{"id":5964,"date":"2025-05-29T13:12:32","date_gmt":"2025-05-29T11:12:32","guid":{"rendered":"https:\/\/www.zsvltava.cz\/fyzika\/?p=5964"},"modified":"2025-10-09T09:29:22","modified_gmt":"2025-10-09T07:29:22","slug":"vakuum-prazdnota-ktera-neni-prazdna","status":"publish","type":"post","link":"https:\/\/www.zsvltava.cz\/fyzika\/?p=5964","title":{"rendered":"Vakuum \u2013 Pr\u00e1zdnota, kter\u00e1 nen\u00ed pr\u00e1zdn\u00e1"},"content":{"rendered":"<p><strong>V b\u011b\u017en\u00e9m jazyce ozna\u010duje vakuum prostor, kde \u201enic nen\u00ed\u201c \u2013 \u017e\u00e1dn\u00fd vzduch, \u017e\u00e1dn\u00e9 \u010d\u00e1stice, \u017e\u00e1dn\u00fd \u017eivot. V technick\u00e9m smyslu v\u0161ak vakuum znamen\u00e1 stav, kdy je tlak plynu ni\u017e\u0161\u00ed ne\u017e atmosf\u00e9rick\u00fd tlak. Dokonal\u00e9 vakuum, ve kter\u00e9m nen\u00ed ani jedna \u010d\u00e1stice, je ide\u00e1l, kter\u00e9ho se sna\u017e\u00edme co nejv\u00edce p\u0159ibl\u00ed\u017eit, ale nikdy ho zcela nedos\u00e1hneme.<\/strong><\/p>\n<p>Slovo vakuum poch\u00e1z\u00ed z latiny. Doslova znamen\u00e1 \u201epr\u00e1zdnota\u201c nebo \u201epr\u00e1zdn\u00e9 m\u00edsto\u201c. Latinsky: vacuus = pr\u00e1zdn\u00fd, vacuum = \u201epr\u00e1zdn\u00fd prostor\u201c. Tento pojem se za\u010dal pou\u017e\u00edvat ve v\u011bdeck\u00e9m kontextu zejm\u00e9na v 17. stolet\u00ed, kdy fyzikov\u00e9 jako <a href=\"https:\/\/www.zsvltava.cz\/fyzika\/?p=6171\">Evangelista Torricelli<\/a> a <a href=\"https:\/\/www.zsvltava.cz\/fyzika\/?p=4960\">Blaise Pascal<\/a> experimentovali s v\u00fdv\u011bvami a sloupci rtuti. Tehdy \u0161lo o kontroverzn\u00ed pojem, proto\u017ee podle Aristotela \u201ep\u0159\u00edroda vakuum nesn\u00e1\u0161\u00ed\u201c (horror vacui) \u2013 my\u0161lenka, \u017ee v p\u0159\u00edrod\u011b nem\u016f\u017ee existovat pr\u00e1zdn\u00fd prostor.<\/p>\n<h2>Jak se vakuum vytv\u00e1\u0159\u00ed a m\u011b\u0159\u00ed?<\/h2>\n<p>Vakuum vytv\u00e1\u0159\u00edme pomoc\u00ed v\u00fdv\u011bv \u2013 za\u0159\u00edzen\u00ed, kter\u00e1 ods\u00e1vaj\u00ed molekuly plynu z uzav\u0159en\u00e9ho prostoru. <\/p>\n<p>M\u00edru vakua m\u011b\u0159\u00edme pomoc\u00ed tlakom\u011br\u016f. Hodnoty se \u010dasto ud\u00e1vaj\u00ed v pascalech (Pa) nebo v torr (mm Hg). Nap\u0159\u00edklad:<\/p>\n<p>Atmosf\u00e9rick\u00fd tlak: \u2248 101 325 Pa<br \/>\nHrub\u00e9 vakuum: \u2248 10\u2075 \u2013 10\u00b2 Pa<br \/>\nSt\u0159edn\u00ed vakuum: \u2248 10\u00b2 \u2013 10\u207b\u00b9 Pa<br \/>\nVysok\u00e9 vakuum: \u2248 10\u207b\u00b9 \u2013 10\u207b\u2075 Pa<br \/>\nUltravysok\u00e9 vakuum: \u2248 10\u207b\u2075 \u2013 10\u207b\u00b9\u2070 Pa<\/p>\n<h2>Pro\u010d je vakuum d\u016fle\u017eit\u00e9 ve fyzice?<\/h2>\n<ul>\n<li>V urychlova\u010d\u00edch \u010d\u00e1stic \u2013 nap\u0159\u00edklad v LHC (CERN) je nutn\u00e9 extr\u00e9mn\u00ed vakuum, aby \u010d\u00e1stice mohly cestovat bez koliz\u00ed s molekulami vzduchu.<\/li>\n<li>V kosmick\u00e9m v\u00fdzkumu \u2013 vesm\u00edr s\u00e1m o sob\u011b je t\u00e9m\u011b\u0159 vakuum, co\u017e m\u00e1 z\u00e1sadn\u00ed vliv na pohyb t\u011bles a \u0161\u00ed\u0159en\u00ed elektromagnetick\u00e9ho z\u00e1\u0159en\u00ed.<\/li>\n<li>Ve v\u00fdrob\u011b \u010dip\u016f a nanotechnologi\u00ed \u2013 \u010dist\u00e9 prost\u0159ed\u00ed bez kontaminace je nezbytn\u00e9.<\/li>\n<li>V kvantov\u00e9 fyzice \u2013 pro pozorov\u00e1n\u00ed kvantov\u00fdch jev\u016f bez ru\u0161iv\u00fdch vliv\u016f.<\/li>\n<\/ul>\n<h2>Je vakuum opravdu pr\u00e1zdn\u00e9?<\/h2>\n<p><strong>A\u010dkoliv si vakuum p\u0159edstavujeme jako \u201enic\u201c, modern\u00ed fyzika ukazuje, \u017ee vakuum nen\u00ed zcela pr\u00e1zdn\u00e9.<\/strong><\/p>\n<p>Podle kvantov\u00e9 teorie pole je i vakuum pln\u00e9 \u201evirtu\u00e1ln\u00edch \u010d\u00e1stic\u201c, kter\u00e9 neust\u00e1le vznikaj\u00ed a zanikaj\u00ed. Tento jev, zn\u00e1m\u00fd jako kvantov\u00e9 fluktuace, m\u00e1 m\u011b\u0159iteln\u00e9 d\u016fsledky:<\/p>\n<p>Casimir\u016fv jev \u2013 dv\u011b kovov\u00e9 desky ve vakuu se p\u0159itahuj\u00ed kv\u016fli zm\u011bn\u011b kvantov\u00fdch fluktuac\u00ed mezi nimi.<\/p>\n<p>Hawkingovo z\u00e1\u0159en\u00ed \u2013 teoreticky vznik\u00e1 u \u010dern\u00fdch d\u011br pr\u00e1v\u011b d\u00edky kvantov\u00fdm fluktuac\u00edm ve vakuu.<\/p>\n<h2>Vakuum a princip neur\u010ditosti<\/h2>\n<p>Podle <a href=\"https:\/\/www.zsvltava.cz\/fyzika\/?p=5968\">Heisenbergova<\/a> principu neur\u010ditosti nelze sou\u010dasn\u011b s nekone\u010dnou p\u0159esnost\u00ed ur\u010dit ur\u010dit\u00e9 dvojice fyzik\u00e1ln\u00edch veli\u010din \u2013 nap\u0159\u00edklad polohu a hybnost \u010d\u00e1stice. Tento princip m\u00e1 z\u00e1sadn\u00ed dopad i na to, jak fyzika ch\u00e1pe vakuum. I kdy\u017e bychom si p\u0159edstavovali, \u017ee ve vakuu nen\u00ed \u017e\u00e1dn\u00e1 \u010d\u00e1stice, kvantov\u00e1 mechanika \u0159\u00edk\u00e1, \u017ee energie elektromagnetick\u00e9ho pole v prostoru nem\u016f\u017ee b\u00fdt zcela nulov\u00e1, proto\u017ee to by znamenalo, \u017ee zn\u00e1me p\u0159esn\u011b jak polohu (v\u0161ude nic), tak energii (rovn\u011b\u017e nula), co\u017e odporuje principu neur\u010ditosti. V\u00fdsledkem je, \u017ee i ve \u201ezcela pr\u00e1zdn\u00e9m prostoru\u201c doch\u00e1z\u00ed k neust\u00e1l\u00e9mu v\u0159en\u00ed virtu\u00e1ln\u00edch \u010d\u00e1stic a anti\u010d\u00e1stic, kter\u00e9 vznikaj\u00ed a op\u011bt zanikaj\u00ed v extr\u00e9mn\u011b kr\u00e1tk\u00e9m \u010dase. <\/p>\n<p>Tento jev je zn\u00e1m jako kvantov\u00e9 fluktuace vakua a je p\u0159\u00edmo d\u016fsledkem neur\u010ditosti v energii a \u010dase. Ukazuje se tedy, \u017ee vakuum nen\u00ed jen prost\u00fd nedostatek hmoty \u2013 je to aktivn\u00ed kvantov\u00e9 pole, kter\u00e9 je v neust\u00e1l\u00e9m pohybu, i kdy\u017e z pohledu klasick\u00e9 fyziky \u201enic neobsahuje\u201c.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>V b\u011b\u017en\u00e9m jazyce ozna\u010duje vakuum prostor, kde \u201enic nen\u00ed\u201c \u2013 \u017e\u00e1dn\u00fd vzduch, \u017e\u00e1dn\u00e9 \u010d\u00e1stice, \u017e\u00e1dn\u00fd \u017eivot. V technick\u00e9m smyslu v\u0161ak vakuum znamen\u00e1 stav, kdy je &#8230;. <\/p>\n","protected":false},"author":1,"featured_media":5993,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13],"tags":[],"class_list":["post-5964","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-zajimavosti"],"_links":{"self":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts\/5964","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5964"}],"version-history":[{"count":7,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts\/5964\/revisions"}],"predecessor-version":[{"id":6179,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/posts\/5964\/revisions\/6179"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=\/wp\/v2\/media\/5993"}],"wp:attachment":[{"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5964"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5964"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zsvltava.cz\/fyzika\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5964"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}