Rayleigh scattering ( / ˈ r eɪ l i / RAY -lee ) is the scattering or deflection of light , or other electromagnetic radiation , by particles with a size much smaller than the wavelength of the radiation. For light frequencies well below the resonance frequency of the scattering medium (normal dispersion regime), the amount of scattering is inversely proportional to the fourth power of the wavelength (e.g., a blue color is scattered much more than a red color as light propagates through air). The phenomenon is named after the 19th-century British physicist Lord Rayleigh (John William Strutt).
32-471: [REDACTED] Look up blue-skies or blue-sky in Wiktionary, the free dictionary. Blue Sky , BlueSky or Bluesky may refer to: Art, entertainment, and media [ edit ] Animation and gaming [ edit ] Blue Sky Studios , a computer animation studio under 20th Century Fox that went defunct in 2021 BlueSky Software ,
64-645: A defunct video game company Looking Glass Studios , a computer game developer originally known as Blue Sky Productions Film and television [ edit ] Blue Sky (1955 film) , a Swedish comedy film Blue Sky (1994 film) , a film starring Jessica Lange and Tommy Lee Jones Blue Sky (TV channel) , a Greek regional television station Blue Sky, blue methamphetamine in the American TV series Breaking Bad , 2008 Blue Sky programming, USA Network 's "optimistic" television shows during 2005-2016 Music [ edit ] Blue Sky Records ,
96-844: A rainbow code for the Fairey Fireflash air-to-air missile Blue Sky navigation pod , an airborne navigational/attack pod Blue Sky (artist) (born 1938), American painter and sculptor formerly known as Warren Edward Johnson Blue Sky Solar Racing , a solar car racing team based at the University of Toronto See also [ edit ] [REDACTED] Search for "blue sky" , "bluesky" , or "sky of blue" on Misplaced Pages. [REDACTED] Search for "blued sky" , "blueish sky" , "bluish sky" , or "blues sky" on Misplaced Pages. Blue Skies (disambiguation) Black sky (disambiguation) Big Sky (disambiguation) " Mr. Blue Sky ",
128-418: A record label started by manager Steve Paul Blue Sky (album) , a 2012 album by Jinny Ng Songs [ edit ] "Blue Sky" (song) , a song by The Allman Brothers Band "Blue Sky", a song by rapper Common, from the album The Dreamer/The Believer "Blue Sky", a song by Patti Griffin, from the album Flaming Red "Blue Sky", a song by Emily West "The Blue Sky", a song by a-ha , from
160-431: A song by ELO Sky blue All pages with titles beginning with Blue Sky All pages with titles containing Blue Sky Sky Blue (disambiguation) Blue Cloud (disambiguation) Blue smoke (disambiguation) Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Blue Sky . If an internal link led you here, you may wish to change
192-596: A stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin Diffuse sky radiation , solar radiation reaching the Earth's surface after Rayleigh scattering Rayleigh scattering , which causes the sky to appear blue. Other uses [ edit ] Bluesky , a social media platform, based on a distributed networking protocol BlueSky Charter School , an online school for Minnesota citizens Blue Sky,
224-502: Is also an important mechanism of wave scattering in amorphous solids such as glass, and is responsible for acoustic wave damping and phonon damping in glasses and granular matter at low or not too high temperatures. This is because in glasses at higher temperatures the Rayleigh-type scattering regime is obscured by the anharmonic damping (typically with a ~ λ dependence on wavelength), which becomes increasingly more important as
256-528: Is given by I s = I 0 1 + cos 2 θ 2 R 2 ( 2 π λ ) 4 ( n 2 − 1 n 2 + 2 ) 2 r 6 {\displaystyle I_{s}=I_{0}{\frac {1+\cos ^{2}\theta }{2R^{2}}}\left({\frac {2\pi }{\lambda }}\right)^{4}\left({\frac {n^{2}-1}{n^{2}+2}}\right)^{2}r^{6}} where R
288-665: Is the distance to the particle and θ is the scattering angle. Averaging this over all angles gives the Rayleigh scattering cross-section of the particles in air: σ s = 8 π 3 ( 2 π λ ) 4 ( n 2 − 1 n 2 + 2 ) 2 r 6 . {\displaystyle \sigma _{\text{s}}={\frac {8\pi }{3}}\left({\frac {2\pi }{\lambda }}\right)^{4}\left({\frac {n^{2}-1}{n^{2}+2}}\right)^{2}r^{6}.} Here n
320-443: Is the particle's radius, λ is the wavelength of the light and x is a dimensionless parameter that characterizes the particle's interaction with the incident radiation such that: Objects with x ≫ 1 act as geometric shapes, scattering light according to their projected area. At the intermediate x ≃ 1 of Mie scattering , interference effects develop through phase variations over the object's surface. Rayleigh scattering applies to
352-461: Is the reason for the blue color of the daytime and twilight sky , as well as the yellowish to reddish hue of the low Sun . Sunlight is also subject to Raman scattering , which changes the rotational state of the molecules and gives rise to polarization effects. Scattering by particles with a size comparable to, or larger than, the wavelength of the light is typically treated by the Mie theory ,
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#1732765813869384-708: Is the refraction index, p is the photoelastic coefficient of the glass, k is the Boltzmann constant , and β is the isothermal compressibility. T f is a fictive temperature , representing the temperature at which the density fluctuations are "frozen" in the material. Rayleigh-type λ scattering can also be exhibited by porous materials. An example is the strong optical scattering by nanoporous materials. The strong contrast in refractive index between pores and solid parts of sintered alumina results in very strong scattering, with light completely changing direction each five micrometers on average. The λ -type scattering
416-526: Is the refractive index of the spheres that approximate the molecules of the gas; the index of the gas surrounding the spheres is neglected, an approximation that introduces an error of less than 0.05%. The fraction of light scattered by scattering particles over the unit travel length (e.g., meter) is the number of particles per unit volume N times the cross-section. For example, air has a refractive index of 1.0002793 at atmospheric pressure, where there are about 2 × 10 molecules per cubic meter, and therefore
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480-931: The dielectric constant ϵ {\displaystyle \epsilon } of a certain region of volume V {\displaystyle V} is different from the average dielectric constant of the medium ϵ ¯ {\displaystyle {\bar {\epsilon }}} , then any incident light will be scattered according to the following equation I = I 0 π 2 V 2 σ ϵ 2 2 λ 4 R 2 ( 1 + cos 2 θ ) {\displaystyle I=I_{0}{\frac {\pi ^{2}V^{2}\sigma _{\epsilon }^{2}}{2\lambda ^{4}R^{2}}}{\left(1+\cos ^{2}\theta \right)}} where σ ϵ 2 {\displaystyle \sigma _{\epsilon }^{2}} represents
512-532: The discrete dipole approximation and other computational techniques. Rayleigh scattering applies to particles that are small with respect to wavelengths of light, and that are optically "soft" (i.e., with a refractive index close to 1). Anomalous diffraction theory applies to optically soft but larger particles. In 1869, while attempting to determine whether any contaminants remained in the purified air he used for infrared experiments, John Tyndall discovered that bright light scattering off nanoscopic particulates
544-437: The variance of the fluctuation in the dielectric constant ϵ {\displaystyle \epsilon } . The blue color of the sky is a consequence of three factors: The strong wavelength dependence of the Rayleigh scattering (~ λ ) means that shorter ( blue ) wavelengths are scattered more strongly than longer ( red ) wavelengths. This results in the indirect blue and violet light coming from all regions of
576-560: The United States that regulate the offering and sale of securities Places [ edit ] Blue Sky, Colorado , U.S. Bluesky, Alberta , Canada Mount Blue Sky , a mountain in Colorado, U.S. formerly called Mount Evans Science [ edit ] Blue skies research (also called blue sky science), scientific research in domains where "real-world" applications are not immediately apparent Bluesky Formation ,
608-712: The album Hunting High and Low Other art, entertainment, and media [ edit ] Blue Sky (manga) , a 2007 Japanese manga Blue sky memo , a document authored by the Central Intelligence Agency (CIA) Business [ edit ] Blue Sky Airlines , an airline in Armenia Blue Sky Aviation Services , a domestic airline in Kenya Blue Sky Beverage Company , a soft drink manufacturer Blue sky law , state laws in
640-546: The benefit of James Clerk Maxwell 's 1865 proof of the electromagnetic nature of light , he showed that his equations followed from electromagnetism . In 1899, he showed that they applied to individual molecules, with terms containing particulate volumes and refractive indices replaced with terms for molecular polarizability . The size of a scattering particle is often parameterized by the ratio x = 2 π r λ {\displaystyle x={\frac {2\pi r}{\lambda }}} where r
672-443: The case when the scattering particle is very small (x ≪ 1, with a particle size < 1/10 of wavelength ) and the whole surface re-radiates with the same phase. Because the particles are randomly positioned, the scattered light arrives at a particular point with a random collection of phases; it is incoherent and the resulting intensity is just the sum of the squares of the amplitudes from each particle and therefore proportional to
SECTION 20
#1732765813869704-1178: The dependence on refractive index in terms of the molecular polarizability α , proportional to the dipole moment induced by the electric field of the light. In this case, the Rayleigh scattering intensity for a single particle is given in CGS-units by I s = I 0 8 π 4 α 2 λ 4 R 2 ( 1 + cos 2 θ ) {\displaystyle I_{s}=I_{0}{\frac {8\pi ^{4}\alpha ^{2}}{\lambda ^{4}R^{2}}}(1+\cos ^{2}\theta )} and in SI-units by I s = I 0 π 2 α 2 ε 0 2 λ 4 R 2 1 + cos 2 ( θ ) 2 . {\displaystyle I_{s}=I_{0}{\frac {\pi ^{2}\alpha ^{2}}{{\varepsilon _{0}}^{2}\lambda ^{4}R^{2}}}{\frac {1+\cos ^{2}(\theta )}{2}}.} When
736-511: The eruption of Mount Tambora in his lifetime. In locations with little light pollution , the moonlit night sky is also blue, because moonlight is reflected sunlight, with a slightly lower color temperature due to the brownish color of the Moon. The moonlit sky is not perceived as blue, however, because at low light levels human vision comes mainly from rod cells that do not produce any color perception ( Purkinje effect ). Rayleigh scattering
768-401: The first character; please check alternative capitalizations and consider adding a redirect here to the correct title. If the page has been deleted, check the deletion log , and see Why was the page I created deleted? Retrieved from " https://en.wikipedia.org/wiki/Blue-skies " Rayleigh scattering Rayleigh scattering results from the electric polarizability of
800-897: The 💕 Look for Blue-skies on one of Misplaced Pages's sister projects : [REDACTED] Wiktionary (dictionary) [REDACTED] Wikibooks (textbooks) [REDACTED] Wikiquote (quotations) [REDACTED] Wikisource (library) [REDACTED] Wikiversity (learning resources) [REDACTED] Commons (media) [REDACTED] Wikivoyage (travel guide) [REDACTED] Wikinews (news source) [REDACTED] Wikidata (linked database) [REDACTED] Wikispecies (species directory) Misplaced Pages does not have an article with this exact name. Please search for Blue-skies in Misplaced Pages to check for alternative titles or spellings. You need to log in or create an account and be autoconfirmed to create new articles. Alternatively, you can use
832-401: The inverse fourth power of the wavelength and the sixth power of its size. The wavelength dependence is characteristic of dipole scattering and the volume dependence will apply to any scattering mechanism. In detail, the intensity of light scattered by any one of the small spheres of radius r and refractive index n from a beam of unpolarized light of wavelength λ and intensity I 0
864-414: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Blue_Sky&oldid=1258883375 " Categories : Disambiguation pages Place name disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages blue-skies From Misplaced Pages,
896-493: The major constituent of the atmosphere, nitrogen, has a Rayleigh cross section of 5.1 × 10 m at a wavelength of 532 nm (green light). This means that about a fraction 10 of the light will be scattered for every meter of travel. The strong wavelength dependence of the scattering (~ λ ) means that shorter (blue) wavelengths are scattered more strongly than longer (red) wavelengths. The expression above can also be written in terms of individual molecules by expressing
928-561: The particles. The oscillating electric field of a light wave acts on the charges within a particle, causing them to move at the same frequency. The particle, therefore, becomes a small radiating dipole whose radiation we see as scattered light. The particles may be individual atoms or molecules; it can occur when light travels through transparent solids and liquids, but is most prominently seen in gases . Rayleigh scattering of sunlight in Earth's atmosphere causes diffuse sky radiation , which
960-406: The sky. The human eye responds to this wavelength combination as if it were a combination of blue and white light. Some of the scattering can also be from sulfate particles. For years after large Plinian eruptions , the blue cast of the sky is notably brightened by the persistent sulfate load of the stratospheric gases. Some works of the artist J. M. W. Turner may owe their vivid red colours to
992-651: The temperature rises. Rayleigh scattering is an important component of the scattering of optical signals in optical fibers . Silica fibers are glasses, disordered materials with microscopic variations of density and refractive index. These give rise to energy losses due to the scattered light, with the following coefficient: α scat = 8 π 3 3 λ 4 n 8 p 2 k T f β {\displaystyle \alpha _{\text{scat}}={\frac {8\pi ^{3}}{3\lambda ^{4}}}n^{8}p^{2}kT_{\text{f}}\beta } where n
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1024-457: Was faintly blue-tinted. He conjectured that a similar scattering of sunlight gave the sky its blue hue , but he could not explain the preference for blue light, nor could atmospheric dust explain the intensity of the sky's color. In 1871, Lord Rayleigh published two papers on the color and polarization of skylight to quantify Tyndall's effect in water droplets in terms of the tiny particulates' volumes and refractive indices . In 1881, with
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