I\u015f\u0131k y\u0131l\u0131, \u0131\u015f\u0131\u011f\u0131n bir y\u0131lda bo\u015flukta kat etti\u011fi mesafeyi ifade eden bir \u00f6l\u00e7\u00fc birimidir. I\u015f\u0131k, evrendeki en h\u0131zl\u0131 \u015feydir ve saniyede yakla\u015f\u0131k 300,000 kilometre h\u0131zla hareket eder. Bu h\u0131zla, \u0131\u015f\u0131k bir y\u0131lda tam 9.46 trilyon kilometre mesafe kat eder. Yani bir \u0131\u015f\u0131k y\u0131l\u0131, \u00e7ok ama \u00e7ok uzun bir mesafeyi ifade etmektedir.<\/p>\n
Evrenimiz \u00f6ylesine b\u00fcy\u00fck ki, kilometre veya mil gibi g\u00fcnl\u00fck hayatta kulland\u0131\u011f\u0131m\u0131z birimler, g\u00f6k cisimlerinin aras\u0131ndaki mesafeleri ifade etmek i\u00e7in yeterli olmuyor. Ve bu y\u00fczden astronomlar, \u0131\u015f\u0131k y\u0131l\u0131n\u0131 kullan\u0131rlar. I\u015f\u0131k y\u0131l\u0131 sayesinde, uzaktaki y\u0131ld\u0131zlar\u0131n, galaksilerin ve di\u011fer g\u00f6k cisimlerinin mesafelerini daha pratik bir \u015fekilde \u00f6l\u00e7ebiliriz ancak bu mesafeleri anlayabilmemiz i\u00e7in I\u015f\u0131k Y\u0131l\u0131’n\u0131n temelini de bilmemiz gerekmektedir. Aksi halde bizim i\u00e7in yaln\u0131zca bir say\u0131dan ibaret olacakt\u0131r.<\/p>\n
I\u015f\u0131k y\u0131l\u0131, sadece mesafe \u00f6l\u00e7mekle kalmaz, ayn\u0131 zamanda zaman hakk\u0131nda da bilgi verir. Uzak bir y\u0131ld\u0131zdan gelen \u0131\u015f\u0131\u011f\u0131 g\u00f6rd\u00fc\u011f\u00fcm\u00fczde, asl\u0131nda o y\u0131ld\u0131z\u0131n y\u0131llar, hatta milyonlarca y\u0131l \u00f6nceki halini g\u00f6r\u00fcyoruz. \u00c7\u00fcnk\u00fc \u0131\u015f\u0131\u011f\u0131n bize ula\u015fmas\u0131 uzun zaman al\u0131r. <\/p>\n
\u00d6rne\u011fin:<\/p>\n
En Yak\u0131n Y\u0131ld\u0131z: G\u00fcne\u015f’e en yak\u0131n y\u0131ld\u0131z sistemi olan Alpha Centauri, yakla\u015f\u0131k 4.37 \u0131\u015f\u0131k y\u0131l\u0131 uzakl\u0131ktad\u0131r. Bu, Alpha Centauri’den \u00e7\u0131kan \u0131\u015f\u0131\u011f\u0131n bize ula\u015fmas\u0131n\u0131n 4.37 y\u0131l s\u00fcrd\u00fc\u011f\u00fc anlam\u0131na gelir.
\nAndromeda Galaksisi: En yak\u0131n b\u00fcy\u00fck galaksi olan Andromeda, yakla\u015f\u0131k 2.5 milyon \u0131\u015f\u0131k y\u0131l\u0131 uzakl\u0131ktad\u0131r. Bu galaksiden gelen \u0131\u015f\u0131k, 2.5 milyon y\u0131l \u00f6nce yola \u00e7\u0131km\u0131\u015ft\u0131r!<\/p>\n
I\u015f\u0131k y\u0131l\u0131 kavram\u0131, evrenin ne kadar b\u00fcy\u00fck ve b\u00fcy\u00fcleyici oldu\u011funu anlamam\u0131za yard\u0131mc\u0131 olur. Gece g\u00f6ky\u00fcz\u00fcne bakt\u0131\u011f\u0131n\u0131zda, asl\u0131nda milyarlarca y\u0131l \u00f6ncesine bak\u0131yorsunuz. I\u015f\u0131k y\u0131l\u0131 sayesinde, evrenin derinliklerini ve uzak ge\u00e7mi\u015fini ke\u015ffetme \u015fans\u0131na sahip\u00a0oluyorsunuz. Olduk\u00e7a d\u00fc\u015f\u00fcnd\u00fcr\u00fcc\u00fc olan bu olay kim olursa olsun d\u00fc\u015f\u00fcnd\u00fcrmekte ve etkilemektedir.<\/p>\n