Me pēhea te whakatau i te pakeke o ngā kōiwi tawhito mā te whakamahi i te ine irirangi
Ko te whakatau i te pakeketanga o ngā kōiwi tawhito he wāhanga matua o te paleontology me te geology. Ki te kore e taea te whakatau tika i te pakeketanga o ngā kōiwi tawhito, ka noho pōuriuri tonu tā tātou tirohanga mō te whanaketanga o te ora i runga i te Ao. Ko tētahi o ngā tikanga pono me te whānui e whakamahia ana mō te whakatau i te pakeketanga o ngā kōiwi tawhito ko te radiometry. Ko te radiometry he tikanga ine e whakamahi ana i ngā mātāpono o te pirau radioactive hei whakatau i te pakeketanga o ngā rauemi. Ka matapakihia e tēnei tuhinga te mahi a te radiometry me pēhea te whakamahinga hei whakatau i te pakeketanga o ngā kōiwi tawhito.
Ngā Mātāpono Taketake o te Ine Reo Irirangi
Ko te mahi a te ine irahiko i runga i te pirau o ngā isotope irahiko. Ko ngā isotope he momo rerekē o ngā huānga matū he rerekē te maha o ngā neutron i roto i ō rātou karihi ngota. Kāore e pumau ngā isotope irahiko, ā, ka pirau ki ngā isotope pumau ake o ngā huānga ōrite, rerekē rānei. He tere pirau pumau tō ia isotope irahiko, e kiia nei ko tōna haurua-ora. Hei tauira, ko te haurua-ora o te waro-14 (C-14) he 5730 tau. Ko te tikanga o tēnei, i ia 5730 tau, ka pirau te haurua o te waro-14 i roto i te tauira ki te hauota-14 (N-14).
Te Tukanga Pirau Irahiko
E whā ngā huarahi matua e inehia ai te tukanga pirau irahiko:
1. Te pirau ārepa (α): Ka tukuna e te karihi ngā matūriki ārepa (e rua ngā porotana me ngā iōnitā e rua).
2. Te pirau beta (β): Ka hurihia e te karihi he neutron hei pūrotene (ka hurihia rānei), ka tukuna he irahiko, he positron rānei, me te neutrino.
3. Te pirau o te gamma (γ): Ka tukuna e te karihi i roto i te āhua whakahihiri ngā hihi gamma kia tae atu ki te āhua pumau.
4. Te hopu irahiko: Ka hopukina e te pūrotene i roto i te karihi tētahi irahiko, ka hurihia hei niutirone.
Ngā Tikanga Irahiko e Whakamahia Ana
He maha ngā momo tikanga ine irirangi e whakamahia ana hei whakatau i te pakeketanga o ngā kōiwi me ngā toka. Anei ētahi o ngā mea tino noa:
1. Waro-14 (C-14):
– Te Whakamahinga: Hei whakatau i te pakeke o ngā rauemi rauropi (hei tauira, ngā wheua, te waro me ngā whakapiri kikokiko) tae atu ki te 50.000 tau.
– Mātāpono: Ka pirau te C-14 ki te N-14. Ko te ōwehenga o te C-14 ki te C-12 (waro pumau) i roto i tētahi tauira ka whakamahia hei tatau i te pakeke o te tauira.
2. Pāhare pākawa-Ākona (K-Ar):
– Whakamahinga: Whakamahia hei whakatau i te pakeke o ngā kohuke me ngā toka puia neke atu i te 100.000 tau te pakeke.
– Mātāpono: Ka pirau te pāhare pākawa-40 (K-40) hei argon-40 (Ar-40). Mā te ine i te ōwehenga o te K-40 me te Ar-40, ka taea te whakatau i te pakeketanga o ngā toka.
3. Ūrāniuma-Mata (U-Pb):
– Whakamahinga: Whakamahia mō ngā toka e miriona ki te piriona tau te pakeke.
– Mātāpono: Ka pirau te ūranium-238 (U-238) hei mata-206 (Pb-206), ā, ka pirau te ūranium-235 (U-235) hei mata-207 (Pb-207). Mā te ine i te ōwehenga o te ūranium ki te mata i roto i tētahi tauira ka kitea te pakeke o te hanganga toka.
4. Rūpidium-Strontium (Rb-Sr):
– Te Whakamahinga: E whakamahia ana hei kōrero mō ngā toka me ngā kohuke tawhito rawa.
– Mātāpono: Ka pirau te Rubidium-87 (Rb-87) hei strontium-87 (Sr-87). Mā te ine i te ōwehenga o te Rb-87 ki te Sr-87 ka āwhina i te whakatau i te pakeke o ngā toka e piriona tau te pakeke.
Te Whakamahinga hei Whakatau i te Tau o ngā Kōhatu Parapara
Tuatahi, he mea nui kia mārama ko ngā kōiwi tawhito he toenga o ngā rauropi kua whakakōhatuhia, ā, he maha ngā wā ka tangohia te mea rauropi taketake. Nō reira, ehara te kōiwi tawhito i te mea e tātarihia tika ana e te ine irirangi, engari ko te toka e karapoti ana, ko te hanganga parataiao rānei.
Ngā Hipanga mō te Whakatau i te Tau o ngā Kōhatu Para:
1. Tāutuhia ngā Paparanga Toka:
Kimihia te wāhi i kitea ai te kōhatu tawhito, ā, tautuhia te momo toka e karapoti ana, te paparanga oneone rānei. Mā tēnei koe e āwhina ki te whiriwhiri i te tikanga ine radiometric e tika ana.
2. Te Tauira:
Tangohia he tauira o te toka, o te paru rānei e tata ana ki te tūāpapa tawhito. Me whakarite kia tangohia te tauira i tētahi wāhi e tiakina pai ana kia kore ai e poke.
3. Te Whakarite Taiwhanga:
I roto i te taiwhanga, whakaritea ngā tauira mō te tātari ine irirangi. Tērā pea ka uru atu ki tēnei te wehewehe i ētahi kohuke mai i te toka.
4. Te Ine i te Isotope Reo Irirangi:
Mā te whakamahi i ngā taputapu motuhake (pēnei i te ine ira papatipu), inehia ngā ōwehenga isotope i roto i tētahi tauira. Ka tatauhia tēnei hua i runga i te haurua-ora o tētahi isotope motuhake.
5. Tātaitanga Tau:
Mā te whakamahi i ngā tātai pāngarau e ahu mai ana i ngā tere pirau me te haurua-ora o ngā isotope, tatauhia te pakeke whanaunga o te tauira.
6. Te Whakatikatika me te Manatoko:
Ko ngā hua ka puta he maha ngā wā e hiahiatia ana kia whakatauritea ki ētahi atu raraunga (pērā i ngā raraunga mai i ētahi atu kōiwi tawhito, i ngā toka kua tawhito rānei). Ka mahia te whakamana mā te whakataurite i ngā hua ki ngā whakamaoritanga whenua o nāianei.
Ngā Painga me ngā Here o te Ine Reo Irirangi
Putanga:
1. Tika: Ka puta he hua tika, pono hoki i tēnei tikanga mō te wā roa.
2. Kore-whakangaro: Kāore tēnei tukanga e kino i te tauira, ā, ka taea te tātari atu, te whakamahi anō rānei.
3. He tino pai mō ngā toka tawhito: He tino whai hua te ine irahiko hei whakatau i te pakeketanga o ngā hanganga toka tawhito, nui atu i ngā kaha o ētahi atu tikanga.
Te Whakatakotoranga:
1. Ngā Rauemi Ora: Kāore e pai ngā tikanga katoa mō ngā rauemi ora. Hei tauira, ka taea anake te whakamahi i te C-14 tae atu ki te 50.000 tau te pakeke, he poto noa iho tēnei ina whakaarohia te whenua.
2. Te Parahanga: Ka pāngia pea ngā hua o te tātari e te parahanga, nō reira me tino tika ngā tikanga kohikohi me te whakahaere i ngā tauira.
3. Te Whakaaro Pūmau o te Isotope: E whakaaro ana tēnei tikanga he pumau te tere pirau o ngā isotope i roto i te wā, ahakoa i ahu mai i ngā taunakitanga pūtaiao, me whai whakaaro ki tēnei i roto i te whakamaoritanga.
Whakamutunga
He taputapu tino nui te ine irahiko i roto i te matawhenua me te paleontology hei whakatau i te pakeketanga o ngā kōiwi me ngā toka. Mā te mārama ki ngā mātāpono taketake o te pirau irahiko me te whakamahinga o ngā momo isotopes, ka taea e ngā kaipūtaiao te waihanga i tētahi rarangi wā tika mō te hītori o te Ao. Ahakoa ōna herenga, ko te pono me te tika o ngā tikanga ine irahiko te tikanga paerewa koura mō te whakatau i te wā matawhenua. Ahakoa te hura i te hītori whanaketanga o te ora, te mārama rānei ki te hanganga me te huringa o tō tātou ao, kei te whai wāhi tonu te ine irahiko ki te hura i ngā mea o mua.
