dispersion

[dih-spur-zhuhn, -shuhn]

noun

1. Also an act, state, or instance of dispersing or of being dispersed.

2. Optics.

   1. the variation of the index of refraction of a transparent substance, as glass, with the wavelength of light, with the index of refraction increasing as the wavelength decreases.

   2. the separation of white or compound light into its respective colors, as in the formation of a spectrum by a prism.

3. Statistics.,  the scattering of values of a variable around the mean or median of a distribution.

4. Military.,  a scattered pattern of hits of bombs dropped under identical conditions or of shots fired from the same gun with the same firing data.

5. Also called disperse system. Physical Chemistry.,  a system of dispersed particles suspended in a solid, liquid, or gas.

6. (initial capital letter),  Diaspora.

dispersion

¹

/ dɪˈspɜːʃən /

noun

1. another word for dispersal

2. physics

   1. the separation of electromagnetic radiation into constituents of different wavelengths

   2. D. a measure of the ability of a substance to separate by refraction, expressed by the first differential of the refractive index with respect to wavelength at a given value of wavelength

3. statistics the degree to which values of a frequency distribution are scattered around some central point, usually the arithmetic mean or median

4. chem a system containing particles dispersed in a solid, liquid, or gas

5. military the pattern of fire from a weapon system

6. 1. the range of speeds of such objects as the stars in a galaxy

   2. the frequency-dependent retardation of radio waves as they pass through the interstellar medium

   3. the deviation of a rocket from its prescribed path

7. ecology the distribution pattern of an animal or a plant population

Dispersion

²

/ dɪˈspɜːʃən /

noun

1. another name for the Diaspora

dispersion

1. The separation by refraction of light or other radiation into individual components of different wavelengths. Dispersion results in most materials because a material's index of refraction depends on the wavelength of the radiation passing through it; thus different wavelengths entering a material along the same path will fan out into different paths within it. Prisms, for example, diffuse white light (which contains an even mixture of visible wavelengths) into its variously colored components; rainbows are an effect of dispersion in water droplets.

Other Word Forms

• nondispersion noun
• predispersion noun

Word History and Origins

Origin of dispersion¹

1350–1400; Middle English dispersio ( u ) n (< Anglo-French ) < Latin dispersiōn- (stem of dispersiō ), equivalent to dispers ( us ) ( disperse ) + -iōn- -ion

Example Sentences

"We have been doing modelling with colleagues at the University of Cambridge and the Met Office which have adapted a nuclear atmospheric dispersion model to Ips," explained Dr Blake.

From BBC

“I am introducing a bill that prohibits the injection, release, or dispersion of chemicals or substances into the atmosphere for the express purpose of altering weather, temperature, climate, or sunlight intensity,” Greene wrote on X.

From Salon

“The number, dispersion, and size of U.S. military bases in the region are not a strength, but have doubled their vulnerability,” the statement said.

From Los Angeles Times

A key question facing the new oversight system is how it can overcome the byzantine dispersion of authority and tension between the different levels of government that beset the current system.

From Los Angeles Times

Four days after the main eruption the Met Office dispersion forecasts showed ash across the UK, the Atlantic, most of Europe and western Russia.

From BBC

Related Words

• diffusion