[{"@context":"https:\/\/schema.org\/","@type":"Article","@id":"https:\/\/www.areon.cz\/jak-zname-stari-zeme\/#Article","mainEntityOfPage":"https:\/\/www.areon.cz\/jak-zname-stari-zeme\/","headline":"Jak zn\u00e1me st\u00e1\u0159\u00ed Zem\u011b","name":"Jak zn\u00e1me st\u00e1\u0159\u00ed Zem\u011b","description":"Jednou z\u00a0v\u011bc\u00ed, kter\u00e9 lidstvo odjak\u017eiva zaj\u00edmaly, je i st\u00e1\u0159\u00ed na\u0161\u00ed planety. Ji\u017e star\u00e9 n\u00e1rody si vypr\u00e1v\u011bly p\u0159\u00edb\u011bhy, kter\u00e9 m\u011bly tuto z\u00e1hadu objasnit, p\u0159\u00edpadn\u011b se na ni sna\u017eili p\u0159ij\u00edt pomoc\u00ed poznatk\u016f, kter\u00e9 m\u011bli tehdy k\u00a0dispozici. Ov\u0161em v\u00a0dne\u0161n\u00ed dob\u011b jsme schopni v\u011bk […]","datePublished":"2024-08-29","dateModified":"2024-08-29","author":{"@type":"Person","@id":"https:\/\/www.areon.cz\/author\/#Person","name":"","url":"https:\/\/www.areon.cz\/author\/","identifier":1,"image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/6b1978a802e1d2522476d4f1a954a19e989b74ba84b3e15a182efb651cc75097?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/6b1978a802e1d2522476d4f1a954a19e989b74ba84b3e15a182efb651cc75097?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"areon.cz","logo":{"@type":"ImageObject","@id":"\/logo.png","url":"\/logo.png","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/www.areon.cz\/wp-content\/uploads\/barvy2_2.jpg","url":"https:\/\/www.areon.cz\/wp-content\/uploads\/barvy2_2.jpg","height":0,"width":0},"url":"https:\/\/www.areon.cz\/jak-zname-stari-zeme\/","about":["V\u011bda"],"wordCount":416,"articleBody":"Jednou z\u00a0v\u011bc\u00ed, kter\u00e9 lidstvo odjak\u017eiva zaj\u00edmaly, je i st\u00e1\u0159\u00ed na\u0161\u00ed planety. Ji\u017e star\u00e9 n\u00e1rody si vypr\u00e1v\u011bly p\u0159\u00edb\u011bhy, kter\u00e9 m\u011bly tuto z\u00e1hadu objasnit, p\u0159\u00edpadn\u011b se na ni sna\u017eili p\u0159ij\u00edt pomoc\u00ed poznatk\u016f, kter\u00e9 m\u011bli tehdy k\u00a0dispozici. Ov\u0161em v\u00a0dne\u0161n\u00ed dob\u011b jsme schopni v\u011bk na\u0161\u00ed planety zjistit pom\u011brn\u011b p\u0159esn\u011b. Byl stanoven na 4,5 miliardy let, p\u0159i\u010dem\u017e \u017eivot na n\u00ed existuje zhruba 3 miliardy let. Jak jsme ale k\u00a0tomuto datu dosp\u011bli? Navzdory tomu, co si mnoz\u00ed mysl\u00ed, nejde jen o prost\u00e9 h\u00e1d\u00e1n\u00ed. Ve skute\u010dnosti n\u00e1m na\u0161e planeta sama nab\u00edz\u00ed d\u016fkazy, kter\u00e9 o jej\u00edm v\u011bku vypov\u00eddaj\u00ed. Jist\u011b, jedn\u00e1 se o horniny, av\u0161ak ne v\u00a0takov\u00e9m slova smyslu, jak bychom si mohli myslet. Rozhodn\u011b nap\u0159\u00edklad nejde o to, \u017ee bychom pou\u017e\u00edvali uhl\u00edkov\u00e9 datov\u00e1n\u00ed, kdy ur\u010dujeme st\u00e1\u0159\u00ed r\u016fzn\u00fdch hornin, dokud nenajdeme tu nejstar\u0161\u00ed. Tak to skute\u010dn\u011b nen\u00ed. Ve skute\u010dnosti jde o jin\u00fd proces, kter\u00fd vyu\u017e\u00edv\u00e1me. Odpov\u011b\u010f n\u00e1m toti\u017e ned\u00e1v\u00e1 nic jin\u00e9ho ne\u017e radiace. Pr\u00e1v\u011b ona je kl\u00ed\u010dem k\u00a0tomu, abychom st\u00e1\u0159\u00ed zem\u011b zjistili s\u00a0definitivn\u00ed platnost\u00ed. V\u011bt\u0161ina lid\u00ed o tom p\u0159\u00edli\u0161 nev\u00ed, av\u0161ak kdy\u017e v\u00a0n\u011bjak\u00e9m p\u0159edm\u011btu \u010di hornin\u011b prob\u00edh\u00e1 radia\u010dn\u00ed proces, pak se ona l\u00e1tka m\u011bn\u00ed. Nap\u0159\u00edklad olovo se tak m\u011bn\u00ed na jin\u00fd prvek s\u00a0men\u0161\u00edm atomov\u00fdm \u010d\u00edslem. A pr\u00e1v\u011b olovo je k\u00a0tomu kl\u00ed\u010dem.Pravdou toti\u017e je, \u017ee olovo m\u00e1 zdaleka nejvy\u0161\u0161\u00ed polo\u010das rozpadu. Jedn\u00e1 se tedy o zdaleka nejstar\u0161\u00ed prvek, kter\u00fd m\u016f\u017eeme nal\u00e9zt, a kter\u00fd byl p\u0159\u00edtomen ji\u017e p\u0159i vzniku Zem\u011b. Sta\u010d\u00ed se tedy pod\u00edvat, kolik olova Zemsk\u00e1 k\u016fra obsahuje, a n\u00e1sledn\u011b se pod\u00edvat, kolik obsahuje produkt\u016f jeho p\u0159em\u011bny. Tak zjist\u00edme, kolik olova se ji\u017e p\u0159em\u011bnilo, a kolik jej je\u0161t\u011b z\u016fst\u00e1v\u00e1. Jeliko\u017e zn\u00e1me i jeho polo\u010das rozpadu, m\u016f\u017eeme snadno vypo\u010d\u00edtat, jak dlouho trvalo, ne\u017e se ono mno\u017estv\u00ed olova p\u0159em\u011bnilo, a z\u00a0toho vypo\u010d\u00edtat, jak je na\u0161e planeta star\u00e1. Jist\u011b, je to pro laika pom\u011brn\u011b komplikovan\u00e1 metoda, av\u0161ak je pom\u011brn\u011b p\u0159esn\u00e1, a nav\u00edc i relativn\u011b snadn\u00e1. Tak si m\u016f\u017eeme b\u00fdt i jisti jej\u00edmi v\u00fdsledky.                                                                                                                                                                                                                                                                                                                                                                                        4.3\/5 - (13 votes)        "},{"@context":"https:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Jak zn\u00e1me st\u00e1\u0159\u00ed Zem\u011b","item":"https:\/\/www.areon.cz\/jak-zname-stari-zeme\/#breadcrumbitem"}]}]