{"id":18287,"date":"2017-12-01T11:31:14","date_gmt":"2017-12-01T08:31:14","guid":{"rendered":"http:\/\/109.232.216.219\/~bilimvegelecek\/?p=18287"},"modified":"2018-02-08T16:04:19","modified_gmt":"2018-02-08T13:04:19","slug":"ligo-yeni-bir-fizigin-baslangiclari","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2017\/12\/01\/ligo-yeni-bir-fizigin-baslangiclari","title":{"rendered":"LIGO: Yeni bir fizi\u011fin ba\u015flang\u0131\u00e7lar\u0131"},"content":{"rendered":"

Bug\u00fcn k\u00fctle\u00e7ekimsel dalgalar\u0131 ke\u015ffetmemizi sa\u011flayan Lazer Giri\u015fim\u00f6l\u00e7eri K\u00fctle\u00e7ekimsel Dalga G\u00f6zlemevi\u2019nin, yani LIGO\u2019nun arka plan\u0131nda say\u0131s\u0131z biliminsan\u0131n\u0131n \u00e7abalar\u0131 ve bir\u00e7ok tart\u0131\u015fma var. S\u00f6z konusu s\u00fcre\u00e7 20. y\u00fczy\u0131lda \u00e7ok yava\u015f yol alm\u0131\u015fken 2015 sonras\u0131 d\u00f6nemde ger\u00e7ekten ba\u015flad\u0131 denilebilir. Bu yeni bilim asl\u0131nda son on y\u0131lda ortaya \u00e7\u0131kt\u0131 ve bu y\u00fczy\u0131l\u0131 \u015fekillendirece\u011fi a\u00e7\u0131k. <\/em><\/p>\n

Ge\u00e7ti\u011fimiz say\u0131da LIGO ara\u015ft\u0131rmalar\u0131na ve k\u00fctle\u00e7ekimsel dalgalara Nobel Fizik \u00d6d\u00fcl\u00fc verilmesinden yola \u00e7\u0131karak LIGO giri\u015fim\u00f6l\u00e7erlerinin temel yap\u0131ta\u015f\u0131 olan Michelson giri\u015fim\u00f6l\u00e7erleri hakk\u0131nda bir yaz\u0131 haz\u0131rlam\u0131\u015ft\u0131k. Michelson ve deneyleri modern fizi\u011fin ba\u015flang\u0131c\u0131n\u0131 olu\u015fturmu\u015ftu. Michelson, ama\u00e7lad\u0131\u011f\u0131 sonu\u00e7lara ula\u015famam\u0131\u015f olsa da, bilim d\u00fcnyas\u0131na olduk\u00e7a farkl\u0131 alanlarda kullan\u0131lacak bir cihaz hediye etmi\u015fti. Bir bak\u0131ma k\u00fctle\u00e7ekimsel dalgalar\u0131 da Michelson bulmu\u015ftu. Gelin \u015fimdi k\u00fctle\u00e7ekimsel dalgalar\u0131 ke\u015ffetmemizi sa\u011flayan, Lazer Giri\u015fim\u00f6l\u00e7eri K\u00fctle\u00e7ekimsel Dalga G\u00f6zlemevi\u2019ni (Laser Interferometer Gravitational Wave Observatory), yani LIGO\u2019yu tan\u0131yal\u0131m; d\u00fcnyan\u0131n en b\u00fcy\u00fck Michelson giri\u015fim\u00f6l\u00e7erinin deneyine ve in\u015fa s\u00fcrecine g\u00f6z atal\u0131m.<\/p>\n

Einstein\u2019\u0131n g\u00f6r\u00fc\u015f\u00fc<\/strong><\/p>\n

Asl\u0131nda Michelson hayattayken Einstein\u2019dan \u00f6nce de dalgalar konusunda analojiler yapan biliminsanlar\u0131 olmu\u015ftu. Frans\u0131z fizik\u00e7i Henri Poincar\u00e9, elektrik y\u00fckl\u00fc cisimlerin hareket etti\u011finde elektromanyetik dalga yaymalar\u0131ndan yola \u00e7\u0131karak k\u00fctlesi olan cisimlerin de hareket ettik\u00e7e dalga yay\u0131p yayamayaca\u011f\u0131n\u0131 tart\u0131\u015fm\u0131\u015f, fakat sav\u0131n\u0131n arkas\u0131n\u0131 getirmemi\u015fti. Einstein k\u00fctlenin uzay\u0131 b\u00fckt\u00fc\u011f\u00fcn\u00fc a\u00e7\u0131klad\u0131\u011f\u0131 genel g\u00f6relili\u011fi 1915 y\u0131l\u0131nda ortaya att\u0131\u011f\u0131nda ise bu t\u00fcr bir dalgan\u0131n varl\u0131\u011f\u0131 konusunda \u015f\u00fcpheliydi, \u00e7\u00fcnk\u00fc y\u00fckl\u00fc bir cismin dalga \u00fcretmesini sa\u011flayan \u015fey y\u00fck\u00fcn art\u0131 ve eksi olarak iki kutbunun olmas\u0131yd\u0131. K\u00fctlenin ise bir kutbu yoktu. Fakat evrenin kendisi dalgalanabilirse, k\u00fctle\u00e7ekimsel dalga yarat\u0131yor olabilirdi. B\u00f6yle bir olas\u0131l\u0131\u011f\u0131n gerektirece\u011fi matematiksel arka plan\u0131 haz\u0131rlayan Alman kuramsal fizik\u00e7i Hermann Weyl ile Einstein k\u00fctle\u00e7ekimsel dalga fikrini ortaya att\u0131lar ve hatta enine-enine, enine-boyuna ve boyuna-boyuna olmak \u00fczere \u00fc\u00e7 farkl\u0131 s\u0131n\u0131fa ay\u0131rd\u0131lar.<\/p>\n

Fakat bu g\u00f6r\u00fc\u015f\u00fcn s\u0131k\u0131nt\u0131lar\u0131 ve tutars\u0131zl\u0131klar\u0131 vard\u0131. Tutars\u0131zl\u0131klar\u0131 Einstein\u2019\u0131n kulland\u0131\u011f\u0131 hesaplama hatalar\u0131na ba\u011flayan \u0130ngiliz astrofizik\u00e7i Arthur Eddington, evren k\u00fcresel koordinat sistemi baz al\u0131narak incelendi\u011finde \u00fc\u00e7 tip de\u011fil, yaln\u0131zca tek tip k\u00fctle\u00e7ekimsel dalgan\u0131n olaca\u011f\u0131, bu \u00fc\u00e7\u00fcn\u00fcn asl\u0131nda o tek dalga t\u00fcr\u00fcn\u00fc olu\u015fturdu\u011funu bir makale ile yay\u0131mlad\u0131. Bunun \u00fczerine 1936 y\u0131l\u0131nda Einstein, ABD\u2019li fizik\u00e7i Arthur Rosen ile k\u00fctle\u00e7ekimsel dalgalar\u0131n hi\u00e7 var olmad\u0131\u011f\u0131n\u0131, e\u011fer varsa da g\u00f6zlenmesinin imk\u00e2ns\u0131z oldu\u011funu, bunun nedeninin de dalgalanan bir evrende yap\u0131lan hesaplamalar\u0131n tekilliklere (\u00e7ok y\u00fcksek miktardaki k\u00fctleler nokta kadar ufak b\u00f6lgelerde topla\u015f\u0131yor, yani anlams\u0131z bir sonu\u00e7) yol a\u00e7mas\u0131 oldu\u011funu iddia eden bir makale kaleme ald\u0131lar. Fakat makalelerdeki hesaplamalarda ortaya \u00e7\u0131kan tekillikler, hesaplama ba\u015fka bir koordinat sisteminde yap\u0131ld\u0131\u011f\u0131nda kolayca a\u015f\u0131labilecek sorunlard\u0131. Yani yap\u0131lan hesaplama yanl\u0131\u015ft\u0131. Einstein\u2019\u0131n makale tasla\u011f\u0131n\u0131 Physical Review<\/em> dergisi ad\u0131na inceleyen kozmolog Howard Robertson, edit\u00f6r s\u0131fat\u0131yla Einstein\u2019a olumsuz geri d\u00f6n\u00fc\u015f yap\u0131nca, bu t\u00fcr akademik dergilerde i\u015flerin nas\u0131l y\u00fcr\u00fcd\u00fc\u011f\u00fcn\u00fc bilmeyen Einstein deliye d\u00f6nm\u00fc\u015ft\u00fc. Nas\u0131l makalesini ba\u015fkalar\u0131na okutmu\u015flard\u0131? Nas\u0131l olur da Albert Einstein\u2019\u0131n makalesini geri \u00e7evirmi\u015flerdi? O anki k\u0131zg\u0131nl\u0131kla Einstein, derginin yapt\u0131\u011f\u0131 geri d\u00f6n\u00fc\u015fleri bile okumay\u0131p hemen makaleyi k\u0131zg\u0131n bir mektupla birlikte oldu\u011fu gibi dergiye tekrar g\u00f6nderdi. Fakat Einstein\u2019\u0131n o d\u00f6nemki asistan\u0131 Leopold Infeld, Einstein\u2019\u0131 ikna etmeyi ba\u015fard\u0131 ve makale, bu kez ba\u015fka bir dergide, yap\u0131lan geri d\u00f6n\u00fc\u015fler de\u011ferlendirilerek, hesaplamalar tekrarland\u0131ktan sonra yay\u0131mland\u0131. Ancak Einstein, k\u00fctle\u00e7ekimsel dalgalar\u0131n ke\u015ffedilemeyece\u011fini, \u00f6l\u00e7menin insan teknolojisiyle imk\u00e2ns\u0131z oldu\u011funu d\u00fc\u015f\u00fcnerek ya\u015fama veda etmi\u015ftir.<\/p>\n

Feynman\u2019\u0131n d\u00fc\u015f\u00fcnce deneyi<\/strong><\/p>\n

Einstein\u2019\u0131n \u00f6l\u00fcm\u00fcn\u00fcn ard\u0131ndan baz\u0131 kuramsal fizik\u00e7iler ve kozmologlar, k\u00fctle\u00e7ekimsel dalgalar\u0131n varl\u0131\u011f\u0131 ve \u00f6zellikleri hakk\u0131nda \u00e7al\u0131\u015fmalar yapm\u0131\u015flard\u0131r. Hatta 1957 y\u0131l\u0131nda ABD Chapel Hill Kuzey Karolina \u00dcniversitesi\u2019nde d\u00fcnyan\u0131n ilk K\u00fctle\u00e7ekimsel Dalga Kongresi organize edildi. Fakat bu kongre t\u00fcm\u00fcyle teorikti ve teorik fizik\u00e7ilerin fikir payla\u015f\u0131mlar\u0131n\u0131 sa\u011flamak ad\u0131na olu\u015fturulmu\u015ftu. Bu kongrede konuya farkl\u0131 bak\u0131\u015f a\u00e7\u0131s\u0131yla bakmay\u0131 ba\u015farabilen \u00fcnl\u00fc fizik\u00e7i Richard Feynman, k\u00fctle\u00e7ekimsel dalgalar\u0131 yakalayabilmek i\u00e7in bir deney d\u00fczene\u011fi \u00f6nerdi. \u201cYap\u0131\u015fkan Boncuk\u201d ad\u0131 verilen d\u00fc\u015f\u00fcnce deneyine g\u00f6re uzun bir ipli\u011fe aras\u0131nda belirli uzakl\u0131k bulunan iki boncuk tak\u0131lacakt\u0131. Bu boncuklar\u0131n aras\u0131ndaki uzakl\u0131k, bir k\u00fctle\u00e7ekimsel dalga gelirse de\u011fi\u015fecek, yani ip hareket edecek, s\u00fcrt\u00fcnme meydana gelecekti. Bu s\u00fcrt\u00fcnme ortam\u0131n milimetrik oranlarda \u0131s\u0131nmas\u0131n\u0131 sa\u011flayacak ve enerjinin korunumu kanununa g\u00f6re \u0131s\u0131 \u00f6l\u00e7\u00fcm\u00fcnden k\u00fctle\u00e7ekimsel dalgan\u0131n sahip oldu\u011fu enerji bulunabilecekti. Hatta k\u00fctle\u00e7ekimsel dalgan\u0131n kuvvetini, yapt\u0131\u011f\u0131 i\u015fi bile bu mant\u0131kla bulabilmek m\u00fcmk\u00fcn olabilirdi. Elbette b\u00f6yle bir d\u00fczenekte ipli\u011fin uzay gibi bir vakum i\u00e7inde ve kilometrelerce uzunlukta olmas\u0131 gerekti\u011fini, bu y\u00fczden b\u00f6yle bir sistemi in\u015fa etmenin neredeyse imk\u00e2ns\u0131z oldu\u011funu s\u00f6ylemeye gerek yok.<\/p>\n

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Solda Weber\u2019in deney d\u00fczene\u011fi, sa\u011fda Weber\u2019in deneyi uygulamas\u0131 s\u0131ras\u0131ndaki foto\u011fraf\u0131.<\/figcaption><\/figure>\n

Weber Kal\u0131plar\u0131<\/strong><\/p>\n

Fakat bu a\u00e7\u0131klama kendisini tatmin etmemi\u015f olsa gerek, Maryland \u00dcniversitesi\u2019nden fizik\u00e7i James Weber, Weber Kal\u0131plar\u0131 ad\u0131 verilen deney d\u00fczenekleri in\u015fa etti. Bir radyo antenine ba\u011fl\u0131 2 metre uzunlu\u011funda bir al\u00fcminyum silindir kal\u0131ptan olu\u015fan d\u00fczenek, s\u00f6z\u00fcm ona k\u00fctle\u00e7ekimsel dalgan\u0131n kal\u0131b\u0131 titre\u015ftirmesi sonucu antenden yap\u0131lacak bir konum tespiti ile k\u00fctle\u00e7ekimsel dalgay\u0131 yakalayacakt\u0131. Weber, 1969 ve 70 y\u0131llar\u0131nda bu y\u00f6ntemle dalga yakalad\u0131\u011f\u0131n\u0131 iddia etti. Fakat yapt\u0131\u011f\u0131 d\u00fczene\u011fi d\u00fcnyan\u0131n \u00e7e\u015fitli yerlerinde kurup deneyen biliminsanlar\u0131 Weber\u2019in \u00f6l\u00e7t\u00fc\u011f\u00fcn\u00fc iddia etti\u011fi verileri alamad\u0131lar. Bug\u00fcn bu t\u00fcr bir d\u00fczenekte, al\u00fcminyum kal\u0131pta, uzunlu\u011funun yaln\u0131zca katrilyonda biri kadar bir oynama ya\u015fanabilece\u011fini ve d\u00f6nemin teknolojisinin b\u00f6yle bir de\u011fi\u015fimi \u00f6l\u00e7meye yeterli olmad\u0131\u011f\u0131n\u0131, dolay\u0131s\u0131yla James Weber\u2019in deneyinin k\u00fctle\u00e7ekimsel dalga yakalayamad\u0131\u011f\u0131n\u0131 biliyoruz. Fakat yine de bu alanda bir ilki ger\u00e7ekle\u015ftirerek k\u00fctle\u00e7ekimsel dalga g\u00f6zlemenin deney ile m\u00fcmk\u00fcn olabilece\u011fini ortaya atan ki\u015fi oldu\u011fundan g\u00f6zlemsel k\u00fctle\u00e7ekimsel dalga biliminin Weber ile ba\u015flad\u0131\u011f\u0131 kabul edilir.<\/p>\n

Hulse ve Taylor\u2019un g\u00f6zlemleri imdada yeti\u015fiyor<\/strong><\/p>\n

Weber deneyinin ba\u015far\u0131s\u0131zl\u0131\u011f\u0131, fizik camias\u0131n\u0131 k\u00fctle\u00e7ekimsel dalga \u00f6l\u00e7\u00fcm\u00fc konusunda hayal k\u0131r\u0131kl\u0131\u011f\u0131na u\u011fratm\u0131\u015f, bu dalgalar\u0131n asla g\u00f6zlenemeyece\u011fini iddia eden sesler y\u00fckselmi\u015fti. K\u00fctle\u00e7ekimsel dalga \u00f6l\u00e7\u00fcm\u00fc \u00fczerine \u00e7al\u0131\u015fan deneysel fizik\u00e7iler de yava\u015f yava\u015f ba\u015fka alanlara kaymaya ba\u015flad\u0131\u011f\u0131 s\u0131rada 1974 y\u0131l\u0131nda umutlar\u0131 yeniden ye\u015ferten bir g\u00f6zlem meydana geldi. Amerikal\u0131 g\u00f6zlemsel astrofizik\u00e7i Alan Russel Hulse ve tez dan\u0131\u015fman\u0131 James Hooton Taylor, \u00e7ift pulsar sistemi g\u00f6zlemi yaparken bu iki cismin birbirine en yak\u0131n konumda temas kurmaya ba\u015flad\u0131klar\u0131 esnada ortamda bir enerji art\u0131\u015f\u0131 g\u00f6rd\u00fcler. Pulsar dinamikleri ve y\u0131ld\u0131z evrimi konusundaki modeller evrenin her yerinde i\u015flerken burada neden i\u015flemesindi? Y\u0131ld\u0131zdan ya da pulsardan ek bir enerji \u00fcretilmedi\u011fine g\u00f6re bu enerji nereden geliyordu? E\u011fer kuram yanl\u0131\u015f de\u011filse geriye tek bir a\u00e7\u0131klama kal\u0131yordu: ortaya \u00e7\u0131kan k\u00fctle\u00e7ekimsel dalgalar k\u00fctle\u00e7ekimsel enerji yarat\u0131yor ve bu da toplam enerjiyi art\u0131r\u0131yor olmal\u0131yd\u0131. Hemen Einstein\u2019\u0131n kuram\u0131 a\u00e7\u0131ld\u0131, hesaplamalar yap\u0131ld\u0131. \u00d6l\u00e7\u00fcmler ile \u00fcretilen enerji tutarl\u0131yd\u0131. Amerikal\u0131 bu iki g\u00f6zlemsel astrofizik\u00e7i, k\u00fctle\u00e7ekimsel dalgalar\u0131n varl\u0131\u011f\u0131n\u0131 dolayl\u0131 yoldan, dalgalar\u0131n kendisini g\u00f6rmeden kan\u0131tlam\u0131\u015flard\u0131. Yakla\u015f\u0131k 30 y\u0131l boyunca bu sistem incelemelerle kay\u0131t alt\u0131nda tutuldu ve tutarl\u0131 sonu\u00e7lar elde edildi. Ard\u0131ndan da Hulse ve Taylor, bu g\u00f6zlemlerinden dolay\u0131 1993 y\u0131l\u0131nda Nobel Fizik \u00f6d\u00fcl\u00fc kazand\u0131lar.<\/p>\n

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Solda Alan Russel Hulse, sa\u011fda James Hooton Taylor. 1993 Nobel \u00d6d\u00fclleri kokteylinde.<\/figcaption><\/figure>\n

Bilim d\u00fcnyas\u0131, art\u0131k k\u00fctle\u00e7ekimsel dalgalar\u0131n varl\u0131\u011f\u0131ndan haberdard\u0131. Fakat yap\u0131lacak \u00e7ok i\u015f vard\u0131 zira k\u00fctle\u00e7ekimsel dalgan\u0131n kendisi de\u011fil, yaln\u0131zca ayak izleri ke\u015ffedilmi\u015fti. Kuramsal fizik\u00e7iler, \u00f6ncelikle olas\u0131l\u0131klara dayal\u0131 olarak k\u00fctle\u00e7ekimsel dalgalar\u0131 s\u0131n\u0131fland\u0131rmaya karar verdiler. \u00dc\u00e7 ana s\u0131n\u0131f \u00f6ng\u00f6r\u00fclm\u00fc\u015ft\u00fc: Stokastik (rastlant\u0131sal), periyodik (d\u00f6nemsel) ve impulsif (itici) k\u00fctle\u00e7ekimsel dalgalar… Rastlant\u0131sal k\u00fctle\u00e7ekimsel dalgalar\u0131n, evrenin ba\u015flang\u0131c\u0131ndan bu yana ya\u015fanm\u0131\u015f t\u00fcm olaylar silsilesinden gelen arka plandaki g\u00fcr\u00fclt\u00fc oldu\u011fu \u00f6ng\u00f6r\u00fclmekteydi. D\u00f6nemsel olanlar\u0131n Nobel \u00f6d\u00fcl\u00fcne lay\u0131k g\u00f6r\u00fclen olayda oldu\u011fu gibi belirli aral\u0131klarla d\u00fczenli olarak ger\u00e7ekle\u015fen k\u00fctle\u00e7ekimsel dalgalar oldu\u011fu \u00f6ng\u00f6r\u00fcl\u00fcyordu. \u0130tici k\u00fctle\u00e7ekimsel dalgalar\u0131n ise tek zamanl\u0131k, bir \u00e7arp\u0131\u015fma yahut i\u00e7 i\u00e7e ge\u00e7me s\u00fcreci sonucu olu\u015ftu\u011fu d\u00fc\u015f\u00fcn\u00fclmekteydi – Buna \u00f6rnek olarak LIGO\u2019nun \u015fu ana kadar buldu\u011fu t\u00fcm k\u00fctle\u00e7ekimsel dalga g\u00f6zlemleri g\u00f6sterilebilir-.<\/p>\n

Giri\u015fim\u00f6l\u00e7er ile \u00f6l\u00e7\u00fcm fikri<\/strong><\/p>\n

Weber\u2019in anten fikri \u00e7ok mant\u0131kl\u0131yd\u0131, fakat o denli bir titre\u015fim i\u00e7in devasa antenler yapmak laz\u0131md\u0131 ki bu da m\u00fcmk\u00fcn de\u011fildi. 1960\u2019larda lazerler yeni yeni ortaya \u00e7\u0131k\u0131yor ve bu alanlarda olduk\u00e7a iyi d\u00fczeyde olan Sovyetler Birli\u011fi\u2019ndeki deneysel fizik \u00e7evrelerinde k\u00fctle\u00e7ekimsel dalga \u00f6l\u00e7\u00fcm\u00fc tart\u0131\u015f\u0131l\u0131yordu. 1966 y\u0131l\u0131nda Mikhail Gertsenschtein ve Vladislav \u0130vanovi\u00e7 Pustovoit ad\u0131nda iki Sovyet fizik\u00e7i, yeterli uzunlukta iki farkl\u0131 Michelson giri\u015fim\u00f6l\u00e7erinin d\u00fcnyan\u0131n farkl\u0131 yerlerine konup aralar\u0131ndaki farklara bak\u0131larak itici t\u00fcrdeki k\u00fctle\u00e7ekimsel dalgalar\u0131n anl\u0131k olarak g\u00f6zlenebilece\u011fini \u00f6ng\u00f6rd\u00fcler. Fakat Sovyetler Birli\u011fi, kendi bilim akademilerinde yaz\u0131lan makalelerin ba\u015fka dillere \u00e7evirip payla\u015f\u0131lmas\u0131na izin vermedi\u011finden, d\u00fcnyada ayn\u0131 konuyu tart\u0131\u015fan fizik\u00e7iler bundan haberdar olamad\u0131lar. Hatta makale 1966 y\u0131l\u0131nda bir kereli\u011fine g\u00fcndeme geldikten sonra Sovyetler Birli\u011fi\u2019nde de t\u00fcm\u00fcyle unutulup gitti.<\/p>\n

Weber, deneyinin ba\u015far\u0131s\u0131zl\u0131\u011f\u0131n\u0131n ard\u0131ndan nerede hata yapt\u0131\u011f\u0131n\u0131 d\u00fc\u015f\u00fcnmeye ba\u015flam\u0131\u015ft\u0131. \u00d6\u011frencileri David Zipoy ve Robert Forward ile birlikte anten yerine interferometre kullanman\u0131n daha etkili olaca\u011f\u0131na kanaat getirdiler. Bu durum Sovyetlerde yap\u0131lan \u00e7al\u0131\u015fmalarla ayn\u0131 y\u0131llarda ger\u00e7ekle\u015fti ve iki taraf da birbirinden haberdar de\u011fildi. 1978 y\u0131l\u0131nda k\u00fctle\u00e7ekimsel dalga \u00f6l\u00e7mek amac\u0131yla in\u015fa edilen ilk giri\u015fim\u00f6l\u00e7eri in\u015fa eden Forward ve Zipoy, 8,5 metre uzunlu\u011funda kollara sahip giri\u015fim\u00f6l\u00e7erden ve d\u00fcnyan\u0131n \u00e7e\u015fitli yerlerinde o zamana kadar kurulmu\u015f giri\u015fim\u00f6l\u00e7erlerden ald\u0131klar\u0131 sonu\u00e7lar\u0131 \u015fu \u015fekilde de\u011ferlendirdiler: \u201cNe Maryland\u2019de, ne Argonne\u2019da, ne Glasgow\u2019da ne de Frascati\u2019de bulunan giri\u015fim\u00f6l\u00e7erlerde bir anormallik, bir uzunluk de\u011fi\u015fimi g\u00f6zlenebildi.\u201d Yani bu deneme de ba\u015far\u0131s\u0131zd\u0131.<\/p>\n

Bu arada Rainer Weiss ad\u0131nda MIT\u2019den bir kuramsal fizik\u00e7i, daha b\u00fcy\u00fck, daha uzun giri\u015fim\u00f6l\u00e7erler in\u015fa etmek i\u00e7in biliminsanlar\u0131n\u0131n birbirinden ba\u011f\u0131ms\u0131z hareket etmemesi gerekti\u011finin fark\u0131na vard\u0131, \u00e7\u00fcnk\u00fc 5 metreyi a\u015fan bir giri\u015fim\u00f6l\u00e7er in\u015fa etmenin bedeli tek bir \u00fcniversite fizik b\u00f6l\u00fcm\u00fc i\u00e7in fazlayd\u0131. Ba\u015fka bir alanda \u00e7al\u0131\u015fan bu kuramsal fizik\u00e7inin, deneysel alandaki bu i\u015fe girmesinin tek nedeni, lisans \u00f6\u011frencilerine verdi\u011fi \u201cGenel G\u00f6relili\u011fe Giri\u015f\u201d dersinde \u00f6\u011frencilerinin bu konudaki sorular\u0131na yan\u0131t verememesiydi. MIT i\u00e7indeki ba\u011flant\u0131lar\u0131n\u0131 kullanarak \u00f6nce Amerikan Ulusal Bilim Kurumuna (National Science Foundation, NSF) ula\u015ft\u0131. NSF\u2019yi, savunma sanayisi b\u00fct\u00e7esinden ayr\u0131lacak para ile bu projeye destek olmaya ikna ettikten sonra \u00fclkeler aras\u0131 i\u015fbirli\u011fini 70\u2019lerde d\u00fcnyada en iyi yapan yer olan Avrupa\u2019ya giderek M\u00fcnih\u2019teki Max Plank Astrofizik Enstit\u00fcs\u00fc\u2019n\u00fcn kap\u0131s\u0131n\u0131 \u00e7ald\u0131. Orada Peter Kafka ad\u0131ndaki fizik\u00e7iyle konu\u015farak \u00fclkeleraras\u0131 k\u00fctle\u00e7ekimsel dalga g\u00f6zlemevi kurma fikrini a\u00e7t\u0131. Kafka, kendisine ilgi \u00e7ekici gelen bu fikri kabul etti ve bir \u0130talyan biliminsan\u0131 grubuyla birlikte 9 metrelik bir giri\u015fim\u00f6l\u00e7er in\u015fas\u0131 i\u00e7in onay ald\u0131lar. Toparlayabildikleri b\u00fct\u00e7e 53.000 dolard\u0131. 9 metre, g\u00fcn\u00fcm\u00fczdeki kilometrelerce uzun giri\u015fim\u00f6l\u00e7erlere k\u0131yasla olduk\u00e7a m\u00fctevaz\u0131 bir rakam… 1975 y\u0131l\u0131nda Sicilya\u2019da d\u00fczenlenen bir kozmoloji konferans\u0131na kat\u0131lan ikili, projelerini sundular. Peter Kafka\u2019n\u0131n sunumu \u00e7ok fazla ele\u015ftiriyle kar\u015f\u0131la\u015ft\u0131. Ekibin Weber\u2019in ya\u015fad\u0131\u011f\u0131 h\u00fczn\u00fc ya\u015fayaca\u011f\u0131n\u0131, \u00e7\u00fcnk\u00fc 9 metrenin de yeterli olmayaca\u011f\u0131n\u0131 iddia edenler fazlayd\u0131. Ayr\u0131ca o d\u00f6nemdeki alg\u0131lay\u0131c\u0131lar\u0131n yeterince hassas olmad\u0131\u011f\u0131 da bildirilmi\u015fti.<\/p>\n

\"\"Konu\u015fmay\u0131 dinleyen \u0130sko\u00e7 deneysel fizik\u00e7i Ronald Drever ise \u00e7ok etkilenmi\u015fti. Ortadaki sorunlar\u0131n fark\u0131na vararak hemen daha hassas alg\u0131lay\u0131c\u0131 \u00fcretme yollar\u0131n\u0131 ara\u015ft\u0131rmak i\u00e7in literat\u00fcr taramas\u0131na ba\u015flad\u0131. Ara\u015ft\u0131rma yapt\u0131\u011f\u0131 kurumun \u00e7ok paras\u0131 olmad\u0131\u011f\u0131ndan al\u00fcminyumdan yapt\u0131\u011f\u0131 ufak iki yar\u0131k \u00fczerinden \u0131\u015f\u0131n de\u011fi\u015fimlerini inceleyen cihazlar \u00fcretmeye giri\u015fti. Drever\u2019in yapt\u0131\u011f\u0131 \u00e7al\u0131\u015fmalar zamanla dikkat \u00e7ekmeye ba\u015flad\u0131 ve 1979 y\u0131l\u0131nda bu konu hakk\u0131nda daha fazla \u00e7al\u0131\u015fman\u0131n yap\u0131ld\u0131\u011f\u0131 Kaliforniya Teknoloji Enstit\u00fcs\u00fc\u2019ne davet edildi.<\/p>\n

Ele\u015ftirilerden sonra projeden vazge\u00e7ilmi\u015fti, fakat yine de kendi ay\u0131rd\u0131klar\u0131 bir b\u00fct\u00e7eyle Almanya\u2019ya 3 metrelik bir giri\u015fim\u00f6l\u00e7er in\u015fa eden Max Planck Enstit\u00fcs\u00fc ekibi, bu giri\u015fim\u00f6l\u00e7erde, ileride yap\u0131lacak daha b\u00fcy\u00fck projeler i\u00e7in duyarl\u0131l\u0131k ve g\u00fcr\u00fclt\u00fc azalt\u0131m\u0131 etkilerini denemeye koyulmu\u015flard\u0131. Bu konuda ba\u015far\u0131ya ula\u015fan M\u00fcnih ekibi, Garching\u2019de bulunan Max Planck Kuantum Opti\u011fi Enstit\u00fcs\u00fc ile birlikte b\u00fcy\u00fck bir projeye imza att\u0131. Bat\u0131 Almanya\u2019n\u0131n ulusal b\u00fct\u00e7esinden ciddi bir katk\u0131 ile 50 metrelik bir giri\u015fim\u00f6l\u00e7er in\u015fa ettiler. Fakat h\u00e2l\u00e2 herhangi bir \u00f6l\u00e7\u00fcm ger\u00e7ekle\u015ftirilememi\u015fti. Daha da b\u00fcy\u00fck bir giri\u015fim\u00f6l\u00e7er yap\u0131lmal\u0131yd\u0131. Ayn\u0131 ekip, bu sefer 3 km uzunlu\u011funda bir giri\u015fim\u00f6l\u00e7er yapmak i\u00e7in Alman h\u00fck\u00fcmetine ba\u015fvurdu. Fakat 50 metreli\u011fi desteklerken zorlanan h\u00fck\u00fcmet, bu \u00f6neriyi kabul etmedi. E\u011fer etmi\u015f olsalard\u0131 belki de Almanya\u2019da k\u00fctle\u00e7ekimsel dalga g\u00f6zlemi yap\u0131labilirdi, \u00e7\u00fcnk\u00fc LIGO\u2019nun ilk giri\u015fim\u00f6l\u00e7erinin uzunlu\u011fu, Alman ekibinin \u00f6nerdi\u011fi uzunluktan yaln\u0131zca bir kilometre daha uzun.<\/p>\n

ABD\u2019de bir giri\u015fim\u00f6l\u00e7er fikri ve LIGO<\/strong><\/p>\n

Alman ekibinin \u00f6yk\u00fcs\u00fc burada biterken Rainer Weiss, Kaliforniya Teknoloji Enstit\u00fcs\u00fc ve NASA ile birlikte \u00e7al\u0131\u015fan Kip Thorne ad\u0131ndaki deneysel fizik\u00e7iyle konu\u015ftu. Thorne\u2019a Almanya\u2019da ya\u015fananlardan s\u00f6z etti ve ABD\u2019de y\u00fcksek duyarl\u0131l\u0131kta ve kilometrelerce uzunlukta bir giri\u015fim\u00f6l\u00e7er in\u015fa ederlerse d\u00fcnyada ilk olacaklar\u0131n\u0131 s\u00f6yledi. Weiss\u2019\u0131n kafas\u0131nda uzayda bir giri\u015fim\u00f6l\u00e7er in\u015fa etmek bile vard\u0131 ve bunun i\u00e7in NASA yetkilileriyle konu\u015fmas\u0131n\u0131 istedi. Weiss\u2019\u0131n proje ismi bile haz\u0131rd\u0131: Laser Interferometer Space Array (Lazer Giri\u015fim\u00f6l\u00e7eri Uzay Anteni) – LISA. (Bu proje de onay ald\u0131 ve ESA ile NASA ekipleri birlikte \u00e7al\u0131\u015farak Pathfinder ad\u0131nda bir uzay arac\u0131 i\u00e7ine koyduklar\u0131 hassas antenleri 2015 y\u0131l\u0131nda uzaya yollad\u0131lar. 2017 y\u0131l\u0131 sonlar\u0131na do\u011fru bu g\u00f6zlemevinin de kullan\u0131ma ge\u00e7mesi planlanmakta) Weiss\u2019\u0131n kafas\u0131ndaki projenin bitim tarihi ise 2035\u2019tir.<\/p>\n

Weiss ve Thorne, ellerindeki imk\u00e2nlar\u0131 dikkate alarak bir plan yapt\u0131lar. \u00d6ncelikle duyarl\u0131l\u0131k sorununu \u00e7\u00f6zmek i\u00e7in bu alanda ara\u015ft\u0131rma yapan insanlar\u0131 bir araya toplamak gerekmekteydi. \u0130sko\u00e7ya\u2019da alg\u0131lay\u0131c\u0131 duyarl\u0131l\u0131\u011f\u0131 ara\u015ft\u0131rmas\u0131 yapan Drever\u2019i Kaliforniya Teknoloji Enstit\u00fcs\u00fc\u2019ne (CALTECH) ald\u0131ran da bu ama\u00e7 do\u011frultusunda Thorne\u2019dur. CALTECH\u2019te i\u015fe ba\u015flar ba\u015flamaz elindeki neredeyse s\u0131n\u0131rs\u0131z imk\u00e2n ile olduk\u00e7a duyarl\u0131 deney aletleri \u00fcreten Drever, 1983 y\u0131l\u0131nda g\u00fc\u00e7l\u00fc lazerler ve duyarl\u0131 alg\u0131lay\u0131c\u0131y\u0131lar ile birka\u00e7 kilometre uzunlu\u011fundaki bir giri\u015fim\u00f6l\u00e7erin yetebilece\u011fini \u00f6ng\u00f6rd\u00fc.<\/p>\n

Ellerindeki g\u00fc\u00e7l\u00fc lazerler ve duyarl\u0131 alg\u0131lay\u0131c\u0131lar ile art\u0131k devletten b\u00fct\u00e7e istemeye haz\u0131r olan Drever, Thorne ve Weiss, CALTECH ve MIT ortak projesi ile NSF\u2019e ba\u015fvurdular. \u00dc\u00e7l\u00fcn\u00fcn NSF\u2019ten talep ettikleri tutar 100 milyon dolard\u0131. Uzun s\u00fcren tart\u0131\u015fmalar ve ara\u015ft\u0131rmalar sonucu ABD\u2019nin bilimsel ilk mega projesi onayland\u0131. NSF\u2019in alt\u0131nda \u00e7al\u0131\u015facak yeni bir kamu kurulu\u015fu olu\u015fturuldu: Lazer \u0130nterferometresi K\u00fctle\u00e7ekimsel Dalga G\u00f6zlemevi – LIGO… Fakat s\u0131k\u0131nt\u0131lar bitmemi\u015fti. Weiss bir teorik fizik\u00e7iydi, Thorne\u2019un \u00e7al\u0131\u015ft\u0131\u011f\u0131 alan aslen k\u00fctle\u00e7ekimsel dalga de\u011fildi ve Drever ise deney aletleri \u00fcreten bir deneysel fizik\u00e7iydi. Dolay\u0131s\u0131yla \u00fc\u00e7l\u00fcn\u00fcn proje y\u00f6netimi odas\u0131ndaki toplant\u0131larda yapt\u0131klar\u0131 tart\u0131\u015fmalar onlar\u0131n tabiriyle tam bir \u015famatayd\u0131. Her biri ayr\u0131 telden \u00e7ald\u0131\u011f\u0131 i\u00e7in s\u00f6zl\u00fc tart\u0131\u015fmalar \u00f6zellikle Drever ve Weiss aras\u0131nda sorunlar yaratm\u0131\u015ft\u0131. Olaylar o kadar b\u00fcy\u00fcd\u00fc ki NSF, ikili aras\u0131ndaki sorunu \u00e7\u00f6zmek i\u00e7in devreye girdi ama ba\u015far\u0131l\u0131 olamay\u0131nca 1984 y\u0131l\u0131nda proje ask\u0131ya al\u0131nd\u0131.<\/p>\n

Bunun \u00fczerine proje y\u00f6netimine el koyan NSF, LIGO\u2019ya m\u00fcd\u00fcr olarak projenin yarat\u0131l\u0131\u015f safhalar\u0131nda pek bulunmayan Rochus E. Vogt ad\u0131nda CALTECH\u2019ten bir fizik profes\u00f6r\u00fcn\u00fc atad\u0131. Bu tart\u0131\u015fmalar s\u0131ras\u0131nda durdurulan projeye b\u00fct\u00e7e de kesilmi\u015fti. Neredeyse yar\u0131da kalacak olan projeye m\u00fcd\u00fcr\u00fcn \u00e7abalar\u0131 sayesinde 1988 y\u0131l\u0131nda yeniden b\u00fct\u00e7e verildi. Fakat bu sefer de yer tahlili konusunda ekip i\u00e7inde fikir ayr\u0131l\u0131klar\u0131 \u00e7\u0131kt\u0131. 1992 y\u0131l\u0131nda giri\u015fim\u00f6l\u00e7eri Drever\u2019in \u00f6nerdi\u011fi yerden ba\u015fka bir yere in\u015fa etmeye ba\u015flayan Vogt ekibine tepki g\u00f6steren Drever ve \u00e7al\u0131\u015fma grubu, toplu olarak projeyi terk etti. Bu anla\u015fmazl\u0131\u011f\u0131 gidermedi\u011fi gerek\u00e7esiyle de Vogt, LIGO m\u00fcd\u00fcrl\u00fc\u011f\u00fcnden al\u0131narak yerine Birle\u015fik Krall\u0131ktan bir deneysel fizik\u00e7i olan Barry Clark Barrish getirildi. Par\u00e7ac\u0131k h\u0131zland\u0131r\u0131c\u0131lar\u0131 gibi b\u00fcy\u00fck projeleri y\u00f6netme ve b\u00fcy\u00fck ekiplerle \u00e7al\u0131\u015fma konusunda deneyimi olan Barrish, Drever\u2019i tekrar ekibe katarak ekibi yeniden toparlad\u0131. NSF\u2019i etkileyerek ek b\u00fct\u00e7e ve s\u00fcre almay\u0131 ba\u015fard\u0131 ve 1994 y\u0131l\u0131nda ekibiyle Hanford Washington ve Livingston Louisiana\u2019da iki tane 4\u2019er kilometre uzunlu\u011funda ikiz giri\u015fim\u00f6l\u00e7erlerin in\u015faat\u0131 ba\u015flad\u0131. 1997 y\u0131l\u0131nda biten kaba in\u015faattan sonra lazerlerin optimizasyonu, do\u011fru filtrelerin \u00fcretimi, alg\u0131lay\u0131c\u0131 duyarl\u0131l\u0131\u011f\u0131 ayarlanmas\u0131 gibi ince i\u015flere ge\u00e7ildi ve 2002 y\u0131l\u0131nda g\u00f6zlemevi faaliyete ba\u015flad\u0131.<\/p>\n

\"\"
Livingston\u2019da bulunan LIGO giri\u015fim\u00f6l\u00e7eri.<\/figcaption><\/figure>\n

B\u00fct\u00fcn d\u00fcnyan\u0131n g\u00f6z\u00fc kula\u011f\u0131 LIGO\u2019dayd\u0131. Fakat 2010 y\u0131l\u0131na kadar durmadan \u00e7al\u0131\u015fan LIGO, bir tane bile k\u00fctle\u00e7ekimsel dalga g\u00f6zleyemedi. Sorun neydi? Yeterince uzun mu de\u011fildi? Yoksa yeterince duyarl\u0131 m\u0131 de\u011fildi? Ya da lazeri mi yeterince g\u00fc\u00e7l\u00fc de\u011fildi? LIGO ekibi yan\u0131t bulamam\u0131\u015ft\u0131 ve sessizlik i\u00e7indeydi. LIGO y\u00f6netimi, sorunun ortam g\u00fcr\u00fclt\u00fcs\u00fcn\u00fcn y\u00fcksekli\u011finden kaynakland\u0131\u011f\u0131n\u0131 d\u00fc\u015f\u00fcnd\u00fc ve b\u00fct\u00fcn sisteme g\u00fcr\u00fclt\u00fc azalt\u0131c\u0131 cihazlar yerle\u015ftirmeye ba\u015flad\u0131. Bunu yaparken alg\u0131lay\u0131c\u0131lar\u0131 da \u00e7\u0131kart\u0131p daha duyarl\u0131 olanlar\u0131yla de\u011fi\u015ftirmeye karar verdiler. G\u00fcncelleme 5 y\u0131l s\u00fcrecekti. 18 Kas\u0131m 2015 tarihinde LIGO\u2019yu yeniden g\u00f6zlemlere a\u00e7maya karar verdiler.<\/p>\n

Asl\u0131nda b\u00fct\u00fcn g\u00fcncellemeler bitmi\u015fti. Erken biten in\u015fa s\u00fcrecinden sonra belli bir s\u00fcre i\u00e7in cihaz\u0131n deneme s\u00fcr\u00fcm\u00fcnde \u00e7al\u0131\u015fmas\u0131na karar verildi. Kamyon \u00e7arpmas\u0131 veya deprem gibi etkilerin grafikleri nas\u0131l etkiledi\u011fine bak\u0131l\u0131p onlar\u0131 azaltan yaz\u0131l\u0131mlar yaz\u0131l\u0131rken 13 Eyl\u00fcl g\u00fcn\u00fc mesai bittikten sonra \u00e7\u0131kan fizik\u00e7iler, geceleyin giri\u015fim\u00f6l\u00e7eri a\u00e7\u0131k b\u0131rakt\u0131lar. 14 Eyl\u00fcl sabaha kar\u015f\u0131 saat 4:50\u2019de 30-g\u00fcne\u015f k\u00fctleli iki karadeli\u011fin birbirine ge\u00e7mesinin k\u00fctle\u00e7ekimsel dalga sinyali LIGO\u2019ya ula\u015ft\u0131. Do\u011fa, LIGO\u2019nun a\u00e7\u0131laca\u011f\u0131 g\u00fcn\u00fc beklememi\u015fti! Bunca sanc\u0131l\u0131 s\u00fcre\u00e7ten ge\u00e7ip ba\u015far\u0131ya ula\u015fan LIGO\u2019ya, k\u00fctle\u00e7ekimsel dalga bilimini ba\u015flatm\u0131\u015f olduklar\u0131 i\u00e7in 2017 Nobel Fizik \u00d6d\u00fcl\u00fc verilmi\u015ftir.<\/p>\n

Say\u0131s\u0131z biliminsan\u0131n\u0131n yer ald\u0131\u011f\u0131 k\u00fctle\u00e7ekimsel dalgalar\u0131 ke\u015ffetme s\u00fcreci 20. y\u00fczy\u0131lda \u00e7ok yava\u015f yol alm\u0131\u015fken 2015 sonras\u0131 d\u00f6nemde ger\u00e7ekten ba\u015flad\u0131 denilebilir. Bu yeni bilim asl\u0131nda son on y\u0131lda ortaya \u00e7\u0131kt\u0131 ve bu y\u00fczy\u0131l\u0131 \u015fekillendirece\u011fi a\u00e7\u0131k.<\/p>\n","protected":false},"excerpt":{"rendered":"

Bug\u00fcn k\u00fctle\u00e7ekimsel dalgalar\u0131 ke\u015ffetmemizi sa\u011flayan Lazer Giri\u015fim\u00f6l\u00e7eri K\u00fctle\u00e7ekimsel Dalga G\u00f6zlemevi\u2019nin, yani LIGO\u2019nun arka plan\u0131nda say\u0131s\u0131z biliminsan\u0131n\u0131n \u00e7abalar\u0131 ve bir\u00e7ok tart\u0131\u015fma var. S\u00f6z konusu s\u00fcre\u00e7 20. y\u00fczy\u0131lda \u00e7ok yava\u015f yol alm\u0131\u015fken 2015 sonras\u0131 d\u00f6nemde ger\u00e7ekten ba\u015flad\u0131 denilebilir. Bu yeni bilim asl\u0131nda son on y\u0131lda ortaya \u00e7\u0131kt\u0131 ve bu y\u00fczy\u0131l\u0131 \u015fekillendirece\u011fi a\u00e7\u0131k. Ge\u00e7ti\u011fimiz say\u0131da LIGO ara\u015ft\u0131rmalar\u0131na ve […]<\/p>\n","protected":false},"author":512,"featured_media":18317,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[2146,26,605],"tags":[2030,277,420,288,1161,1744],"class_list":["post-18287","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-166-sayi","category-fizik","category-unlu-deneyler","tag-dusunce-deneyleri","tag-einstein","tag-feynman","tag-fizik","tag-kutlecekim","tag-ligo"],"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