BRATISLAVA – Jedin\u00e9 zrkadlo na obe\u017enej dr\u00e1he rozsvieti no\u010dn\u00fa oblohu tak, \u017ee v okruhu desiatok kilometrov prestan\u00fa by\u0165 pri poh\u013eade na osvetlen\u00fa oblas\u0165 vidite\u013en\u00e9 hviezdy. Vypl\u00fdva to z v\u00fdpo\u010dtov vedcov zo Slovenskej akad\u00e9mie vied (SAV), Univerzity Komensk\u00e9ho (UK) v Bratislave a Princetonskej univerzity, ktor\u00ed ako prv\u00ed na svete op\u00edsali, \u010do sa s tak\u00fdm svetlom deje v zemskej atmosf\u00e9re. Informoval o tom hovorca SAV Jozef Bedn\u00e1r.<\/p>\n
Pl\u00e1novan\u00e9 zrkadlo s hranou 54 metrov sa na oblohe objav\u00ed ako bodov\u00fd zdroj pribli\u017ene 40-kr\u00e1t jasnej\u0161\u00ed ne\u017e spln. Na zemi pod\u013ea vedcov vytvor\u00ed osvetlenie 9,5 luxu, teda \u00farove\u0148 pouli\u010dnej lampy. \u201eKto sa ocitne priamo v l\u00fa\u010di, uvid\u00ed oblohu ako kr\u00e1tko po z\u00e1pade slnka a nerozozn\u00e1 ani tie najjasnej\u0161ie hviezdy. E\u0161te 14 kilometrov od osvetlen\u00e9ho miesta bude obloha na mnoh\u00fdch miestach jasnej\u0161ia ne\u017e pri splne a vo vzdialenosti 34 kilometrov sa nad krajinou bude t\u00fd\u010di\u0165 vidite\u013en\u00fd sveteln\u00fd st\u013ap. Nadmern\u00e9 presvetlenie oblohy od jedin\u00e9ho zrkadla bude merate\u013en\u00e9 do zhruba 30 kilometrov. Ak by rovnak\u00e9 miesto osvet\u013eovalo 400 zrkadiel naraz, osvetlenie dosiahne 2400 luxov, pribli\u017ene desa\u0165tis\u00edcn\u00e1sobok splnu, a \u017eiaru bude vidie\u0165 e\u0161te 80 kilometrov \u010faleko,\u201c uviedli zo SAV.<\/p>\n
\u201eDoteraz sa hovorilo najm\u00e4 o tom, \u010di zrkadl\u00e1 ovplyvnia pozorovania cez \u010falekoh\u013eady. N\u00e1\u0161 model ukazuje, \u017ee probl\u00e9m je ove\u013ea v\u00e1\u017enej\u0161\u00ed. Roz\u017eiari sa cel\u00fd objem atmosf\u00e9ry nad osvet\u013eovan\u00fdm miestom a hviezdy zmizn\u00fa v okruhu desiatok kilometrov. Pritom ide o optimistick\u00fd scen\u00e1r, preto\u017ee v\u00fdpo\u010dty sme robili zatia\u013e len pre bezobla\u010dn\u00e9 podmienky,\u201c povedal Miroslav Kocifaj z \u00dastavu stavebn\u00edctva a architekt\u00fary SAV a\u00a0Fakulty matematiky, fyziky a informatiky UK.<\/p>\n
Nejde o hypotetick\u00fa \u00favahu. Americk\u00e1 firma Reflect Orbital dostala v j\u00fali 2026 od americk\u00e9ho regul\u00e1tora FCC povolenie vypusti\u0165 pilotn\u00fd satelit EARENDIL-1 so zrkadlom 18 kr\u00e1t 18 metrov. Z v\u00fd\u0161ky pribli\u017ene 600 kilometrov m\u00e1 odr\u00e1\u017ea\u0165 slne\u010dn\u00e9 svetlo a na povrchu Zeme osvetli\u0165 kruh s polomerom 2,5 kilometra. Pilotn\u00fd satelit je predvojom kon\u0161tel\u00e1cie zhruba 50.000 v\u00e4\u010d\u0161\u00edch zrkadiel s rozmermi 54 kr\u00e1t 54 metrov.<\/p>\n
Odpor astronomickej spolo\u010dnosti<\/p>\n
Povolenie bolo pod\u013ea vedcov vydan\u00e9 bez pos\u00fadenia vplyvov na \u017eivotn\u00e9 prostredie a postavila sa proti nemu aj Americk\u00e1 astronomick\u00e1 spolo\u010dnos\u0165. Ch\u00fdbal toti\u017e fyzik\u00e1lny opis toho, ako tak\u00e9 zrkadl\u00e1 ovplyvnia sveteln\u00e9 podmienky v no\u010dnej atmosf\u00e9re. Doteraj\u0161ie modely sveteln\u00e9ho zne\u010distenia r\u00e1tali len s pozemn\u00fdmi zdrojmi, ktor\u00e9 svietia smerom nahor. Pre \u00fazky l\u00fa\u010d prich\u00e1dzaj\u00faci z obe\u017enej dr\u00e1hy nadol rie\u0161enie neexistovalo.<\/p>\n
T\u00edm ho postavil na modeli MSOS vyvinutom na SAV, ktor\u00fd vie vypo\u010d\u00edta\u0165 rozpt\u00fdlen\u00e9 svetlo v \u013eubovo\u013enom bode priestoru. Namiesto pozemn\u00fdch l\u00e1mp do\u0148 vedci vlo\u017eili podmienku na hornej hranici atmosf\u00e9ry, ktor\u00e1 opisuje svetlo vstupuj\u00face zhora. Hlavnou prek\u00e1\u017ekou bolo, \u017ee ku\u017ee\u013e l\u00fa\u010da je pr\u00edli\u0161 \u00fazky – vo v\u00fdpo\u010dtovej sieti zaberie v\u017edy len jednu bunku. Rozptyl svetla prv\u00e9ho r\u00e1du preto museli odvodi\u0165 analyticky a viacn\u00e1sobn\u00fd rozptyl dopo\u010d\u00edta\u0165 modelom. \u201eVon si rozdiel medzi tmavou oblohou a s\u00famrakom v\u0161imne ka\u017ed\u00fd, a\u00a0to aj vo vzdialenosti desiatok kilometrov od miesta, ktor\u00e9 zrkadlo osvet\u013euje,\u201c dodal Kocifaj.<\/p>\n
\u0160t\u00fadiu zverejnil \u010dasopis The Astrophysical Journal Letters. Ako by tak\u00e1 noc vyzerala pre be\u017en\u00e9ho pozorovate\u013ea, ukazuj\u00fa vizualiz\u00e1cie, ktor\u00e9 na z\u00e1klade v\u00fdpo\u010dtov pripravil Joel Hartman z Princetonskej univerzity.<\/p>\n","protected":false},"excerpt":{"rendered":"BRATISLAVA – Jedin\u00e9 zrkadlo na obe\u017enej dr\u00e1he rozsvieti no\u010dn\u00fa oblohu tak, \u017ee v okruhu desiatok kilometrov prestan\u00fa by\u0165…\n","protected":false},"author":2,"featured_media":169911,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[6],"tags":[48163,43,40,44,39,42,45,41,2176,1911,48162],"class_list":["post-169910","post","type-post","status-publish","format-standard","has-post-thumbnail","category-slovensko","tag-nocna-obloha","tag-sk","tag-slovak","tag-slovak-republic","tag-slovakia","tag-slovencina","tag-slovenska-republika","tag-slovensko","tag-vesmir","tag-zaujimavosti","tag-zrkadla"],"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@sk\/117209239799059266","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/posts\/169910","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/comments?post=169910"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/posts\/169910\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/media\/169911"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/media?parent=169910"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/categories?post=169910"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/sk\/wp-json\/wp\/v2\/tags?post=169910"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}