{"id":26151,"date":"2018-06-02T14:28:08","date_gmt":"2018-06-02T11:28:08","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=26151"},"modified":"2018-06-02T14:34:55","modified_gmt":"2018-06-02T11:34:55","slug":"hubble-uzay-genisliyor-dedi-mi","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2018\/06\/02\/hubble-uzay-genisliyor-dedi-mi","title":{"rendered":"Hubble \u201cuzay geni\u015fliyor\u201d dedi mi?"},"content":{"rendered":"

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\u00dcnl\u00fc astrofizik\u00e7i Edwin Hubble<\/strong> 1936 y\u0131l\u0131nda yay\u0131mlatt\u0131\u011f\u0131 The Realm of Nebulae<\/em><\/strong> adl\u0131 kitab\u0131n\u0131n hi\u00e7bir yerinde \u201cuzay geni\u015fliyor\u201d demedi\u011fi gibi, \u00e7al\u0131\u015fmas\u0131n\u0131 yanl\u0131\u015f yorumlayan evrenbilimcileri de uyar\u0131yor.<\/p>\n

Hubble zaman\u0131nda g\u00f6kadalar, eliptik, sarmal, \u00e7ubuklu sarmal, d\u00fczensiz olarak s\u0131n\u0131fland\u0131r\u0131l\u0131yordu (\u015eekil 1). Hubble, 60 adet Sb<\/em> t\u00fcr\u00fc g\u00f6kada \u00fczerinde yapt\u0131\u011f\u0131 \u00e7al\u0131\u015fmada, g\u00f6kadalar\u0131n g\u00f6r\u00fcn\u00fcrdeki parlakl\u0131\u011f\u0131yla g\u00f6kada tayflar\u0131ndaki \u00e7izgilerin sergiledi\u011fi k\u0131rm\u0131z\u0131ya kayma aras\u0131nda do\u011frusal bir ba\u011f\u0131nt\u0131n\u0131n varl\u0131\u011f\u0131n\u0131 saptam\u0131\u015ft\u0131 (\u015eekil 2).<\/p>\n

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\u015eekil 1 (sol). G\u00f6kadalar\u0131n Hubble s\u0131n\u0131flamas\u0131. E ve S t\u00fcrleri aras\u0131ndaki ge\u00e7i\u015f t\u00fcr\u00fc S0\u2019d\u0131r. a, b, c,\u00a0 d, m dizisi ile g\u00f6sterilen g\u00f6kadalar\u0131n sarmal kollar\u0131 disk \u00e7evresinde s\u0131k\u0131 s\u0131k\u0131ya sar\u0131l\u0131 ve iyi tan\u0131mlanm\u0131\u015f kollardan, a\u00e7\u0131k, par\u00e7alanm\u0131\u015f kollara do\u011fru gidi\u015fi anlat\u0131r.
\u015eekil 2 (sa\u011f). Hubble\u2019\u0131n Sb t\u00fcr\u00fc g\u00f6kadalar i\u00e7in olu\u015fturdu\u011fu fotografik salt parlakl\u0131k-h\u0131z logaritmas\u0131 grafi\u011fi.<\/figcaption><\/figure>\n

Hubble, sarmal kollu g\u00f6kadalar \u00fczerine yapt\u0131\u011f\u0131 bir \u00e7al\u0131\u015fmada, g\u00f6kadalar\u0131n g\u00f6zlenebilir iki niceli\u011fi aras\u0131ndaki ili\u015fkiye bakt\u0131: 1) tayf \u00e7izgilerinde g\u00f6zlenen k\u0131rm\u0131z\u0131ya kayma ve 2) foto\u011frafik salt parlakl\u0131k, Mpg<\/sub><\/em>. E\u011fer z<\/em> k\u0131rm\u0131z\u0131ya kaymas\u0131n\u0131n h\u0131z k\u00f6kenli oldu\u011fu varsay\u0131m\u0131n\u0131 kullan\u0131rsak; \"\"ba\u011f\u0131nt\u0131s\u0131 yard\u0131m\u0131yla k\u0131rm\u0131z\u0131ya kaymalar\u0131 h\u0131z cinsinden betimleyebiliriz. Salt veya g\u00f6r\u00fcn\u00fcrdeki parlakl\u0131\u011f\u0131 da uzakl\u0131k mod\u00fcl\u00fc yard\u0131m\u0131yla uzakl\u0131k cinsinden betimleyebiliriz.<\/p>\n

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Yukar\u0131daki \u015fekilde (\u00fcst) g\u00f6zlemciyle kaynak aras\u0131nda h\u0131z fark\u0131 olmayan bir durumda al\u0131nan tayf \u00e7izgileri; (alt) g\u00f6zlemciyle kayna\u011f\u0131n birbirinden uzakla\u015fmas\u0131 durumunda al\u0131nan k\u0131rm\u0131z\u0131ya kaym\u0131\u015f tayf \u00e7izgileri g\u00f6r\u00fcl\u00fcyor. \u00c7izgilerin her biri hidrojen, helyum, karbon, kalsiyum, vb. kimyasal elementlere aittir.<\/figcaption><\/figure>\n

Bu durumda (z<\/em>, M<\/em>pg<\/sub>) i\u015flevi (v<\/em>, d<\/em>) i\u015flevine denk k\u0131l\u0131n\u0131r; burada d<\/em>, g\u00f6kada uzakl\u0131\u011f\u0131d\u0131r. Sonra, g\u00f6zlem \u201cnoktalar\u0131n\u0131\u201d bir grafi\u011fe d\u00f6keriz. \u201cBelli sa\u00e7\u0131lmalar g\u00f6steren bu noktalar bir\u00e7ok korelasyon e\u011frisince temsil edilebilir. Bu e\u011frilerin her biri verileri iyi bir bi\u00e7imde temsil eder. G\u00f6zlemci bu e\u011friler i\u00e7inden, genel bilgilerimizle tutarl\u0131 olan en basitini se\u00e7er. Tart\u0131\u015ft\u0131\u011f\u0131m\u0131z bu durumda, k\u0131rm\u0131z\u0131ya kaymayla g\u00f6r\u00fcn\u00fcrdeki parlakl\u0131k veya h\u0131zla uzakl\u0131k aras\u0131nda do\u011frusal bir ili\u015fki oldu\u011fu onanm\u0131\u015ft\u0131r.\u201d (Edwin Hubble, Realm of the Nebulae<\/em>, New Haven, Yale University Press, London, MDCCCCXXXVI, 1936, s.3).<\/p>\n

Ufkumuz geni\u015fliyor, uzay\u0131m\u0131z de\u011fil!<\/strong><\/p>\n

E\u011fer g\u00f6zlenebilir \u00e7evrenimiz i\u00e7indeki t\u00fcm g\u00f6kcisimleri ayn\u0131 do\u011frusal ba\u011f\u0131nt\u0131ya uyarsa, bu sonucun evrenin geni\u015fledi\u011fine i\u015faret etti\u011fi yorumunu yapabiliriz. Sarmal kollu g\u00f6kadalar o d\u00f6nemde bilinen toplam t\u00fcrler i\u00e7inde % 25 oran\u0131ndad\u0131r. Hubble, Realm of the Nebulae<\/em> adl\u0131 e\u015fsiz kitab\u0131nda ilgili okuyucuyu bir konuda s\u00fcrekli uyar\u0131yor: \u201cG\u00f6zlemler, k\u0131rm\u0131z\u0131ya kayman\u0131n ger\u00e7ekten de devinimi temsil edip etmedi\u011fini iyice ortaya \u00e7\u0131karmadan \u00f6nce herhangi bir kozmolojik yarg\u0131ya var\u0131lmamal\u0131d\u0131r\u2026 Bu arada, k\u0131rm\u0131z\u0131ya kaymalar, uygunluk a\u00e7\u0131s\u0131ndan h\u0131z \u00f6l\u00e7ekleriyle anlat\u0131labilir. K\u0131rm\u0131z\u0131ya kayman\u0131n davran\u0131\u015f bi\u00e7imi h\u0131z kaymalar\u0131nkine benzemektedir. Dikkatli bir bi\u00e7imde kurdu\u011fumuz t\u00fcmcelerimizde \u2018g\u00f6r\u00fcn\u00fcrdeki h\u0131z\u2019 kavram\u0131n\u0131 kullanmal\u0131 ve genel kullan\u0131m\u0131 i\u00e7inde \u2018g\u00f6r\u00fcn\u00fcrdeki\u2019 s\u0131fat\u0131n\u0131 dikkate almasak da varl\u0131\u011f\u0131n\u0131 daima an\u0131msamal\u0131y\u0131z\u2026 Tan\u0131m gere\u011fi g\u00f6zlenebilir evrenin tam ortas\u0131nday\u0131z. Yak\u0131n kom\u015fulu\u011fumuzu olduk\u00e7a iyi tan\u0131yoruz. Uzakl\u0131klar\u0131n artmas\u0131yla birlikte bilgimiz azal\u0131yor, \u00fcstelik h\u0131zla azal\u0131yor. En sonunda teleskoplar\u0131m\u0131z\u0131n s\u0131n\u0131r\u0131na eri\u015fiyoruz. O s\u0131n\u0131rda art\u0131k g\u00f6lgeleri \u00f6l\u00e7meye ba\u015fl\u0131yoruz. Burada \u00f6l\u00e7\u00fcm yan\u0131lg\u0131lar\u0131m\u0131z\u0131n yan\u0131 s\u0131ra bize ipucu olabilecek g\u00f6r\u00fcnt\u00fcleri de ara\u015ft\u0131rmaya ba\u015fl\u0131yoruz. Ara\u015ft\u0131rmalar\u0131m\u0131z s\u00fcrecek. Deneysel-g\u00f6zlemsel kaynaklar\u0131m\u0131z tamamen t\u00fckenmedik\u00e7e d\u00fc\u015fsel spek\u00fclasyon alan\u0131na kaymam\u0131za gerek yok.\u201d (ayn\u0131 kaynak).<\/p>\n

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Renk \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fc: x Persei y\u0131ld\u0131z\u0131n\u0131n tayf\u0131 \u00f6nce IUE sonra da Hubble Uzay Teleskopu (HST GHRS-LSA) ile al\u0131nm\u0131\u015ft\u0131r. Hubble Uzay teleskopunun 1302 \u00c5 dalgaboyunda alg\u0131lad\u0131\u011f\u0131 uydu \u00e7izgiyi \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fc daha d\u00fc\u015f\u00fck olan erken d\u00f6nem IUE uydusu alg\u0131layamam\u0131\u015ft\u0131r.<\/figcaption><\/figure>\n

Hubble kendi \u00e7al\u0131\u015fmalar\u0131n\u0131n s\u0131n\u0131r\u0131n\u0131n ay\u0131rd\u0131ndayd\u0131. \u201cG\u00f6kbilim tarihi giderek geni\u015fleyen \u00e7evrenimizin (ufkumuzun) tarihidir\u201d derken belli \u00f6l\u00e7eklerdeki \u00e7al\u0131\u015fmalar\u0131n ge\u00e7erlilik s\u0131n\u0131rlar\u0131n\u0131n geni\u015fleyen \u00e7evrenle s\u00fcrekli denetlenmesi gereklili\u011fini vurguluyordu. Burada bir uyar\u0131 yapmakta yarar var; \u00e7evrenimizi geni\u015fleten etmenler, ilerleyen teknolojiye ko\u015fut olarak artan alga\u00e7lar\u0131m\u0131z\u0131n a\u00e7\u0131sal, renk ve zaman \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fcd\u00fcr. \u00d6rne\u011fin, teleskopumuzun \u00e7ap\u0131 b\u00fcy\u00fcd\u00fck\u00e7e daha uzaklar\u0131 g\u00f6rmeye ba\u015fl\u0131yoruz, di\u011fer bir deyi\u015fle, \u201c\u00e7evrenimiz geni\u015fliyor\u201d. Bu geni\u015flemenin \u201cuzay\u0131n geni\u015flemesiyle\u201d ilgisi yoktur!<\/p>\n

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A\u00e7\u0131sal \u00e7\u00f6z\u00fcn\u00fcrl\u00fck: (sol) a\u00e7\u0131sal \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fcn artmas\u0131yla bulutsu izlenimi veren ortam\u0131n asl\u0131nda \u00e7ift y\u0131ld\u0131z dizgesi oldu\u011fu anla\u015f\u0131l\u0131yor.\u00a0 (sa\u011f) Bir g\u00f6kadan\u0131n g\u00f6r\u00fcnt\u00fcs\u00fcnde a\u00e7\u0131sal \u00e7\u00f6z\u00fcn\u00fcrl\u00fck A-B-C-D s\u0131ras\u0131yla g\u00f6r\u00fcnt\u00fcde netli\u011fi sa\u011fl\u0131yor.<\/figcaption><\/figure>\n
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Zaman \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fc: (sol) Bir atarca modeli. \u00d6zekteki mavi nokta n\u00f6tron y\u0131ld\u0131z\u0131; beyaz \u00e7ember yay par\u00e7alar\u0131 manyetik alan kuvvet \u00e7izgileri; mavi renkli beysbol sopas\u0131 benzeri b\u00f6lgeler n\u00f6tron y\u0131ld\u0131z\u0131n manyetik u\u00e7lak b\u00f6lgelerinde \u00fcretilen radyo dalgalar\u0131. N\u00f6tron y\u0131ld\u0131z\u0131n d\u00f6nme d\u00f6nemi saniyenin fraksiyonlar\u0131ndad\u0131r; (sa\u011f) Atarcadan g\u00f6zlemciye ard\u0131\u015f\u0131k olarak gelen de\u011fi\u015fik frekanslardaki \u2018deniz feneri benzeri patlamalar\u2019. Zaman \u00e7\u00f6z\u00fcn\u00fcrl\u00fc\u011f\u00fc bu denli geli\u015fmeden \u00f6nce atarcadan alg\u0131lanan radyo dalgalar\u0131 s\u00fcrekliymi\u015f izlenimi veriyordu.<\/figcaption><\/figure>\n

Kuazarlar ger\u00e7ekten \u00e7ok uzakta m\u0131?<\/strong><\/p>\n

Yinelemede yarar var: k\u0131rm\u0131z\u0131ya kayma de\u011ferleri en \u00e7ok 0,5 olan Sb <\/em>t\u00fcr\u00fc g\u00f6kadalar i\u00e7in saptanm\u0131\u015f olan bu ili\u015fkiyi, k\u0131rm\u0131z\u0131ya kaymalar\u0131 \u00f6l\u00e7\u00fclmemi\u015f olan di\u011fer g\u00f6kadalara dek uzatan biliminsanlar\u0131 Eddington<\/strong> ve Lemaitre<\/strong>\u2019d\u0131r. Evet, \u201cser\u00e7enin iki aya\u011f\u0131 iki kanad\u0131 ve gagas\u0131 var ve u\u00e7ar. \u00d6yleyse, iki aya\u011f\u0131, iki kanad\u0131 ve gagas\u0131 olan her ku\u015f u\u00e7ar\u201d gibisinden bir \u00f6nerme, hindi, deveku\u015fu, tavuk, evcil \u00f6rdek vb. kanatl\u0131lar i\u00e7in ge\u00e7erli de\u011fildir! Dahas\u0131, Hubble zaman\u0131nda bilinmeyen ancak bug\u00fcn g\u00f6kada yaz\u0131n\u0131na girmi\u015f olan de\u011fi\u015fik t\u00fcrden g\u00f6kadalar vard\u0131r. Bunlar \u2018toptanc\u0131\u2019 isimleriyle Etkin G\u00f6kada \u00c7ekirdekleri<\/strong> (AGN) olarak an\u0131lmaktad\u0131r. Bu g\u00f6kadalar, sarmal kollular\u0131n toplam n\u00fcfus i\u00e7indeki % 25 oran\u0131n\u0131 kim bilir ne denli k\u00fc\u00e7\u00fcltt\u00fc!<\/p>\n

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\u015eekil 3. Hubble kutusu (\u201cHubble\u2019s Box\u201d) d\u0131\u015f\u0131ndaki baz\u0131 g\u00f6kadalar ve kuazarlar do\u011frusal ba\u011f\u0131nt\u0131 ile betimlenemez. Bu nedenle evrenin geni\u015flemesinden s\u00f6z etmek do\u011fru de\u011fildir.<\/figcaption><\/figure>\n

\u2018Ne\u2019li\u011fine k\u0131saca de\u011findi\u011fimiz kuazarlar ger\u00e7ekten \u00e7ok uzakta m\u0131? Kuazarlar\u0131n sergiledi\u011fi k\u0131rm\u0131z\u0131ya kayman\u0131n \u2018inan\u0131lmaz\u2019 boyutlar\u0131, kozmolojik k\u0131rm\u0131z\u0131ya kayma<\/strong> kavram\u0131n\u0131 g\u00fcndeme getirmi\u015ftir. Kozmolojik k\u0131rm\u0131z\u0131ya kayma, Doppler kaymas\u0131 ve \u00e7ekimsel k\u0131rm\u0131z\u0131ya kaymadan farkl\u0131d\u0131r. Kozmolojik k\u0131rm\u0131z\u0131ya kayma uzay\u0131n geni\u015flemesinin do\u011furdu\u011fu bir etki olarak sunulur. Ancak, bunu s\u00f6yleyebilmek i\u00e7in Hubble kutusunun<\/strong> d\u0131\u015f\u0131nda yer alan t\u00fcm g\u00f6kadalar\u0131n veya g\u00f6kcisimlerinin da\u011f\u0131l\u0131m\u0131n\u0131n da do\u011frusal yasaya uygun olmas\u0131 gerekir (\u015eekil 3).<\/p>\n

\u015eekil 4 kuazarlar i\u00e7in \u00e7izilmi\u015f olan Hubble ili\u015fkisidir<\/strong>. Asl\u0131nda \u201cili\u015fkisizli\u011fi\u201d demek daha do\u011frudur. Ger\u00e7ekten de kuazarlar\u0131n g\u00f6r\u00fcn\u00fcrdeki parlakl\u0131\u011f\u0131 ile k\u0131rm\u0131z\u0131ya kaymalar\u0131 aras\u0131nda bir ili\u015fkinin varl\u0131\u011f\u0131ndan s\u00f6z edebilmek i\u00e7in \u2018bilim kar\u015f\u0131t\u0131\u2019 derecesinde yanl\u0131 olmak gerekiyor.<\/p>\n

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\u015eekil 4. Kuazarlar i\u00e7in Hubble ba\u011f\u0131nt\u0131s\u0131. Grafikteki noktalar\u0131n bir do\u011fru ile anlat\u0131lamayaca\u011f\u0131na dikkat ediniz.<\/figcaption><\/figure>\n

\u015eekil 4\u2019deki g\u00f6zlem verilerine \u00e7ok \u00e7e\u015fitli istatistiksel y\u00f6ntemler uygulanmas\u0131na, ayn\u0131 verilerin de\u011fi\u015fik bi\u00e7imlerde yerle\u015ftirilmi\u015f olmas\u0131na kar\u015f\u0131n veri noktalar\u0131n\u0131n da\u011f\u0131l\u0131m\u0131 asla ve asla e\u011fimi 5 olmas\u0131 gereken bir do\u011fru ile temsil edilememi\u015ftir. E\u011fer bunu ba\u015farabilseydik, di\u011fer bir deyi\u015fle, Hubble\u2019\u0131n Sb <\/em>t\u00fcr\u00fc g\u00f6kadalar i\u00e7in saptad\u0131\u011f\u0131 do\u011frusal ili\u015fkinin, Hubble kutucu\u011funun d\u0131\u015f\u0131nda da ge\u00e7erli oldu\u011funu g\u00f6sterebilseydik, evrenin geni\u015fledi\u011finden s\u00f6z edebilirdik.<\/p>\n","protected":false},"excerpt":{"rendered":"

\u00dcnl\u00fc astrofizik\u00e7i Edwin Hubble 1936 y\u0131l\u0131nda yay\u0131mlatt\u0131\u011f\u0131 The Realm of Nebulae adl\u0131 kitab\u0131n\u0131n hi\u00e7bir yerinde \u201cuzay geni\u015fliyor\u201d demedi\u011fi gibi, \u00e7al\u0131\u015fmas\u0131n\u0131 yanl\u0131\u015f yorumlayan evrenbilimcileri de uyar\u0131yor. Hubble zaman\u0131nda g\u00f6kadalar, eliptik, sarmal, \u00e7ubuklu sarmal, d\u00fczensiz olarak s\u0131n\u0131fland\u0131r\u0131l\u0131yordu (\u015eekil 1). Hubble, 60 adet Sb t\u00fcr\u00fc g\u00f6kada \u00fczerinde yapt\u0131\u011f\u0131 \u00e7al\u0131\u015fmada, g\u00f6kadalar\u0131n g\u00f6r\u00fcn\u00fcrdeki parlakl\u0131\u011f\u0131yla g\u00f6kada tayflar\u0131ndaki \u00e7izgilerin sergiledi\u011fi k\u0131rm\u0131z\u0131ya kayma […]<\/p>\n","protected":false},"author":475,"featured_media":26152,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[30,19,26],"tags":[247,3382,291,3383],"class_list":["post-26151","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-astronomi","category-bilim-gundemi","category-fizik","tag-astrofizik","tag-edwin-hubble","tag-galaksiler","tag-kuazar"],"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