Mene ne radiocarbon Dating?

Radiocarbon Dating ya canza ra'ayinmu na baya 50,000 shekaru. Farfesa Willard Libby farko nuna shi a cikin shekara ta 1949, wanda ya sa aka daga baya bayar da kyautar Nobel.

Dating hanyar

Jigon radiocarbon Dating ne kwatanta uku daban-daban carbon isotopes. Isotopes da wani kashi da wannan adadin protons a cikin nucleus din amma daban-daban lambobin na neutrons. Wannan yana nufin cewa manyan sinadaran kama su da daban-daban talakawa.

A total taro na isotope YAKE denoted da lamba index. Duk da yake da m isotopes ¹² C da ¹³ C ne barga, da heaviest isotope ¹⁴ C (radiocarbon) ne rediyoaktif. Its core ne don haka babban abin da shi ne m.

A kan lokaci ¹⁴ C - tushe radiocarbon - decomposes cikin nitrogen ¹⁴ N. Mafi yawa daga cikin carbon-14 da aka halitta a cikin sama yanayi inda neutrons wanda ake generated da cosmic haskoki amsa tare da sunadaran ¹⁴ N.

Ya sa'an nan oxidized a cikin ¹⁴ CO _2, shiga cikin yanayi da kuma Mixes da ¹² CO ₂ da ¹³ CO _2. Carbon dioxide da ake amfani da tsire-tsire a lokacin photosynthesis, kuma daga can ya wuce ta abinci sarkar. Saboda haka, wani shuka da dabbobi a cikin sarkar (har da mutane) zai kasance da daidai adadin ¹⁴ C idan aka kwatanta da ¹² C a wani yanayi (rabo na C ^14: C ^12).

gazawa

Lokacin da dabbobi mutu, da nama ne ba maye gurbin da rediyoaktif lalata na ¹⁴ C zama a bayyane yake. Ta hanyar 55.000 shekaru ^{na 14} C da aka raba haka da cewa shi ne ba zai yiwu don auna sharan.

Mene ne radiocarbon Dating? Rediyoaktif lalata za a iya amfani da a matsayin "Agogon", saboda shi ba ya dogara ne a kan zahirin (msl, zazzabi) da kuma sinadaran (msl, ruwa da abun ciki) yanayi. Ga 5730 shekaru, shi ne zuwa kashi rabin ^{na 14th} C, dauke a cikin samfurin.

Saboda haka, idan muka sani da rabo daga ¹⁴ C: ¹² C a lokacin da mutuwa da kuma na yanzu rabo, za ka iya lissafta yadda da yawa lokaci ya wuce. Abin baƙin ciki, don gane su ba haka sauki.

Radiocarbon analysis: kuskure

The ^{adadin 14} C a cikin yanayi, saboda haka a tsire-tsire da dabbobi, ba ko da yaushe akai. Alal misali, shi dabam dangane da yadda da yawa cosmic haskoki isa Earth. Ya dogara da hasken rana aiki da Magnetic filin na wannan duniya tamu.

Abin farin, shi ne zai yiwu don auna saɓani a cikin samfurori kwanan rana ta wasu hanyoyin. Za ka iya ƙidaya girma zobba na itãce, kuma canje-canje a radiocarbon ciki. "K kwana" za a iya gina daga wadannan bayanai.

A halin yanzu, aikin ne underway a kan fadada da kuma kyautata. A shekarar 2008, ya yiwu a calibrate kawai radiocarbon kwanakin to 26.000 shekaru. Yau kwana mika wa 50,000 shekaru.

Abin da za a iya auna?

Ba dukkan kayan za a iya kwanan rana ta wannan hanya. Mafi, idan ba dukan, na gudanar da mahadi ba da damar for radiocarbon analysis. Wasu inorganic jamiái kamar aragonite bangaren na bawo ƙila za a kwanan rana, kamar yadda a yi amfani da samuwar ma'adinai carbon-14.

Materials cewa an kwanan rana daga kafuwarta na hanyar hada da gawayi, itace, twigs, tsaba, kasusuwa, bawo, fata, peat, silt, gona, gashi, tukwane, fure da bango zane-zane, murjãni, ragowar jini, nama, takarda, takarda, guduro da ruwa.

A radiocarbon karfe bincike ne ba zai yiwu ba idan ba dauke da carbon-14. A ware suna, da na baƙin ƙarfe, kerarre daga kwal da ake amfani.

biyu lissafin

Saboda wannan wahala, radiocarbon kwanakin an gabatar a hanyoyi biyu. A uncalibrated ma'aunai suna bauta a yawan shekaru har 1950 (BP). Calibrated zabi kuma gabatar a matsayin BC. e., da kuma bayan, kazalika ta hanyar calBP raka'a (calibrated zuwa yanzu, har 1950). Wannan shi ne "mafi kyau kimanta" na ainihin shekaru na samfurin, amma ya kamata ka iya komawa zuwa ga tsohon data da kuma calibrate su a matsayin sabon karatu ne kullum Ana ɗaukaka k kwana.

The yawa da kuma ingancin

Na biyu wahala ne musamman low na ruwan dare na ¹⁴ C. kawai 0,0000000001% na carbon a cikin yanayi a yau ne ¹⁴ C, wanda ya haddasa m wuya daga cikin ji da kuma sa shi musamman m zuwa samu.

A farkon shekaru na radiocarbon bincike na lalata kayayyakin bukaci babbar samfurori (misali, rabin na mutum femur). Mutane da yawa dakunan gwaje-gwaje ake yanzu ta amfani da wani taro spectrometer da totur (AMS), wanda za a iya gane da kuma gwada gaban daban-daban isotopes, kuma ƙidaya yawan adadin mutane da mutum sunadaran carbon-14.

Wannan hanya na bukatar kasa da 1 gram na kashi, amma 'yan kasashen iya iya fiye da daya ko biyu daga cikin AMS, da darajar da ya wuce dubu 500,. $. Alal misali, Australia yana da biyu kawai irin wannan na'urorin ya kasance iya samar da radiocarbon analysis, kuma su ne fiye da isar da yawa na duniya masu tasowa.

Tsabta - da lamuni na daidaito

Bugu da kari, samfurori dole ne sosai tsabtace na carbon samu daga m da kuma ƙasa. Wannan yana da muhimmanci musamman ga sosai tsohon kayan. Idan 1% na kashi a cikin samfurin shekaru 50 da dubu. Years zai zo daga zamani pollutant, shi, bã ya ɗaukar biyu sorokatysyacheletnyaya.

Saboda wannan dalili, masu bincike suna kullum tasowa sabon hanyoyin da tasiri tsaftacewa kayan. Ba za su yi tasiri a kan sakamakon, wanda ya bada radiocarbon analysis. The daidaito daga cikin Hanyar ya karu muhimmanci da ci gaban da wani sabon Hanyar magani tare da kunna carbon ABOx-SC. Wannan yarda, misali, jinkirta zuwa na farko da mutane a Australia ga fiye da dubu 10. Years.

Radiocarbon bincike: mai sharhi

Hanyar tabbatar da cewa tun da fitowan na Duniya dauki yawa fiye da dubu 10. Years da aka ambata a cikin Littafi Mai Tsarki, an akai-akai soki creationists. Alal misali, suna da'awar cewa sama da 50 da dubu. Years, a can ya zama babu carbon-14 samfurori, amma a kwal, man fetur da iskar gas, shekaru, zaci su zama shekaru miliyoyi, shi ya ƙunshi ma'auni yawa na wannan isotope, wanda ya tabbatar da radiocarbon analysis. Ji kuskure a lokaci guda fiye da baya radiation, daga abin da ba shi yiwuwa a rabu da a cikin dakin gwaje-gwaje. E. A samfurin wanda ba ya dauke da wani rediyoaktif carbon zarra, nuna kwanan wata 50 th. S. Duk da haka, wannan al'amari ba jefa shakka a kan Dating shafukan da ma kasa shaida cewa mai, kwal da iskar gas ne a karkashin cewa shekaru.

Creationists kuma nuna wasu oddities radiocarbon analysis. Alal misali, Dating na ruwa tare mollusk m da shekaru kamar yadda fiye da shekaru 2,000, wanda, a cikin ra'ayi, raunana wannan hanya. A gaskiya sami mafi yawansu Shellfish shirya daga carbon farar ƙasa, kuma humus abun ciki na ¹⁴ C wanda shi ne sosai low, tun wadannan ma'adanai ne sosai haihuwa, kuma bã su samun damar zuwa Air carbon. Radiocarbon analysis, da daidaito da a wannan harka za a iya tambayar, a cikin sauran na harka. Wood, ga misali, ba shi da irin matsalar, watau. K. A shuka samu carbon kai tsaye daga iska, wanda ya ƙunshi cikakken kashi na ¹⁴ C.

Wata gardamar directed a kan hanya ne gaskiya cewa itatuwa ne iya samar da wata guda shekara fiye da daya zobe. Wannan gaskiya ne, amma mafi sau da yawa ta faru da cewa ba su samar da shekara-shekara zobba. Bristlecone Pine, a kan tushen da wanda za'ayi a mafi yawan ma'aunai ne 5% kasa zobba fiye da ta ainihin shekaru.

Kafa kwanan wata

Radiocarbon bincike - ba kawai a hanya, amma kuma m binciken a mu da kuma yanzu. A Hanyar yarda da archaeologists sanya binciken a cikin shekara-shekara domin, tare da bukatar a rubuce ko tsabar kudi.

A 19th da kuma farkon karni na 20th, shi ne wuce yarda da haƙuri, kuma m archaeologists Associated kumar kasko, da na dutse kayan aikin na daban-daban na labarin kasa yankunan da binciken kamance a siffofi da kuma alamu. Sa'an nan, ta amfani da ra'ayin cewa abu styles sun samo asali da kuma zama mafi hadaddun a kan lokaci, za su iya sanya su domin.

Saboda haka, a manyan Dome kabari (da aka sani da Tolosa) a kasar Girka dauke precursors irin Tsarin kan Scottish tsibirin Maeshowe. Wannan na goyon bayan ra'ayin cewa gargajiya wayewar na kasar Girka da Roma sun kasance a cibiyar na bidi'a.

Duk da haka, a sakamakon da radiocarbon gwaje-gwaje bayyana cewa Scottish kaburburan sun dubban shekaru girmi Greek. Northern dabbanci su iya tsara sifofi, kama da classic.

Sauran sanannun aikin shi ne aiki na Shroud na Turin da na da lokaci, Dating na Tekun Littafan lokacin Kristi, da kuma 'yan rigima periodization zane a Chauvet kogo shekaru 38.000 calBP (game da 32,000 BP), dubban shekaru a baya fiye da sa ran.

Radiocarbon bincike da aka ma amfani a kayyade lokacin nau'i nau'i na mammoths da kuma gudummawar da muhawara a kan ko zamani mutane da kwatanta hadu ko ba.

A isotope ¹⁴ C ne ba kawai used to ƙayyade da shekaru. Radiocarbon Dating Hanyar damar daya ya yi nazarin teku wurare dabam dabam da kuma gano motsi da kwayoyi a ko'ina cikin jiki, amma wannan shi ne wani topic for wani labarin.