Ubunzima bomhlaba

Isijikelezi-langa sethu esinguMhlaba siye sahlolisiswa saza saphandwa zizazinzulu ukutyhubela imbali. Enye yezona zinto zimangalisayo malunga neplanethi yi ubunzima bomhlaba. Ekubeni kuyinto engenakulinganiswa ngokuthe ngqo, iindlela ezahlukeneyo zokulinganisa ngokungangqalanga ziyimfuneko.

Ngenxa yesi sizathu, siza kunikela eli nqaku ukukuxelela yonke into oyifunayo ukuba uyazi malunga nobuninzi bomhlaba, indlela abaye bakwazi ngayo ukuyibala kunye neziphi iimpawu ezinayo.

IPlanethi yoMhlaba neempawu zayo

Yiplanethi yesithathu yesixokelelwano selanga, ukuqala elangeni, phakathi kweVenus kunye neMars. Ngokutsho kolwazi lwethu lwangoku, kuphela kweso sijikelezi-langa siphela esigcina ubomi. Igama layo livela kwiLatin Terra, isithixo saseRoma, isiGrike samandulo esilingana neGaia, esinxulunyaniswa nokuzala kunye nokuzala. Udla ngokubizwa ngokuba yiTellus mater okanye Terra mater (uMama woMhlaba) kuba zonke izinto eziphilayo ziphuma esibelekweni sakhe.

Ukususela kumaxesha amandulo, abantu baye baphupha ngokufumanisa imida yomhlaba kunye nokuhlola zonke iimbombo zomhlaba. Iinkcubeko zamandulo zazikholelwa ukuba ayinasiphelo, okanye inokuphelela ekuweleni enzonzobileni. Nanamhlanje, kukho abantu abagxininisa ukuba umhlaba uthe tyaba, ukuba umngxuma kunye nezinye iingcamango zamayelenqe.

Nangona kunjalo, Ngenxa yenzululwazi nobugcisa, ngoku sinemifanekiso emihle yesijikelezi-langa sethu. Siyazi nokuba zenziwe njani iileya zangaphakathi kunye nokuba yintoni eyayikho ngaphambi kokuba abantu bavele kumphezulu wawo.

Imvelaphi kunye nokwakheka

Umhlaba wenziwe malunga ne-4550 yezigidigidi zeminyaka eyadlulayo. ukusuka kwizinto ezenza yonke inkqubo yelanga, ekuqaleni njengelifu leenkwenkwezi zegesi kunye nothuli lwe-cosmic. Iplanethi ithathe i-10 ukuya kwi-20 yezigidi zeminyaka ukuyilwa, kunye namafu egesi ajikelezayo njengoko umphezulu wayo uphola kwaye wenza i-atmosphere yanamhlanje.

Ekugqibeleni, ngenxa yomsebenzi we-seismic wexesha elide, mhlawumbi ngenxa yempembelelo eqhubekayo yeemeteors, uMhlaba unezinto eziyimfuneko kunye neemeko zomzimba eziyimfuneko ukuze kuvele amanzi angamanzi.

Ngombulelo koku, umjikelo we-hydrological unokuqalisa, unceda iplanethi ukuba iphole ngokukhawuleza kwinqanaba apho ubomi bunokuqala khona. Ngokuhamba kwexesha, ubuninzi bamanzi alulwelo phezu komhlaba bubangela ukuba isijikelezi-langa sethu sibonakale luhlaza okwesibhakabhaka xa sijongwe emajukujukwini.

Ubunzima bomhlaba

Umhlaba sisijikelezi-langa sesihlanu ngobukhulu kwisixokelelwano sezijikelezi-langa yaye kuphela kweso esikwaziyo ukuxhasa ubomi. Ingqukuva ineepali ezisicaba kancinane kunye nobubanzi obuyi-12.756 km kumphakamo we-ikhweyitha (6.378,1 km radius kwi-ikhweyitha). Yiba ubunzima be-5,9736 x 10²⁴ kg kunye noxinzelelo lwe-5,515 g/cm3, eyona iphakamileyo kwisixokelelwano selanga. Ikwanayo nesantya somxhuzulane se-9,780327 m/s2.

Njengezinye iiplanethi ezingaphakathi njengeMars kunye neMercury, uMhlaba yiplanethi enamatye enomgangatho oqinileyo kunye nombindi wentsimbi engamanzi (ngenxa yobushushu kunye noxinzelelo lomxhuzulane wayo), ngokungafaniyo nezinye iiplanethi ezinegesi njengeVenus okanye iJupiter. Umphezulu wayo wohlulwe kwi-atmosfera yegesi, i-hydrosphere engamanzi kunye ne-geosphere eqinileyo.

Babalwa njani ubunzima boMhlaba?

Ngokucacileyo, oku akwenziwa ngokubeka iplanethi kwibhalansi. Ubuncinci hayi kwinqanaba lokwenyani. Kwasetyenziswa umlinganiselo wendalo iphela isikali seCavendish. Elo yayiligama lokugqibela lenzululwazi eyaqala yalinganisa ngokuchanekileyo ubunzima boMhlaba.

Wakwenza oko ngowe-1798, yaye kwiminyaka eli-113 kamva, uIsaac Newton omkhulu (1643-1727) wayila iLaw of Universal Gravitation (LGU) yakhe ngowe-1685. Kwiminyaka eli-189 kamva, uGalileo omkhulu wakhomba iteleskopu yakhe esibhakabhakeni. Wakwenza oko ngowe-1609. Okumangalisayo kukuba, uHenry Cavendish (1731-1810) wamisela ubuninzi besi sijikelezi-langa ngaphandle kokushiya indlu yakhe.

Enyanisweni, akazange ayenze ngehlathi. I-East Cavendish wayengumntu othe khunubembe, edakumbile kwaye engumntu ombi, kodwa emhle. Ngokwethiyori, iqala nge-LGU kaNewton, esixelela ukuba "naziphi na izidumbu ezibini, ezijongwa ngokuba ziindawo ezininzi, zitsalwa omnye komnye ngamandla axhomekeke ngokuthe ngqo kubuninzi bazo, ziphindaphindwe ngokuguquguquka kwexabiso elingaziwayo, elaziwa namhlanje njenge-gravitational constant. . . Oku kungaguquguqukiyo kuthelekiswa nesikwere somgama weNewtonian phakathi kwabo."

Njengomthetho jikelele, wasebenzisa ukuseta okwenzelwe inxalenye ngumhlobo wakhe uJohn Michell. Umfundisi okrelekrele kunye nejoloji enengqondo, wasweleka ngaphambi kokuba enze uvavanyo lokujonga ukuxinana koMhlaba. Ukusuka kwimbono yejoloji, lo ngowona myalelo unomdla wobukhulu.  Ngelo xesha uCavendish wathenga izixhobo zakhe waza wazifaka kwenye yezindlu zakhe zaseLondon.

Izikali kunye nesigxina

Isixhobo sineebhola ezimbini zokukhokela, I-30 cm ububanzi, inqunyanyiswe kwisakhelo sensimbi, kunye neebhola ezimbini ezincinci ze-5 cm ububanzi, ixhonywe kufuphi nebhola yokuqala kwaye idityaniswe enye kwenye ngeengcingo ezicolekileyo zobhedu.

Ngokusisiseko, imilinganiselo ye-torsion yenzelwe ukulinganisa ukunyakaza okujijekileyo okudalwe kwiingcingo ngokutsalwa kwe-gravitational kwi-pulleys ezigcina zihamba xa iibhola ezinkulu zihamba phezu kweebhola ezincinci.

Ingxaki kukuba umxhuzulane mncinane kangangokuba nayiphi na into engalindelekanga inokugqwesa iziphumo. Yiyo loo nto uCavendish eyiqhuba ekude. Ukuze ukusondela kwabaphandi kungaphazamisi uhlengahlengiso lwezixhobo, wasebenzisa iteleskopu awayeyifake ngaphandle kwegumbi. Wayisebenzisa ukuze afunde isikali esichanileyo, esikhanyiswa sisibane esimxinwa esiphuma ngaphandle kwegumbi.

Sithetha ngovakalelo lomyalelo we-0,025cm, okungekho nto imbi. Uvavanyo oluchubekileyo. Njengoko bekulindelekile, ibhola encinci yaqala ukujikeleza, itsalwa yibhola enkulu. Emva kwezibalo ezithile, uCavendish wakwazi ukufumanisa ixabiso le-gravitation eqhubekayo evela kubuninzi babo kunye nokuhamba. Eli linyathelo lokuqala, elilandelwa kukumisela umyinge wokuxinana koMhlaba kwaye emva koko kumiselwe ubunzima boMhlaba, ukubala i-gravity engaguqukiyo i-G.

Ngombulelo ku-G, kwakunokwenzeka ukubala ubunzima boMhlaba. Ukwazi ububanzi bayo, amandla okutsala umhlaba, kunye nexabiso elikufutshane le-G, uCavendish wenza la manani. Iziphumo ziyamangalisa.

Ndiyathemba ukuba ngolu lwazi unokufunda ngakumbi malunga nobunzima boMhlaba kunye neempawu zawo.