Ukukhanya

Ukukhanya noma isokhanya / isonkanya kungenye yemiyonzi yenzubawonga ngaphakathi kwesinaba somungco wenzubawonga esibonwa ngeso lenyama. Isokhanya imvama lichasiswa njengelinebangacuphi eliphakathi kwamamithancu angama-400–700 (nm), aqondene nomjinge wamahazakhulu angama-750–420, maphakathi nensibomvu (enamabangacuphi amade) kanye nezukhwithi (enamabangacuphi amafushane).

Kumchazandalo, ibizo elithi "ukukhanya" lingabhekisela kabanzi kumiyonzi yenzubawonga yanoma iliphi ibangacuphi, kungakhathaliseki ukuba iyabonakala noma cha. Ngalowomqondo, imisebentathu, amagu X, amachadaza, namaza omsakazo konke kungukukhanya. Izakhi eziyinhloko zokukhanya ziyi-intensity, ukuhlakazeka kokuqombotha (propagation of direction), umungco womjingo noma ibangacuphi kanye nokuluthuzeka. Ijubane lokukhanya elinyeni, amamitha ayizi- 299 792 458 ngomzuzwana (m/s), kuyingxenye yenzinzo (constants) eliyisisekelo semvelo. Njengazo zonke izinhlobo zemiyonzi yenzubawonga, ukukhanya okubonakalayo busabalala ngezinhlayiyana ezingenasisindo ezibizwa amabane ezimelela imingako yenzubawonga (electromagnetic field), futhi zingahlaziywa kokubili njengamaza nanjengezinhlayiyana.

Umthombo oyinhloko wokukhanya kwemvelo emhlabeni ilanga. Ngokomlando, omunye umthombo wokukhanya kubantu bekungumlilo, kusuka kumathezi asendulo kufika ezibanini zanamuhla zamafutha. Ngokuthuthukiswa kwezibani zamazuba nohlelo lwesidlakathii, ukukhanyisa ngamazuba sekuthathe isikhundla sokukhanya komlilo ngokufanele.

 uMungco wenzubawonga nesokhanya
Ngokuvamile, imiyonzi yenzubawonga ijinjwa ngebangacuphi phakathi kwamaza omsakazo, amachadaza, insibomvu, umungco obonakalayo esiwushwayiza njengokukhanya, uzukhwithi, amagu-X nemisebentathu. Igama elithi "imiyonzi" lishiya ngaphandle Umzuba, ubuwonga nezinkundla esiseduze.

 Ijubane lokukhanya 

Ijubane lokukhanya elinyeni uchasiswa ngokuthi uyizi-299 792 458 imitha ngokomzuzwana. Inani eligxilile lokukhanya ngokwemivo yokulinganisa liwumphumela wesiminya esithi imitha kusebenza lona ukuchasisa leli jubane. Zonke izinhlobo zemiyonzi yenzubawonga zinyakaza ngejubane elifanayo elinyeni.