorption to emission.)
The complete range of electromagnetic waves on a continuous distribution from a very low range of frequencies and energylevels, with a correspondingly long wavelength, to a very high range of frequencies and energy levels, with a correspondingly short wavelength. Included on the electromagnetic spectrum are long-wave and short-wave radio; microwaves; infrared, visible, and ultraviolet light; x rays, and gamma rays.
A transverse wave with electric and magnetic fields that emanate from it. These waves are propagated by means of radiation.
The result of a process that occurs when internal energy from one system is transformed into energy that is carried away from it by electromagnetic radiation. An emission spectrum for any given system shows the range of electromagnetic radiation it emits. (Compare emission to absorption.)
The transfer of energy to an atom, either by collisions or due to radiation.
A type of luminescence whereby a substance absorbs radiation and begins to re-emit the radiation 10 −6 seconds after absorption. Usually the wavelength of emission is longer than the wavelength of the radiation the substance absorbed. Fluorescent luminescence stops within 10 −5 seconds after the energy source is removed.
The number of waves passing through a given point during the interval of one second. The higher the frequency, the shorter the wavelength.
A unit for measuring frequency, named after ninetenth-century German physicist Heinrich Rudolf Hertz (1857-1894).
The generation of light without heat. There are two principal varieties of luminescence, fluorescence and phosphorescence.
A type of luminescence involving a delayed emission of radiation following absorption. The delay may take as much as several minutes, but phosphorescence continues to appear after the energy source has been removed.
The act or state oftravelling from one place to another.
In a general sense, radiation can refer to anything that travels in astream, whether that stream be composed of subatomic particles or electromagnetic waves.
A term describing materials which are subject to a form of decay brought about by the emission of high-energy particles or radiation, including alpha particles, beta particles, or gamma rays.
The continuous distribution of properties in an ordered arrangement across an unbroken range. Examples of spectra (the plural of "spectrum") include the colors of visible light, the electromagnetic spectrum of which visiblelight is a part, as well as emission and absorption spectra.
A wave in which the vibration or motion is perpendicular to the direction in which the wave is moving.
An area of space devoid of matter, including air.
The distance between a crest and the adjacent crest, or the trough and an adjacent trough, of a wave. The shorter the wavelength, the higher the frequency.
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