{"id":37486,"date":"2019-10-11T03:20:01","date_gmt":"2019-10-11T00:20:01","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=37486"},"modified":"2019-10-11T10:20:45","modified_gmt":"2019-10-11T07:20:45","slug":"olbers-paradoksu-nedir","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2019\/10\/11\/olbers-paradoksu-nedir","title":{"rendered":"Olbers paradoksu nedir?"},"content":{"rendered":"

Yakla\u015f\u0131k 200 y\u0131l \u00f6nce, Heinrich Wilhelm Olbers (1758- 1840) ad\u0131nda bir Alman astronom, \u015f\u00f6yle bir soru g\u00fcndeme getirmi\u015fti: E\u011fer sonsuz uzayda, sonsuz say\u0131da y\u0131ld\u0131z d\u00fczg\u00fcn olarak yay\u0131lm\u0131\u015f ise, geceleyin g\u00f6ky\u00fcz\u00fcn\u00fcn karanl\u0131k olmamas\u0131, p\u0131r\u0131l p\u0131r\u0131l \u0131\u015f\u0131ldamas\u0131 gerekecektir.<\/p>\n

Bu sav\u0131n\u0131n gerek\u00e7esini de Olbers \u015f\u00f6yle a\u00e7\u0131kl\u0131yordu: Merkezinde bulundu\u011fumuz bir k\u00fcre alal\u0131m ve bu k\u00fcrenin yar\u0131\u00e7ap\u0131 b\u00fcy\u00fcd\u00fck\u00e7e nas\u0131l bir de\u011fi\u015fim olaca\u011f\u0131n\u0131 d\u00fc\u015f\u00fcnelim. I\u015f\u0131\u011f\u0131n \u015fiddeti uzakl\u0131\u011f\u0131n karesi ile ters orant\u0131l\u0131 olarak de\u011fi\u015fti\u011fine g\u00f6re, bu k\u00fcre \u00fczerinde bulunan y\u0131ld\u0131zlar\u0131n parlakl\u0131klar\u0131 uzakl\u0131\u011f\u0131n karesi ile ters orant\u0131l\u0131 olarak azalacakt\u0131r. Buna kar\u015f\u0131l\u0131k, e\u011fer y\u0131ld\u0131zlar uzayda d\u00fczg\u00fcn olarak da\u011f\u0131lm\u0131\u015f iseler, k\u00fcrenin \u00fczerindeki y\u0131ld\u0131zlar\u0131n say\u0131s\u0131, bu y\u00fczeyin y\u00fcz\u00f6l\u00e7\u00fcm\u00fc ile (yani k\u00fcrenin yar\u0131\u00e7ap\u0131n\u0131n karesi ile) orant\u0131l\u0131 olarak artacakt\u0131r. Bu iki z\u0131t etki birbirini yok edece\u011finden, her bir k\u00fcre y\u00fczeyinde bulunan y\u0131ld\u0131zlar\u0131n bize g\u00f6nderece\u011fi toplam \u0131\u015f\u0131k \u015fiddeti ayn\u0131 kalacakt\u0131r. Her katman\u0131n bize g\u00f6nderece\u011fi e\u015fit \u0131\u015f\u0131k \u015fiddetlerinin toplam\u0131n\u0131n sonsuz olmas\u0131 gerekir.<\/p>\n

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Alman astronom Olbers\u2019in g\u00fcndeme getirdi\u011fi soru, kendi ad\u0131yla an\u0131lan bir paradoksa d\u00f6n\u00fc\u015fm\u00fc\u015ft\u00fcr: E\u011fer sonsuz uzayda, sonsuz say\u0131da y\u0131ld\u0131z d\u00fczg\u00fcn olarak yay\u0131lm\u0131\u015f ise, geceleyin g\u00f6ky\u00fcz\u00fcn\u00fcn karanl\u0131k olmamas\u0131, p\u0131r\u0131l p\u0131r\u0131l \u0131\u015f\u0131ldamas\u0131 gerekecektir. O d\u00f6nemde konu o kadar g\u00fcncelle\u015fmi\u015fti ki, Olbers paradoksuna \u00e7are arayanlar kervan\u0131na \u015fairler de kat\u0131lm\u0131\u015ft\u0131. Amerikal\u0131 \u015fair Edgar Allan Poe, 1848\u2019de yazd\u0131\u011f\u0131 \u201cEureka\u201d adl\u0131 \u015fiirinde, en arka planda yer alan y\u0131ld\u0131zlar\u0131n \u0131\u015f\u0131n\u0131mlar\u0131n\u0131n, \u0131\u015f\u0131\u011f\u0131n h\u0131z\u0131n\u0131n sonlu olmas\u0131ndan dolay\u0131, hen\u00fcz bize ula\u015famad\u0131\u011f\u0131n\u0131 ileri s\u00fcr\u00fcyordu.<\/figcaption><\/figure>\n

Olbers, paradoksu \u00e7\u00f6zmek i\u00e7in \u015f\u00f6yle bir \u00f6neride bulunmu\u015ftu: Uzay absorblay\u0131c\u0131 (so\u011furucu) bir madde ile dolu oldu\u011fundan, \u00e7ok uzak y\u0131ld\u0131zlar\u0131n \u0131\u015f\u0131n\u0131m\u0131 bu ortam taraf\u0131ndan so\u011furuluyor ve bize ula\u015fam\u0131yor.<\/p>\n

Ancak, ezeli (sonsuz ge\u00e7mi\u015fi olan) bir evrende, so\u011furucu ortam ile y\u0131ld\u0131zlardan gelen \u0131\u015f\u0131n\u0131m aras\u0131nda eninde sonunda termodinamik denge olu\u015faca\u011f\u0131ndan, so\u011furucu ortam da so\u011furdu\u011fu \u0131\u015f\u0131n\u0131m kadar parlak olacak ve soru gene \u00e7\u00f6z\u00fclmemi\u015f olacak.<\/p>\n

O d\u00f6nemde konu o kadar g\u00fcncelle\u015fmi\u015fti ki, astronomlar\u0131n derdine \u00e7are arayanlar kervan\u0131na \u015fairler de kat\u0131lm\u0131\u015ft\u0131. Amerikal\u0131 \u015fair Edgar Allan Poe (1809-1849), 1848 y\u0131l\u0131nda yazm\u0131\u015f oldu\u011fu \u201cEureka\u201d adl\u0131 \u015fiirinde, en arka planda olan y\u0131ld\u0131zlar\u0131n \u0131\u015f\u0131n\u0131mlar\u0131n\u0131n, \u0131\u015f\u0131\u011f\u0131n h\u0131z\u0131n\u0131n sonlu olmas\u0131ndan dolay\u0131, hen\u00fcz bize ula\u015famam\u0131\u015f olaca\u011f\u0131n\u0131 ileri s\u00fcr\u00fcyordu. Ancak bu \u00e7\u00f6z\u00fcm \u00f6nerisi de, sonsuz ge\u00e7mi\u015fi olan evren kavram\u0131 ile ba\u011fda\u015fm\u0131yordu.<\/p>\n

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16. y\u00fczy\u0131lda yay\u0131mlanm\u0131\u015f bu \u00fcnl\u00fc grav\u00fcrde, merakl\u0131 bir adam, ba\u015f\u0131n\u0131 s\u0131n\u0131rdan uzat\u0131p ne var ne yok diye bak\u0131yor.<\/figcaption><\/figure>\n

Sorun asl\u0131nda sonsuz Euklides uzay\u0131 ve ezeli (sonsuz ge\u00e7mi\u015fi olan) evren varsay\u0131mlar\u0131ndan kaynaklan\u0131yordu. Ancak bu kavramlar, Newton paradigmas\u0131n\u0131n sonucu olarak, klasik fizikte o kadar yerle\u015fmi\u015fti ki, terk edilmesi s\u00f6z konusu olam\u0131yor, aksi halde ba\u015fka zorluklar\u0131n ortaya \u00e7\u0131kmas\u0131na neden oluyordu. \u00d6rne\u011fin, Euklides uzay\u0131n\u0131n sonlu olabilmesi i\u00e7in, duvar gibi bir s\u0131n\u0131r ile \u00e7evrilmesi gerekiyor. O zaman \u201cs\u0131n\u0131r paradoksu\u201d denilen, \u201cBu s\u0131n\u0131rlar\u0131n \u00f6tesinde ne var?\u201d sorusu g\u00fcndeme geliyor. (16.y\u00fczy\u0131lda yay\u0131mlanm\u0131\u015f \u00fcnl\u00fc grav\u00fcrde, s\u0131n\u0131rdan \u00f6teye ba\u015f\u0131n\u0131 uzat\u0131p, ne var ne yok diye bakan merakl\u0131 adam\u0131 hat\u0131rlay\u0131n.<\/p>\n

Bug\u00fcn, y\u0131ld\u0131zlar\u0131n uzayda d\u00fczg\u00fcn (\u00fcniform) olarak da\u011f\u0131lmay\u0131p, galaksi dedi\u011fimiz topluluklar halinde oldu\u011funu biliyoruz. Ancak, y\u0131ld\u0131zlar\u0131n yerine galaksileri koyarak, Olbers\u2019in savlar\u0131 tekrarlanabilir. \u0130leride g\u00f6rece\u011fimiz gibi, \u201cgeni\u015fleyen evren\u201d kuram\u0131 modelleri, bu sorunu \u00e7\u00f6zebilmi\u015ftir.<\/p>\n

Kaynak:<\/strong>Metin Hotinli, 50 Soruda B\u00fcy\u00fck Patlama Kuram\u0131, Kas\u0131m 2010, 2.Bask\u0131 s. 55-57<\/p>\n","protected":false},"excerpt":{"rendered":"

Yakla\u015f\u0131k 200 y\u0131l \u00f6nce, Heinrich Wilhelm Olbers (1758- 1840) ad\u0131nda bir Alman astronom, \u015f\u00f6yle bir soru g\u00fcndeme getirmi\u015fti: E\u011fer sonsuz uzayda, sonsuz say\u0131da y\u0131ld\u0131z d\u00fczg\u00fcn olarak yay\u0131lm\u0131\u015f ise, geceleyin g\u00f6ky\u00fcz\u00fcn\u00fcn karanl\u0131k olmamas\u0131, p\u0131r\u0131l p\u0131r\u0131l \u0131\u015f\u0131ldamas\u0131 gerekecektir. Bu sav\u0131n\u0131n gerek\u00e7esini de Olbers \u015f\u00f6yle a\u00e7\u0131kl\u0131yordu: Merkezinde bulundu\u011fumuz bir k\u00fcre alal\u0131m ve bu k\u00fcrenin yar\u0131\u00e7ap\u0131 b\u00fcy\u00fcd\u00fck\u00e7e nas\u0131l bir […]<\/p>\n","protected":false},"author":429,"featured_media":37487,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[19],"tags":[248,1651,5407,2733,392,404],"class_list":["post-37486","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilim-gundemi","tag-astronomi","tag-galaksi","tag-olbers","tag-paradoks","tag-uzay","tag-yildizlar"],"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