{"id":35959,"date":"2019-08-11T03:37:55","date_gmt":"2019-08-11T00:37:55","guid":{"rendered":"https:\/\/bilimvegelecek.com.tr\/?p=35959"},"modified":"2019-08-15T11:49:27","modified_gmt":"2019-08-15T08:49:27","slug":"bilimin-onculeri-william-harvey-1578-1657","status":"publish","type":"post","link":"https:\/\/bilimvegelecek.com.tr\/index.php\/2019\/08\/11\/bilimin-onculeri-william-harvey-1578-1657","title":{"rendered":"Bilimin \u00d6nc\u00fcleri: William Harvey (1578-1657)"},"content":{"rendered":"

Atronomide Kopernik\u2019in, fizikte Galileo\u2019nun ba\u015flatt\u0131\u011f\u0131 devrimci at\u0131l\u0131m\u0131 t\u0131pta Harvey ger\u00e7ekle\u015ftirir. Kan dola\u015f\u0131m\u0131 \u00fczerindeki \u00e7al\u0131\u015fmas\u0131yla bilim tarihine ge\u00e7en Harvey, yaln\u0131z bu \u00e7al\u0131\u015fmas\u0131yla de\u011fil, t\u0131p alan\u0131nda yerle\u015fik \u00f6nyarg\u0131lar\u0131 k\u0131rmakta g\u00f6sterdi\u011fi diren\u00e7le de \u00f6nc\u00fc ki\u015fili\u011fini kan\u0131tlam\u0131\u015ft\u0131r. \u00d6zel ya\u015fam\u0131 renksiz ve tekd\u00fcze ge\u00e7en Harvey\u2019in bilim adam\u0131 olarak b\u00fcy\u00fckl\u00fc\u011f\u00fcn\u00fc iki \u00f6zelli\u011finde bulmaktay\u0131z: 1) Ger\u00e7e\u011fin, k\u00f6keni hangi otoriteye dayan\u0131rsa dayans\u0131n \u00f6nyarg\u0131larda de\u011fil, nesnel g\u00f6zlem verilerinde oldu\u011fu inanc\u0131; 2) Dini inan\u00e7lardan kaynaklanm\u0131\u015f bile olsa her t\u00fcrl\u00fc ba\u011fnazl\u0131\u011fa kar\u015f\u0131 durma cesareti.<\/p>\n

Ya\u015fad\u0131\u011f\u0131 d\u00f6nemde b\u00fcy\u00fcc\u00fcl\u00fck, resmi yasa\u011fa kar\u015f\u0131n, halk kesiminde yayg\u0131n bir uygulamayd\u0131. O s\u0131rada y\u0131k\u0131ma yol a\u00e7an b\u00fcy\u00fck bir deniz f\u0131rt\u0131nas\u0131ndan h\u00fck\u00fcmet b\u00fcy\u00fcc\u00fcleri sorumlu tutmu\u015ftu. Bu gerek\u00e7e ile yakalanan bir grup savunmas\u0131z zavall\u0131 insan\u0131 \u00f6l\u00fcm cezas\u0131ndan Kral\u2019\u0131n ba\u015fhekimi Harvey kurtar\u0131r. Harvey\u2019in, do\u011fal y\u0131k\u0131mlarla\u201db\u00fcy\u00fcc\u00fcl\u00fck\u201d denen prati\u011fin bir ili\u015fkisi olmad\u0131\u011f\u0131na ba\u015fta Kral olmak \u00fczere yetkilileri inand\u0131rmas\u0131 kolay olmam\u0131\u015ft\u0131, ku\u015fkusuz.<\/p>\n

\u0130ngiltere\u2019de k\u00fc\u00e7\u00fck bir kasabada 1 Nisan g\u00fcn\u00fc d\u00fcnyaya gelen William \u00e7ocuklu\u011fu boyunca arkada\u015flar\u0131n\u0131n, \u201cNisan Bal\u0131\u011f\u0131\u201d sata\u015fmalar\u0131na hedef olmu\u015ftu. Varl\u0131kl\u0131 babas\u0131 ayn\u0131 zamanda kentin belediye ba\u015fkan\u0131yd\u0131. William 15 ya\u015f\u0131na geldi\u011finde, \u00fcniversiteye girmeye haz\u0131rd\u0131; s\u0131k\u0131 bir s\u0131navdan ge\u00e7erek Cambridge\u2019e girmeyi ba\u015fard\u0131. Bilimin di\u011fer kollar\u0131nda oldu\u011fu gibi t\u0131pta da g\u00f6zlem ve deneyin a\u011f\u0131rl\u0131k kazanmaya ba\u015flad\u0131\u011f\u0131 d\u00f6nemdi bu! \u00d6yle ki, \u00fcniversiteye ilk kez, \u00f6l\u00fcm cezas\u0131na \u00e7arpt\u0131r\u0131lan iki su\u00e7lunun cesetleri \u00fczerinde inceleme yapma izni verilmi\u015fti. William\u2019\u0131n t\u0131p alan\u0131nda ya\u015fam boyu yo\u011funla\u015fan ilgisi, i\u015fte te\u015frih masas\u0131ndaki bu incelemeye kat\u0131lmas\u0131yla ba\u015flar. Orta\u00e7a\u011f boyunca astronomi ile t\u0131p \u00f6n planda tutulan ba\u015fl\u0131ca iki \u00e7al\u0131\u015fmayd\u0131. Astronominin b\u00fcy\u00fck otoritesi Ptolemy, Aristoteles\u00e7i d\u00fc\u015f\u00fcncenin dokunulmaz simgesiydi.<\/p>\n

\"\"
Harvey incelemelerini daha ileri g\u00f6t\u00fcrerek, damarlar\u0131n kan\u0131n ak\u0131\u015f\u0131na tek y\u00f6nl\u00fc ge\u00e7it verdi\u011fini belirler. Bu ge\u00e7itler \u201c\u00e7ek-valf\u201d i\u015flevi g\u00f6ren kanatlarla donat\u0131lm\u0131\u015ft\u0131r. Kanatlar atardamarlarda kan\u0131n v\u00fccuda ak\u0131\u015f\u0131n\u0131, toplardamarlarda kalbe d\u00f6n\u00fc\u015f\u00fcn\u00fc sa\u011flamaktad\u0131r.<\/figcaption><\/figure>\n

T\u0131pta ise \u00f6\u011fretisi tart\u0131\u015fmas\u0131z kabul edilen otorite Bergamal\u0131 Galen (MS 131-201) idi. Roma \u0130mparatoru Marcus Aurelius\u2019un (MS 121 – 180) hekimi olan Galen, \u00f6zellikle anatomi alan\u0131ndaki \u00e7al\u0131\u015fmalar\u0131yla \u00fcnl\u00fcyd\u00fc. O zaman insan cesedi \u00fczerinde incelemeye izin yoktu. Galen ister istemez \u00e7al\u0131\u015fmalar\u0131nda domuz, k\u00f6pek, maymun gibi hayvan \u00f6l\u00fcleriyle yetinmek zorundayd\u0131. Bu y\u00fczden, incelemeleri s\u0131n\u0131rl\u0131 kalman\u0131n \u00f6tesinde birtak\u0131m yanl\u0131\u015fl\u0131klara d\u00fc\u015fmekten kurtulamaz. R\u00f6nesans d\u00f6neminde insan cesedi \u00fczerinde inceleme serbest b\u0131rak\u0131lm\u0131\u015ft\u0131. Ancak anatomi profes\u00f6rleri te\u015frih i\u015fini asistanlar\u0131na b\u0131rakt\u0131klar\u0131 i\u00e7in \u00f6nemli bir ilerleme sa\u011flanam\u0131yor, Galen \u00f6\u011fretisi etkisini s\u00fcrd\u00fcr\u00fcyordu.<\/p>\n

Bu gelene\u011fi ilk sorgulayan bilim adam\u0131 Andreas Vesalius olur. Padua \u00dcniversitesi\u2019nin 23 ya\u015f\u0131ndaki bu gen\u00e7 profes\u00f6r\u00fc (1514-1561) anatomi \u00e7al\u0131\u015fmalar\u0131n\u0131 kendisi \u00fcstlenir, inceleme y\u00f6ntem ve ara\u00e7lar\u0131n\u0131 geli\u015ftirmede \u00f6nemli ad\u0131mlar atar. \u0130nsan V\u00fccut Yap\u0131s\u0131 \u00dczerine adl\u0131 yap\u0131t\u0131nda g\u00f6zlem ve bulgular\u0131n\u0131 ortaya koyan Vesalius, Galen \u00f6\u011fretisinde saptad\u0131\u011f\u0131 yanl\u0131\u015fl\u0131klar\u0131 belirtmekten de geri kalmaz. Anatomi g\u00f6zlemsel bir bilim olma yoluna onunla girer. Ne var ki, Vesalius fizyolojideki \u00e7al\u0131\u015fmalar\u0131nda ayn\u0131 ba\u015far\u0131y\u0131 g\u00f6steremez. O da geleneksel \u00f6\u011fretiye uyarak v\u00fccuda al\u0131nan besinin \u00f6nce karaci\u011ferde \u201cdo\u011fal ruh\u201d kazand\u0131\u011f\u0131, sonra kalpte ya\u015famsal ruha, beyinde ise hayvansal ruha d\u00f6n\u00fc\u015ft\u00fc\u011f\u00fc inanc\u0131ndayd\u0131.<\/p>\n

Ger\u00e7ek bir nesne olmaktan \u00e7ok bir \u00f6zellik sayd\u0131\u011f\u0131 hayvansal ruhu, sinir sistemi arac\u0131l\u0131\u011f\u0131yla, bedensel devinim ve davran\u0131\u015flar\u0131 d\u00fczenleyen bir g\u00fc\u00e7 olarak alg\u0131l\u0131yordu. \u201cMetafiziksel\u201d diyebilece\u011fimiz bu t\u00fcr saplant\u0131lar\u0131na kar\u015f\u0131n, Vesalius\u2019un bir g\u00f6zleminin bug\u00fcn de ge\u00e7erlili\u011fini korudu\u011fu s\u00f6ylenebilir: \u201cBeynin yap\u0131s\u0131na gelince, \u015fimdiye dek inceledi\u011fim maymun, k\u00f6pek, kedi vb. d\u00f6rt ayakl\u0131 hayvanlar\u0131n nerdeyse ayr\u0131nt\u0131larda bile insanla benzerlik i\u00e7inde oldu\u011funu g\u00f6rd\u00fcm.\u201d<\/p>\n

Harvey, Cambridge\u2019de ba\u015flad\u0131\u011f\u0131 t\u0131p \u00f6\u011frenimini, Vesalius ve Galileo\u2019nun adlar\u0131yla \u00fcn kazanan Padua \u00dcniversitesi\u2019nde s\u00fcrd\u00fcr\u00fcr. Ama gen\u00e7 bilim adam\u0131 arad\u0131\u011f\u0131n\u0131 bulamaz: Vesalius\u2019un a\u00e7t\u0131\u011f\u0131 \u00e7\u0131\u011f\u0131r \u00f6l\u00fcm\u00fcnden sonra terk edilmi\u015f, Galen \u00f6\u011fretisi yeniden egemenli\u011fini kurmu\u015ftu. Hayal k\u0131r\u0131kl\u0131\u011f\u0131na u\u011frayan Harvey duruma katlan\u0131r, diplomas\u0131n\u0131 al\u0131ncaya dek tepkisini ortaya koymaz. \u00dclkesine d\u00f6nd\u00fc\u011f\u00fcnde, \u00f6\u011frenimine ara verdi\u011fi \u00fcniversitesi onu \u00f6\u011fretim g\u00f6revlisi olarak kabul eder. Esmer ve \u00e7elimsiz Harvey b\u00fcy\u00fck bir isten\u00e7le koyuldu\u011fu \u00e7al\u0131\u015fmas\u0131nda sergiledi\u011fi ba\u015far\u0131 ve \u00fcst\u00fcn yetene\u011fiyle \u00e7ok ge\u00e7meden \u00f6nc\u00fc konumuna gelir. Ayn\u0131 zamanda Saray\u2019\u0131n ba\u015fhekimidir. Kral Birinci Charles\u2019\u0131n Cromwel (1599 -1658) kar\u015f\u0131s\u0131nda yenilgiye u\u011fray\u0131p idam edilmesine kar\u015f\u0131n, Harvey sayg\u0131nl\u0131\u011f\u0131n\u0131 yitirmez, ara\u015ft\u0131rmalar\u0131n\u0131 daha yo\u011fun bir \u00e7abayla s\u00fcrd\u00fcr\u00fcr. \u015eimdi sorulabilir: William Harvey\u2019i bilimin \u00f6nc\u00fcleri aras\u0131na y\u00fccelten ba\u015far\u0131s\u0131 neydi?<\/p>\n

Bu soruya verece\u011fimiz yan\u0131t iki nokta i\u00e7ermektedir, ilk nokta Harvey\u2019in titiz ve sab\u0131rl\u0131 bir g\u00f6zlemci olarak verdi\u011fi \u00f6rnektir. Kalbin yap\u0131 ve i\u015fleyi\u015fine ili\u015fkin yerle\u015fik \u00f6\u011freti \u00f6nyarg\u0131ya dayanan hatalarla y\u00fckl\u00fcyd\u00fc. \u00d6rne\u011fin, damarlardaki kan\u0131n maviye \u00e7almas\u0131, arterlerdeki kan\u0131n ise a\u00e7\u0131k k\u0131rm\u0131z\u0131 olmas\u0131 iki ayr\u0131 sistem olarak alg\u0131lanm\u0131\u015ft\u0131. Ancak kan\u0131n bir sistemden di\u011ferine nas\u0131l ge\u00e7ti\u011fi bir sorundu. Galen ve onu izleyenler ge\u00e7i\u015fi, septumun (kalbi ortadan ikiye b\u00f6len dikey duvar\u0131n) ince g\u00f6zenekli bir doku oldu\u011fu varsay\u0131m\u0131yla a\u00e7\u0131klam\u0131\u015flard\u0131. Oysa septum hi\u00e7bir s\u0131z\u0131nt\u0131ya elvermeyen kat\u0131 bir yap\u0131ya sahiptir. D\u00fczeltilmesi gereken bir ba\u015fka hata da, kan\u0131n ak\u0131\u015f\u0131n\u0131 sa\u011flamak i\u00e7in kalple birlikte arterlerin de genle\u015fti\u011fi inanc\u0131yd\u0131. De\u011finece\u011fimiz ikinci nokta, Harvey\u2019in inceleme y\u00f6ntemidir. Hayvanlar\u0131 canl\u0131 olarak incelemeyi ilk kez Harvey denemi\u015ftir. G\u00f6\u011f\u00fcslerini a\u00e7arak kalbin at\u0131\u015f\u0131n\u0131 do\u011frudan g\u00f6zlemliyordu. Kalp de\u011fi\u015fimli olarak atan ve duran bir i\u015fleyi\u015f i\u00e7indeydi. Eline ald\u0131\u011f\u0131nda kalbin gene n\u00f6betle\u015fe sertle\u015fip gev\u015fedi\u011fini duyumsuyor; sertle\u015fti\u011finde organ\u0131n kas\u0131l\u0131p solgunla\u015ft\u0131\u011f\u0131m, gev\u015fedi\u011finde geni\u015fleyip k\u0131rm\u0131z\u0131la\u015ft\u0131\u011f\u0131n\u0131 g\u00f6r\u00fcyordu. G\u00f6zlemleri sonunda onu \u015f\u00f6yle bir yarg\u0131ya ula\u015ft\u0131r\u0131r: Kalp \u201ci\u00e7i bo\u015fluk\u201d pompa gibi \u00e7al\u0131\u015fan bir kast\u0131r; \u00f6yle ki, eyleme ge\u00e7ti\u011finde i\u00e7 bo\u015flu\u011fu daralmakta ve kan d\u0131\u015fa y\u00f6nelik ak\u0131\u015fa ge\u00e7mektedir; gev\u015fedi\u011finde ise tam tersine kan geni\u015fleyen i\u00e7 bo\u015flu\u011fa d\u00f6nmektedir.<\/p>\n

Kalbin kas\u0131lmas\u0131yla atardamarlar\u0131n kan ta\u015f\u0131ma d\u0131\u015f\u0131nda nab\u0131z at\u0131\u015f\u0131 da verdi\u011fini belirleyen Harvey, ta\u015f\u0131nan kan\u0131n miktar\u0131n\u0131 da saptama yoluna gider. Kalbin her at\u0131\u015f\u0131nda yakla\u015f\u0131k 30 gr kan pompalad\u0131\u011f\u0131n\u0131 hesaplar. (Bu, dakikada 72 vuru\u015f oldu\u011funa g\u00f6re bir dakikada yakla\u015f\u0131k 5 litre, bir g\u00fcnde 6200 litre demektir.)<\/p>\n

\u015ea\u015f\u0131rt\u0131c\u0131 buldu\u011fu bu olguyu Harvey a\u00e7\u0131klamadan duramazd\u0131. Bu kadar \u00e7ok kan\u0131n pompalanmas\u0131 ancak \u00e7evrimsel bir ak\u0131\u015fla olas\u0131yd\u0131. \u00d6yleyse, kan dola\u015f\u0131m\u0131 hipotezi a\u00e7\u0131klay\u0131c\u0131 tek se\u00e7enekti onun i\u00e7in. Bu a\u00e7\u0131klamada kalbin \u00e7al\u0131\u015fmas\u0131, her t\u00fcrl\u00fc gizemli g\u00fc\u00e7lerden uzak, salt mekanik bir i\u015fleyi\u015f olarak alg\u0131lanm\u0131\u015ft\u0131r. [Kan dola\u015f\u0131m\u0131 hipotezinin olgusal olarak do\u011frulanmas\u0131 mikroskopun icad\u0131n\u0131 bekler. \u0130talyan bilgini Malpighi (1628 – 1694) 1661\u2019de mikroskopla kurba\u011fa akci\u011ferinde, atardamarlarla toplardamarlar\u0131n, k\u0131lcaldamarlar arac\u0131l\u0131\u011f\u0131yla birbirine ba\u011fl\u0131 oldu\u011funu saptar.]<\/p>\n

Harvey incelemelerini daha ileri g\u00f6t\u00fcrerek, damarlar\u0131n kan\u0131n ak\u0131\u015f\u0131na tek y\u00f6nl\u00fc ge\u00e7it verdi\u011fini belirler. Bu ge\u00e7itler \u201c\u00e7ek-valf\u201d i\u015flevi g\u00f6ren kanatlarla donat\u0131lm\u0131\u015ft\u0131r. Kanatlar atardamarlarda kan\u0131n v\u00fccuda ak\u0131\u015f\u0131n\u0131, toplardamarlarda kalbe d\u00f6n\u00fc\u015f\u00fcn\u00fc sa\u011flamaktad\u0131r.<\/p>\n

Harvey kan dola\u015f\u0131m\u0131na ili\u015fkin bulu\u015funu 1628\u2019de Latince yazd\u0131\u011f\u0131 k\u00fc\u00e7\u00fck bir kitapta, Hayvanlarda Kalp ve Kan Devinimine \u0130li\u015fkin Anatomik Bir Tez, ortaya koymu\u015ftu. 1651\u2019de yay\u0131mlanan ikinci kitab\u0131 embriyoloji konusunda Antik\u00e7a\u011f\u2019dan o g\u00fcne uzanan yakla\u015f\u0131k 2 biny\u0131ll\u0131k d\u00f6nemde yap\u0131lan en \u00f6nemli incelemeyi i\u00e7eriyordu.<\/p>\n

Ger\u00e7e\u011fi \u00f6nyarg\u0131larda de\u011fil, nesnel g\u00f6zlem verilerinde arayan, kutsal da say\u0131lsa dogmalara boyun e\u011fmeyen Harvey, bilimdeki ba\u015far\u0131lar\u0131n\u0131n yan\u0131 s\u0131ra \u00f6zg\u00fcr ara\u015ft\u0131rma gelene\u011finin kurulmas\u0131nda \u00f6d\u00fcn vermez ki\u015fili\u011fiyle de bilim tarihinde sayg\u0131n yerini alm\u0131\u015ft\u0131r.<\/p>\n

Kaynak: <\/strong>Cemal Y\u0131ld\u0131r\u0131m, Bilimin \u00d6nc\u00fcleri, Bilim ve Gelecek Kitapl\u0131\u011f\u0131, Ekim 2014, 28.Bask\u0131, s. 99-102<\/p>\n","protected":false},"excerpt":{"rendered":"

Atronomide Kopernik\u2019in, fizikte Galileo\u2019nun ba\u015flatt\u0131\u011f\u0131 devrimci at\u0131l\u0131m\u0131 t\u0131pta Harvey ger\u00e7ekle\u015ftirir. Kan dola\u015f\u0131m\u0131 \u00fczerindeki \u00e7al\u0131\u015fmas\u0131yla bilim tarihine ge\u00e7en Harvey, yaln\u0131z bu \u00e7al\u0131\u015fmas\u0131yla de\u011fil, t\u0131p alan\u0131nda yerle\u015fik \u00f6nyarg\u0131lar\u0131 k\u0131rmakta g\u00f6sterdi\u011fi diren\u00e7le de \u00f6nc\u00fc ki\u015fili\u011fini kan\u0131tlam\u0131\u015ft\u0131r. \u00d6zel ya\u015fam\u0131 renksiz ve tekd\u00fcze ge\u00e7en Harvey\u2019in bilim adam\u0131 olarak b\u00fcy\u00fckl\u00fc\u011f\u00fcn\u00fc iki \u00f6zelli\u011finde bulmaktay\u0131z: 1) Ger\u00e7e\u011fin, k\u00f6keni hangi otoriteye dayan\u0131rsa dayans\u0131n \u00f6nyarg\u0131larda […]<\/p>\n","protected":false},"author":429,"featured_media":35960,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[3845],"tags":[5166,5168,2807,640,5167],"class_list":["post-35959","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-bilimin-onculeri","tag-bilim-insani","tag-inceleme","tag-kalp","tag-tip","tag-william-harvey"],"acf":[],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/35959","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\/429"}],"replies":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/comments?post=35959"}],"version-history":[{"count":0,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/posts\/35959\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media\/35960"}],"wp:attachment":[{"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/media?parent=35959"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/categories?post=35959"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/bilimvegelecek.com.tr\/index.php\/wp-json\/wp\/v2\/tags?post=35959"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}