Yeni bir \u00e7al\u0131\u015fma, d\u00fcnyan\u0131n i\u00e7 \u00e7ekirde\u011finde demir ve nikelin yan\u0131 s\u0131ra silikonun var oldu\u011funu \u00f6ne s\u00fcr\u00fcyor. Japon biliminsanlar\u0131, D\u00fcnya\u2019n\u0131n \u00e7ekirde\u011findeki \u201ceksik bir element\u201din kimli\u011fini tespit ettiklerini d\u00fc\u015f\u00fcn\u00fcyorlar. Demir ve nikelden sonra gezegenimizin merkezinin \u00f6nemli bir b\u00f6l\u00fcm\u00fcn\u00fc olu\u015fturdu\u011funa inan\u0131lan element, onlarca y\u0131ld\u0131r aran\u0131yor.<\/p>\n
\u015eimdilerde, derin i\u00e7 b\u00f6lgelerde bulunan y\u00fcksek s\u0131cakl\u0131k ve bas\u0131n\u00e7lar yeniden yarat\u0131larak yap\u0131lan deneylerden elde edilen sonu\u00e7lara g\u00f6re, en olas\u0131 aday\u0131n silikon oldu\u011fu ileri s\u00fcr\u00fcl\u00fcyor.<\/p>\n
Bu ke\u015fif, d\u00fcnyam\u0131z\u0131n nas\u0131l olu\u015ftu\u011funu daha iyi anlamam\u0131za yard\u0131mc\u0131 olabilir.<\/p>\n
Ara\u015ft\u0131rman\u0131n y\u00f6neticisi Tohoku \u00dcniversitesi\u2019nden Eiji Ohtani, BBC News<\/em>\u2019e verdi\u011fi deme\u00e7te \u201cSilisyumun \u00f6nemli bir element oldu\u011funa inan\u0131yoruz; a\u011f\u0131rl\u0131\u011f\u0131n\u0131n yakla\u015f\u0131k y\u00fczde 5\u2019inin demir olmas\u0131 nedeniyle demir-nikel ala\u015f\u0131mlar\u0131na \u00e7\u00f6z\u00fclm\u00fc\u015f olabilir\u201d diyor.<\/p>\n <\/p>\n Ula\u015fmas\u0131 zor<\/em><\/strong><\/p>\n D\u00fcnyan\u0131n en i\u00e7 k\u0131sm\u0131, yakla\u015f\u0131k 1200 km (745 mil) yar\u0131\u00e7apl\u0131 kat\u0131 bir top olarak d\u00fc\u015f\u00fcn\u00fcl\u00fcr. Do\u011frudan ara\u015ft\u0131rmak i\u00e7in \u00e7ok derindir, bilimadamlar\u0131 bunun yerine sismik dalgalar\u0131n bu b\u00f6lgeden ge\u00e7erkenki durumlar\u0131n\u0131 ara\u015ft\u0131r\u0131r. \u00c7ekirde\u011fin a\u011f\u0131rl\u0131\u011f\u0131n\u0131n yakla\u015f\u0131k y\u00fczde 85\u2019ini demir, yakla\u015f\u0131k y\u00fczde 10\u2019unu ise nikel olu\u015fturur.<\/p>\n Eiji Ohtani ve ekibi, \u00e7ekirde\u011fin y\u00fczde 5\u2019ini olu\u015fturan belirsiz elementleri ara\u015ft\u0131rmak i\u00e7in demir ve nikel ala\u015f\u0131mlar\u0131 \u00fcretti ve onlar\u0131 silikonla kar\u0131\u015ft\u0131rd\u0131. Sonra onlar\u0131 i\u00e7 \u00e7ekirdekte bulunan muazzam bas\u0131n\u00e7 ve s\u0131cakl\u0131klara maruz b\u0131rakt\u0131lar. Bu kar\u0131\u015f\u0131m\u0131n, D\u00fcnya\u2019n\u0131n i\u00e7 k\u0131sm\u0131nda g\u00f6r\u00fclen sismik verilerle e\u015fle\u015fti\u011fini ke\u015ffettiler.<\/p>\n Prof Ohtani, silikon varl\u0131\u011f\u0131n\u0131 do\u011frulamak i\u00e7in daha fazla \u00e7al\u0131\u015fmaya ihtiya\u00e7 duyuldu\u011funu ve bu olas\u0131l\u0131\u011f\u0131n di\u011fer elementlerin varl\u0131\u011f\u0131n\u0131 ekarte etmedi\u011fini s\u00f6yledi.<\/p>\n <\/p>\n \u00c7ekirdek olu\u015fumu<\/em><\/strong><\/p>\n Ara\u015ft\u0131rmalar \u00fczerine yorum yapan Cambridge \u00dcniversitesi\u2019nden Prof. Simon Redfern \u015funlar\u0131 s\u00f6yl\u00fcyor: \u201cBu zorlu deneyler ger\u00e7ekten heyecan verici, \u00e7\u00fcnk\u00fc 4,5 milyar y\u0131l \u00f6nce \u00e7ekirde\u011fin ilk kez gezegenin kayal\u0131k b\u00f6lgelerinden ayr\u0131lmaya ba\u015flamas\u0131yla birlikte, D\u00fcnya\u2019n\u0131n i\u00e7yap\u0131s\u0131n\u0131n ilk olu\u015fumundan hemen sonraki haline bir pencere a\u00e7abilir. Ancak di\u011fer ara\u015ft\u0131rmac\u0131lar son zamanlarda oksijenin de \u00e7ekirde\u011fin \u00f6nemli bir par\u00e7as\u0131 olabilece\u011fini \u00f6ne s\u00fcrmektedir.\u201d<\/p>\n Redfern, neler oldu\u011funu bilmenin, biliminsanlar\u0131n\u0131n D\u00fcnya\u2019n\u0131n olu\u015fumu s\u0131ras\u0131nda ortaya \u00e7\u0131kan ko\u015fullar\u0131 daha iyi anlamalar\u0131na yard\u0131mc\u0131 olabilece\u011fini de ekliyor. \u00d6zellikle, yerin erken d\u00f6nemlerinde, oksijenin b\u00fcy\u00fck \u00f6l\u00e7\u00fcde s\u0131n\u0131rl\u0131 oldu\u011fu i\u00e7 k\u0131sm\u0131n\u0131n, \u00a0indirgeme ko\u015fullar\u0131 bab\u0131nda bilinip bilinemeyece\u011fi konusuna. \u00a0Ya da oksijenin oksitleyici olarak tan\u0131mlanabilecek kadar bol olup olmad\u0131\u011f\u0131na.<\/p>\n Prof Ohtani\u2019nin sonu\u00e7lar\u0131na g\u00f6re, d\u00f6rt milyar y\u0131ldan daha uzun s\u00fcre \u00f6nce D\u00fcnya\u2019n\u0131n \u00e7ekirde\u011fine daha fazla miktarda silikon eklenmi\u015fse, bu, gezegenin geri kalan\u0131n\u0131 oksijen y\u00f6n\u00fcnden zengin yapard\u0131. Ama e\u011fer, bunun yerine, oksijen, kendisini \u00e7evreleyen kayal\u0131k mantodan ayr\u0131lacak olan \u00e7ekirde\u011fin girdab\u0131na kap\u0131lsayd\u0131, \u00e7ekirdek elementi t\u00fcketirdi.<\/p>\n Prof Redfern \u015funlar\u0131 ekliyor: \u201cBir bak\u0131ma, bu iki se\u00e7enek de, D\u00fcnya\u2019n\u0131n \u00e7ekirde\u011finin ilk olu\u015fmaya ba\u015flad\u0131\u011f\u0131 ko\u015fullara \u00e7ok ba\u011fl\u0131 olan ger\u00e7ek alternatiflerdir. En son elde edilen sonu\u00e7lar, kavray\u0131\u015f\u0131m\u0131za katk\u0131da bulunuyor, ancak hik\u00e2ye hen\u00fcz bitmi\u015f de\u011fil.\u201d<\/p>\n Prof. Ohtani ara\u015ft\u0131rmas\u0131n\u0131n sonu\u00e7lar\u0131n\u0131, San Francisco\u2019daki Amerikan Jeofizik Birli\u011fi sonbahar toplant\u0131s\u0131na sunmu\u015ftur.<\/p>\n <\/p>\n