Omunye wemibuzo abantu nososayensi ababili abahlale bezibuza yona ukuthi Ukujikeleza komhlaba kuncipha. Impendulo ithi yebo. Umhlaba wehla. Iplanethi iyancipha futhi ijikeleza kancane. Ijubane layo lokuzungeza linquma ubude besikhathi samahora angu-24 osuku, futhi igcina inkambiso yokwehla, okuthi nakuba ingavamile futhi ingabikezeli, ihlala njalo futhi izwakala ngenxa yokubhekwa nokubala kwezibalo kwezazi zezinkanyezi.
Ngakho-ke, sizonikezela lesi sihloko ukuze sikutshele konke odinga ukukwazi mayelana nokuthi ukujikeleza komhlaba kunciphisa kanjani ijubane nokuthi kunamiphi imiphumela empilweni.
Ingabe ukuzungeza komhlaba kuhamba kancane?
Nakuba isivinini sokujikeleza singashintshi futhi akulula ukusibala, ukuthambekela ukuthi sizungeze kancane kancane. Okwesibili okungeziwe okwengezwe ewashini bekungoJuni 30, 2015. U-2015 ube namasekhondi angu-86.401, isekhondi elilodwa ngaphezu kokujwayelekile. I-ejensi yomhlaba wonke ehlonishwayo, i-International Earth Rotation and Reference System Service (IERS), iphethe ukulinganisa njalo ukujikeleza komhlaba futhi idinga isaziso sezinyanga eziyisithupha lapho kufanele kwengezwe isekhondi.
Ukujikeleza komhlaba kuncipha ngenxa yamagagasi enyanga nezinye izici, njengokushintsha komkhathi (umoya), okunomthelela obonakalayo ekusheshiseni noma ekunciphiseni ijubane. Uma utholwa, umehluko phakathi kwesikhathi se-astronomical (UT1) nesikhathi se-athomu (UTM) ungaphezu kwamasekhondi angu-0,9, futhi imizuzwana yokugxuma ingabikezelwa.
Ukulinganisa kwemizuzwana ye-leap kwethulwa ngaphansi kwamazinga esayensi ngokuphelele ukuze kunxeshezelwe ithonya lezici zangaphandle ezifana amandla adonsela phansi enyanga, ukuncibilika kwezigxobo noma izenzakalo ze-geological ezifana nokuzamazama komhlaba, ama-tsunami noma ukuqhuma kwentaba-mlilo, okubangela izinguquko emhlabeni. Noma isiphi isenzakalo esingashintsha ukusatshalaliswa kobunzima boMhlaba, kusukela enkabeni kuya oqweqweni, sithinta izinga lokujikeleza, kodwa imiphumela ayilindelekile.
Ngaphandle kwalesi sesibili, esikhule izikhathi ezingaphezu kuka-20 kusukela ngeminyaka yawo-1970, amawashi esiwasebenzisela ukulinganisa isikhathi ngeke ahambisane nesikhathi sezinkanyezi, isikhathi sangempela, futhi ngenxa yalokho ngeke alandele ukujikeleza kwamaplanethi nokuma kwawo ngokuphathelene nelanga. Umhlaba ubulokhu uncipha isikhathi eside. Ezigidini zeminyaka edlule, izinsuku zazimfushane kakhulu futhi isikhathi phakathi kokuphuma nokushona kwelanga sasifinyezwa ngamahora ambalwa.
Ukujikeleza komhlaba kuncipha kanye nobudlelwano bawo nomoya-mpilo
Ukukhuphuka kwamazinga komoyampilo ekuqaleni komlando woMhlaba kwavula indlela yezinhlobonhlobo ezimangalisayo zezilwane. Kodwa sekungamashumi eminyaka ososayensi bezama ukuchaza izici ezilawula le nqubo kancane kancane, okuyinto Sekuthathe iminyaka ecishe ibe yizigidi ezi-2.000.
Manje, ithimba labacwaningi bamazwe ngamazwe liphakamisa ukuthi ukwanda kwesikhathi sokukhanya kwelanga ezinsukwini zokuqala Zomhlaba - ukujikeleza kwamaplanethi amancane kancane kancane kancane kancane ngokuhamba kwesikhathi, okwenza izinsuku zibe zinde - kungenzeka ukuthi kukhulise inani lomoya-mpilo okhishwa ukukhanya kwe-photosynthetic nge i-cyanobacteria, eyanquma isikhathi se-oxygenation yeplanethi.
Iziphetho zabo zagqugquzelwa ucwaningo lwemiphakathi ephilayo yama-microbial eyakhula ezimeni ezimbi kakhulu. ngaphansi kwechibi le-Lake Huron elingamamitha angama-30 ngaphansi komhlaba. Amanzi asesiqhingini esimaphakathi sase-U.S. i-tiankeng anesulfure ephezulu futhi anomoya-mpilo omncane, futhi amagciwane anombala ogqamile achuma lapho kucatshangwa ukuthi angama-analogi amahle ezinto eziphilayo ezinengqamuzana elilodwa ezakha amakoloni afanayo kumakhaphethi ezinkulungwaneni zeminyaka edlule phezu komhlaba. Zomhlaba kanye nasolwandle.
Abacwaningi babonise ukuthi izinsuku ezinde zandisa inani le-oxygen ekhishwe ama-photosynthetic microbial mats. Lokhu okutholakele, nakho, kukhomba isixhumanisi ebesingacatshangelwa ngaphambili phakathi komlando wokuphila komoyampilo womhlaba nezinga lawo lokuzungeza. Ngenkathi uMhlaba manje uzungeza eksisini yawo njalo emahoreni angama-24, ebuntwaneni boMhlaba usuku lwalungathatha amahora ayisi-6.
Setha iwashi emuva umzuzwana noma ihora?
Izizwe ezimbalwa ezinamandla kakhulu nezinamandla emhlabeni, eziholwa yi-United States, iFrance noma iJalimane, zikhuthaza ukuthi kuqedwe lo mzuzwana owengeziwe futhi kukalwe ukuhamba kwesikhathi ngokuphelele ngokuya ngokuzungeza kwama-athomu ekhabhoni angekho. I-Cesium ilawula ukuhamba kwesikhathi kumawashi e-athomu futhi inembe kakhulu.
La mazwe agcizelela ukuthi zonke izilungiso zingenziwa ngesikhathi esisodwa, enezela ihora (imizuzwana engu-3600) njalo ngemva kweminyaka engu-600, okuyisu elibonakala libambezela ukugwema ukubhekana nenkinga. Yebo, kukhona ukuthambekela kokucabanga ukuyisusa, nokwenza ngamabhulokhi amakhulu, ukwengeza ihora elilodwa njalo eminyakeni engama-500, kodwa igebe phakathi kwesikhathi esimakwe yilanga nesikhathi somphakathi esimakwe ngamawashi e-athomu liyoba likhulu futhi likhulu. Amasistimu e-GPS anesikhathi sawo azibe lezi zilungiselelo.
Ukungaboni ngaso linye nelinye iqembu lamazwe, njenge-United Kingdom noma i-China, elisekela ukugcina indawo yesibili kube yimbangela yezingxoxo ezishisayo phakathi kwezombusazwe, ubuchwepheshe nesayensi. Kubameli abaqinile bokugcina izibalo ezinembile zesikhathi ngokusekelwe ekujikelezeni komhlaba, ukususa lowo mzuzwana owengeziwe kuzofana nokuxosha isikhathi sempucuko ukuze singavumelani neqiniso lezinkanyezi. Uma ucabangela ukudlula kwamakhulu, izinkulungwane noma izigidi zeminyaka, lokho kubukeka njengokulungiswa kanye noshintsho oluncane, isekhondi elilodwa ngaphezulu onyakeni, kungaba ngaphezu kwemizuzwana eyizigidi ezingu-31. Kulinganiselwa ukuthi ngaphandle kokunyuka, kuzolahleka ihora elilodwa njalo eminyakeni engama-600.
Nakuba izinga lokuzungezisa lingejwayelekile noma lingabikezeleki, ubuchwepheshe bamanje nolwazi lwesayensi kuvumela umzuzwana olandelayo ukuthi ubikezelwe eminyakeni emibili kusukela manje. I-IERS ilula kakhulu ngesaziso sezinyanga eziyisi-6 kuphela. Ayikho imodeli yokubikezela. Umthelela omkhulu yiNyanga, lapho uMhlaba uguga njalo, wehlisa umhlaba ngama-millisecond ambalwa.
Kube nokwenzeka ukususa ukungabaza mayelana nokuthi ukuzungeza komhlaba kunciphisa ijubane nokuthi kunamiphi imiphumela.