Ukutyhubela imbali, abantu baye baziva besithanda kakhulu isibhakabhaka, kungekuphela nje ngexesha lobusuku bocamngca obuphembelela ubukho obukhoyo, kodwa nangexesha lokukhanya kwemini, xa sibonisa intaphane yemibala eqaqambileyo. Ngexesha elithile ebomini bethu, sonke siye sazibuza ukuba kutheni isibhakabhaka sibonakala siluhlaza okwesibhakabhaka okanye kutheni sijika i-orenji kunye neetoni ezibomvu ngexesha lokutshona kwelanga. Lo mbuzo waqala wasonjululwa nguLord Rayleigh, okwabizwa ngokuba nguJohn William Strutt, ingcali yezibalo eyafumanisa oku ekupheleni kwenkulungwane ye-19.
Kweli nqaku siza kukucacisela Isiphumo seRayleigh, iimpawu zayo kunye nokuba kutheni isibhakabhaka siluhlaza.
Isiphumo seRayleigh
ILanga likhupha uluhlu olubanzi lwemitha ye-electromagnetic, kubandakanywa ukukhanya okubonakalayo, okuqhelekileyo kwaziwa njengokukhanya okumhlophe. Okubangel 'umdla kukuba, ukukhanya okumhlophe ngokwenene kuyindibaniselwano yayo yonke imibala yomnyama, kunye ne-violet ingowona bude bufutshane kwaye ibomvu yeyona inde. Njengoko Ukukhanya kwelanga kuhamba kwi-atmosfera, kudibana nezinto ezahlukeneyo ezifana neegesi, amasuntswana aqinileyo kunye neemolekyuli zamanzi.. Xa la masuntswana engaphantsi kweshumi le-micrometer, abangela ukusasazeka kokukhanya okumhlophe macala onke, kugxininise ngakumbi ekukhanyeni okuluhlaza okwesibhakabhaka.
Olu khetho lokukhanya okuluhlaza okwesibhakabhaka lunokucaciswa yi-coefficient yokusasazwa, ebalwa kusetyenziswa ifomula 1/λ4, apho λ imele ubude bobude. Ekubeni i-violet kunye nokukhanya okuluhlaza okwesibhakabhaka kunowona bude bufutshane kwi-spectrum ebonakalayo, zivelisa i-quotient ephezulu xa ifakwe endaweni yefomula, ethi . Esi siganeko saziwa ngokuba yiRayleigh scattering.
Ngenxa yoko, imitha esasaziweyo idibanisa kunye neengqungquthela zegesi ezisebenza njengendawo ekhanyayo, ezibangela ukuba zigobe kwakhona kwaye zikhulise amandla abo.
Kutheni isibhakabhaka siluhlaza?
Ukuqwalasela olu lwazi lukhankanywe ngasentla, umntu unokulindela ukuba isibhakabhaka sibonakale mfusa endaweni yeblue ngenxa yobude baso obufutshane. Nangona kunjalo, oku akunjalo kuba iliso lomntu alikhathaleli kakhulu kumbala we-violet. Ngaphandle koko, Ukukhanya okubonakalayo kuqulethe umlinganiselo ophezulu wemitha ye-wavelength eluhlaza okwesibhakabhaka kune-violet.
Kwiimeko apho amasuntswana adlula ubude be-waveleng ngobukhulu, ukusabalalisa okungafaniyo akwenzeki. Endaweni yoko, zonke iinxalenye zokukhanya okumhlophe zisasazwe ngokulinganayo. Esi siganeko sichaza inkangeleko emhlophe yamafu, ekubeni amathontsi amanzi awakhayo engaphezulu kweshumi le-micrometer ububanzi. Noko ke, xa la mathontsi amanzi exinana, ukukhanya akunakudlula kuzo, okukhokelela kwinkangeleko engwevu ehambelana nokugquma kwamafu.
Nangona kunjalo, kufuneka kuqondwe ukuba isibhakabhaka asigcini i-blue hue rhoqo. Ngenxa yoko, i-phenomenon ye-Rayleigh yokusabalalisa ayichazi ngokupheleleyo ubukho bemibala eyahlukeneyo ebomvu ngexesha lokuphuma kwelanga nokutshona kwelanga. Nangona kunjalo, kukho ingcaciso ngale nyaniso.
Njengoko iLanga litshona lize lingene kwisigaba sobumnyama, ukuma kwalo elundini phayaa kubangela ukuba ukukhanya kuhambe umgama omkhudlwana ukuze kufike kuthi, kungasekho ncakasana. Olu tshintsho kwi-engile lukhokelela kwisiganeko esisezantsi, esibangela ukuba ukukhanya okuluhlaza okwesibhakabhaka kusasazeke ngaphambi kokuba kufike emehlweni ethu. Kunoko, . Kubalulekile ukuqaphela ukuba ukusasazeka kweRayleigh kuyaqhubeka ukwenzeka, kodwa kwindawo eyahlukileyo ngaphakathi kwi-atmosfera kunokuba iLanga likwinqanaba layo eliphezulu.
Historia
Ukutyhubela imbali, isibhakabhaka siye sayitsala ingqalelo yethu emini nasebusuku. Isebenze njengeseyile yentelekelelo yethu ukubhadula. Ngokwendalo, umdla kunye nophando lwezenzululwazi alukhululwanga kulo mtsalane. Njengezinye izinto ezenzeka mihla le, ezinjengokutshintsha kombala wamagqabi okanye imvelaphi yemvula, abaphandi baye bazama ukufumanisa izinto ezifihlakeleyo zesibhakabhaka. Kunokuba iwunciphise umtsalane wayo ongaqondakaliyo, izinto eziye zayifumanisa ziye zasenza nzulu ukuqonda noxabiso lwethu.
Ngexesha lovavanyo lwakhe lwe-infrared ngo-1869, uRayleigh wakhubeka kwisiphumo ebesingalindelekanga: ukukhanya okusasazwe ngamasuntswana amancinane kunombala oluhlaza okwesibhakabhaka. Oku kwamkhokelela ekubeni acinge ukuba ukusasazeka okufanayo kokukhanya kwelanga kwakungunobangela wombala ozuba esibhakabhakeni. Noko ke, akazange akwazi ukusichaza ngokupheleleyo isizathu sokuba kukhethwe ukukhanya okuluhlaza okanye isizathu sokuba umbala wesibhakabhaka ugqame kangaka, echaza uthuli olusesibhakabhakeni njengekuphela kwengcaciso.
Umsebenzi wakhe obalaseleyo wombala nokwahlulahlula ukukhanya esibhakabhakeni wapapashwa ngowe-1871. Usukelo lwakhe yayikukuba umlinganiselo wempembelelo kaTyndall kumathontsi amanzi ngokubala ubukho bamasuntswana amancinane kunye nezalathisi zawo ezibonisa ukukhenkceza. Ukwakha phezu kobungqina bukaJames Clerk Maxwell bangaphambili bendalo yokukhanya kwe-electromagnetic, uRayleigh wabonisa ngo-1881 ukuba ii-equations zakhe zilandelwa kwi-electromagnetism. Ukwandisa oko akufumanisileyo ngo-1899, wandisa isicelo kwiimolekyuli ezizimeleyo, ethatha indawo yamagama anxulumene namasuntswana amasuntswana kunye nezalathisi eziphinda-phindayo ngokwemigaqo ye-molecular polarizability.
Ukusasazwa kwizixhobo ze-porous
Izinto ezinamazinyo ziyakwazi ukubonisa ukusasazwa kohlobo lukaRayleigh, olulandela ipateni yokuchithakala kwe-λ-4. Lo mcimbi ubonakala ngokukodwa kwizinto eziphathekayo ze-nanoporous, apho kukho ukungafani okuphawulekayo kwi-index ye-refractive phakathi kwee-pores kunye neengxenye eziqinileyo ze-alumina e-sintered. Ngenxa yoko, i ukukhanya okusasazeka iba bukhali ngendlela emangalisayo, ibangela ukuba itshintshe indlela malunga neemicrometer ezintlanu.
Oku kuphawuleka kokuziphatha kokusasazwa kubangelwe kulwakhiwo olukhethekileyo lwe-nanoporous oluphunyezwe ngenkqubo ye-sintering, ebandakanya ukusetyenziswa kwe-alumina ye-monodispersive powder ukwenza usasazo olumxinwa lobungakanani bepore, ngokuqhelekileyo malunga ne-70 nm.
