{"id":35441,"date":"2019-07-22T03:15:57","date_gmt":"2019-07-22T00:15:57","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=35441"},"modified":"2019-07-24T14:14:57","modified_gmt":"2019-07-24T11:14:57","slug":"karanlik-enerji-nedir","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2019\/07\/22\/karanlik-enerji-nedir","title":{"rendered":"Karanl\u0131k enerji nedir?"},"content":{"rendered":"

Hubble\u2019\u0131n Evren\u2019in geni\u015fliyor oldu\u011funu ke\u015ffetmesinden bu yana b\u00fct\u00fcn g\u00f6kbilimciler Evren\u2019in geni\u015fleme h\u0131z\u0131n\u0131n -i\u00e7erdi\u011fi maddenin k\u00fctle\u00e7ekim etkisi nedeniyle- yava\u015flamas\u0131 gerekti\u011fini d\u00fc\u015f\u00fcnme e\u011filiminde olmu\u015ftur. Bu nedenle 1998 ve 199 y\u0131llar\u0131nda birbirinden ba\u011f\u0131ms\u0131z \u00e7al\u0131\u015fan iki ekip (Saul Perlmutter ve Brian Schimidt\u2019in liderli\u011findeki) Evren\u2019in geni\u015fleme h\u0131z\u0131n\u0131n artt\u0131\u011f\u0131n\u0131 ke\u015ffetti\u011finde g\u00f6kbilim d\u00fcnyas\u0131nda b\u00fcy\u00fck bir \u015fa\u015fk\u0131nl\u0131k ya\u015fanm\u0131\u015ft\u0131. Uzak g\u00f6kadalardaki s\u00fcpernovalar \u00fczerinden yap\u0131lan hesaplara dayanan bu bulgu daha sonra iki farkl\u0131 ekip taraf\u0131ndan ba\u015fka geli\u015fmi\u015f ayg\u0131tlarla yinelendi ve ayn\u0131 sonuca ula\u015f\u0131ld\u0131: Evren giderek daha h\u0131zl\u0131 geni\u015fliyordu. G\u00f6zlemler Evren\u2019in geni\u015flemesine yol a\u00e7an bir \u201cenerji\u201dnin varl\u0131\u011f\u0131na i\u015faret ediyordu. Peki, ama neydi bu enerji?<\/p>\n

Bu sorunun en net yan\u0131t\u0131: \u201cBilmiyoruz\u201ddur. Ger\u00e7ekten de karanl\u0131k enerji kar\u015f\u0131s\u0131ndaki bilgisizli\u011fimiz karanl\u0131k madde kar\u015f\u0131s\u0131ndaki bilgisizli\u011fimizden bile daha b\u00fcy\u00fckt\u00fcr. Onun hakk\u0131nda neredeyse hi\u00e7bir \u015fey bilinmiyor. Karanl\u0131k enerjiye ili\u015fkin bilinen temel iki olgu \u015funlard\u0131r:<\/p>\n

1.Evren\u2019de d\u00fczg\u00fcn bir da\u011f\u0131l\u0131m\u0131 var. Her yerde hemen hemen ayn\u0131 yo\u011funlukta bulunuyor.<\/p>\n

2.Evren\u2019in geni\u015flemesiyle birlikte yo\u011funlu\u011fu azalm\u0131yor, sabit kal\u0131yor.<\/p>\n

T\u0131pk\u0131 karanl\u0131k madde gibi karanl\u0131k enerji de g\u00f6r\u00fcnmezdir. Ancak karanl\u0131k enerjinin k\u00fctle\u00e7ekim etkisi Evren\u2019in i\u00e7ine \u00e7\u00f6kmesini desteklemez; tersine geni\u015flemesini destekler, onun geni\u015fleme h\u0131z\u0131n\u0131 artt\u0131r\u0131r. Bir ba\u015fka deyi\u015fle karanl\u0131k enerji k\u00fctle\u00e7ekime ters y\u00f6nde i\u015fleyen -nesneleri birbirinden uzakla\u015ft\u0131ran- bir k\u00fctle-itim kuvveti gibidir.<\/p>\n

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T\u00fcm\u00fcyle bo\u015f uzayda asl\u0131nda atomalt\u0131 par\u00e7ac\u0131k ve kar\u015f\u0131 par\u00e7ac\u0131klar\u0131n s\u00fcrekli olu\u015fup yok oldu\u011fu ve bu etkinli\u011fin de \u00e7ok \u00e7ok zay\u0131f olsa da bir \u201cbas\u0131n\u00e7\u201d yaratt\u0131\u011f\u0131 d\u00fc\u015f\u00fcn\u00fcl\u00fcyor.<\/figcaption><\/figure>\n

Elimizde \u015fimdilik karanl\u0131k enerjiye ili\u015fkin geli\u015ftirilen birbirinden farkl\u0131, \u015fu \u201colas\u0131\u201d kuramlardan -d\u00fc\u015f\u00fcnceler de denebilir- ba\u015fka bir \u015fey yok:<\/p>\n

1.Karanl\u0131k enerji, \u015fiddeti \u00e7ok d\u00fc\u015f\u00fck, homojen da\u011f\u0131l\u0131m g\u00f6steren ve uzay\u0131n kendisiyle ili\u015fkili bir t\u00fcr enerjidir. Buna \u201cvakum enerjisi\u201d denir.<\/p>\n

2.Karanl\u0131k enerji, vakum enerjisinden biraz farkl\u0131 olarak zamana ve konuma g\u00f6re de\u011fi\u015fen bir t\u00fcr enerji olabilir. Buna \u201cbe\u015finci element\u201d denir.<\/p>\n

3.Asl\u0131nda karanl\u0131k enerji diye bir \u015fey yoktur; k\u00fctle\u00e7ekim kuvvetinin kendi eksikli\u011finden kaynaklanan ama g\u00f6remedi\u011fimiz bir durumla kar\u015f\u0131 kar\u015f\u0131ya olabiliriz.<\/p>\n

Bu d\u00fc\u015f\u00fcnceler aras\u0131nda bilim insanlar\u0131 taraf\u0131ndan en tutulan\u0131 \u015fimdilik \u201cvakum enerjisi kuram\u0131\u201dd\u0131r. Bo\u015flukta hi\u00e7bir \u015fey bulunmad\u0131\u011f\u0131n\u0131 -zaten bunun i\u00e7in bo\u015fluk dendi\u011fini- biliriz. Ancak g\u00fcn\u00fcm\u00fcz fizi\u011fi \u201cbo\u015fluk\u201d olgusuna biraz farkl\u0131 bak\u0131yor. Buna g\u00f6re bizim \u201cbo\u015f\u201d dedi\u011fimiz uzayda birtak\u0131m atomalt\u0131 par\u00e7ac\u0131klar ve kar\u015f\u0131 par\u00e7ac\u0131klar s\u00fcrekli olu\u015fup yok olur. Bunlar yeni bir dizi par\u00e7ac\u0131k de\u011fildir; tersine hepsi de bildi\u011fimiz par\u00e7ac\u0131klard\u0131r: fotonlar, elektronlar, pozitronlar vs. Bu s\u00fcre\u00e7 \u00e7ok \u00e7ok zay\u0131f da olsa bir bas\u0131n\u00e7 yarat\u0131r. \u00c7ok \u00e7ok zay\u0131f olmas\u0131na kar\u015f\u0131n Evren\u2019in engin b\u00fcy\u00fckl\u00fc\u011f\u00fcne da\u011f\u0131lm\u0131\u015f oldu\u011fundan \u00e7ok etkili bir kuvvet olarak kar\u015f\u0131m\u0131za \u00e7\u0131kar.<\/p>\n

Peki, acaba t\u0131pk\u0131 karanl\u0131k madde gibi karanl\u0131k enerjinin de Evren\u2019imizin \u015fekillenmesinde bir rol\u00fc olmu\u015f mudur? Son yap\u0131lan g\u00f6zlemlere g\u00f6re ilk dokuz milyar y\u0131l boyunca Evren\u2019in geni\u015fleme h\u0131z\u0131n\u0131n giderek yava\u015flad\u0131\u011f\u0131 ama g\u00fcn\u00fcm\u00fczden yakla\u015f\u0131k be\u015f milyar y\u0131l kadar \u00f6nce yeniden artmaya ba\u015flad\u0131\u011f\u0131 ortaya \u00e7\u0131km\u0131\u015ft\u0131r. \u0130lk dokuz milyar y\u0131l boyunca Evren\u2019in geni\u015fleme h\u0131z\u0131n\u0131n yava\u015fl\u0131yor olu\u015fu g\u00f6kadalar\u0131n birbirlerine daha yak\u0131n oldu\u011fu d\u00f6nemlerde k\u00fctle\u00e7ekim kuvvetinin daha g\u00fc\u00e7l\u00fc hissedilmesinden kaynaklan\u0131r. Ayn\u0131 zamanda Evren k\u00fc\u00e7\u00fckken g\u00f6kadalar aras\u0131 bo\u015fluk yani karanl\u0131k enerjinin kayna\u011f\u0131 da k\u00fc\u00e7\u00fckt\u00fc. Bir ba\u015fka deyi\u015fle hem vakum enerjisinin kayna\u011f\u0131 k\u00fc\u00e7\u00fckt\u00fc hem de onun tersi y\u00f6nde i\u015fleyen k\u00fctle\u00e7ekim kuvveti daha etkiliydi. Ancak Evren geni\u015fledik\u00e7e bu denge de\u011fi\u015fmeye ba\u015flad\u0131: K\u00fctle\u00e7ekim kuvvetinin etkisi azal\u0131rken vakum enerjisi giderek g\u00fc\u00e7lendi. Yakla\u015f\u0131k be\u015f milyar y\u0131l \u00f6nceki bir \u201ce\u015fik an\u0131\u201dndan sonra Evren\u2019in geni\u015fleme h\u0131z\u0131 artmaya ba\u015flad\u0131. Bundan b\u00f6yle Evren\u2019imize as\u0131l \u015fekil veren g\u00fc\u00e7 karanl\u0131k enerji oldu. \u015eu anki resme g\u00f6re Evren\u2019imiz -e\u011fer bilinmeyen bir nedenle g\u00fcn\u00fcn birinde ters bir etki ortaya \u00e7\u0131kmazsa- geni\u015flemesini artan bir h\u0131zla sonsuza dek s\u00fcrd\u00fcrecek.<\/p>\n

Kaynak: <\/strong>\u00c7a\u011flar Sunay, 50 Soruda Evren, Bilim ve Gelecek Kitapl\u0131\u011f\u0131, Ekim 2011, s.239-242<\/p>\n","protected":false},"excerpt":{"rendered":"

Hubble\u2019\u0131n Evren\u2019in geni\u015fliyor oldu\u011funu ke\u015ffetmesinden bu yana b\u00fct\u00fcn g\u00f6kbilimciler Evren\u2019in geni\u015fleme h\u0131z\u0131n\u0131n -i\u00e7erdi\u011fi maddenin k\u00fctle\u00e7ekim etkisi nedeniyle- yava\u015flamas\u0131 gerekti\u011fini d\u00fc\u015f\u00fcnme e\u011filiminde olmu\u015ftur. Bu nedenle 1998 ve 199 y\u0131llar\u0131nda birbirinden ba\u011f\u0131ms\u0131z \u00e7al\u0131\u015fan iki ekip (Saul Perlmutter ve Brian Schimidt\u2019in liderli\u011findeki) Evren\u2019in geni\u015fleme h\u0131z\u0131n\u0131n artt\u0131\u011f\u0131n\u0131 ke\u015ffetti\u011finde g\u00f6kbilim d\u00fcnyas\u0131nda b\u00fcy\u00fck bir \u015fa\u015fk\u0131nl\u0131k ya\u015fanm\u0131\u015ft\u0131. Uzak g\u00f6kadalardaki s\u00fcpernovalar \u00fczerinden yap\u0131lan […]<\/p>\n","protected":false},"author":429,"featured_media":35442,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[3624],"tags":[1676,657,1675,1084,4635],"class_list":["post-35441","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-sorularla-bilim","tag-elektron","tag-evren","tag-foton","tag-karanlik-madde","tag-pozitron"],"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