Amandla Okujikeleza Kweplanethi kanye Nokuguquka
Ukujikeleza kanye nokuguquka kuyizinyathelo ezimbili eziyisisekelo ezakha "isigqi" seplanethi. Ukujikeleza kuwukujikeleza kweplanethi ku-axis yayo, kanti ukuguquka kuwukuhamba kweplanethi ezungeze inkanyezi yayo—eSistimu Yelanga, leyo nkanyezi yiLanga. Lezi zinyathelo ezimbili zingase zizwakale zilula, kodwa amandla angemuva kwazo ahilela i-physics ecebile: amandla adonsela phansi, umfutho we-angular, i-torque, ukusebenzisana kwamagagasi, kanye nomthelela wesimo seplanethi esingesiyindilinga. Kulokhu kuvela izenzakalo ezibalulekile ezahlukahlukene, njengokushintshana kwemini nobusuku, izinkathi zonyaka, umehluko ebude bemini, ngisho nokuzinza kwesimo sezulu sesikhathi eside.
1. Ukujikeleza: Umshini Wesikhathi Sansuku Zonke Weplanethi
Ukujikeleza kunquma ubude bosuku lweplanethi. Umhlaba uthatha cishe amahora angama-23 nemizuzu engama-56 ukujikeleza kanye uma kuqhathaniswa nezinkanyezi ezikude (usuku oluseceleni), kodwa cishe amahora angama-24 uma kuqhathaniswa neLanga (usuku lwelanga) ngoba uMhlaba nawo ujikeleza iLanga. Amanye amaplanethi anezikhathi zokujikeleza ezihlukahluka kakhulu. I-Jupiter ijikeleza ngokushesha kakhulu—cishe amahora ayi-10—kuyilapho i-Venus ijikeleza kancane kakhulu, cishe izinsuku ezingama-243 zoMhlaba, ngisho nakwelinye icala (ukubuyela emuva).
Ku-physics, ukujikeleza kuhlobene nomfutho we-angular. Lapho iplanethi yakheka kusuka kudiski yegesi nothuli (idiski ye-protoplanetary), ukushayisana kanye nokwanda kwesisindo kuvame ukunikeza ukujikeleza kokuqala. Ngenxa yokuthi umfutho we-angular uvame ukulondolozwa, amaplanethi agcina ukujikeleza kwawo ngaphandle kokuthi kusetshenziswe amandla angaphandle abalulekile. Kodwa-ke, ukujikeleza "akuzinzile" ngokuphelele; kungashintsha kancane ngenxa yokusebenzisana kwamandla adonsela phansi nezinye izidalwa zasezulwini, ikakhulukazi amandla olwandle.
Ukujikeleza nakho kuthinta ukuma kweplanethi. Amaplanethi ajikelezayo ngokushesha avame ukuzwa ukugoba: ukukhukhumala enkabazwe kanye nokugoba kancane ezinsikeni. I-Jupiter ne-Saturn zibonisa ngokucacile lo mphumela. Lokhu kugoba kungaphezu nje kokuma; kuthinta insimu yamandla adonsela phansi yeplanethi futhi kungathonya amandla okujikeleza kwama-satellite ayo.
Ngaphezu kwalokho, ukujikeleza kunemiphumela enamandla emoyeni nasolwandle ngamandla eCoriolis. Emhlabeni, la mandla avimbela imimoya nemisinga yolwandle, abumba amaphethini okujikeleza komhlaba, asize ekwakheni izivunguvungu nama-anticyclone, futhi athonye ukusatshalaliswa kokushisa. Emaplanethini ajikelezayo ngokushesha, izivunguvungu zingaba zikhulu kakhulu futhi ziqhubeke isikhathi eside, njengeGreat Red Spot kuJupiter.
2. Inguquko: Uhambo Lonyaka kanye neJiyomethri Yomjikelezo
Ukuguquka kwamaplanethi kulawula "unyaka" kanye nesakhiwo sezinkathi zonyaka. Ngokwemithetho kaKepler, ukuzungeza kwamaplanethi ngokuvamile kuyi-ellipses lapho iLanga ligxile khona. Ijubane lamaplanethi nalo liyahlukahluka: lihamba ngokushesha eduze kwe-perihelion (iphuzu eliseduze neLanga) futhi lihamba kancane e-aphelion (iphuzu elikude kakhulu). Lesi simiso siwumphumela wokulondolozwa komfutho we-angular kanye namandla e-orbital.
Isikhathi sokuzungeza sincike ebangeni elimaphakathi ukusuka enkanyezini: lapho iplanethi ikude, unyaka wayo mude. Lokhu kufingqwe nguMthetho Wesithathu kaKepler: isikwele sesikhathi sokuzungeza silingana ne-cube ye-axis ye-semi-major ye-orbit. Ngakho-ke, iMercury ithatha izinsuku ezingu-88 kuphela zoMhlaba ukuqeda umjikelezo owodwa, kanti iNeptune ithatha iminyaka engaba ngu-165 yoMhlaba.
Kodwa uguquko alugcini nje ngoku "jikeleza"; luphinde luhilele ukuzwakala kwe-orbital. Amanye amaplanethi nama-satellite angabanjwa ngesilinganiso esithile, esizinzile sezikhathi ze-orbital. Isibonelo esidumile yi-resonance engu-3:2 phakathi kwe-Pluto ne-Neptune, okusiza ekuvimbeleni ukuthi zingashayisani yize izindlela zazo ze-orbital zibonakala zihlangana ekubukeni.
3. Ukuthambekela Kwe-Axial Nezinkathi
Izinkathi zonyaka zithonywa kakhulu ukuthambekela kwe-axis yokujikeleza koMhlaba (ukungapheleli) uma kuqhathaniswa nendiza ezungeza umhlaba. Umhlaba uthambekele cishe ku-23,5°, ngakho-ke ngesikhathi sokuguquka kwawo, ingxenye ezungeza umhlaba ethambekele eLangeni ihlangabezana nehlobo, kanti enye ingxenye ihlangabezana nobusika. Uma ukuthambekela kwe-axial kuseduze no-0°, izinkathi zonyaka zizoba buthaka kakhulu. Ngokuphambene nalokho, uma ukuthambekela kukhulu kakhulu, izinkathi zonyaka zingaba nzima kakhulu.
I-Uranus iyisibonelo esimangalisayo: ukuthambekela kwayo kwe-axial kungama-98°, njengokungathi "izungeza" iLanga. Ngenxa yalokho, isigxobo esisodwa singabhekana neLanga amashumi eminyaka, sikhiqize amaphethini okukhanya kwesizini ahluke kakhulu kwewoMhlaba. Lokhu kuguquguquka kunemiphumela emikhulu ekushiseni komoya, ukwakheka kwamafu, kanye nokuziphatha komoya womhlaba wonke.
Ngaphezu kokuthambekela kwe-axial, ukuthambekela kwe-orbital (ukuthi i-orbital iyi-elliptical kangakanani) nakho kungashintsha izinkathi zonyaka. I-Mars inamandla amakhulu kuneMhlaba, ngakho ibanga layo ukusuka eLangeni liyahlukahluka kakhulu unyaka wonke. Lokhu kubangela ukuthi izinkathi ku-Mars zihluke ngamandla phakathi kwezingxenye ezisenyakatho neziseningizimu.
4. Ukusebenzisana kwe-Tidal kanye nokuvela kokujikeleza
Esinye sezici ezibaluleke kakhulu ezishintsha ukujikeleza ngokuhamba kwesikhathi amandla olwandle. Uma iplanethi iseduze nomunye umzimba omkhulu—njengenyanga noma inkanyezi—amandla adonsela phansi awadonsi zonke izingxenye zeplanethi ngokulinganayo. Lo mehluko ekukhanga udala ulwandle oluvundlile. Uma lokhu kuqhuma kungahambelani kahle nomugqa oxhumanisa imizimba emibili (isibonelo, ngenxa yokujikeleza), kudalwa i-torque enganciphisa noma isheshise ukujikeleza.
EMhlabeni, ukusebenzisana kwamaza neNyanga kunciphisa kancane kancane ukujikeleza koMhlaba (kwandisa usuku) futhi ngasikhathi sinye kusunduza iNyanga ngamasentimitha ambalwa ngonyaka. Ngokwesilinganiso sejiyoloji, izinsuku zoMhlaba zazimfushane esikhathini esidlule. Inqubo efanayo ingabangela ukuthi into ivalwe ngamaza, lapho isikhathi sokujikeleza silingana nesikhathi sokuguquka, ukuze uhlangothi olulodwa luhlale lubhekene nento yamaza. INyanga ivalwe ngamaza eMhlabeni; amaplanethi amaningi aseduze nezinkanyezi zawo kucatshangwa ukuthi nawo avalwe ngamaza, kanye nemiphumela emikhulu esimweni sezulu (olunye uhlangothi luhlala lusemini, olunye ubusuku).
I-Mercury inikeza isibonelo esithakazelisayo: itholakala ku-resonance ye-spin-orbit engu-3:2. Lokhu kusho ukuthi i-Mercury ijikeleza kathathu kuzo zonke izindlela ezimbili ezenzayo ezizungeze iLanga. Lesi simo esizinzile sibangelwa ukuhlanganiswa kokungajwayelekile kwe-orbit kanye nama-torque avela eLangeni.
5. Ukuzibusa, Ukuzikhukhumeza, kanye ne-Axial “Wobble”
I-axis yokujikeleza kweplanethi ayihlali ikhombe iphuzu elifanayo esibhakabhakeni. Ingadlula ekuqhubekeni, ukunyakaza okuhamba kancane, okuntengantengayo njengesihloko esijikelezayo. EMhlabeni, ukuqhubekela phambili kwenzeka esikhathini esiyiminyaka engaba ngu-26.000, okuthonywe kakhulu ukudonswa yiLanga neNyanga ekujikelezeni koMhlaba. Ngenxa yokuqhubekela phambili, "inkanyezi ye-pole" iyashintsha ngokuhamba kwesikhathi: okwamanje yiPolaris, kodwa yayihlukile eminyakeni eyizinkulungwane edlule.
Ngaphezu kwe-precession, kukhona i-nutation, ukunyakaza okuncane ekuhambeni kwe-precession okuthonywa ukushintshashintsha kokujikeleza kweNyanga nezinye izici. I-Precession kanye ne-nutation kunegalelo ekushintsheni kwesimo sezulu kwesikhathi eside uma kuhlanganiswa nezinguquko ekungajwayelekile kanye nokuthambekela kwe-axial—okuvame ukuxoxwa ngakho kumongo wemijikelezo yeMilankovitch.
6. Umthelela Esimweni Sezulu, Isimo Sezulu, kanye Nokuhlala Kwabantu
Ukuguquguquka kokujikeleza nokuguquka kubalulekile hhayi nje kuphela kwezinkanyezi kodwa futhi nasekuhlaleni kwamaplanethi. Ubude bosuku buthinta umehluko wokushisa phakathi kosuku nobusuku. Ukujikeleza okuhamba kancane kakhulu kungabangela ukuthi usuku lushise kakhulu kanti ubusuku buphole kakhulu, ngaphandle kokuthi umkhathi ujiyile ngokwanele ukujikeleza ukushisa. Ukuthambekela kwe-Axial kuthonya ukuhlukahluka kwesizini; ukuthambekela okukhulu kungaphonsela inselelo ukuzinza kohlelo lwendalo. Ukungajwayelekile okuphezulu kungabangela amaplanethi ukuthi abhekane nomehluko omkhulu ekushiseni unyaka wonke.
EMhlabeni, inhlanganisela yokujikeleza okusheshayo, umoya osebenzayo kanye nolwandle, kanye nokuthambekela okulinganiselwe kwe-axial kudala isimo sezulu esizinzile esivumela impilo eyinkimbinkimbi. Kodwa-ke, lokhu kuzinza akuqinisekisiwe; kungumphumela wokulingana okuguquguqukayo kwesikhathi eside kakhulu.
Isiphetho
Ukujikeleza kwamaplanethi kanye nokuguquka kuyizinyathelo ezimbili ezilula ezikhiqiza imiphumela eyinkimbinkimbi. Ukujikeleza kubumba usuku, kuthonya ukuma kweplanethi, kulawula ukujikeleza komkhathi, futhi kuxhumana namandla olwandle. Ukuguquka kunquma unyaka, i-orbital geometry, i-resonance, kanye namaphethini okwamukela amandla avela enkanyezini. Ukuthambekela kwe-axial, i-orbital eccentricity, ukukhiya kolwandle, kanye ne-precession kubonisa ukuthi "amawashi" amaplanethi ahlala eshintsha futhi eshintsha. Ngokuqonda lezi zinguquko, asiqondi nje kuphela ukuthi amaplanethi ahamba kanjani kodwa futhi nokuthi kungani enezinkathi, isimo sezulu, ngisho nekhono lokusekela ukuphila.
