Karbon 14 ile tarihlendirme y\u00f6nteminin hatal\u0131 sonu\u00e7lar verdi\u011fi anla\u015f\u0131l\u0131nca yeni y\u00f6ntemler bulundu.Bunlardan bir tanesi,topraktan yap\u0131lm\u0131\u015f cisimler i\u00e7inde kalan elektronlar\u0131 \u00f6l\u00e7en termol\u00fcminesans sistemidir.Bir di\u011fer sistem de bir \u00f6rne\u011fin elektromagnetik dalga bombard\u0131man\u0131na tutulup,elektron titre\u015fimlerinin \u00f6l\u00e7\u00fclmesini sa\u011flayan elektron spin rezonans\u0131d\u0131r.Ama bu gibi y\u00f6ntemler 200.000 y\u0131ldan daha ya\u015fl\u0131 cisimlerin tarihlendirilmesini sa\u011flayamad\u0131lar.Kaya\u00e7lar gibi inorganik maddeler i\u00e7in ise hi\u00e7 i\u015fe yaramad\u0131lar.Oysa Yerk\u00fcre\u2019nin ya\u015f\u0131n\u0131 belirlemenin yolu kaya\u00e7lar\u0131n tarihlendirilmesinden ge\u00e7iyordu.<\/p>\n
Kaya\u00e7lar\u0131n tarihlendirilmesi i\u015flemini zorla\u015ft\u0131ran sorunlar\u0131n b\u00fcy\u00fckl\u00fc\u011f\u00fc bilimadamlar\u0131n\u0131 umutsuzlu\u011fa s\u00fcr\u00fcklemi\u015fti.1920\u2019li y\u0131llarda jeoloji art\u0131k g\u00f6zden d\u00fc\u015fm\u00fc\u015f bir bilim dal\u0131 haline gelmi\u015fti.\u00d6zellikle \u0130ngiltere\u2019de bu bilim i\u00e7in mali kaynaklar iyice k\u0131s\u0131tlanm\u0131\u015f bulunuyordu.
\nArthur Holmes 1890 y\u0131l\u0131nda Durham\u2019da do\u011fmu\u015f olan bir \u0130ngiliz vatanda\u015f\u0131d\u0131r.1915 y\u0131l\u0131nda i\u00e7 s\u0131cakl\u0131k da\u011f\u0131l\u0131m\u0131na dayal\u0131 \u0131s\u0131l hesaplamalardan yararlanarak Yerk\u00fcre\u2019nin ya\u015f\u0131na ili\u015fkin tahminler geli\u015ftirdi.1924-1943 y\u0131llar\u0131 aras\u0131nda Durham \u00dcniversitesi\u2019nde profes\u00f6rl\u00fck g\u00f6revini y\u00fcr\u00fctt\u00fc.1943-1965 y\u0131llar\u0131 aras\u0131nda Edinburg \u00dcniversitesi\u2019nde jeoloji ve mineraloji dal\u0131nda dersler verdi.
\n\u0130ngiltere\u2019de jeoloji i\u00e7in mali kaynaklar\u0131n k\u0131s\u0131tland\u0131\u011f\u0131 1920\u2019li y\u0131llarda Holmes kariyerinin zirvesinde olmas\u0131na ra\u011fmen Durham \u00dcniversitesi\u2019nde de durum ayn\u0131yd\u0131.Jeoloji b\u00f6l\u00fcm\u00fcn\u00fcn t\u00fcm kadrosu y\u0131llarca Holmes\u2019tan ibaret kald\u0131.Radyometrik kaya\u00e7 tarihlendirme \u00e7al\u0131\u015fmalar\u0131n\u0131 s\u00fcrd\u00fcrebilmek i\u00e7in s\u0131k s\u0131k ekipman \u00f6d\u00fcn\u00e7 al\u0131yor ya da \u00e7ok basit d\u00fczenekler kullan\u0131yordu.Bir defas\u0131nda basit bir hesap makinesi i\u00e7in hesaplamalar\u0131n\u0131 aylarca ertelemek zorunda kalm\u0131\u015ft\u0131. Ailesinin ge\u00e7imini sa\u011flamak i\u00e7in akademik \u00e7evreden uzak kal\u0131yordu.Bir s\u00fcre antikac\u0131 d\u00fckkan\u0131 i\u015fletmek zorunda kald\u0131.\u00d6ylesine paras\u0131zl\u0131k \u00e7ekiyordu ki, Jeoloji Derne\u011fi\u2019nin aidat\u0131n\u0131 bile \u00f6deyemiyordu.Buna ra\u011fmen kuram\u0131n\u0131 geli\u015ftirdi.<\/p>\n
Asl\u0131nda Holmes\u2019\u0131n \u00e7al\u0131\u015fmalar\u0131nda kulland\u0131\u011f\u0131 teknik kuramsal a\u00e7\u0131dan basitti.\u0130lk kez 1904 y\u0131l\u0131nda Ernest Rutherford taraf\u0131ndan g\u00f6zlemlenmi\u015f bir s\u00fcre\u00e7ten yola \u00e7\u0131k\u0131yordu.Baz\u0131 atomlar,tahmin edilmesi m\u00fcmk\u00fcn bir h\u0131zla bozunuyor ve bir elementten di\u011ferine d\u00f6n\u00fc\u015f\u00fcyordu.Bu bozunma h\u0131z\u0131 bir \u00e7e\u015fit saat g\u00f6revi g\u00f6rebilirdi.\u00d6rne\u011fin potasyum-40\u2019\u0131n argon-40\u2019a d\u00f6n\u00fc\u015fmesi i\u00e7in gereken s\u00fcre bilinirse ve her birinin s\u00f6z konusu \u00f6rnekteki miktarlar\u0131 \u00f6l\u00e7\u00fcl\u00fcrse bir maddenin ya\u015f\u0131 hesaplanabilir. Holmes\u2019\u0131n katk\u0131s\u0131, kaya\u00e7lar\u0131n ya\u015f\u0131n\u0131 hesaplamak i\u00e7in uranyumun kur\u015funa bozunma h\u0131z\u0131n\u0131 \u00f6l\u00e7mek oldu.B\u00f6ylece Yerk\u00fcre\u2019nin ya\u015f\u0131n\u0131 hesaplayabilece\u011fini umuyordu.Ancak,\u00e7ok k\u00fc\u00e7\u00fck \u00f6rneklerden \u00e7ok duyarl\u0131 \u00f6l\u00e7\u00fcmler \u00e7\u0131karabilecek geli\u015fmi\u015f aletleri yoktu.Bu nedenle 1946 y\u0131l\u0131nda Yerk\u00fcre\u2019nin en az 3 milyar y\u0131ll\u0131k,muhtemelen \u00e7ok daha ya\u015fl\u0131 oldu\u011funu ilan etti.Bilim d\u00fcnyas\u0131 onun metodolojisini \u00f6vmekle birlikte ilan etti\u011fi rakam\u0131 benimsemedi.Onlara g\u00f6re Holmes,Yerk\u00fcre\u2019nin ya\u015f\u0131n\u0131 de\u011fil,sadece Yerk\u00fcre\u2019yi olu\u015fturan maddelerin ya\u015f\u0131n\u0131 bulmu\u015ftu.<\/p>\n
Harrison Scott Brown,1917 do\u011fumlu,ABD vatanda\u015f\u0131 bir jeokimyac\u0131d\u0131r.G\u00f6kta\u015flar\u0131n\u0131n ya\u015f\u0131 ve k\u00f6keni ile bunlar\u0131n Yerk\u00fcre\u2019nin kimyasal yap\u0131s\u0131 ili\u015fkileri \u00fczerinde uzmanla\u015fm\u0131\u015ft\u0131r.Ayn\u0131 zamanda kimyasal elementleri tarihlemekte yararlan\u0131lan tekni\u011fin de yarat\u0131c\u0131s\u0131d\u0131r. Brown,Chicago \u00dcniversitesi\u2019nde g\u00f6revli iken,tortullar\u0131n katmanla\u015fmas\u0131yla de\u011fil,\u0131s\u0131nmayla olu\u015fmu\u015f olan korkaya\u00e7lardaki kur\u015fun izotoplar\u0131n\u0131 sayman\u0131n bir y\u00f6ntemini geli\u015ftirmi\u015fti.Bunun son derece usand\u0131r\u0131c\u0131 bir \u00e7al\u0131\u015fma gerektirece\u011fini anlad\u0131\u011f\u0131 i\u00e7in gen\u00e7 bir bilim adam\u0131 olan Clair Patterson\u2019u bilimsel inceleme projesi olarak bu i\u015fle g\u00f6revlendirdi.\u0130\u015fte bu g\u00fcnlerde Holmes, Yerk\u00fcre\u2019nin en az 3 milyar y\u0131ll\u0131k,muhtemelen \u00e7ok daha ya\u015fl\u0131 oldu\u011funu ilan etmi\u015fti.<\/p>\n
Clair Patterson,proje \u00fczerinde \u00e7al\u0131\u015fmaya 1948 y\u0131l\u0131nda ba\u015flad\u0131.7 y\u0131l boyunca steril bir laboratuvarda \u00e7al\u0131\u015farak,dikkatle se\u00e7ilmi\u015f eski kaya\u00e7 \u00f6rneklerindeki kur\u015fun\/uranyum oranlar\u0131n\u0131n \u00e7ok hassas \u00f6l\u00e7\u00fcmlerini yapt\u0131.
\nYerk\u00fcre\u2019nin ya\u015f\u0131n\u0131 \u00f6l\u00e7menin as\u0131l zorlu\u011fu,kur\u015funlu ve uranyumlu kristaller i\u00e7eren eski kaya\u00e7lara duyulan ihtiya\u00e7tan ileri geliyordu.Zira bunlar,hemen hemen gezegenin kendisi kadar ya\u015fl\u0131yd\u0131.Daha gen\u00e7 ya\u015ftaki \u00f6rnekler kullan\u0131lamazd\u0131,o zaman ara\u015ft\u0131rma \u00e7ok yan\u0131lt\u0131c\u0131 sonu\u00e7lar verirdi.Ama bu denli eski kaya\u00e7lara da nadiren rastlan\u0131yordu.Asl\u0131nda ya\u015fl\u0131 \u00f6rneklerin az bulunur olmas\u0131,o g\u00fcnlerde levha tektoni\u011finin bilinmemesi y\u00fcz\u00fcndendi.Bu nedenle Patterson,son derece s\u0131n\u0131rl\u0131 malzeme ile \u00e7al\u0131\u015fmak zorundayd\u0131.Daha sonra,Yerk\u00fcre d\u0131\u015f\u0131ndan gelen ta\u015flar\u0131 kullanarak kaya\u00e7 k\u0131tl\u0131\u011f\u0131n\u0131 a\u015fabilece\u011fini ak\u0131l etti.B\u00f6ylece g\u00f6zlerini g\u00f6kta\u015flar\u0131na y\u00f6neltti.<\/p>\n
Patterson\u2019un bu d\u00fc\u015f\u00fcncesi ilk bak\u0131\u015fta olduk\u00e7a iddial\u0131 g\u00f6r\u00fcn\u00fcyordu.Ama do\u011fru oldu\u011fu ileriki y\u0131llarda kan\u0131tlanacak olan varsay\u0131mda bulunmu\u015ftu. G\u00f6kta\u015flar\u0131n\u0131n \u00e7o\u011fu G\u00fcne\u015f Sistemi\u2019nin ilk olu\u015fumundan arta kalan maddelerdi ve i\u00e7 kimyalar\u0131 hemen hemen bozulmam\u0131\u015f haldeydi.Uzayda dolanan bu ta\u015flar\u0131n ya\u015f\u0131 bulunursa yeterince yak\u0131n bir tahminle Yerk\u00fcre\u2019nin ya\u015f\u0131 da bulunurdu.Gelgelelim t\u0131pk\u0131 eski kaya\u00e7lar gibi g\u00f6kta\u015flar\u0131 da yery\u00fcz\u00fc \u00fczerinde bol de\u011fildi ve onlardan al\u0131nm\u0131\u015f \u00f6rneklere ula\u015fmak \u00e7ok zordu.Ayr\u0131ca Brown\u2019un \u00f6l\u00e7\u00fcm tekni\u011fi pratikte uygulanam\u0131yordu.\u00dcst\u00fcne \u00fcstl\u00fck Patterson\u2019un \u00f6rnekleri havayla her temas edi\u015flerinde b\u00fcy\u00fck dozlarda atmosferik kur\u015fun kirlenmesine u\u011fruyordu.\u0130\u015fte Patterson\u2019u steril bir laboratuvarda \u00e7al\u0131\u015fmaya mecbur eden nedenler bunlard\u0131. 7 y\u0131l boyunca son testte kullanaca\u011f\u0131 uygun \u00f6rnekler toplamak i\u00e7in \u00e7al\u0131\u015ft\u0131.Nihayet 1953 y\u0131l\u0131nda bu i\u015fi tamamlad\u0131 ve \u00f6rneklerini Illinois\u2019te bulunan Argonne Laboratuvar\u0131\u2019na g\u00f6t\u00fcrd\u00fc.Orada son model bir k\u00fctle-spektrograf\u0131 ile \u00e7al\u0131\u015fma olana\u011f\u0131 buldu.Bu makine,eski kristaller i\u00e7ine sinmi\u015f olan \u00e7ok k\u00fc\u00e7\u00fck uranyum ve kur\u015fun miktarlar\u0131n\u0131 saptay\u0131p \u00f6l\u00e7ebiliyordu.
\nK\u0131sa bir s\u00fcre sonra,Wisconsin\u2019de d\u00fczenlenen bir toplant\u0131da, Yerk\u00fcre i\u00e7in art\u0131 ya da eksi 70 milyon y\u0131l olarak kesin bir ya\u015f ilan etti:<\/p>\n","protected":false},"excerpt":{"rendered":"
Karbon 14 ile tarihlendirme y\u00f6nteminin hatal\u0131 sonu\u00e7lar verdi\u011fi anla\u015f\u0131l\u0131nca yeni y\u00f6ntemler bulundu.Bunlardan bir tanesi,topraktan yap\u0131lm\u0131\u015f cisimler i\u00e7inde kalan elektronlar\u0131 \u00f6l\u00e7en termol\u00fcminesans sistemidir.Bir di\u011fer sistem de bir \u00f6rne\u011fin elektromagnetik dalga bombard\u0131man\u0131na tutulup,elektron titre\u015fimlerinin \u00f6l\u00e7\u00fclmesini sa\u011flayan elektron spin rezonans\u0131d\u0131r.Ama bu gibi y\u00f6ntemler 200.000 y\u0131ldan daha ya\u015fl\u0131 cisimlerin tarihlendirilmesini sa\u011flayamad\u0131lar.Kaya\u00e7lar gibi inorganik maddeler i\u00e7in ise hi\u00e7 i\u015fe yaramad\u0131lar.Oysa …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1403,1406],"tags":[4152,2134,4153,2828,2762,4151,3088,4150,4154],"class_list":["post-1464","post","type-post","status-publish","format-standard","hentry","category-odevler","category-sosyal-bilgiler-odevleri","tag-elektromagnetik","tag-elektron","tag-goktaslari","tag-gunes-sistemi","tag-jeoloji","tag-karbon-14","tag-kayaclar","tag-yerkure-yasinin-belirlenmesi","tag-yerkurenin-yasi"],"_links":{"self":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts\/1464","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/comments?post=1464"}],"version-history":[{"count":0,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts\/1464\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/media?parent=1464"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/categories?post=1464"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/tags?post=1464"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}