\nZaman kavram\u0131n\u0131n tam olarak anla\u015f\u0131lmas\u0131, \u00f6zellikle fizik biliminde pozitif ba\u011flamda \u00e7ok b\u00fcy\u00fck bir s\u0131\u00e7ray\u0131\u015fa vesile olmu\u015ftur. Simetrik bir devinim olan g\u00fcne\u015fin do\u011fmas\u0131 ve batmas\u0131 (G\u00fcnd\u00fcz-gece) olay\u0131 insano\u011flunun ezelden beri a\u015fina oldu\u011fu bir kavram oldu\u011fundan pratik hayat\u0131nda kulland\u0131\u011f\u0131 bir\u00e7ok olguyu bu kavram do\u011frultusunda s\u0131raya yerle\u015ftiriyordu.
\nMesela sabah koyunlar otlaklara \u00e7\u0131kart\u0131l\u0131r ak\u015fam yat\u0131l\u0131r gibi. G\u00fcnd\u00fcz-gece kavram\u0131 zaman kavram\u0131n\u0131n ilk tohumudur diyebiliriz. Daha sonralar\u0131 insano\u011flu \u00e7ok \u00f6zel durumlarla kar\u015f\u0131la\u015fm\u0131\u015f ve o an ya\u015fad\u0131klar\u0131 zaman\u0131 veya daha \u00f6nce yapt\u0131klar\u0131n\u0131 ya da daha sonra yapacaklar\u0131n\u0131 zaman kavram\u0131 alt\u0131nda tan\u0131mlama gere\u011fi duymu\u015ftur. B\u00f6yle bir kavram olu\u015fturmak i\u00e7inde herkse g\u00f6re sabit bir niceli\u011fi zaman \u00f6l\u00e7\u00fcs\u00fc olarak tan\u0131mlamak gerekti\u011fini fark etmi\u015ftir. Bu do\u011frultuda 1960 y\u0131l\u0131ndan \u00f6nce, zaman standard\u0131 \u201cortalama g\u00fcne\u015f g\u00fcn\u00fc\u201d cinsinden hesaplanm\u0131\u015ft\u0131r. Ortalama g\u00fcne\u015f saniyesi bir g\u00fcne\u015f g\u00fcn\u00fcn\u00fcn (1\u204460)(1\/60)(1\/24)\u2019\u00fc olarak al\u0131nm\u0131\u015ft\u0131.[1] Ama bu kavram geli\u015fen teknoloji kar\u015f\u0131s\u0131nda yetersiz kalm\u0131\u015f, hassasiyetini geli\u015fen teknoloji kar\u015f\u0131s\u0131nda g\u00fcnden g\u00fcne kaybetmi\u015ftir bunun \u00fczerine bilim adamlar\u0131 1967 y\u0131l\u0131nda zaman kavram\u0131 i\u00e7in yeni bir sabit geli\u015ftirmi\u015flerdir: Atomik saat. Bu olguya g\u00f6re sezyum atomunun 9 192 631 770 defa titre\u015fim yapt\u0131\u011f\u0131 s\u00fcreye 1 saniye denilmi\u015ftir. \u00c7ok kesin ve net gibi g\u00f6z\u00fcken bu tan\u0131m \u015fimdiki zamanlarda geli\u015fen nano \u2013teknolojinin ihtiya\u00e7lar\u0131n\u0131 kar\u015f\u0131lamakta zorlanmaktad\u0131r.<\/p>\n
Modern fizikte zaman kavram\u0131n\u0131n \u00f6nemi Einstein ile beraber ortaya \u00e7\u0131km\u0131\u015ft\u0131r. Einstein\u2019dan \u00f6nceleri ge\u00e7erli olan Newton fizi\u011fi uzay-zaman\u0131 ayr\u0131 ele alarak, zaman\u0131; evrenin her noktas\u0131 i\u00e7in mutlak kabul etmekte ve zaman\u0131n b\u00fct\u00fcn referans sistemlerinden ba\u011f\u0131ms\u0131z oldu\u011funu s\u00f6ylemekteydi. Einstein bu kavram\u0131n yanl\u0131\u015f olabilece\u011fini daha o g\u00fcnlerde kestiriyordu. I\u015f\u0131k h\u0131z\u0131 ve zaman aras\u0131nda bir kopma noktas\u0131 olabilece\u011fini d\u00fc\u015f\u00fcnen Einstein bu d\u00fc\u015f\u00fcncesini baz\u0131 \u00f6rneklerle desteklemeye \u00e7al\u0131\u015ft\u0131. Mesela bir saat kulesinin yak\u0131nlar\u0131nda oldu\u011funu tasavvur eden Einstein, saat kulesinin tam 12 yi g\u00f6sterdi\u011fini varsaym\u0131\u015ft\u0131r. O saat kulesinin Einstein\u2019a saatin tam 12\u2019i oldu\u011funu g\u00f6stermesi, \u0131\u015f\u0131k \u0131\u015f\u0131nlar\u0131n\u0131n \u00f6nce saat kulesine ve oradan da Einstein\u2019\u0131n g\u00f6zlerine yans\u0131mas\u0131 demektir. Ama burada bir gariplik vard\u0131r; \u0131\u015f\u0131k \u0131\u015f\u0131nlar\u0131 tam saat kulesindeyken de Einstein\u2019\u0131n g\u00f6zlerine gelirken ald\u0131\u011f\u0131 yol boyunca da dahil olmak \u00fczere b\u00fct\u00fcn bir zaman aral\u0131\u011f\u0131nda hep ayn\u0131 bilgiyi ta\u015f\u0131d\u0131\u011f\u0131n\u0131(saatin 12 oldu\u011fu bilgisi) g\u00f6rm\u00fc\u015ft\u00fcr ve \u0131\u015f\u0131k \u0131\u015f\u0131nlar\u0131 i\u00e7in zaman\u0131n durdu\u011fu sonucuna ula\u015fm\u0131\u015ft\u0131r. Einstein \u201ce\u011fer o \u0131\u015f\u0131k \u0131\u015f\u0131n\u0131n\u0131n \u00fczerinde yolculuk yapsayd\u0131m d\u00fcnyay\u0131 nas\u0131l g\u00f6r\u00fcrd\u00fcm\u201d diye d\u00fc\u015f\u00fcn\u00fcr ve bu d\u00fc\u015f\u00fcncesinde y\u0131llar sonra bulaca\u011f\u0131 \u00f6zel g\u00f6relilik teorisinin altyap\u0131s\u0131 bulundu\u011fu a\u00e7\u0131k\u00e7a g\u00f6r\u00fclmektedir.<\/p>\n
Einstein \u00f6zel g\u00f6relilik teorisinde k\u0131saca; evrende hi\u00e7bir ivmeli hareket eden nesnenin \u0131\u015f\u0131k h\u0131z\u0131na ula\u015famayaca\u011f\u0131n\u0131 s\u00f6yler. Einstein bu durumu \u015f\u00f6yle \u00f6zetlemektedir; \u201cG\u00f6relilik kuram\u0131na uygun olarak m k\u00fctleli bir maddeci\u011fin kinetik enerjisi m.v\u00b2\/2 ifadesiyle de\u011fil, mc\u00b2\/\u221a1-v\u00b2\/c\u00b2 ifadesi verecektir. V h\u0131z\u0131, c \u0131\u015f\u0131k h\u0131z\u0131na yakla\u015ft\u0131k\u00e7a, bu ifade de sonsuza yakla\u015fmaktad\u0131r. Bu y\u00fczden, ivmeyi yaratmak i\u00e7in kullan\u0131lan enerji ne kadar b\u00fcy\u00fck olursa olsun, h\u0131z her zaman c\u2019den k\u00fc\u00e7\u00fck kalmal\u0131d\u0131r.\u201dYani yeterli g\u00fc\u00e7te bir roket yapt\u0131\u011f\u0131m\u0131z\u0131 d\u00fc\u015f\u00fcnelim. I\u015f\u0131k h\u0131z\u0131na \u00e7ok yak\u0131n h\u0131zlara ula\u015fmam\u0131za ra\u011fmen h\u0131z\u0131 artt\u0131rmakta \u0131srar etti\u011fimiz taktir de verdi\u011fimiz enerji s\u00fcrekli olarak k\u00fctleye d\u00f6n\u00fc\u015fecektir. Ba\u015fka bir deyi\u015fle k\u00fctlesi olan hi\u00e7bir \u015fey \u0131\u015f\u0131k h\u0131z\u0131na ula\u015famaz. Zaten \u0131\u015f\u0131\u011f\u0131 olu\u015fturan taneciklere(fotonlara) bakt\u0131\u011f\u0131m\u0131zda k\u00fctlesiz olduklar\u0131n\u0131 g\u00f6zlemleriz. Ayr\u0131ca fotonlar \u0131\u015f\u0131k h\u0131z\u0131nda hareket etmeleri zamanlar\u0131n\u0131n olmamas\u0131 anlam\u0131na gelir yani s\u0131f\u0131r zamanda hareket ederler. G\u00f6relilik teorisiyle birlikte zaman\u0131n g\u00f6receli bir kavram oldu\u011fu ortaya \u00e7\u0131km\u0131\u015f ve yepyeni bir bilimin(modern fizik) kap\u0131s\u0131 aralanm\u0131\u015f oldu. Einstein\u2019\u0131n 1905 y\u0131l\u0131nda ileri s\u00fcrd\u00fc\u011f\u00fc \u00f6zel g\u00f6relili\u011fin iki post\u00fclas\u0131n\u0131n(1)Birbirlerine g\u00f6re d\u00fczg\u00fcn do\u011fru hareket yapan t\u00fcm g\u00f6zlemciler i\u00e7in \u0131\u015f\u0131k h\u0131z\u0131 ayn\u0131d\u0131r. 2) Birbirlerine do\u011fru hareket halindeki t\u00fcm g\u00f6zlemciler i\u00e7in fizik kanunlar\u0131 ayn\u0131d\u0131r.) yan\u0131 s\u0131ra evrendeki bilinen 3 boyut haricinde birde zaman boyutunun oldu\u011funu ortaya koymas\u0131 fizik dal\u0131ndaki en b\u00fcy\u00fck devrim olarak nitelendirilmektedir.<\/p>\n
\u015eimdi zaman\u0131n g\u00f6receli\u011fi kavram\u0131n\u0131 en iyi \u015fekilde \u00f6zetleyen ve \u00e7ok pop\u00fcler bir \u00f6rnek olmas\u0131na ra\u011fmen hala kavram hatalar\u0131n\u0131n yap\u0131ld\u0131\u011f\u0131 ikizler paradoksuna Richard GOTT\u2019un \u00f6zg\u00fcn anlat\u0131m\u0131yla bakal\u0131m: \u201c\u0130kiz k\u0131z karde\u015fler, D\u00fcnya ve Evren(orijinali Earth ve Astra\u2019d\u0131r.) bu paradoksun klasik \u00f6rne\u011fidir. Tahmin etti\u011finiz gibi D\u00fcnya D\u00fcnya\u2019da kal\u0131r, Evren ise bir roketle \u0131\u015f\u0131k h\u0131z\u0131n\u0131n %80 h\u0131z\u0131yla Alpha Centauri y\u0131ld\u0131z\u0131na gider. Alpha Centauri D\u00fcnya\u2019dan 4 \u0131\u015f\u0131k y\u0131l\u0131 uzakl\u0131kta oldu\u011funa g\u00f6re, Evren\u2019in oraya var\u0131\u015f\u0131 5 \u0131\u015f\u0131k y\u0131l\u0131 s\u00fcrer. Evren\u2019in saati D\u00fcnya\u2019n\u0131n saatine g\u00f6re %40 daha yava\u015f ilerler, Bu nedenle Evren bu yolculukta sadece 3 y\u0131l ya\u015flan\u0131rken; D\u00fcnya, Evren\u2019in y\u0131ld\u0131za var\u0131\u015f\u0131n\u0131 5 y\u0131l olarak \u00f6l\u00e7er. Evren, Alpha Centauri\u2019ye ula\u015ft\u0131\u011f\u0131 anda y\u00f6n de\u011fi\u015ftirir ve yine \u0131\u015f\u0131k h\u0131z\u0131n\u0131n %80\u2019i bir h\u0131zla geri d\u00f6ner. D\u00f6n\u00fc\u015f yolculu\u011fu yine ayn\u0131 \u015fekilde D\u00fcnya taraf\u0131ndan 5 y\u0131l, Evren taraf\u0131ndan da 3 y\u0131l olarak \u00f6l\u00e7\u00fcl\u00fcr. Sonu\u00e7 olarak Evren D\u00fcnya\u2019ya vard\u0131\u011f\u0131nda; kendisinin toplam 6 y\u0131l, D\u00fcnyan\u0131n ise toplam 10 y\u0131l ya\u015fland\u0131\u011f\u0131n\u0131 g\u00f6r\u00fcr. Yani Evren d\u00fcnya zaman\u0131na g\u00f6re 4 y\u0131l ileri gitmi\u015ftir. \u0130\u015fte paradoks tam bu noktada ortaya \u00e7\u0131kar. Evren \u0131\u015f\u0131k h\u0131z\u0131n\u0131n %80\u2019i h\u0131zla Alpha Centauri\u2019ye do\u011fru giderken, roketin cam\u0131ndan bak\u0131p, asl\u0131nda D\u00fcnya\u2019n\u0131n \u0131\u015f\u0131k h\u0131z\u0131n\u0131n %80 h\u0131z\u0131yla gitti\u011fini ve kendisinin sabit durdu\u011funu ileri s\u00fcrebilir. Bu d\u00fc\u015f\u00fcncedeki yanl\u0131\u015f \u015fudur; \u0130kiz karde\u015fler ayn\u0131 deneyimleri ya\u015famad\u0131lar. D\u00fcnya\u2019da bulunan D\u00fcnya, y\u00f6n de\u011fi\u015ftirmeksizin sabit bir h\u0131zla hareket eden bir g\u00f6zlemci(D\u00fcnya\u2019n\u0131n G\u00fcne\u015f etraf\u0131ndaki h\u0131z\u0131 ihmal ediliyor) oldu\u011fundan Einstein\u2019\u0131n ilk post\u00fclas\u0131n\u0131 sa\u011flar(post\u00fclay\u0131 hat\u0131rlayal\u0131m: Birbirine g\u00f6re d\u00fczg\u00fcn do\u011fru hareket yapan t\u00fcm g\u00f6zlemciler i\u00e7in \u0131\u015f\u0131k h\u0131z\u0131 ayn\u0131d\u0131r). Buna kar\u015f\u0131n Evren, y\u00f6n de\u011fi\u015ftirmeksizin sabit h\u0131zla hareket eden bir g\u00f6zlemci de\u011fildir. Evren, Alpha Centauri\u2019ye vard\u0131\u011f\u0131nda y\u00f6n de\u011fi\u015fitirir. \u0130\u015fte \u00fczerinde durulmas\u0131 gereken en kritik nokta \u201cy\u00f6n de\u011fi\u015ftirme\u201d olgusudur. \u015eimdi Evren\u2019in bu yolculuk s\u0131ras\u0131nda neler d\u00fc\u015f\u00fcnd\u00fc\u011f\u00fcne bakal\u0131m: Evren, Alpha Centauri\u2019ye do\u011fru giderken camdan bakar ve D\u00fcnya\u2019n\u0131n \u0131\u015f\u0131k h\u0131z\u0131n\u0131n %80 i h\u0131zla hareket etti\u011fini g\u00f6r\u00fcr. Alpha Centauriye vard\u0131\u011f\u0131nda saatine bakar ve 3 y\u0131l ge\u00e7ti\u011fini g\u00f6r\u00fcr, bunun \u00fczerine \u0131\u015f\u0131k h\u0131z\u0131n\u0131n %80\u2019i h\u0131zla hareket eden D\u00fcnya\u2019daki D\u00fcnya\u2019n\u0131n ka\u00e7 y\u0131l ya\u015fland\u0131\u011f\u0131n\u0131 bulmak i\u00e7in i\u015flem yapar ve \u00e7\u0131kard\u0131\u011f\u0131 sonu\u00e7 1,8 y\u0131l olur. Yani kendisi 3 y\u0131l, D\u00fcnya ise 1,8 y\u0131l ya\u015flanm\u0131\u015ft\u0131r Evrene g\u00f6re. Alpha Centauriye vard\u0131\u011f\u0131nda Evren konumunu D\u00fcnyaya do\u011fru \u00e7evirir. \u0130\u015fte tam bu y\u00f6n de\u011fi\u015ftirme hareketini yapt\u0131\u011f\u0131 anda uzay-zaman\u0131 farkl\u0131 bir e\u011fimle diler ve asl\u0131nda hareket edenin kendisi oldu\u011funu alg\u0131lar. D\u00f6n\u00fc\u015f yolu boyunca yine \u0131\u015f\u0131k h\u0131z\u0131n\u0131n %80\u2019i h\u0131zla hareket eden ve D\u00fcnya\u2019ya varan Evren, yapt\u0131\u011f\u0131 hesaplar sonucunda d\u00f6n\u00fc\u015f yolu boyunca D\u00fcnya\u2019n\u0131n 8,2 y\u0131l dolay\u0131s\u0131yla 8,2(d\u00f6n\u00fc\u015f) +1,8(gidi\u015f) olmak \u00fczere toplamda 10 y\u0131l ya\u015fland\u0131\u011f\u0131n\u0131 kendisinin ise 3+3 y\u0131l olmak \u00fczere 6 y\u0131l ya\u015fland\u0131\u011f\u0131 sonucuna var\u0131r. G\u00f6r\u00fcld\u00fc\u011f\u00fc gibi ortada paradoks yoktur. Evren\u2019in D\u00fcnya\u2019daki olaylar\u0131n e\u015f zamanl\u0131 oldu\u011funa dair olan fikri \u201cd\u00f6n\u00fc\u015f hareketi\u201d sonras\u0131nda tamamen de\u011fi\u015fir ve asl\u0131nda hareket edenin kendisi oldu\u011funu alg\u0131lar. Yani b\u00f6ylece her iki karde\u015finde ya\u015flar\u0131 hakk\u0131ndaki hesaplar\u0131n\u0131n do\u011fru oldu\u011fu ortaya \u00e7\u0131kar.\u201d Burada da \u00e7ok net bir bi\u00e7imde g\u00f6r\u00fcld\u00fc\u011f\u00fc \u00fczere zaman g\u00f6receli bir kavramd\u0131r. Ama bu g\u00f6relilik fizik yasalar\u0131n\u0131 kesinlikle etkilememektedir. Fizik yasalar\u0131 sahip olduklar\u0131 simetri sayesinde(o da belki bir ba\u015fka yaz\u0131n\u0131n konusu olabilir) her ko\u015fulda kesinli\u011fini muhafaza etmektedir.<\/p>\n
\u015eu unutulmamal\u0131d\u0131r ki, e\u011fer h\u0131z, zaman gibi kavramlardan bahsediyorsak anlam karga\u015fas\u0131n\u0131 \u00f6nlemek i\u00e7in mutlaka bir referans noktas\u0131 belirtmeliyiz. Kim bilir beklide zaman kavram\u0131n\u0131 daha ayr\u0131nt\u0131l\u0131 bir \u015fekilde anlayabilirsek bir\u00e7ok bilim adam\u0131n\u0131n ve bilim-kurgu yap\u0131mc\u0131s\u0131n\u0131n fantezisi olan gelece\u011fe ve ge\u00e7mi\u015fe yolculuk rutin yap\u0131lan i\u015flerden birisi olacakt\u0131r.<\/p>\n","protected":false},"excerpt":{"rendered":"
Zaman kavram\u0131n\u0131n tam olarak anla\u015f\u0131lmas\u0131, \u00f6zellikle fizik biliminde pozitif ba\u011flamda \u00e7ok b\u00fcy\u00fck bir s\u0131\u00e7ray\u0131\u015fa vesile olmu\u015ftur. Simetrik bir devinim olan g\u00fcne\u015fin do\u011fmas\u0131 ve batmas\u0131 (G\u00fcnd\u00fcz-gece) olay\u0131 insano\u011flunun ezelden beri a\u015fina oldu\u011fu bir kavram oldu\u011fundan pratik hayat\u0131nda kulland\u0131\u011f\u0131 bir\u00e7ok olguyu bu kavram do\u011frultusunda s\u0131raya yerle\u015ftiriyordu. Mesela sabah koyunlar otlaklara \u00e7\u0131kart\u0131l\u0131r ak\u015fam yat\u0131l\u0131r gibi. G\u00fcnd\u00fcz-gece kavram\u0131 zaman …<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1407,1403],"tags":[2722,6722,6854,6853],"class_list":["post-2794","post","type-post","status-publish","format-standard","hentry","category-fen-ve-teknoloji-odevleri","category-odevler","tag-einstein","tag-modern-fizik","tag-newton-fizigi","tag-zaman-kavrami-ve-ikizler-paradoksu"],"_links":{"self":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts\/2794","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=2794"}],"version-history":[{"count":0,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/posts\/2794\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/media?parent=2794"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/categories?post=2794"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.islamidavet.com\/kutuphane\/wp-json\/wp\/v2\/tags?post=2794"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}