dispersion

View more Science videos

For more information on dispersion, visit Britannica.com.

The separation, by refraction, interference, scattering, or diffraction, of acoustic and electromagnetic radiation or energy into its constituent wavelengths or frequencies. For a refracting, transparent substance, such as a prism of glass, the dispersion is characterized by the variation of refractive index with change in wavelength of the radiation. Refractive index (n) is defined as the ratio of the velocity of the radiation in free space (air at standard temperature and pressure for sound, and a vacuum for electromagnetic radiation) to the velocity in the substance in question. I. Newton used a small hole in a window shade and a glass prism to disperse sunlight into a visible spectrum, from violet through red. Using a second prism, he showed that no further decomposition of any of the spectral colors could be achieved. See also Optical prism; Refraction of waves.

The condition where the refractive index decreases as wavelength increases is termed normal dispersion. The opposite condition is termed anomalous dispersion, and almost always occurs in regions outside the range of visible wavelengths.

noun

The passing out or spreading about of something: circulation, dispersal, dissemination, distribution. See collect/distribute.

n. 1. a scattered pattern of hits around the mean point of impact of bombs and projectiles dropped or fired under identical conditions.

2. in antiaircraft gunnery, the scattering of shots in range and deflection about the mean point of explosion.

3. the spreading or separating of troops, materiel, establishment, or activities which are usually concentrated in limited areas to reduce vulnerability.

4. in chemical and biological operations, the dissemination of agents in liquid or aerosol form.

5. in airdrop operations, the scatter of personnel and/or cargo in the drop zone.

6. in naval control of shipping, the reberthing of a ship in the periphery of the port area or in the vicinity of the port for its own protection in order to minimize the risk of damage from attack.

See the Introduction, Abbreviations and Pronunciation for further details.

1. Any gas, liquid, or solid containing finely dispersed particles in suspension.
2. A paint containing finely dispersed particles of pigment or latex.

A term used in statistics that refers to the location of a set of values relative to a mean or average level.

Investopedia Says:
In finance, dispersion is used to measure the volatility of different types of investment strategies. Returns that have wide dispersions are generally seen as more risky because they have a higher probability of closing dramatically lower than the mean. In practice, standard deviation is the tool that is generally used to measure the dispersion of returns. 

Related Links:
Find out how to adjust your portfolio when the market fluctuates to increase your potential return. Volatility's Impact On Market Returns
How do you choose a fund with an optimal risk-reward combination? We teach you about standard deviation, beta and more! Understanding Volatility Measurements
Use these calculations to uncover the risk involved in your investments. Using Historical Volatility To Gauge Future Risk
Understanding how money is made and lost over time can help you improve your returns. Overcoming Compounding's Dark Side
Learn how to follow the efficient frontier to better returns. Modern Portfolio Theory Stats Primer

(DOD, NATO) 1. A scattered pattern of hits around the mean point of impact of bombs and projectiles dropped or fired under identical conditions. 2. In antiaircraft gunnery, the scattering of shots in range and deflection about the mean point of explosion. 3. The spreading or separating of troops, materiel, establishments, or activities which are usually concentrated in limited areas to reduce vulnerability. 4. In chemical and biological operations, the dissemination of agents in liquid or aerosol form. 5. In airdrop operations, the scatter of personnel and/or cargo on the drop zone. 6. In naval control of shipping, the reberthing of a ship in the periphery of the port area or in the vicinity of the port for its own protection in order to minimize the risk of damage from attack. See also circular error probable; convoy dispersal point; delivery error; deviation; dispersion error; horizontal error.

1. the selective separation of an inhomogeneous emission according to some criterion (especially frequency, particle mass, speed, or energy); e.g. the separation of heterochromatic light into its components.
2. any system in which particles of any nature (e.g. solid, liquid, gas, or composite) are dispersed in a solid, liquid, or gas of different composition.
3. (in statistics) the extent to which values of a statistical frequency distribution are scattered around a mean or median value.

1. the act of scattering or separating; the condition of being scattered.
2. the incorporation of one substance into another.
3. a colloid solution.

• Environment, Ecology, and Animal Behavior - dispersion: way in which species uses its habitat, such as colonial or solitary
• Optics - dispersion: refraction of polychromatic light into spectrum of its component wavelengths
• Branches, Laws, Theories, and Techniques - dispersion: separation between different wavelengths in spectrum

Dansk (Danish)
n. - spredning, opløsning, udbredelse, farvespredning

Nederlands (Dutch)
verstrooiing, spreiding

Français (French)
n. - (gén, Phys) dispersion, (Hist) dispersion

Deutsch (German)
n. - Zerstreuung, Diaspora, Verteilung, Streuung

Ελληνική (Greek)
n. - διασπορά, σκόρπισμα, διάχυση

Italiano (Italian)
dispersione, ripartizione

Português (Portuguese)
n. - dispersão (f), distribuição (f)

Русский (Russian)
разгон, рассеивание

Español (Spanish)
n. - dispersión, diseminación, diáspora

Svenska (Swedish)
n. - spridning, upplösning

中文（简体）(Chinese (Simplified))
分散, 散布, 传播, 消散

中文（繁體）(Chinese (Traditional))
n. - 分散, 散佈, 傳播, 消散

한국어 (Korean)
n. - 산포도, (빛의) 분산, 흩어지게 함

日本語 (Japanese)
n. - 分散

العربيه (Arabic)
‏(الاسم) التوزيع, تفريق, تقزح الضوء ( تحلل الضوء الأبيض الى ألوان قوس, قزح عبر منشور)‏

עברית (Hebrew)
n. - ‮פיזור, פירוד, יהדות התפוצות, נפיצה, הפזורה היהודית‬

If you are unable to view some languages clearly, click here.