Duk da sarkakiya na batun, farfesa na Jami'ar Princeton Stephen Gubser yana ba da taƙaitacciyar gabatarwa, mai sauƙi, da kuma nishadantarwa zuwa ɗayan wuraren da aka fi muhawara a fannin kimiyyar lissafi a yau. Baƙar fata abubuwa ne na gaske, ba kawai gwajin tunani ba! Baƙaƙen ramukan suna da matuƙar dacewa daga mahangar ka'ida, tunda sun fi sauƙi a lissafin lissafi fiye da yawancin abubuwan astrophysical, kamar taurari. Abubuwa suna ban mamaki lokacin da ya bayyana cewa baƙar fata ba su da gaske baƙar fata.
Menene ainihin cikin su? Yaya za ku yi tunanin fadowa cikin baƙar fata? Ko watakila mun riga mun fada cikinsa kuma ba mu sani ba tukuna?
A cikin Geometry na Kerr, akwai kewayar geodesic, gabaɗaya an rufe su a cikin ergosphere, tare da kaddarorin masu zuwa: barbashi da ke motsawa tare da su suna da ƙarfin kuzari mara kyau waɗanda suka fi ƙarfin darajar sauran talakawa da kuzarin motsa jiki na waɗannan barbashi da aka ɗauka tare. Wannan yana nufin cewa jimlar kuzarin waɗannan barbashi ba su da kyau. Wannan yanayin ne ake amfani dashi a cikin tsarin Penrose. Yayin da yake cikin ergosphere, jirgin da ke hako makamashi ya harba wani majigi ta yadda zai rika tafiya tare da daya daga cikin wadannan wurare da makamashi mara kyau. Bisa ka'idar kiyaye makamashi, jirgin yana samun isassun makamashin motsa jiki don ramawa ga asarar da aka yi da shi daidai da makamashin na'urar, kuma baya ga samun daidaitaccen makamashin da ba a iya amfani da shi ba. Tun da ma'aunin ya kamata ya ɓace a cikin rami na baki bayan an harbe shi, zai yi kyau a yi shi daga wani nau'i na sharar gida. A gefe guda, baƙar fata za ta ci komai, amma a gefe guda, zai dawo mana da kuzari fiye da yadda muka saka jari. Don haka, ƙari, makamashin da muke saya zai zama "kore"!
Matsakaicin adadin kuzarin da za'a iya fitar da shi daga ramin baki na Kerr ya dogara da saurin yadda ramin ke jujjuyawa. A cikin mafi girman yanayin (a iyakar saurin juyi mai yuwuwar), ƙarfin jujjuyawar lokacin sararin samaniya yana ɗaukar kusan kashi 29% na jimlar ƙarfin rami mai duhu. Wannan bazai yi kama da yawa ba, amma ku tuna cewa juzu'i ne na jimlar yawan sauran! Don kwatantawa, ku tuna cewa injinan nukiliyar da ke amfani da makamashin lalatawar rediyoaktif yana amfani da ƙasa da kashi ɗaya cikin goma na kashi ɗaya na makamashi daidai da yawan adadin kuzari.
Matsakaicin lissafin lokacin sararin samaniya a sararin sararin samaniya na baƙar fata mai jujjuyawar ya sha bamban da lokacin sararin samaniya na Schwarzschild. Mu bi binciken mu mu ga me ya faru. Da farko, komai yayi kama da shari'ar Schwarzschild. Kamar yadda yake a da, lokacin sararin samaniya ya fara rugujewa, yana jan komai tare da shi zuwa tsakiyar ramin baƙar fata, kuma sojojin ruwa sun fara girma. Amma a cikin yanayin Kerr, kafin radius ya tafi sifili, rushewar ya ragu kuma ya fara juyawa. A cikin baƙar rami mai jujjuyawa cikin sauri, wannan zai faru tun kafin magudanar ruwa su yi ƙarfi don yin barazana ga amincin binciken. Don fahimtar dalilin da ya sa wannan ya faru, bari mu tuna cewa a cikin injiniyoyi na Newtonian lokacin juyawa, ƙarfin da ake kira centrifugal ya tashi. Wannan karfi ba ɗaya daga cikin mahimman ƙarfin jiki ba: yana tasowa ne sakamakon haɗin gwiwar aiki na asali, wanda ya zama dole don tabbatar da yanayin juyawa. Za a iya tunanin sakamakon a matsayin tasiri mai tasiri wanda ke jagorantar waje-ƙarfin centrifugal. Kuna jin shi yana jujjuya kaifi a cikin mota mai motsi da sauri. Idan kuma ka taba hawa keken kaushi to ka san cewa da sauri ya rika jujjuyawa sai ka danne dogo domin idan ka saki sai a jefar da kai waje. Wannan kwatankwacin lokacin sarari bai dace ba, amma yana samun ma'ana daidai. Ƙaƙwalwar angular a cikin sararin samaniya na Kerr baƙar fata yana ba da ingantaccen ƙarfi na tsakiya wanda ke magance jan hankali. Yayin da rugujewar sararin samaniya ke jan lokacin sararin samaniya zuwa ƙaramin radi, ƙarfin tsakiya yana ƙaruwa kuma a ƙarshe zai iya fara tunkarar rugujewar sannan ya juya shi.
A daidai lokacin da rushewar ya tsaya, binciken ya kai matakin da ake kira sararin sama na ciki na black hole. A wannan lokacin, magudanar ruwa ba su da yawa, kuma binciken, da zarar ya ketare sararin taron, yana ɗaukar lokaci kaɗan kawai don isa gare shi. Duk da haka, kawai saboda lokacin sararin samaniya ya daina rushewa ba yana nufin cewa matsalolinmu sun ƙare ba kuma cewa juyawa ya kawar da rashin daidaituwa a cikin rami na Schwarzschild. Wannan har yanzu yana da nisa! Bayan haka, a tsakiyar shekarun 1960, Roger Penrose da Stephen Hawking sun tabbatar da tsarin ka'idodin ka'idoji guda ɗaya, wanda daga ciki ya biyo bayan cewa idan aka sami rugujewar gravitational, ko da gajere ne, to ya kamata a sami wani nau'i na mufuradi. A cikin shari'ar Schwarzschild, wannan abu ne mai tattare da duk wani nau'i na murkushewa wanda ke mamaye duk sararin samaniya a sararin sama. A cikin maganin Kerr, singularity yana nuna hali daban kuma, dole ne in ce, ba zato ba tsammani. Lokacin da binciken ya isa sararin sama na ciki, kerr singularity yana bayyana kasancewarsa - amma ya zama a cikin dalilin da ya gabata na layin binciken. Kamar dai ma'abocin addini ya kasance koyaushe, amma yanzu ne binciken ya ji tasirinsa ya kai gare shi. Za ku ce wannan yana da kyau, kuma gaskiya ne. Kuma akwai rashin daidaituwa da yawa a cikin hoton sararin samaniya, wanda kuma a bayyane yake cewa wannan amsar ba za a iya la'akari da ƙarshe ba.
Matsala ta farko tare da rashin daidaituwa da ke bayyana a baya na mai kallo wanda ya kai sararin samaniya shine cewa a wannan lokacin ma'auni na Einstein ba zai iya yin hasashen abin da zai faru da sararin samaniya a waje da sararin samaniya ba. Wato, a cikin ma'ana, kasancewar maɗaukaki na iya haifar da komai. Wataƙila abin da zai faru a zahiri za a iya bayyana mana ta hanyar ka'idar jimla nauyi, amma daidaitawar Einstein ba mu da damar sani. Kawai saboda sha'awa, mun bayyana a ƙasa abin da zai faru idan muna buƙatar cewa tsaka-tsakin sararin samaniya ya kasance mai santsi kamar yadda zai yiwu a lissafin lissafi (idan ayyukan awo sun kasance, kamar yadda masu ilimin lissafi suka ce, "analytic"), amma babu wani tushe na zahiri na zahiri. don irin wannan zato No. A hakikanin gaskiya, matsala ta biyu tare da sararin sama na ciki tana nuna daidai da akasin haka: a cikin sararin duniya na ainihi, wanda kwayoyin halitta da makamashi ke wanzuwa a waje da ramukan baƙar fata, lokacin sararin samaniya a sararin sama na ciki ya zama mai tsanani sosai, kuma madauki mai kama da singularity yana tasowa a can. Ba shi da ɓarna kamar ƙarfin ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan ƙayatarwa a cikin mafita na Schwarzschild, amma a kowane hali kasancewarsa yana jefa shakku kan sakamakon da ya biyo baya daga ra'ayin kyawawan ayyukan nazari. Wataƙila wannan abu ne mai kyau - zato na fadada nazari ya ƙunshi abubuwa masu ban mamaki.
Ainihin, na'urar lokaci tana aiki a cikin yanki na rufaffiyar masu lankwasa masu kama da lokaci. Nisa daga singularity, babu rufaffiyar lallausan lokaci mai kama da juna, kuma baya ga rundunonin ƙin yarda a cikin yanki na singularity, lokacin sararin samaniya yana kama da al'ada. Duk da haka, akwai hanyoyi (ba su da geodesic, don haka kuna buƙatar injin roka) wanda zai kai ku zuwa yankin rufaffiyar lokaci mai kama. Da zarar kun isa wurin, zaku iya motsawa ta kowace hanya tare da t coordinate, wanda shine lokacin mai kallo mai nisa, amma a cikin lokacinku zaku ci gaba koyaushe. Wannan yana nufin cewa za ku iya zuwa duk lokacin da kuke so, sannan ku koma wani yanki mai nisa na lokacin sararin samaniya - har ma ku isa can kafin ku tafi. Tabbas, yanzu duk rikice-rikicen da ke da alaƙa da ra'ayin tafiyar lokaci suna rayuwa: alal misali, menene idan, ta hanyar yin tafiya na lokaci, kun shawo kan kanku na baya don barin shi? Amma ko irin wannan nau'in lokaci-lokaci na iya wanzuwa da kuma yadda za a iya warware rikice-rikicen da ke tattare da shi tambayoyi ne da suka wuce iyakar wannan littafi. Duk da haka, kamar yadda tare da matsalar "blue singularity" a kan sararin ciki, haɗin kai na gabaɗaya ya ƙunshi alamun cewa yankuna na lokaci-lokaci tare da rufaffiyar lokaci-lokaci ba su da kwanciyar hankali: da zaran ka yi ƙoƙari ka haɗa wani nau'i na taro ko makamashi. , waɗannan yankuna na iya zama guda ɗaya. Bugu da ƙari, a cikin ramukan baƙar fata masu jujjuya da ke samuwa a cikin sararin samaniyar mu, ita ce "launi mai launin shuɗi" da kanta wanda zai iya hana samuwar yanki na talakawa (da duk sauran sararin samaniyar Kerr wanda fararen ramukan ke kaiwa). Duk da haka, gaskiyar cewa haɗin kai na gaba ɗaya yana ba da damar irin waɗannan baƙon mafita yana da ban sha'awa. Tabbas, yana da sauƙi a bayyana su a matsayin Pathology, amma kada mu manta cewa Einstein da kansa da yawancin mutanen zamaninsa sun faɗi abu ɗaya game da ramukan baƙi.
» Ana iya samun ƙarin bayani game da littafin a
Don Khabrozhiteley 25% rangwame ta amfani da coupon - Baƙar fata
Bayan biyan kuɗin takardar littafin, za a aika da sigar lantarki ta hanyar imel.
source: www.habr.com