Imibono kanye namamodeli endawo yonke
Indawo yonke iyisamba sesikhala, isikhathi, izinto, kanye namandla njengoba sizazi. Selokhu abantu baqala ukubuka isibhakabhaka ebusuku, imibuzo mayelana nomsuka, ukuma, kanye nesiphetho sendawo yonke iye yavusa ilukuluku. Kwisayensi yanamuhla, ukuqonda indawo yonke kwakhiwe ngemibono namamodeli—imiqondo emibili ehlobene kodwa ehlukene. Inkolelo-mbono iwuhlaka oluchazayo olusekelwa ubufakazi futhi olukwazi ukubikezela izenzakalo, kuyilapho imodeli iwukubonakaliswa okuhlelekile (ngokuvamile kwezibalo) okusetshenziselwa ukuchaza ingxenye ethile yendawo yonke ngokusekelwe kuleyo nkolelo-mbono. Lesi sihloko sixoxa ngezinye zezinkolelo-mbono ezinkulu namamodeli akha i-cosmology yanamuhla.
1. Kusukela Ku-Cosmology Yakudala Kuya Ku-Cosmology Yanamuhla
Ezikhathini zakuqala, imibono yendawo yonke yayithonywe kakhulu yifilosofi kanye nokubona okulinganiselwe. Imodeli kaPtolemy ye-geocentric yabeka uMhlaba enkabeni yendawo yonke, kanti imodeli kaCopernicus ye-heliocentric yashintsha indawo ibe yiLanga. Nakuba lezi zinguquko zazibonakala zilula, zabangela uguquko lwesayensi: indawo yonke yayingaqondwa ngezibalo kanye nokubuka okuhlelekile.
UNewton wabe esethula amandla adonsela phansi emhlabeni wonke, echaza ukunyakaza kwamaplanethi nezinto eziwayo ngemithetho efanayo. Kodwa-ke, i-cosmology yaseNewtonian yabhekana nenkinga lapho isetshenziswa ezikalini ezinkulu kakhulu: uma indawo yonke yayingenamkhawulo futhi ifana, ukudonswa kwamandla adonsela phansi kufanele kubangele ukuthi iwe. Lokhu kungezwani kwavula indlela yenkolelo-mbono yokuhlobana.
2. Ubudlelwano Obujwayelekile: Isisekelo Sesayensi Yezinkanyezi Yanamuhla
U-Albert Einstein, nge-General Theory of Relativity (1915), washintsha indlela esiqonda ngayo amandla adonsela phansi. Esikhundleni samandla akhangayo kaNewton, amandla adonsela phansi abhekwa njengokugoba kwesikhala nesikhathi okubangelwa ubunzima namandla. Lesi simiso sibalulekile ngoba indawo yonke esikalini sendawo yonke ayinakuchazwa ngokwanele ngobuchwepheshe besimanje.
Ukuhlobana okuvamile kuvumela ososayensi ukwakha imodeli yezibalo eguquguqukayo yendawo yonke: indawo yonke inganda noma inciphe kuye ngokuqukethwe kwayo kwamandla nezinto. U-Einstein ngokwakhe ekuqaleni wayehlose indawo yonke engaguquki, ngakho wanezela i-cosmological constant. Kodwa-ke, okwabonwa kamuva kwabonisa ukuthi indawo yonke iyanda ngempela, okwenza i-expansion dynamics ibe yinto ebalulekile ye-cosmology.
3. Imodeli ye-Big Bang: Umsuka kanye nokuvela kwendalo yonke
Imodeli ye-Big Bang iyincazelo eyamukelwa kabanzi ngemvelaphi yendawo yonke esiyibukayo. Umqondo wayo oyinhloko ukuthi indawo yonke yaqala esimweni esishisayo kakhulu nesiminyene, yabe isinwebeka futhi iphola eminyakeni eyizigidigidi. I-Big Bang kwakungeyona "ukuqhuma" endaweni engenalutho, kodwa kwakuwukwanda kwendawo ngokwayo.
Ubufakazi obuthathu obuyinhloko bokubuka busekela lo modeli. Okokuqala, okubonwe ngu-Edwin Hubble kubonise ukuthi imithala iyaqhela komunye nomunye; lapho umthala uqhela kakhulu, kulapho ubonakala sengathi uyashesha khona ukuhamba. Okwesibili, isizinda se-cosmic microwave (CMB), esatholakala ngo-1965, "siwuphawu lokushisa" lwendawo yonke yokuqala. Okwesithathu, ubuningi bezinto zokukhanya ezifana ne-hydrogen, i-helium, ne-lithium kuhambisana nezibikezelo ze-Big Bang nucleosynthesis.
I-Big Bang ayiphenduli konke, ikakhulukazi umbuzo othi "kwenzekeni ku-t=0" noma imbangela yokuqala. Kodwa-ke, njengesibonelo sokuvela kwendawo yonke kusukela ezigabeni zayo zokuqala kuze kube manje, inamandla futhi ivuselelwa njalo ngedatha yesibonakude yesimanje.
4. Imodeli Yokukhuphuka Kwentengo Yendawo Yonke: Ukuchaza Ububushelelezi Bendawo Yonke
Imodeli yokwehla kwamandla emvelo yethulwa ukuze ibhekane nezinkinga eziningana ku-Big Bang ejwayelekile, njengenkinga ye-horizon (kungani i-CMB ibonakala ifana esibhakabhakeni, yize izindawo ezikude kakhulu kwakungafanele zibe nesikhathi "sokuxhumana") kanye nenkinga yokuba yisicaba (kungani i-geometry yendawo yonke ibonakala iseduze kakhulu nokuba yisicaba).
Ukwehla kwamandla emali kusikisela ukuthi engxenyeni yokuqala yomzuzwana ngemva kweBig Bang, indawo yonke yanda ngokushesha okukhulu. Lokhu kukhula "kwanciphisa" indawo yonke, okwenza izindawo eziqhelelene kakhulu manje ezazikade zisondelene isikhathi eside ngokwanele ukuze zifinyelele ukufana. Ukwehla kwamandla emali kubikezela nokushintshashintsha okuncane kwe-quantum okwaba yizinto ezandulela izakhiwo ezinkulu njengemithala kanye namaqoqo emithala—into ehambisana nephethini ye-anisotropy encane ku-CMB.
5. Izinto Ezimnyama: Isibonelo Sokuchaza Amandla Adonsela Phansi “Angekho”
Lapho izazi zezinkanyezi zilinganisa ijubane lokujikeleza kwemithala, zathola umphumela omangalisayo: izinkanyezi emaphethelweni emithala zazihamba ngokushesha kakhulu kunalokho obekulindelwe ukube bekukhona izinto ezibonakalayo kuphela. Izenzakalo ezifanayo zenzeka ekulensini kwamandla adonsela phansi kanye nokuguquguquka kwamaqoqo emithala. Ukuze kuchazwe lokhu, i-cosmology yanamuhla yethula ingxenye "yezinto ezimnyama," into engakhiphi ukukhanya kodwa enomoya odonsela phansi.
Amamodeli ezinto ezimnyama abalulekile ekwakhiweni kwesakhiwo se-cosmic. Ngaphandle kwezinto ezimnyama, ukwakheka kwemithala bekuyoba kancane kakhulu, okwenza kube nzima ukuchaza amaphethini esakhiwo esiwabona namuhla. Naphezu kobufakazi obuqinile bamandla adonsela phansi, izinhlayiya ezakha izinto ezimnyama azikatholakali ngokuqondile. Ukuhlolwa okuningi komhlaba kanye nokubonwa kwezinkanyezi kuyaqhubeka ukuze kutholakale abantu abangaba khona.
6. Amandla Amnyama: Kungani Indawo Yonke Ikhula Ngokushesha?
Ngasekupheleni kweminyaka yama-1990, ukubonwa kwe-supernovae yohlobo lwe-Ia kwabonisa ukuthi ukwanda kwendawo yonke kwakunganciphisi ijubane ngenxa yamandla adonsela phansi, kodwa kunalokho kwanda ngokushesha. Ukuze bachaze lokhu kusheshisa, ososayensi basikisela ukuba khona kwamandla amnyama, uhlobo lwamandla oludala ingcindezi engemihle futhi luqhube ukwanda okusheshayo.
Enye yamamodeli alula kakhulu amandla amnyama yi-cosmological constant (Lambda, Λ), eye yaphinde yavela. Ngaphakathi kwalolu hlaka, imodeli ye-cosmological esetshenziswa kakhulu namuhla yi-ΛCDM (Lambda Cold Dark Matter), ephakamisa ukuthi indawo yonke yakhiwe amandla amnyama (cishe angu-68%), into emnyama ebandayo (cishe angu-27%), kanye ne-normal matter (cishe u-5%). Le modeli iphumelele kakhulu ekuchazeni isizinda se-microwave ye-cosmic, isakhiwo esikhulu, kanye nokuziphendukela kwemvelo kwe-cosmic, yize uhlobo lwamandla amnyama luhlala luyimfihlakalo.
7. Imodeli Yejiyometri Yomhlaba Wonke: Isicaba, Ivulekile, Noma Ivaliwe
Ukuhlobana okuvamile kuvumela indawo yonke ukuthi ibe namajiyometri ahlukene kuye ngokuthi ingakanani i-energy-matter density yayo. Kalula nje, kunezindlela ezintathu ezingenzeka: indawo yonke evaliwe (i-positive curvature), indawo yonke eyisicaba (zero curvature), noma indawo yonke evulekile (negative curvature). Idatha ye-CMB, ikakhulukazi evela emisebenzini efana ne-WMAP kanye ne-Planck, ikhombisa ukuthi indawo yonke iseduze kakhulu ne-flat.
Le geometry ihlobene nesiphetho sesikhathi eside sendawo yonke. Indawo yonke evaliwe ingaphela "ngokuqhekeka okukhulu" (ukuwa), kuyilapho indawo yonke evulekile noma eyisicaba ivame ukuqhubeka nokukhula. Kodwa-ke, ngokuba khona kwamandla amnyama, izimo zesikhathi esizayo ziba nzima kakhulu, okuhlanganisa nokwenzeka "kwe-Big Freeze" (ukupholisa okuqhubekayo) noma ngisho "nokuqhekeka okukhulu" uma ukwanda kushesha kakhulu.
8. Ithiyori ye-Quantum kanye namandla adonsela phansi: Ukufuna Ithiyori Yakho Konke
I-General relativity iphumelela kakhulu ezikalini ezinkulu, kuyilapho i-quantum mechanics iphumelela kakhulu ezikalini ezincane. Inselele enkulu ku-physics yanamuhla ukuhlanganisa lokhu okubili kumbono we-quantum gravity. Ezinye izindlela ezaziwayo yi-string theory kanye ne-loop quantum gravity. I-string theory ithi izinhlayiya eziyisisekelo ziyadlidliza "izintambo" ezinesilinganiso esisodwa, kuyilapho i-loop quantum gravity izama ukulinganisa isikhathi sesikhala ngokwaso.
Ngokwesimo se-cosmology, amandla adonsela phansi e-quantum abalulekile ekuqondeni izimo zokuqala zendawo yonke, njengangaphambi kokwehla kwamandla emali noma ngisho nencazelo engokoqobo ye-Big Bang singularity. Kuvele amamodeli amaningana ahlukile, njenge-"bounce cosmology," okubonisa ukuthi indawo yonke yadlula emijikelezweni yokwanda nokuncipha ngaphandle kokungafani kokuqala.
Isiphetho
Imibono namamodeli mayelana nendawo yonke ayaqhubeka nokukhula njengoba ukubuka kanye nobuchwepheshe buqhubeka. Ubudlelwano obujwayelekile buyisisekelo se-cosmology yanamuhla, kuyilapho amamodeli e-Big Bang kanye ne-inflation echaza imvelaphi yawo kanye nokuvela kwawo kwasekuqaleni. Izinto ezimnyama kanye namandla amnyama kunikeza uhlaka lokuqonda ukuguquguquka kwemithala kanye nokukhula kwayo okusheshayo, yize uhlobo lwazo oluqondile lungachazwa. Okwamanje, ukusesha inkolelo-mbono yamandla adonsela phansi e-quantum kuyisinyathelo esibalulekile ekuphenduleni imibuzo ejulile mayelana nemvelaphi yesikhala nesikhathi.
I-Cosmology ikhombisa ukuthi ukuqonda indawo yonke akukhona nje ukubuka izinkanyezi nemithala, kodwa futhi nokwakha izincazelo ezihambisanayo, ezingahlolwa, nezihlala zicwengisisiwe. Lapho sifunda okwengeziwe ngendawo yonke, kulapho kucaca khona ukuthi ulwazi lomuntu luyinqubo eqhubekayo—kusukela kumamodeli alula kuya ekuqondeni okujulile ngokoqobo ngokwalo.
