{"id":5142,"date":"2016-04-18T19:32:52","date_gmt":"2016-04-18T16:32:52","guid":{"rendered":"http:\/\/bilimvegelecek.com.tr\/?p=5142"},"modified":"2016-04-18T19:32:52","modified_gmt":"2016-04-18T16:32:52","slug":"yercekimi-sabitinin-degeri-neden-bu-kadar-degisken","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2016\/04\/18\/yercekimi-sabitinin-degeri-neden-bu-kadar-degisken","title":{"rendered":"Yer\u00e7ekimi sabitinin de\u011feri neden bu kadar de\u011fi\u015fken?"},"content":{"rendered":"<p><strong>G\u00f6rsel a\u00e7\u0131klamas\u0131: <\/strong>\u00d6l\u00e7\u00fclen 13 farkl\u0131 G de\u011feri, 5,9 y\u0131ll\u0131k LOD (g\u00fcn uzunlu\u011fu) \u00f6l\u00e7\u00fcmleriyle \u00f6rt\u00fc\u015f\u00fcyor. Ayk\u0131r\u0131 de\u011ferler 2014\u2019teki kuantum \u00f6l\u00e7\u00fcmlerinden ve sapma oldu\u011fu bilinen 1996 de\u011ferlerinden olu\u015fuyor. Ye\u015fil nokta 5,9 y\u0131ll\u0131k periyot ortadan kald\u0131r\u0131ld\u0131\u011f\u0131nda elde edilen ortalama de\u011feri temsil ediyor. \u00a9 J. D. Anderson, et al. \u00a9 2015 EPLA<\/p>\n<p>&nbsp;<\/p>\n<p>Newton\u2019\u0131n yer\u00e7ekimi sabiti ge\u00e7ti\u011fimiz 40 y\u0131l boyunca \u00e7ok kez \u00f6l\u00e7\u00fcld\u00fc, ama sonu\u00e7lar rasgele veya sistem hatas\u0131 olarak de\u011ferlendirilemeyecek kadar de\u011fi\u015fkendi. Yak\u0131n zamanda biliminsanlar\u0131 \u00f6l\u00e7\u00fclen G de\u011ferlerinin sin\u00fcs dalgas\u0131 gibi 5,9 y\u0131ll\u0131k periyotlara sahip oldu\u011funu \u00f6l\u00e7t\u00fc. Onlara g\u00f6re, de\u011fi\u015fen G de\u011fil, ama bir \u015fey \u00f6l\u00e7\u00fcmleri etkiliyor.<\/p>\n<p>Bu \u201c\u015fey\u201din ne oldu\u011funa dair bir ipucu olarak, biliminsanlar\u0131 g\u00fcn uzunlu\u011fu (Length of Day-LOD) da denilen, D\u00fcnya\u2019n\u0131n kendi etraf\u0131ndaki 5,9 y\u0131ll\u0131k d\u00f6n\u00fc\u015f periyotlar\u0131n\u0131n, G \u00f6l\u00e7\u00fcmleriyle birebir \u00f6rt\u00fc\u015ft\u00fc\u011f\u00fcn\u00fc \u00f6l\u00e7t\u00fc. Biliminsanlar\u0131 G\/LOD ili\u015fkisine neyin yol a\u00e7t\u0131\u011f\u0131n\u0131 tam olarak s\u00f6yleyemeseler de, k\u00fc\u00e7\u00fck bir olas\u0131l\u0131kla D\u00fcnya\u2019n\u0131n merkezinde d\u00f6nen ak\u0131mlarla a\u00e7\u0131klanabilece\u011fini \u00f6nerdiler. De\u011fi\u015fen ak\u0131mlar D\u00fcnya\u2019n\u0131n LOD ile ilgili olarak d\u00f6nme eylemsizli\u011fini de\u011fi\u015ftiriyor olabilir ve yo\u011funluk de\u011fi\u015fimleri de G\u2019yi etkiliyor olabilir.<\/p>\n<p>CalTech\u2019ten emekli biliminsan\u0131 John D. Anderson, G ve g\u00fcn uzunlu\u011fu aras\u0131ndaki ili\u015fkiye dair <em>EPL<\/em>\u2019de bir makale yay\u0131mlad\u0131. Makaleye g\u00f6re, G\u2019nin de\u011fi\u015fimleri tahmin edilebilir bir \u015fekilde \u00f6l\u00e7\u00fclebiliyor. Anderson, 5,9 y\u0131ll\u0131k periyot tespit edildikten sonra \u00e7o\u011fu laboratuvar \u00f6l\u00e7\u00fcm\u00fcn\u00fcn buna bir sigmal\u0131k sapmayla uydu\u011funu s\u00f6yledi.<\/p>\n<p>Hem Newton\u2019\u0131n yer\u00e7ekimi kanununu hem de Einstein\u2019\u0131n genel g\u00f6relili\u011fini anlamak i\u00e7in sabit G de\u011feri bizim i\u00e7in \u00f6nemli. G sezgisel bir kavram de\u011fil ve yer\u00e7ekimi y\u00fcz\u00fcnden h\u0131zland\u0131r\u0131lan bir cismin ivmesi de (g, 9,81 m\/s<sup>2<\/sup>) de\u011fil.<\/p>\n<p>G\u2019nin resmi de\u011feri 6,673889 \u00d7 10<sup>\u221211<\/sup>\u00a0N\u00b7(m\/kg)<sup>2 <\/sup>ama analiz edilen 13 veriye g\u00f6re de\u011fer 6,672 \u00d7 10<sup>\u221211<\/sup>\u00a0N\u00b7(m\/kg)<sup>2<\/sup>\u00a0dan 6,675 \u00d7 10<sup>\u221211<\/sup>\u00a0N\u00b7(m\/kg)<sup>2<\/sup>\u2019a kadar de\u011fi\u015fiyor ve bu yakla\u015f\u0131k on binde birlik (10<sup>-4<\/sup>) bir de\u011fi\u015fim anlam\u0131na geliyor. Bu de\u011fi\u015fimler \u00e7o\u011funlukla \u00f6l\u00e7\u00fcm uyu\u015fmazl\u0131\u011f\u0131 olarak d\u00fc\u015f\u00fcn\u00fcl\u00fcrd\u00fc, \u00e7\u00fcnk\u00fc di\u011fer temel kuvvetlere g\u00f6re yer\u00e7ekimi daha zay\u0131f ve bu sebepten G\u2019yi \u00f6l\u00e7mek olduk\u00e7a zor.<\/p>\n<p>&nbsp;<\/p>\n<p><a href=\"http:\/\/bilimvegelecek.com.tr\/wp-content\/uploads\/yer\u00e7ekimi-de\u011fi\u015fimi-1.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-5143\" src=\"http:\/\/bilimvegelecek.com.tr\/wp-content\/uploads\/yer\u00e7ekimi-de\u011fi\u015fimi-1-300x185.jpg\" alt=\"yer\u00e7ekimi de\u011fi\u015fimi 1\" width=\"300\" height=\"185\" \/><\/a><\/p>\n<p><em>G\u00fcne\u015f d\u00f6ng\u00fcs\u00fc (toplam g\u00fcne\u015f lekesi say\u0131s\u0131n\u0131n ayl\u0131k ortalamas\u0131, siyah \u00e7izgi) G verileri ile s\u00fcrekli hizal\u0131 de\u011fil. \u00a9 J. D. Anderson, et al. \u00a92015 EPLA<\/em><\/p>\n<p>&nbsp;<\/p>\n<p>\u00d6l\u00e7mede zorluklar olmas\u0131na ra\u011fmen, yeni \u00e7al\u0131\u015fma \u00f6l\u00e7\u00fcmlerin kusurlu olmad\u0131\u011f\u0131n\u0131 \u00f6ng\u00f6r\u00fcyor, onun yerine \u00f6l\u00e7\u00fcm s\u00fcrecinde bir fakt\u00f6r de\u011fi\u015fiyor. Biliminsanlar\u0131n\u0131n ilk \u00f6nerisi 11 y\u0131ll\u0131k g\u00fcne\u015f periyotlar\u0131n\u0131n yakla\u015f\u0131k yar\u0131s\u0131 olarak d\u00fc\u015f\u00fcn\u00fclen 5,9 y\u0131ld\u0131. G\u00fcne\u015f aktivitesindeki de\u011fi\u015fimler G\u00fcne\u015f lekelerinin say\u0131s\u0131n\u0131 de\u011fi\u015ftirir ve bu D\u00fcnya\u2019n\u0131n atmosferini etkiler. Sonu\u00e7 olarak, D\u00fcnya\u2019n\u0131n d\u00f6nme eylemsizli\u011fi etkilenir. Fakat daha yak\u0131ndan incelendi\u011finde, G\u00fcne\u015f d\u00f6ng\u00fcs\u00fcn\u00fcn G verileriyle tamamen uyumlu olmad\u0131\u011f\u0131 g\u00f6r\u00fclm\u00fc\u015ft\u00fcr.<\/p>\n<p>Ara\u015ft\u0131rmac\u0131lar daha sonra 2013\u2019te <em>Nature<\/em>\u2019da yay\u0131mlanm\u0131\u015f ve 5,9 y\u0131ll\u0131k d\u00f6ng\u00fcy\u00fc LOD ile ili\u015fkilendiren bir makaleyi ele ald\u0131lar. Oradaki verilere g\u00f6re, g\u00fcn uzunlu\u011fu her g\u00fcn \u00e7ok az de\u011fi\u015fiyor. Baz\u0131 g\u00fcnler \u00e7ok az uzun, baz\u0131 g\u00fcnler \u00e7ok az k\u0131sa. LOD de\u011fi\u015fimleri D\u00fcnya\u2019n\u0131n kendi ekseni etraf\u0131ndaki d\u00f6n\u00fc\u015f h\u0131z\u0131yla ilgilidir ve son \u00e7al\u0131\u015fmaya g\u00f6re buradaki periyodik dalgalanmalar G ile m\u00fckemmel bir uyum i\u00e7inde. (Buradaki g\u00fcn uzunlu\u011fu \u00f6l\u00e7\u00fcmleri D\u00fcnya\u2019n\u0131n d\u00f6n\u00fc\u015f\u00fcn\u00fcn Ay y\u00fcz\u00fcnden olu\u015fan gelgitlerle uzun zaman aral\u0131\u011f\u0131nda de\u011fi\u015fmesinden farkl\u0131d\u0131r.)<\/p>\n<p>Aradaki yak\u0131n ili\u015fkiye ra\u011fmen, LOD de\u011fi\u015fimleri on binde birlik (10<sup>-4<\/sup>) de\u011fi\u015fimi a\u00e7\u0131klamada yetersizdir, \u00e7\u00fcnk\u00fc LOD\u2019nin G\u2019ye etkisi 10<sup>-5 <\/sup>seviyesindedir. LOD de\u011fi\u015fimleri, G de\u011fi\u015fimlerine sebep olamayaca\u011f\u0131na g\u00f6re, ara\u015ft\u0131rmac\u0131lar D\u00fcnya\u2019n\u0131n merkezindeki hareketlerin de\u011fi\u015fiminin veya ba\u015fka jeofiziksel s\u00fcre\u00e7lerin de etkisi olabilece\u011fini tahmin ediyor.<\/p>\n<p>De\u011fi\u015fimlerin \u201cyeni fizik\u201d ile a\u00e7\u0131klanabilece\u011fi d\u00fc\u015f\u00fcn\u00fclse de, biliminsanlar\u0131 bunun m\u00fcmk\u00fcn olmad\u0131\u011f\u0131na inan\u0131yor. Al\u0131nan 13 \u00f6l\u00e7\u00fcmden birisi LENS-14 isimli ilk kuantum \u00f6l\u00e7\u00fcm\u00fc idi. \u00d6l\u00e7\u00fclen G de\u011feri ayk\u0131r\u0131 iki noktadan b\u00fcy\u00fck olan\u0131yd\u0131 ve bu noktalar\u0131n di\u011feri sorunlu oldu\u011fu bilinen 1996 deneyi idi. Daha fazla kuantum \u00f6l\u00e7\u00fcm\u00fc yap\u0131larak bu \u00f6l\u00e7\u00fcmlerin neden klasik \u00f6l\u00e7\u00fcmlerden sapt\u0131\u011f\u0131n\u0131n anla\u015f\u0131lmas\u0131 laz\u0131m.<\/p>\n<p>Ek olarak, biliminsanlar\u0131 G\/LOD ili\u015fkisinin hik\u00e2yenin t\u00fcm\u00fc oldu\u011funa ikna olmu\u015f de\u011filler ve gelecekte yeni ba\u011flant\u0131lar ara\u015ft\u0131rmay\u0131 planl\u0131yorlar. Anderson, D\u00fcnya \u00e7evresindeki uzay ara\u00e7lar\u0131n\u0131 sebepsiz h\u0131zland\u0131ran periyodik tuhafl\u0131\u011f\u0131n (earth flyby anomaly) bu konuyla ili\u015fkisinin ara\u015ft\u0131r\u0131laca\u011f\u0131n\u0131 s\u00f6yledi.<\/p>\n<p><strong>\u00a0<\/strong><\/p>\n<p><strong>\u00c7eviren: Nazl\u0131 Turan<\/strong><\/p>\n<p><strong><em>Bo\u011fazi\u00e7i \u00dcniv. Makine M\u00fchendisli\u011fi B\u00f6l\u00fcm\u00fc YL<\/em><\/strong><\/p>\n<p><strong>\u00a0<\/strong><\/p>\n<p><strong>\u00a0<\/strong><\/p>\n<p><strong>Kaynak: <\/strong>http:\/\/phys.org\/news\/2015-04-gravitational-constant-vary.html<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>G\u00f6rsel a\u00e7\u0131klamas\u0131: \u00d6l\u00e7\u00fclen 13 farkl\u0131 G de\u011feri, 5,9 y\u0131ll\u0131k LOD (g\u00fcn uzunlu\u011fu) \u00f6l\u00e7\u00fcmleriyle \u00f6rt\u00fc\u015f\u00fcyor. Ayk\u0131r\u0131 de\u011ferler 2014\u2019teki kuantum \u00f6l\u00e7\u00fcmlerinden ve sapma oldu\u011fu bilinen 1996 de\u011ferlerinden olu\u015fuyor. Ye\u015fil nokta 5,9 y\u0131ll\u0131k periyot ortadan kald\u0131r\u0131ld\u0131\u011f\u0131nda elde edilen ortalama de\u011feri temsil ediyor. \u00a9 J. D. Anderson, et al. \u00a9 2015 EPLA &nbsp; Newton\u2019\u0131n yer\u00e7ekimi sabiti ge\u00e7ti\u011fimiz 40 y\u0131l [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":5143,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[30,19,26],"tags":[],"class_list":["post-5142","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-astronomi","category-bilim-gundemi","category-fizik"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/5142","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/comments?post=5142"}],"version-history":[{"count":0,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/5142\/revisions"}],"wp:attachment":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media?parent=5142"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/categories?post=5142"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/tags?post=5142"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}