{"id":184,"date":"2021-12-02T12:49:39","date_gmt":"2021-12-02T11:49:39","guid":{"rendered":"https:\/\/kids.esa.int\/cosmic_distances2\/"},"modified":"2026-10-08T00:25:13","modified_gmt":"2026-10-07T22:25:13","slug":"cosmic_distances2","status":"publish","type":"post","link":"https:\/\/kids.esa.int\/cs\/cosmic_distances2\/","title":{"rendered":"Kosmick\u00e9 vzd\u00e1lenosti"},"content":{"rendered":"
\n

Vesm\u00edr je obrovsk\u00fd. Je tak nesm\u00edrn\u011b rozlehl\u00fd, \u017ee je velmi t\u011b\u017ek\u00e9 si p\u0159edstavit p\u0159\u00edslu\u0161n\u00e9 vzd\u00e1lenosti, a to i mezi objekty v na\u0161em bezprost\u0159edn\u00edm okol\u00ed, tedy ve Slune\u010dn\u00ed soustav\u011b. Kdyby astronomov\u00e9 k popisu t\u011bchto vzd\u00e1lenost\u00ed pou\u017e\u00edvali kilometry, museli by uv\u00e1d\u011bt velmi velk\u00e1 \u010d\u00edsla. Proto se pro zjednodu\u0161en\u00ed a aby byla \u010d\u00edsla men\u0161\u00ed a sn\u00e1ze uchopiteln\u00e1, pou\u017e\u00edvaj\u00ed se jin\u00e9 jednotky m\u011b\u0159en\u00ed.<\/p>\n<\/div>\n

Astronomick\u00e1 jednotka<\/h2>\n

Vzd\u00e1lenost mezi Zem\u00ed a Sluncem \u010din\u00ed p\u0159ibli\u017en\u011b sto pades\u00e1t milion\u016f kilometr\u016f. Jedn\u00e1 se o velk\u00e9 \u010d\u00edslo, a proto astronomov\u00e9 k popisu t\u00e9to vzd\u00e1lenosti pou\u017e\u00edvaj\u00ed astronomickou jednotku. Jedna astronomick\u00e1 jednotka, zkr\u00e1cen\u011b \u2018au\u2019, odpov\u00edd\u00e1 vzd\u00e1lenosti mezi Zem\u00ed a Sluncem. Pou\u017e\u00edv\u00e1 se k porovn\u00e1n\u00ed vzd\u00e1lenost\u00ed dal\u0161\u00edch t\u011bles ve Slune\u010dn\u00ed soustav\u011b, jako jsou Slunce, planety, komety a asteroidy.<\/p>\n

Sv\u011bteln\u00fd rok<\/h2>\n

A co mimo na\u0161i slune\u010dn\u00ed soustavu? Jak daleko je to k nejbli\u017e\u0161\u00ed hv\u011bzd\u011b, Proxima Centauri? Proxima Centauri je vzd\u00e1len\u00e1 asi 38 000 000 000 000 km (t\u0159icet osm milion\u016f milion\u016f kilometr\u016f). Je to tak daleko, \u017ee kdyby k t\u00e9to hv\u011bzd\u011b let\u011bla kosmick\u00e1 lo\u010f, trvalo by j\u00ed to asi 75 000 let.<\/p>\n

Pou\u017e\u00edv\u00e1n\u00ed astronomick\u00e9 jednotky k popisu vzd\u00e1lenost\u00ed hv\u011bzd (a objekt\u016f mimo na\u0161i slune\u010dn\u00ed soustavu) astronom\u016fm ve skute\u010dnosti p\u0159\u00edli\u0161 nepom\u00e1h\u00e1, proto\u017ee jim to ned\u00e1v\u00e1 mal\u00e1 \u010d\u00edsla, se kter\u00fdmi by mohli pracovat. Vzd\u00e1lenost k Promixe Centauri \u010din\u00ed p\u0159ibli\u017en\u011b 265 000 au. Je tedy zapot\u0159eb\u00ed jin\u00e1 jednotka! K m\u011b\u0159en\u00ed vzd\u00e1lenosti (alespo\u0148 k hv\u011bzd\u00e1m, kter\u00e9 jsou k n\u00e1m nejbl\u00ed\u017ee) lze proto pou\u017e\u00edt sv\u011bteln\u00e9 roky.<\/p>\n

Sv\u011btlo je nejrychlej\u0161\u00ed v\u011bc, kterou zn\u00e1me. Vesm\u00edrem se sv\u011btlo m\u016f\u017ee pohybovat rychlost\u00ed t\u00e9m\u011b\u0159 300 000 km\/s. Sv\u011bteln\u00fd rok je vzd\u00e1lenost, kterou sv\u011btlo uraz\u00ed za jeden rok, co\u017e je 9 461 000 000 000 kilometr\u016f! Cesta na tuto vzd\u00e1lenost k nejbli\u017e\u0161\u00ed hv\u011bzd\u011b k Slune\u010dn\u00ed soustav\u011b trv\u00e1 sv\u011btlu p\u0159ibli\u017en\u011b 4,2 roku, proto astronomov\u00e9 uv\u00e1d\u011bj\u00ed, \u017ee Proxima Centauri je vzd\u00e1len\u00e1 4,2 sv\u011bteln\u00fdch let.<\/p>\n

To je jen ta nejbli\u017e\u0161\u00ed hv\u011bzda. No\u010dn\u00ed obloha je pln\u00e1 hv\u011bzd z na\u0161\u00ed galaxie, Ml\u00e9\u010dn\u00e9 dr\u00e1hy. Nejbli\u017e\u0161\u00ed velk\u00e1 galaxie k Ml\u00e9\u010dn\u00e9 dr\u00e1ze je vzd\u00e1len\u00e1 neuv\u011b\u0159iteln\u00fdch dva a p\u016fl milionu sv\u011bteln\u00fdch let. A to je jen ta nejbli\u017e\u0161\u00ed! Mnoho galaxi\u00ed, kter\u00e9 jsou rovn\u011b\u017e pln\u00e9 hv\u011bzd, je tis\u00edckr\u00e1t d\u00e1l. Vesm\u00edr je obrovsk\u00fd!<\/p>","protected":false},"excerpt":{"rendered":"

Space is huge. It is so immense that is very difficult to imagine the distances involved, even between the objects in our local neighbourhood, the Solar System. If astronomers used […]<\/p>\n","protected":false},"author":5,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"esa_banner_image":"https:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2011\/01\/andromeda_our_nearest_large_galactic_neighbour2\/17880143-2-eng-GB\/Andromeda_our_nearest_large_galactic_neighbour.jpg","esa_banner_description":"","esa_banner_credit":"infrared: ESA\/Herschel\/PACS\/SPIRE\/J.\u00a0Fritz, U.\u00a0Gent; X-ray: ESA\/XMM-Newton\/EPIC\/W. Pietsch, MPE; optical: R. Gendler","esa_banner_licence":"ESA Standard Licence","esa_banner_detail_url":"https:\/\/www.esa.int\/ESA_Multimedia\/Images\/2011\/01\/Andromeda_our_nearest_large_galactic_neighbour2","esa_external_url":"","esa_external_new_window":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":true},"categories":[10,11,19],"tags":[],"panel":[],"language":[],"age":[],"duration":[],"resource_type":[],"audience":[],"wf_post_folders":[],"class_list":["post-184","post","type-post","status-publish","format-standard","hentry","category-learn","category-our-universe","category-story-of-the-universe"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/posts\/184","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/users\/5"}],"replies":[{"embeddable":true,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/comments?post=184"}],"version-history":[{"count":1,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/posts\/184\/revisions"}],"predecessor-version":[{"id":1327,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/posts\/184\/revisions\/1327"}],"wp:attachment":[{"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/media?parent=184"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/categories?post=184"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/tags?post=184"},{"taxonomy":"panel","embeddable":true,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/panel?post=184"},{"taxonomy":"language","embeddable":true,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/language?post=184"},{"taxonomy":"age","embeddable":true,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/age?post=184"},{"taxonomy":"duration","embeddable":true,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/duration?post=184"},{"taxonomy":"resource_type","embeddable":true,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/resource_type?post=184"},{"taxonomy":"audience","embeddable":true,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/audience?post=184"},{"taxonomy":"wf_post_folders","embeddable":true,"href":"https:\/\/kids.esa.int\/cs\/wp-json\/wp\/v2\/wf_post_folders?post=184"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}