Je to ten v\u016fbec nejd\u011bsiv\u011bj\u0161\u00ed a\u00a0nejm\u00e9n\u011b kompromisn\u00ed z\u00e1kon v\u00a0cel\u00e9m vesm\u00edru. Naz\u00fdv\u00e1 se \u0161ipka \u010dasu. Rod\u00edme se, st\u00e1rneme a\u00a0nakonec um\u00edr\u00e1me. Hork\u00e1 k\u00e1va ponechan\u00e1 na stole v\u017edy vychladne. A\u00a0pokud upust\u00edte syrov\u00e9 vaj\u00ed\u010dko na podlahu, rozbije se na tis\u00edc kousk\u016f. Nikdy v\u00a0historii vesm\u00edru se nestalo, \u017ee by se kousky sko\u0159\u00e1pky samy vznesly ze zem\u011b, \u017eloutek se scelil a\u00a0vaj\u00ed\u010dko v\u00e1m sko\u010dilo zp\u011bt do dlan\u011b.<\/p>\n
Tento jednosm\u011brn\u00fd proud ud\u00e1lost\u00ed popisuje druh\u00fd termodynamick\u00fd z\u00e1kon a\u00a0pojem zvan\u00fd entropie<\/a> (m\u00edra neuspo\u0159\u00e1danosti syst\u00e9mu). V\u00a0klasick\u00e9 fyzice je to naprost\u00e9 dogma. \u010cas plyne pouze dop\u0159edu, chaos se neust\u00e1le zv\u011bt\u0161uje a\u00a0to, co se u\u017e stalo, nelze vr\u00e1tit.<\/p>\n V\u011bdci a\u00a0vizion\u00e1\u0159i o\u00a0cestov\u00e1n\u00ed v\u00a0\u010dase snili cel\u00e1 stalet\u00ed, ale neust\u00e1le nar\u00e1\u017eeli na neprostupnou ze\u010f na\u0161\u00ed reality. A\u017e dote\u010f.<\/p>\n Zpr\u00e1va, kter\u00e1 ned\u00e1vno prob\u011bhla v\u011bdeckou komunitou, zn\u00ed jako \u010dist\u00e1 hollywoodsk\u00e1 fikce: v\u011bdc\u016fm se poda\u0159ilo vr\u00e1tit \u010das o\u00a0zlomek vte\u0159iny zp\u011bt. K\u00a0t\u00e9to ud\u00e1losti nedo\u0161lo v\u00a0tajn\u00e9m vl\u00e1dn\u00edm bunkru za pomoci upraven\u00e9ho DeLoreanu, ale uvnit\u0159 nejpokro\u010dilej\u0161\u00edch v\u00fdpo\u010detn\u00edch stroj\u016f sou\u010dasnosti. Sled ud\u00e1lost\u00ed po anal\u00fdze v\u00fdsledk\u016f p\u0159inutil i\u00a0ty nejchyt\u0159ej\u0161\u00ed mozky planety p\u0159ehodnotit v\u0161e, co jsme si dosud mysleli o\u00a0samotn\u00e9m p\u0159edivu na\u0161\u00ed existence.<\/p>\n Kvantov\u00fd stroj \u010dasu: Zkrat v\u00a0z\u00e1konech termodynamiky<\/p>\n Abychom pochopili tento monument\u00e1ln\u00ed moment, nesm\u00edme se d\u00edvat na sv\u011bt lidsk\u00fdma o\u010dima. Mus\u00edme se pono\u0159it do mikrosv\u011bta subatom\u00e1rn\u00edch \u010d\u00e1stic, kde nevl\u00e1dnou pravidla sira Isaaca Newtona, ale naprosto bizarn\u00ed z\u00e1kony kvantov\u00e9 mechaniky<\/a>.<\/p>\n T\u00fdm \u0161pi\u010dkov\u00fdch v\u00fdzkumn\u00edk\u016f ze spole\u010dnosti IBM vyu\u017eil k\u00a0tomuto p\u0159elomov\u00e9mu experimentu sv\u016fj kvantov\u00fd po\u010d\u00edta\u010d. M\u00edsto klasick\u00fdch bit\u016f, kter\u00e9 zn\u00e1me z\u00a0na\u0161ich notebook\u016f a\u00a0kter\u00e9 mohou nab\u00fdvat pouze hodnot 0\u00a0nebo 1, vyu\u017e\u00edv\u00e1 tento stroj takzvan\u00e9 qubity<\/a> (kvantov\u00e9 bity). Ty mohou d\u00edky jevu zvan\u00e9mu superpozice existovat ve v\u00edce stavech sou\u010dasn\u011b.<\/p>\n V\u00fdzkumn\u00edci z\u00a0laborato\u0159\u00ed IBM Quantum vzali skupinu t\u011bchto qubit\u016f<\/a> a\u00a0nastavili jim po\u010d\u00e1te\u010dn\u00ed kvantov\u00fd stav. N\u00e1sledn\u011b stiskli pomysln\u00e9 tla\u010d\u00edtko \u201eplay\u201c a\u00a0nechali tento stav p\u0159irozen\u011b se vyv\u00edjet v\u00a0\u010dase kup\u0159edu. \u010c\u00e1stice na sebe za\u010daly p\u016fsobit, syst\u00e9m se stal slo\u017eit\u011bj\u0161\u00edm a\u00a0chaos nar\u016fstal. V\u00a0klasick\u00e9m sv\u011bt\u011b by se syst\u00e9m zkr\u00e1tka vyv\u00edjel d\u00e1l a\u00a0d\u00e1l.<\/p>\n Ale pak v\u011bdci ud\u011blali n\u011bco, z\u00a0\u010deho doslova mraz\u00ed v\u00a0z\u00e1dech. Aplikovali do syst\u00e9mu naprosto precizn\u00ed, speci\u00e1ln\u011b navr\u017eenou matematickou operaci. Tento pulz nevr\u00e1til zp\u011bt jen samotn\u00e9 \u010d\u00e1stice. On obr\u00e1til samotn\u00fd vektor v\u00fdvoje syst\u00e9mu. Qubity se za\u010daly fyzicky vracet do stavu, ve kter\u00e9m byly o\u00a0vte\u0159inu d\u0159\u00edve. Syst\u00e9m se doslova \u201eod-vyvinul\u201c zp\u011bt do sv\u00e9ho v\u00fdchoz\u00edho bodu. \u0160ipka \u010dasu se zkr\u00e1tka obr\u00e1tila<\/a>.<\/p>\n Z\u00e1zrak zvan\u00fd \u201eodm\u00edch\u00e1n\u00ed vaj\u00ed\u010dka\u201c<\/p>\n Pro\u010d je tento \u00fasp\u011bch tak obrovsk\u00fd? K\u00a0pochopen\u00ed pou\u017eijme pr\u00e1v\u011b onu analogii s\u00a0rozbit\u00fdm vaj\u00ed\u010dkem, kterou pro vysv\u011btlen\u00ed kvantov\u00fdch fenom\u00e9n\u016f s\u00a0oblibou pou\u017e\u00edvaj\u00ed sami fyzici.<\/p>\n P\u0159edstavte si, \u017ee chcete na p\u00e1nvi odm\u00edchat u\u017e zam\u00edchan\u00e1 vaj\u00ed\u010dka tak, abyste odd\u011blili b\u00edlek od \u017eloutku. V\u00a0klasick\u00e9 fyzice (v na\u0161em makrosv\u011bt\u011b) by to vy\u017eadovalo, abyste znali p\u0159esnou polohu, rychlost a\u00a0sm\u011br ka\u017ed\u00e9ho jednotliv\u00e9ho atomu vaj\u00ed\u010dka na p\u00e1nvi a\u00a0na v\u0161echny z\u00a0nich ve stejn\u00e9m zlomku milisekundy aplikovali absolutn\u011b p\u0159esnou opa\u010dnou s\u00edlu. A\u00a0to nejen na vaj\u00ed\u010dko, ale i\u00a0na atomy vzduchu kolem n\u011bj a\u00a0molekuly tepla z\u00a0p\u00e1nve. Je to matematicky a\u00a0fyzik\u00e1ln\u011b nekone\u010dn\u011b nepravd\u011bpodobn\u00e9.<\/p>\n V kvantov\u00e9m sv\u011bt\u011b po\u010d\u00edta\u010de se ale p\u0159esn\u011b tohle stalo.<\/p>\n V\u011bdci v\u00a0podstat\u011b vzali rozbit\u00e9, zam\u00edchan\u00e9 kvantov\u00e9 vaj\u00ed\u010dko a\u00a0s vyu\u017eit\u00edm spr\u00e1vn\u00fdch protokol\u016f a\u00a0p\u0159esn\u011b na\u010dasovan\u00fdch operac\u00ed donutili v\u0161echny \u010d\u00e1stice, aby zatan\u010dily sv\u016fj tanec pozp\u00e1tku a\u00a0slo\u017eily se zp\u011bt do dokonal\u00e9, nedot\u010den\u00e9 sko\u0159\u00e1pky.<\/p>\n Tento experiment nen\u00ed \u010dasocestov\u00e1n\u00edm v\u00a0tom smyslu, \u017ee by n\u011bkdo nastoupil do stroje a\u00a0potkal dinosaury. P\u0159esto dokazuje n\u011bco mnohem hlub\u0161\u00edho a\u00a0d\u016fle\u017eit\u011bj\u0161\u00edho:<\/p>\n Kvantov\u00e1 \u0161ipka \u010dasu nen\u00ed fixn\u00ed betonov\u00e1 ze\u010f. Je to sm\u011br, kter\u00fd sice p\u0159irozen\u011b plyne kup\u0159edu, ale pod dokonalou kontrolou spr\u00e1vn\u00fdch kvantov\u00fdch protokol\u016f ho lze zastavit, zmanipulovat a\u00a0obr\u00e1tit.<\/p>\n