Zera repasi

Icho, zvirinani kwenguva, iyo yega nyika pane hupenyu. Inongova chinhambwe chakakodzera kubva kuzuva kuti paigona kuva nemvura muchimiro chemvura uye tembiricha inokwana zvakakwana kuti mamirioni ezvinomera nemhuka zvikure. Pasi.

Une makore mangani? Rwendo rwake rwekuve zvaari nhasi rwave rwakareba uye rwakazara nenjodzi. Nzvimbo yekunze haisi nzvimbo yakachengeteka. Asi, Ndeapi makore epasi uye akaverengerwa sei?

Pasi pane makore mangani?

Kunyangwe pasina nhamba chaiyo, Nyika yedu inozivikanwa kunge ingangoita makore mabhiriyoni mana nezana. Geologists uye geophysicists vakakwanisa kuverenga zera nekuyera mwero iwo zvinhu zveiyo radioactive simbi uranium inoora ichitungamira. Zvakare, vachishandisa nzira dze radiometric yekufambidzana, ivo vawana zera remeteorite, rakafanana nerePasi neMwedzi.

Iyo yekare inozivikanwa mineral ndeye zirconium kubva kuJack Hills nzvimbo yeWestern Australia. Ivo vanofungidzirwa kunge vane mamirioni makumi mana nemazana mana emakore. Iwo ekare meteorite anowanikwa mune yezuva system, ndiko kuti, calcium-aluminium-yakawanda inclusions, ane makore 4.404 mamirioni. Izvi zvinoreva kuti Solar System yakatanga kuumba makore zviuru mazana mana nemazana mana nemakumi mana neshanu apfuura.

Imwe fungidziro inoti pasi rakatanga kuumbika nguva pfupi yadarika mushure mekuita kwemameteorite, asi hazvisati zvichikwanisika kuratidza zera rayo chairo.

Kutanga dzidziso

Kwenguva yakareba zvaifungidzirwa kuti nyika yanga iri pano nekusingaperi, kudzamara nyanzvi dzezvisikwa dzakatanga kunzwisisa shanduko dzakasiyana idzo pasi pano dzaive dzave kuita kana dzichiongorora marongero ayo. Nicolas Steno aive mumwe wekutanga kuona kubatana pakati pezvakasara nezvakambotaurwa. Kuma 1790, muBritishistist William Smith akafungidzira kuti kana matombo maviri panzvimbo dzakasiyana aine zvisaririra zvakafanana, zvaive zvakanyanya kuti mativi ese akabva panguva imwechete. Makore gare gare muzukuru wake, John Phillips, akaverenga achishandisa hunyanzvi uhu kuti zera repasi raizove makore angangoita mamirioni makumi mapfumbamwe nematanhatu.

Nyanzvi yezvakasikwa Mikhail Lomonosov akafunga kuti Nyika yakaumbwa yakazvimiririra kubva kune zvakasara, mazana emakore zviuru zvisati apfuura. Muna 1779 wechiFrenchististist Comte Du Buffon akaita kuyedza: akagadzira diki diki iro rakaumbwa rakafanana neepasi uyezve akayera mwero waro wekutonhora. Nekudaro, akafungidzira zera repasi pamakore zviuru makumi manomwe nezvishanu.

Zvisinei, Yakanga iri kusvika muna 1830 apo geologist anonzi Charles Lyell akataura kuti nyika iri kuramba ichichinja. Izvi, kunyange hazvo nhasi chiri chinhu chechisikigo uye chine musoro zvachose, panguva iyoyo yaive fungidziro, nekuti vaifunga kuti nyika yakanga iri chinhu chakamira, kuti yakangochinja kuburikidza nenjodzi dzinongoitika dzega.

Masvomhu

Muviri we Glasgow William Thomson akaburitsa muna 1862 huwandu hwekuverenga hunofungidzira zera repasi redu kuva pakati pemamiriyoni makumi maviri nemana nemazana mana emakore.. Ishe Kelvin, vanozodaidzwa kunzi akadaro, vakafungidzira kuti Nyika yakaumbwa sebhora rakaumbwa, uye vakaverenga nguva yaitora kutonhorera kusvika padanho repakati nepakati (14ºC). Pasinei nezvose, mageologist haana kugutsikana kuti iyi fungidziro yaive yechokwadi.

Charles Darwin, akadzidza mabasa aLyell, akaronga dzidziso yake yekusarudzwa kwezvakasikwa, maitiro ayo akateedzana shanduko muzvinhu zvipenyu uye, chokwadika, nguva yaidikanwa kuti zviitike.. Naizvozvo, akafunga kuti mazana mana emamiriyoni emakore aisakwana.

Muna 1856 nyanzvi yefizikisi yekuGerman Hermann von Helmholt uye muna 1892 nyanzvi yezvemuchadenga yekuCanada Simon Newcomb, vakapa maverengero avo. Yekutanga yaive makore makumi maviri nemaviri emakore, uye yechipiri mamiriyoni gumi nemasere. Masayendisiti akange asvika pamatanho aya nekuverenga nguva ingadai yakatora kuti Zuva rishanduke kusvika pahupamhi hwaro nekusimba kubva nebula regasi neguruva kwarakabva.

Iko kukura kweiyo radiometric kufambidzana

Parizvino tinogona kuve neruzivo rwekuti matombo ekare nemaminerari akadii nekuda kweradiometric kufambidzana, inova Maitiro akagadzirwa naArthur Holmes pakutanga kwezana ramakore rechimakumi maviri uye zvinoenderana nehukuru hwesotopu inonzi baba uye yeumwe kana vamwe vazukuru vane hafu yeupenyu inozivikanwa.

Radiometric kudanana kwakatanga kuburitswa muna 1907 naBertran Boltwood uye nhasi ndiyo sosi huru yeruzivo nezvezera rematombo, kana Nyika yepasi pachayo. Pane nzira dzakasiyana dzekufambidzana, dzinova:

• Carbon 14 nzira: Inobatsira kufambidzana mune zvekuchera matongo, anthropology, climatology, oceanography, ivhu sainzi, uye zvichangoburwa geology.
• Potassium-argon nzira: inoshandiswa mu geology.
• Rubidium-etrontium nzira: inoshandiswa mukufambidzana kwematombo ekare epasirese pamwe neyemwedzi miestras.
• Thorium 230 nzira: inoshandiswa mune yekare kwazvo sediment kufambidzana.
• Nzira dzekutungamira: inoshandiswa mu geology.

Saka, Holmes akaita zviyero pamasampuli edombo uye muna 1911 akagumisa kuti wekare aive nemakore zviuru mazana 1600.. Asi idzi kuverenga hakuna kuvimbika zvakanyanya. Makore maviri gare gare, mhedzisiro yakaburitswa ichiratidza kuti izvo zvinhu zvine isotopu, ayo akasiyana akasiyana ane akasiyana masasi. Muma30, isotopu yakaratidzirwa kuve iine nuclei yakaumbwa nenhamba dzakasiyana dzeasina kwazvakarerekera zvikamu kana neutron.

Basa raHolmes rakafuratirwa kusvika kuma1920, apo Muna 1921 pamusangano wepagore weBritish Association yeKufambira Mberi kweSainzi nhengo dzakasimbisa kuti zera repasi raive makore mabhirioni mashoma, uye kuti radiometric kufambidzana kwaive kwakavimbika. Muna 1927 akaburitsa rake bhuku »Nguva yePasi, Sumo yeGeological Pfungwa maakaverenga kuti yaive pakati pemakore zviuru mazana 1600 kusvika zviuru zvitatu.

Kuma 1931 National Reserach Council, yeNational Academy yeSainzi yeUnited States, yakagadza komiti kuti izive kuti zera repasi rakanga riri rei. Holmes, ari mumwe wevanhu vashoma vaiziva hunyanzvi hwekufambidzana neradiometric, akakokwa kuzoshanda kukomiti. Chirevo chavo chakataura kuti radiometric kufambidzana ndiyo chete nzira yakatendeka yaigona kushandiswa kuona kuteedzana kwenguva dze geologic.

Pakupedzisira, CC Patterson akaverenga zera rePasi muna 1956 achishandisa isotope kufambidzana kweiyo uranium inotungamira kuora cheni yemameteorite.

Nyika yedu ichine mamirioni mazhinji emakore ehupenyu pamberi payo. Kana pakupedzisira dzidziso yekuti Zuva "richamedza" pasi kana rashanduka kuita hofori tsvuku, tinogona kuva nechokwadi chekuti icharamba ichitenderedza nyeredzi mambo kweanenge makore mashanu emabhiriyoni.