Izithunywa Eziyisithupha Ezivela Emkhathini

NGUMLOBELI WE-PHAPHAMA! EJAPANE

NJALO kufika izithunywa ezivela emkhathini. Ziphethe ukwaziswa okumangalisayo ngendawo yonke ebanzi esizungezile. Lezi zithunywa, eziyisithupha sezizonke, zihamba ngejubane lokukhanya, elingamakhilomitha angu-300 000 ngomzuzwana. Esinye sazo siyabonakala, kodwa zonke ezinye azibonakali ngeso lenyama. Ziyini?

Uxhaxha Lwemisebe Yokukhanya

Sekuyiminyaka engaphezu kwengu-300 kwaziwa ukuthi lapho ukukhanya kudlula engilazini enezinhlangothi ezintathu, kukhipha imibala engu-7 eyinhloko yothingo. Lokhu kubonisa ukuthi ukukhanya okuvamile kuqukethe yonke imibala engu-7 yothingo ngokulandelana kobomvu, osawolintshi, ophuzi, oluhlaza okotshani, oluhlaza okwesibhakabhaka, oluhlaza ngokunsomi (indigo), nonsomi.

Ukukhanya kubhekwa njengokugeleza kwezinhlayiya ezingenasisindo ezibizwa ngokuthi ama-photon, futhi ezinezici zamaza. Ibanga eliphakathi kwamaza libizwa ngokuthi i-wavelength futhi libalwa ngesilinganiso esibizwa ngokuthi i-angstrom, esifushaniswa ngokuthi Å. Silingana nengxenye eyodwa kweziyizigidi eziyinkulungwane zemitha. Ukukhanya okubonakalayo kunesilinganiso sama-angstrom aphakathi kuka-4000 no-7000, futhi ukukhanya okunamaza anobude obuhlukahlukene kuvela njengemibala ehlukahlukene.—Bheka umfanekiso, ekhasini 15.

Nokho, ama-photon angase abe namanye ama-wavelength. Imisebe yama-photon, ebizwa ngokuthi ukukhishwa kwemisebe yokukhanya, ibizwa ngamagama ahlukahlukene kuye ngama-wavelength ayo. Ngaphansi kwama-angstrom angu-4000, njengoba ama-wavelength eba mafushane kunawamaza okukhanya okubonakalayo, amaza okukhanya aqhubeka ebonakala njengokukhishwa kwemisebe e-ultraviolet (UV), ama-X ray, nama-gamma ray. Lapho emade kunama-angstrom angu-7000, lamaza awasabonakali kodwa aba sengxenyeni yoxhaxha lwemisebe yokukhanya e-infrared kuya emazeni omsakazo. Lezi-ke “izithunywa eziyisithupha” ezivela emkhathini. Zithwala ingcebo yokwaziswa ngezindikimba zasezulwini. Ake sibone ukuthi zihlolwa kanjani ukuze kutholakale ukwaziswa okuyigugu.

Ukukhanya Okubonakalayo —Isithunywa Sokuqala

Kusukela esikhathini lapho uGalileo ahlola umkhathi ngesibonakude sakhe ngo-1610 kuze kube ngo-1950, izazi zezinkanyezi ngokuyinhloko zazisebenzisa izibonakude ukuze zihlole indawo yonke. Zazazi kuphela ingxenye ebonakalayo yoxhaxha lwemisebe yokukhanya. Ezinye izinto ezisemkhathini zazingabonakali ngokucacile ngezibonakude, futhi izazi zezinkanyezi zathwebula lezi zithombe ukuze zizihlole. Manje, sekuvame imishini yokuthungatha yama-electron eyaziwa ngokuthi ama-charge-coupled device, enamandla ngokuphindwe izikhathi eziyishumi kuya kwezingu-70 kunefilimu yokuthwebula izithombe. Lesi sithunywa esibonakalayo sinikeza ukwaziswa ngokuphathelene nesisindo sezinkanyezi, izinga lokushisa, namakhemikhali kanye nebanga.

Ukuze kutholwe ukukhanya, kwakhiwa izibonakude ezinkulu kunanini ngaphambili. Kusukela ngo-1976 isibonakude esikhulu kunazo zonke emhlabeni bekuyisibonakude esingamamitha ayisithupha eZelenchukskaya Astrophysical Observatory, eRussia. Nokho, ngo-April 1992, kwaqedwa isibonakude esisha i-Kecka eMauna Kea eHawaii. Kunokuba sibe nesibuko esisodwa kuphela, isibonakude i-Keck sinenhlanganisela yezingxenye zezibuko ezingu-36 ezinezinhlangothi eziyisithupha. Lezi zingxenye zinobukhulu obungamamitha ayishumi lapho zihlangene.

Kunesinye isibonakude i-Keck esakhiwayo buqamama nesokuqala, manje esibizwa ngokuthi i-Keck I, futhi lezi zibonakude ezimbili zingase zikwazi ukusebenza njenge-interferometer yokuhlola. Lokhu kuhilela ukuzixhumanisa nge-computer lezi zibonakude ezimbili ezingamamitha ayishumi, okungaphumela ekhonweni lokubona elingalingana nesibuko esisodwa esinobukhulu obungamamitha angu-85. Elithi “ikhono lokubona” libhekisela ekhonweni lokubona imininingwane.

I-Tokyo National Astronomical Observatory yakha isibonakude sokubona/se-infrared esingamamitha angu-8,3, i-Subaru (igama lesiJapane leqoqo lezinkanyezi i-Pleiades), eMauna Kea. Sizoba nesibuko esincane esisekelwe iziqondisi ezingu-261 ezizolungisa ukuma kwalesi sibuko kanye njalo ngomzuzwana ukuze zilungise noma ikuphi ukuphazamiseka ebusweni baso. Kwakhiwa nezinye izibonakude ezinkulu, ngakho ngokuqinisekile sizofunda okwengeziwe esithunyweni sokuqala—ukukhanya okubonakalayo.

Amaza Omsakazo—Isithunywa Sesibili

Ukugeleza kwamaza omsakazo okuvela kuyi-Milky Way kwatholwa okokuqala ngo-1931, kodwa kwaze kwaba ngawo-1950 lapho izazi zezinkanyezi ezisebenzisa amaza omsakazo zaqala khona ukusebenza nezazi zezinkanyezi ezisebenzisa izibonakude. Lapho kutholakala ukugeleza kwamaza omsakazo okuvela emkhathini, okwakungabonakali ngezibonakude kwaqapheleka. Ukuhlola amaza omsakazo kwakwenza kwaba nokwenzeka ukubona inkaba yomthala wethu.

I-wavelength yamaza omsakazo inkulu kuneyokukhanya okubonakalayo, ngakho kudingeka izingcingo zamaza ezinkulu ukuze kutholwe izimpawu zawo. Ukuze asetshenziswe kuyi-radio astronomy, kuye kwakhiwa izingcingo zamaza ezinobukhulu obungamamitha angu-90 noma ngaphezulu. Njengoba ikhono lokunemba lingelihle ngisho nasemathuluzini amakhulu kangako, izazi zezinkanyezi zixhumanisa izibonakude zamaza omsakazo eziwuxhaxha nge-computer ngenqubo ebizwa ngokuthi i-radio interferometry. Lapho kuba nebanga elikhulu phakathi kwezibonakude, kulapho ikhono lokucacisa liba ngcono khona.

Esinye isimiso esinjalo sihilela uthi lwamaza olungamamitha angu-45 lwe-Nobeyama Radio Observatory eJapane; uthi lwamaza olungamamitha ayikhulu eBonn, eJalimane; kanye nesibonakude esingamamitha angu-37 e-United States. Isimiso esinjena sibizwa ngokuthi i-very long baseline interferometry (VLBI), futhi sinekhono lokubona eliyingxenye eyodwa kweziyinkulungwane ze-arc second, noma ikhono lokubona into engamamitha-skwele angu-1,8 enyangeni.b Le-VLBI ithiywa nje ubukhulu bomhlaba.

I-Nobeyama Radio Observatory ithuthukisa indlela yokuthola lesi sithunywa ngokubeka uthi lwamaza omsakazo olungamamitha ayishumi emkhathini. Kumelwe lucitshwe eJapane ngo-1996 futhi luyoxhunyaniswa nezibonakude zamaza omsakazo eJapane, eYurophu, e-United States, nase-Australia, kwakhiwe uxhaxha olungamakhilomitha angu-30 000. Ngamanye amazwi, lesi simiso siyofana nesibonakude esikhulu esinobukhulu obuphinda umhlaba kathathu! Siyoba nekhono lokubona eliyi-arc second engu-0,0004, okusho ukuthi siyokwazi ukubona into engamasentimitha angu-70 enyangeni. Njengoba sibizwa ngokuthi i-VLBI Space Observatory Programme, noma i-VSOP uma sifushaniswa, siyosetshenziselwa ukudweba nokuhlola izinkaba zemithala nama-quasar, lapho kucatshangwa khona ukuthi kunemigodi emnyama emikhulukazi. Njengesithunywa sesibili esisendaweni yonke, amaza omsakazo afeza izimangaliso futhi ayoqhubeka enikeza ukwaziswa ngomsuka wawo.

Ama-X Ray—Isithunywa Sesithathu

Ama-X ray okuqala atholwa ngo-1949. Njengoba ama-X ray engenakungena emkhathini womhlaba, kwadingeka ukuba izazi zezinkanyezi zilinde ukwakhiwa kwamarokhethi neziphuphutheki zokuzenzela ukuze zithole ukwaziswa okuvela kulesi sithunywa. Ama-X ray aphehleka emazingeni okushisa aphakeme kakhulu futhi kanjalo anikeza ukwaziswa ngemikhathi yezinkanyezi ezishisayo, izinsalela zezinkanyezi ezinkulu eziqhumayo, amaqoqo emithala, ama-quasar, nemigodi emnyama ecatshangelwayo.—Bheka i-Phaphama! ka-March 22, 1992, amakhasi 5-9.

Ngo-June 1990 kwacitshwa isiphuphutheki i-Roentgen futhi saphumelela ekudwebeni yonke indawo enama-X ray. Ukwaziswa okwaqoqwa kwabonisa imithombo yama-X ray eyizigidi ezine esakazeke kuwo wonke umkhathi. Nokho, kunokubengezela okungaziwa okungemuva phakathi nalemithombo. Kungenzeka kuvela emaqoqweni ama-quasar, okucatshangwa ukuthi ayizinkaba ezinamandla zemithala eseduze nalokho ezinye izazi zezinkanyezi ezikubiza ngokuthi “unqenqema lwendawo yonke ebonakalayo.” Ngesikhathi esifanele, singabheka phambili ekutholeni ukwaziswa okwengeziwe okuvela kulesi sithunywa esingama-X ray.

Ukukhishwa Kwemisebe E-infrared—Isithunywa Sesine

Imisebe yokuqala e-infrared yabonakala ngawo-1920. Njengoba umhwamuko uvimba ukukhishwa kwemisebe e-infrared, ukuze kutholakale imiphumela engcono kakhulu kusetshenziswa iziphuphutheki ezizungezayo ukuze kuhlolwe lesi sithunywa. Ngo-1983 kwasetshenziswa i-Infrared Astronomical Satellite (IRAS) ukuze kudwetshwe wonke umkhathi we-infrared futhi kwatholwa imithombo ye-infrared engu-245 389. Cishe amaphesenti angu-9 (22 000) alezi zinto abonakala eyimithala eqhelile.

Izibonakude azikwazi ukubona kuzo zonke izindawo ezinegesi nothuli emkhathini. Nakuba kunjalo, lesi sithunywa sesine senza kube nokwenzeka “ukubona” ngalé kwalolu thuli futhi siyinzuzo kakhulu ekuhloleni inkaba yomthala wethu. Ososayensi bahlela ukuthumela emkhathini isibonakude se-infrared esibizwa ngokuthi i-Space Infrared Telescope Facility, esinamandla ngokuphindwe izikhathi ezingu-1000 kune-IRAS.

Ukukhishwa Kwemisebe E-ultraviolet—Isithunywa Sesihlanu

Ukukhishwa okukhulu kwemisebe yokuqala e-ultraviolet (UV) kwabonakala ngo-1968. Ungqimba lwe-ozone luvimbela iningi lalokhu kukhishwa kwemisebe ekufikeni ebusweni bomhlaba. I-Hubble Space Telescope, eyacitshwa ngo-April 1990, iklanyelwe ukubona kokubili ukukhishwa kwemisebe ebonakalayo ne-ultraviolet futhi izogxila kuma-quasar angu-30 aqhele ngebanga leminyaka eyizigidi zezinkulungwane eziyishumi uma uhamba ngejubane lokukhanya.c Ngamanye amazwi, ukuhlola lesi sithunywa se-ultraviolet kwenza kube nokwenzeka ukubona ukuthi indawo yonke yayinjani eminyakeni engaba izigidi eziyizinkulungwane eziyishumi edlule. Kuthenjwa ukuthi lesi sithunywa siyokwembula izimfihlakalo eziningi zendawo yonke.

Ama-gamma Ray—Isithunywa Sesithupha

Ama-gamma ray awukukhishwa kwemisebe okunamandla kakhulu okunama-wavelength amafushane ngempela. Ngenhlanhla, umoya osemkhathini uvimbela iningi lalemisebe eyingozi ekufikeni ebusweni bomhlaba. Lesi sithunywa sihlanganiswa nezenzakalo ezinobudlova endaweni yonke. Ngo-April 5, 1991, i-National Aeronautics and Space Administration yaciba i-Gamma Ray Observatory emkhathini. Izohlola izenzakalo ezihilela ama-quasar, izinkanyezi ezinkulu eziqhumayo, ama-pulsar, imigodi emnyama ecatshangelwayo, nezinye izinto ezikude.

Ngenxa yenkathi yokuhlolwa komkhathi, izazi zezinkanyezi seziyakwazi ukuhlola lonke uxhaxha lwemisebe yokukhanya, kusukela emazeni omsakazo kuya kuma-gamma ray. Ngempela, kuyinkathi yokuchuma ezazini zezinkanyezi. Lapho ‘siphakamisela amehlo ethu phezulu,’ sesiyakwazi ‘ukubona’—ngosizo lwezithunywa eziyisithupha ezivela emithonjeni yezinkanyezi—ukuhlakanipha okumangalisayo koMdali wakho konke. (Isaya 40:26; IHubo 8:3, 4) Njengoba izazi zezinkanyezi ziqhubeka zichaza ukwaziswa okuthwelwe yilezi zithunywa, siyoqhubeka sizizwa ngendlela uJobe azizwa ngayo eminyakeni engaphezu kwengu-3000 edlule: “Bheka, lokhu kungamaphethelo nje ezindlela zakhe, izwi lokunyenyeza nje elizwakalayo ngaye.”—Jobe 26:14.

[Imibhalo yaphansi]

[Ishadi ekhasini 15]

(Ukuze ubone ukuthi indaba ihlelwe kanjani, bheka encwadini)

0.1Å Ama-“gamma ray”

1Å Ama-X “ray”

10Å

100Å Ama-UV

1,000Å

4000-7000Å Ukukhanya okubonakalayo

10,000Å Amaza e-“infrared”

10μ

100μ Amaza omsakazo

1mm

1cm

10cm

1m

[Isithombe ekhasini 15]

Ngesibonakude sasemkhathini samaza omsakazo i-VSOP, kuyokwenzeka ukubona into engamasentimitha angu-70 enyangeni

[Umthombo]

VSOP: Courtesy of Nobeyama Radio Observatory, Japan

[Isithombe ekhasini 15]

Umdwebo wesibonakude sokubona/se-“infrared” i-Subaru, esakhiwayo manje

[Umthombo]

Subaru: Courtesy of National Astronomical Observatory, Japan