[{"@context":"https:\/\/schema.org\/","@type":"Article","@id":"https:\/\/www.hasty.cz\/jak-zname-tak-presne-stari-nasi-planety-a-vesmiru\/#Article","mainEntityOfPage":"https:\/\/www.hasty.cz\/jak-zname-tak-presne-stari-nasi-planety-a-vesmiru\/","headline":"Jak zn\u00e1me tak p\u0159esn\u011b st\u00e1\u0159\u00ed na\u0161\u00ed planety a vesm\u00edru?","name":"Jak zn\u00e1me tak p\u0159esn\u011b st\u00e1\u0159\u00ed na\u0161\u00ed planety a vesm\u00edru?","description":"Dnes je ji\u017e v\u0161eobecn\u011b zn\u00e1mo, \u017ee na\u0161e planeta je star\u00e1 p\u0159ibli\u017en\u011b 4,5 miliardy let, p\u0159i\u010dem\u017e \u017eivot se na n\u00ed objevil […]","datePublished":"2022-03-22","dateModified":"2023-06-07","author":{"@type":"Person","@id":"https:\/\/www.hasty.cz\/author\/#Person","name":"","url":"https:\/\/www.hasty.cz\/author\/","identifier":1,"image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/9cac53ffad5d6e0659d72eaf216400c165f8fbf396c79017c66698a8aa5be23d?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/9cac53ffad5d6e0659d72eaf216400c165f8fbf396c79017c66698a8aa5be23d?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"hasty.cz","logo":{"@type":"ImageObject","@id":"\/logo.png","url":"\/logo.png","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/www.hasty.cz\/wp-content\/uploads\/zeme3_5.jpg","url":"https:\/\/www.hasty.cz\/wp-content\/uploads\/zeme3_5.jpg","height":0,"width":0},"url":"https:\/\/www.hasty.cz\/jak-zname-tak-presne-stari-nasi-planety-a-vesmiru\/","about":["V\u011bda"],"wordCount":454,"articleBody":"Dnes je ji\u017e v\u0161eobecn\u011b zn\u00e1mo, \u017ee na\u0161e planeta je star\u00e1 p\u0159ibli\u017en\u011b 4,5 miliardy let, p\u0159i\u010dem\u017e \u017eivot se na n\u00ed objevil zhruba o miliardu let pozd\u011bji. Vesm\u00edr s\u00e1m je pochopiteln\u011b mnohem star\u0161\u00ed. Jeho v\u011bk je v\u00a0sou\u010dasnosti odhadov\u00e1n na 14 miliard let. To jsou velmi dlouh\u00e9 \u010dasov\u00e9 \u00faseky, a v\u011bt\u0161ina lid\u00ed si je ani nedok\u00e1\u017ee p\u0159edstavit. Zjednodu\u0161en\u00e9 p\u0159irovn\u00e1n\u00ed je nap\u0159\u00edklad to, \u017ee kdyby se cel\u00fd \u017eivot Zem\u011b smrsknul na 24 hodin, my lid\u00e9 to nejsme je\u0161t\u011b ani sekundu.\u00a0Takto dlouh\u00e1 doba sebou samoz\u0159ejm\u011b p\u0159in\u00e1\u0161\u00ed i ur\u010ditou skepsi. Mnoz\u00ed lid\u00e9 se ptaj\u00ed, jak vlastn\u011b v\u011bdci k\u00a0t\u011bmto \u010d\u00edsl\u016fm dosp\u011bli. Koneckonc\u016f, fosilie z\u00a0doby formov\u00e1n\u00ed na\u0161\u00ed planety nejsp\u00ed\u0161 nenajdeme, a uhl\u00edkov\u00e9 datov\u00e1n\u00ed tak\u00e9 nen\u00ed mo\u017en\u00e9 pou\u017e\u00edt, nebo\u0165 v\u00a0t\u00e9 dob\u011b je\u0161t\u011b neexistovaly organick\u00e9 slou\u010deniny.\u00a0\u00a0Zde n\u00e1m v\u0161ak m\u016f\u017ee pomoci star\u00e1 zn\u00e1m\u00e1 radiace. Je velmi dob\u0159e zn\u00e1mo, \u017ee ka\u017ed\u00fd radioaktivn\u00ed izotop m\u00e1 ur\u010ditou dobu rozpadu, tedy dobu, za kterou ztrat\u00ed svou radioaktivitu. Tyto doby jsou dnes samoz\u0159ejm\u011b dob\u0159e zn\u00e1my, nebo\u0165 je lze pom\u011brn\u011b lehce zm\u011b\u0159it v\u00a0laboratorn\u00edch podm\u00ednk\u00e1ch. Jak n\u00e1m to ale pom\u016f\u017ee?\u00a0Pom\u011brn\u011b jednodu\u0161e. Existuj\u00ed i izotopy, kter\u00e9 maj\u00ed polo\u010das rozpadu v\u00a0\u0159\u00e1du miliard let. Jejich studiem, \u010di sp\u00ed\u0161e studiem toho, kolik jich je\u0161t\u011b nen\u00ed p\u0159em\u011bn\u011bno, m\u016f\u017eeme pom\u011brn\u011b p\u0159esn\u011b stanovit minim\u00e1ln\u00ed st\u00e1\u0159\u00ed na\u0161\u00ed planety.\u00a0\u00a0S\u00a0vesm\u00edrem samotn\u00fdm je to pom\u011brn\u011b slo\u017eit\u011bj\u0161\u00ed. Zde pou\u017e\u00edv\u00e1me n\u011bco, co se naz\u00fdv\u00e1 \u010derven\u00fd posun. Jednodu\u0161e \u0159e\u010deno, sign\u00e1ly cestuj\u00edc\u00ed na skute\u010dn\u011b velk\u00e9 vzd\u00e1lenosti (v \u0159\u00e1du tis\u00edc\u016f sv\u011bteln\u00fdch let a v\u00edce), jsou z\u00a0na\u0161eho pohledu posunuty. B\u011bhem sv\u00e9 cesty se sign\u00e1l posune bl\u00ed\u017ee k\u00a0\u010derven\u00e9mu spektru. A \u010d\u00edm v\u00edce je posunut\u00fd, t\u00edm d\u00e9le cestoval, a t\u00edm je tedy tak\u00e9 star\u0161\u00ed.\u00a0Nyn\u00ed tedy nezb\u00fdv\u00e1 nic jin\u00e9ho, ne\u017e analyzovat kosmick\u00fd \u0161um, kter\u00fd k\u00a0n\u00e1m neust\u00e1le proud\u00ed, a jeho \u010derven\u00fd posun. Ten, kter\u00fd je posunut\u00fd nejv\u00edce, k\u00a0n\u00e1m cestoval nejd\u00e9le, a je tedy nejstar\u0161\u00ed. V\u00fdpo\u010dtem pak lze ur\u010dit jeho st\u00e1\u0159\u00ed, a t\u00edm i minim\u00e1ln\u00ed st\u00e1\u0159\u00ed cel\u00e9ho vesm\u00edru.\u00a0Samoz\u0159ejm\u011b, nejedn\u00e1 se o perfektn\u00ed metody, av\u0161ak d\u00e1vaj\u00ed n\u00e1m pom\u011brn\u011b p\u0159esnou p\u0159edstavu, jak je n\u00e1\u0161 vesm\u00edr i v\u011bci okolo n\u00e1s star\u00e9. A to n\u00e1m pom\u016f\u017ee p\u0159i dal\u0161\u00edm v\u00fdzkumu.                                                                                                                                                                                                                                                                                                                                                                                        4.1\/5 - (10 votes)        "},{"@context":"https:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Jak zn\u00e1me tak p\u0159esn\u011b st\u00e1\u0159\u00ed na\u0161\u00ed planety a vesm\u00edru?","item":"https:\/\/www.hasty.cz\/jak-zname-tak-presne-stari-nasi-planety-a-vesmiru\/#breadcrumbitem"}]}]