Kungani isikhathi sokuphuma kwelanga sishintsha unyaka wonke?
Context:Nakuba kubonakala sengathi iLanga "liyaphuma" emkhathizwe, empeleni ukunyakaza koMhlaba yikho okubangela ukuba iLanga libonakale. Ukukhohlisa kwelanga elihambayo kubangelwa ukuthi ababheki bomhlaba basesimweni sokubhekisela esijikelezayo; lokhu kuhamba okubonakalayo kwabangela ukuba amasiko amaningi abe nezinganekwane nezinkolo ezakhiwe ezungeze imodeli ye-geocentric, eyayibusa kwaze kwaba yilapho isazi sezinkanyezi uNicolaus Copernicus sakha imodeli yakhe ye-heliocentric ngekhulu le-16. Ngokwezifundo zezinkanyezi, ukuphuma kwelanga kwenzeka isikhashana nje: umzuzu lapho ingxenye engenhla yeLanga ibonakala ihlangana khona nomkhathizwe. Nokho, inkulumo ethi ukuphuma kwelanga ngokuvamile ibhekisela ezikhathini zangaphambi nangemva kwalesi sikhathi: I-Twilight, isikhathi sasekuseni lapho isibhakabhaka sikhanya khona, kodwa ilanga lingakabonakali. Ukuqala kokushona kwelanga kwasekuseni kubizwa ngokuthi ukusa kwezinkanyezi. Isikhathi ngemva kokuphuma kweLanga lapho imibala ekhangayo nemiphumela yesimo sezulu isibonakala khona. Isikhathi sokuphuma kwelanga siyahlukahluka phakathi nonyaka futhi sithonywa ububanzi nobude besibukeli, ukuphakama, nesikhathi sendawo. Lezi zinguquko ziqhutshwa ukuthambekela kwe-axial yoMhlaba, ukujikeleza kwansuku zonke koMhlaba, ukunyakaza kweplanethi emzileni wayo waminyaka yonke we-elliptical ezungeze iLanga, kanye nokujikeleza okuhlangene koMhlaba nenyanga okuzungezile. I-analemma ingasetshenziselwa ukwenza izibikezelo ezilinganiselwe zesikhathi sokuphuma kwelanga. Ekupheleni kwebusika nasentwasahlobo, ukuphuma kwelanga njengoba kubonakala ezindaweni ezinamazinga okushisa aphansi kwenzeka kusenesikhathi usuku ngalunye, kufinyelele esikhathini sayo sokuqala eduze kwe-solstice yasehlobo; nakuba usuku oluqondile luhluka ngokwamazinga okushisa. Ngemva kwalesi sikhathi, isikhathi sokuphuma kwelanga siya ngokuhamba kwesikhathi usuku ngalunye, sifinyelele esiphelweni saso esikhathini esithile esizungeze i - solstice yasebusika. Ukwehluka phakathi kwezinsuku ze-solstice nesikhathi sokuphuma kwelanga sokuqala noma sokugcina kubangelwa ukungafani kwe-orbit yomhlaba nokuthambekela kwe-axis yayo, futhi kuchazwa yi-analemma, engasetshenziswa ukubikezela izinsuku. Ukuhlukahluka ekuqhekekeni komkhathi kungashintsha isikhathi sokuphuma kwelanga ngokushintsha ukuma kwalo okubonakalayo. Eduze nezingqimba zomhlaba, ukuhluka kwesikhathi sosuku kukhulu kakhulu, ngoba iLanga liwela umkhathizwe nge-engeli elincane kakhulu futhi ngaleyo ndlela liphuma kancane. Ukucabangela ukuphazamiseka komkhathi nokulinganisa kusuka emaphethelweni angaphambili kwandisa kancane ubude besikhathi sosuku uma kuqhathaniswa nobusuku. Kodwa-ke, i-sunrise equation, esetshenziselwa ukuthola isikhathi sokuphuma nokushona kwelanga, isebenzisa isikhungo somzimba seLanga ekubaleni, inganaki ukuqhuma komkhathi kanye ne-angle engeyona zero engaphansi kwediski yelanga.
Isikhathi sokuphuma kwelanga siyahlukahluka phakathi nonyaka futhi sithonywa ububanzi nobude besibukeli, ukuphakama, nesikhathi sendawo. Lezi zinguquko ziqhutshwa ukuthambekela kwe-axial yoMhlaba, ukujikeleza kwansuku zonke koMhlaba, ukunyakaza kweplanethi emjikelezweni wayo waminyaka yonke we-elliptical ezungeze iLanga, kanye nokujikeleza okuhlangene koMhlaba nenyanga okuzungezile.