{"id":15777,"date":"2016-05-01T12:05:39","date_gmt":"2016-05-01T09:05:39","guid":{"rendered":"http:\/\/109.232.216.219\/~bilimvegelecek\/?p=15777"},"modified":"2018-01-04T12:10:08","modified_gmt":"2018-01-04T09:10:09","slug":"fizik-evrenin-yasini-nasil-hesapliyor","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2016\/05\/01\/fizik-evrenin-yasini-nasil-hesapliyor","title":{"rendered":"Fizik evrenin ya\u015f\u0131n\u0131 nas\u0131l hesapl\u0131yor?\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0"},"content":{"rendered":"

David A. Weintraub\u2019a 2011 y\u0131l\u0131nda Amerikan Yay\u0131nc\u0131lar Birli\u011fi Kozmoloji ve Astronomi \u00d6d\u00fcl\u00fc\u2019n\u00fc kazand\u0131ran Evren Ka\u00e7 Ya\u015f\u0131nda?<\/em> 2015\u2019in son g\u00fcnlerinde Alfa Yay\u0131nlar\u0131 bilim dizisinden Ula\u015f Apak \u00e7evirisiyle \u00e7\u0131kt\u0131.<\/p>\n

\"\"Kitaplar\u0131n -\u00f6zelllikle bilim ve bilim tarihi kitaplar\u0131n\u0131n- isimleri, bende her zaman kitap hakk\u0131nda h\u0131zl\u0131 bir \u00f6nyarg\u0131 olu\u015ftur. \u201cEvren Ka\u00e7 Ya\u015f\u0131nda?\u201d<\/em> ad\u0131n\u0131 g\u00f6rd\u00fc\u011f\u00fcmde de kafamda yine h\u0131zl\u0131 bir yarg\u0131 olu\u015ftu ve kitab\u0131 isteksizce okumaya ba\u015flad\u0131m. Ancak kitab\u0131n derinli\u011fini ve g\u00f6kbilim tarihini son derece titiz \u015fekilde ele al\u0131\u015f\u0131n\u0131 g\u00f6rd\u00fck\u00e7e, sahip oldu\u011fum \u00f6nyarg\u0131n\u0131n ne denli yanl\u0131\u015f oldu\u011funu anlam\u0131\u015f oldum. Bu kitap astronomi tarihini, matemati\u011fin karma\u015f\u0131k diline h\u00e2kim olmayan \u00fcniversite \u00f6\u011frencileri i\u00e7in, se\u00e7meli ders olarak okutulabilecek d\u00fczeyde geni\u015f bir perspektiften ele al\u0131yor. Bunu yaparken de hik\u00e2yeyi durdurup gerekli fiziksel bilgileri sunan k\u0131sa a\u00e7\u0131klamalar\u0131 ihmal etmiyor. \u00d6rne\u011fin g\u00f6kta\u015flar\u0131n\u0131n ya\u015f\u0131n\u0131 belirlemek i\u00e7in kullan\u0131lan y\u00f6ntemlerden h\u0131zl\u0131ca bahsetmek yerine, duraksay\u0131p okuyucuya nefes ald\u0131r\u0131yor ve radyoaktiviteye dair anla\u015f\u0131l\u0131r bilgileri sunuyor.<\/p>\n

Bilimciler evrenin yakla\u015f\u0131k 13,7 milyar ya\u015f\u0131nda oldu\u011fu konusunda hemfikirler. \u00d6yleyse bu say\u0131ya nas\u0131l ula\u015f\u0131ld\u0131? Evrenin ya\u015f\u0131n\u0131n belirlenmesi sadece 20. ve 21. y\u00fczy\u0131l bilimsel ke\u015fiflerinin bir ba\u015far\u0131s\u0131 de\u011fil; g\u00f6ky\u00fcz\u00fcne ilk bak\u0131ld\u0131\u011f\u0131 anda ortaya \u00e7\u0131km\u0131\u015f ve g\u00fcn\u00fcm\u00fcze kadar s\u00fcrmekte olan tarihsel bir birikimin sonucudur. Bu ya\u015f\u0131 bulmak bir a\u00e7\u0131dan bak\u0131ld\u0131\u011f\u0131nda temelde s\u0131n\u0131rlama probleminden ibarettir: Evrenin i\u00e7erisindeki her \u015fey mant\u0131ken evrenden ya\u015fl\u0131 olamaz, yani en yak\u0131n\u0131m\u0131zdaki \u015feylerin ya\u015flar\u0131n\u0131 \u00f6l\u00e7erek evrenin ya\u015f\u0131na bir alt s\u0131n\u0131r getirebiliriz. Beri yandan modern astrofizik tekniklerini kullanarak da evrende bulunmas\u0131 gereken, fakat bulunmayan \u015feyler \u00fczerinden bir \u00fcst s\u0131n\u0131r koyabiliriz. \u015e\u00f6yle ki, ger\u00e7ekle\u015fmesi ka\u00e7\u0131n\u0131lmaz bir fiziksel s\u00fcreci g\u00f6zlemleyemiyorsak, tek \u00e7\u0131kar yolumuz o s\u00fcrecin ger\u00e7ekle\u015fece\u011fi kadar zaman ge\u00e7medi\u011fini savlamakt\u0131r. B\u00f6ylece sa\u011fdan ve soldan s\u0131k\u0131\u015ft\u0131rmalar yaparak evrenin ya\u015f\u0131n\u0131n tam olarak hangi aral\u0131kta oldu\u011fu saptanabilir.<\/p>\n

\"\"David A. Weintraub ilk olarak \u201cD\u00fcnya evrenden ya\u015fl\u0131 olamaz\u201d diyerek i\u015fe koyuluyor ve D\u00fcnya\u2019n\u0131n ya\u015f\u0131n\u0131n bulunu\u015f \u00f6yk\u00fcs\u00fcn\u00fc anlatmaya ba\u015fl\u0131yor. Mitolojik metinlerin aksine D\u00fcnya\u2019n\u0131n ya\u015f\u0131n\u0131n belirlenmesi bir radyoaktivite problemidir. Prensipte D\u00fcnya\u2019daki en ya\u015fl\u0131 ta\u015f\u0131 al\u0131p radyoaktif y\u00f6ntemlerle ya\u015f\u0131n\u0131 \u00f6l\u00e7ersek D\u00fcnya\u2019n\u0131n da ya\u015f\u0131n\u0131 bulabiliriz (En az\u0131ndan bir alt s\u0131n\u0131r getirdi\u011fimizi s\u00f6yleyebiliriz).<\/p>\n

D\u00fcnya\u2019n\u0131n ya\u015f\u0131n\u0131 bularak evrenin ya\u015f\u0131na ilk alt s\u0131n\u0131r\u0131 getirdikten sonra, g\u00f6z\u00fcn\u00fc G\u00fcne\u015f Sistemi\u2019ne diken Weintraub, bu hik\u00e2yeyi anlatarak yoluna devam ediyor. Daha da da uzakla\u015farak y\u0131ld\u0131zlar\u0131n ya\u015flar\u0131n\u0131n, galaksimizin ya\u015f\u0131n\u0131n, di\u011fer galaksilerin ya\u015flar\u0131n\u0131n nas\u0131l hesapland\u0131\u011f\u0131na dair geni\u015f ve anla\u015f\u0131l\u0131r bilgiler verip, evrenin ya\u015f\u0131 i\u00e7in getirdi\u011fi alt ve \u00fcst s\u0131n\u0131r\u0131 s\u00fcrekli zorluyor.<\/p>\n

Beyaz c\u00fcceler i\u00e7in so\u011fuma s\u00fcrelerinden evrenin ya\u015f\u0131n\u0131n 11-13 milyardan b\u00fcy\u00fck oldu\u011fu ortaya \u00e7\u0131k\u0131yor. \u00d6te yandan, a\u015f\u0131r\u0131 so\u011fuk ve s\u00f6n\u00fck beyaz c\u00fccelerin yoklu\u011fu da evrenin ya\u015f\u0131 i\u00e7in 15 milyar y\u0131ll\u0131k bir \u00fcst s\u0131n\u0131r koyuyor. Bunun d\u0131\u015f\u0131nda k\u00fcresel y\u0131ld\u0131z k\u00fcmelerinin d\u00f6n\u00fc\u015f noktalar\u0131ndan ve evrenin geni\u015fleme h\u0131z\u0131ndan yola \u00e7\u0131k\u0131larak evren i\u00e7in yeniden ya\u015f tayinleri yap\u0131l\u0131yor ve hesaplanan t\u00fcm say\u0131lar, evrenin 13,5-14 milyar y\u0131l aras\u0131nda bir ya\u015fta oldu\u011funa i\u015faret ediyor.<\/p>\n

Sonlara do\u011fru ise modern kozmolojinin en temel dayanaklar\u0131ndan biri olan kozmik mikrodalga fon \u0131\u015f\u0131n\u0131m\u0131<\/strong>na geni\u015f \u00e7er\u00e7evede de\u011finen yazar, bu \u0131\u015f\u0131n\u0131m\u0131n bulunu\u015f \u00f6yk\u00fcs\u00fcn\u00fc, neden bu denli \u00f6nemli oldu\u011funu, nas\u0131l yorumlanmas\u0131 gerekti\u011fini, evrenin ya\u015f\u0131 ve evrendeki madde da\u011f\u0131l\u0131m\u0131yla ne gibi ili\u015fkileri oldu\u011funu okura ustaca aktar\u0131yor.<\/p>\n

Yakla\u015f\u0131k 350 sayfa olan bir kitapta bu kadar fazla bilginin g\u00fczel bir kurguyla sunulmas\u0131, Evren Ka\u00e7 Ya\u015f\u0131nda<\/em>\u2019y\u0131 s\u0131radan pop\u00fcler bilim kitaplar\u0131ndan bir ad\u0131m \u00f6teye ta\u015f\u0131y\u0131p k\u00fc\u00e7\u00fck bir evren rehberi haline getiriyor. Y\u0131ld\u0131zlar\u0131n evriminden s\u00fcpernova patlamalar\u0131na, karanl\u0131k maddeden karanl\u0131k enerjiye kadar geni\u015f yelpazedeki bilgileri, zekice kurgulanm\u0131\u015f benzetmelerle okuyucuya aktaran bu kitap, fizik ve astronomiye merakl\u0131 okuyucular\u0131 doyuracak derecede dolu ve keyifli.<\/p>\n

– Evren Ka\u00e7 Ya\u015f\u0131nda?, David A. Weintraub, 2010, \u0130ng. \u00c7ev. Ula\u015f Apak, Alfa Yay\u0131nlar\u0131, 2015, 365 s. <\/em><\/p>\n","protected":false},"excerpt":{"rendered":"

David A. Weintraub\u2019a 2011 y\u0131l\u0131nda Amerikan Yay\u0131nc\u0131lar Birli\u011fi Kozmoloji ve Astronomi \u00d6d\u00fcl\u00fc\u2019n\u00fc kazand\u0131ran Evren Ka\u00e7 Ya\u015f\u0131nda? 2015\u2019in son g\u00fcnlerinde Alfa Yay\u0131nlar\u0131 bilim dizisinden Ula\u015f Apak \u00e7evirisiyle \u00e7\u0131kt\u0131. Kitaplar\u0131n -\u00f6zelllikle bilim ve bilim tarihi kitaplar\u0131n\u0131n- isimleri, bende her zaman kitap hakk\u0131nda h\u0131zl\u0131 bir \u00f6nyarg\u0131 olu\u015ftur. \u201cEvren Ka\u00e7 Ya\u015f\u0131nda?\u201d ad\u0131n\u0131 g\u00f6rd\u00fc\u011f\u00fcmde de kafamda yine h\u0131zl\u0131 bir yarg\u0131 […]<\/p>\n","protected":false},"author":634,"featured_media":15778,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[184,26,513],"tags":[657,1840,288],"class_list":["post-15777","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-147-sayi","category-fizik","category-kitapcil","tag-evren","tag-evrenin-yasi","tag-fizik"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t