Isakhono Sobunjineli Sebhere Emhlophe
IBHERE emhlophe inokufundisa uluntu okuninzi mayela nokusebenzisa amandla elanga, ngokutsho kwezazinzulu ezithile. Isazinzulu ngezinto zemvelo uRichard E. Grojean saqala ukuba nomdla kule ngcamango phakathi kwiminyaka yee-1970, emva kokuba kufunyenwe okuthile okubangel’ umdla ngezi zilwanyana zimhlophe zihlala kwiNcam engeNtla yoMhlaba.
Amagosa obalo lwezilwanyana zasendle eKhanada afumanisa ukuba akanakusuka nje ngokulula azifote ngendlela eqhelekileyo esesibhakabhakeni ezi zidalwa, ekubeni zingabonakali kakuhle kumhlaba obonakala umhlophe. Nefilimu ebanga imibala ebomvu, ngokuqhelekileyo eluncedo kakhulu ekufoteni izilwanyana ezinegazi elishushu, ayizange isebenze. Ezi zilwanyana zazikhuselwe kakhulu buboya bazo ngokokude ifilimu ingakwazi ukulinganisela ubushushu bazo. Noko ke, xa kwathi kwasetyenziswa ifilimu yeultraviolet, iintini ezimhlophe neebhere ezimhlophe zabonakala zimnyama yaye zahluke ngokupheleleyo kwindawo emhlophe ezazikuyo. IThe Toronto Star inikela le ngxelo, “Ngoxa imitha yeultraviolet yayibetheka nje ibuye ekhephini, ezi zilwanyana zaziyamkela.”
Kutheni? Ngokutsho kwezazinzulu ngezinto zemvelo uGrojean noGregory Kowalski, ongunjingalwazi obambiseneyo kwicandelo lobunjineli ngoomatshini, impendulo ikuboya bebhere. Ekupheleni kwespectrum (umgca-mabala) esingabonakaliyo nesinemitha yeultraviolet, uboya bebhere bunqakula ama-90 ekhulwini okukhanya kweultraviolet buze buwadlulisele kwisikhumba esimnyama ngaphantsi, ngaloo ndlela bugcina ibhere isithile. KwiNcam engeNtla yoMhlaba, apho iqondo lokubanda lidla ngokuhla liye kwiqondo lama-29 ngaphantsi kuka-0 ngokwesikali sikaCelsius, amandla oboya bebhere okuyigcina ifudumele ayaphawuleka. Ngokwahlukileyo koko, izixhobo eziqhelekileyo zokuguqula imitha yelanga ibe ngumbane ezisemaphahleni ezindlu azisebenzi ngendlela efanayo. Enyanisweni, okaKowalski yena uthelekelela ukuba ezi zixhobo ezenziwe ngabantu kusenokuthiwa zisebenza ngomlinganiselo wama-50 ekhulwini xa kusetyenziswa imigaqo yoboya bebhere emhlophe.
Kwicala elibonakalayo lespectrum, uboya busebenza ngendlela eyahlukileyo; ama-90 ekhulwini okukhanya afika abetheke eboyeni aze abuyele emva. Oku kubangela ukuba ibhere ibonakale imhlophe qhwa, nakubeni uboya bona ngokunokwabo bungekho mhlophe koko bungenambala. Ubumhlophe boboya bubangela ukuba ibhere ikwazi ukuzingela ingabonakali kwiNcam engeNtla yoMhlaba enekhephu. Bambi abakhi-mkhanya bade bazibona iibhere ezimhlophe zigquma iimpumlo zazo ezimnyama njengoko zichwechwela ixhoba lazo, ngokungathi ziyayiqonda into yokuba kufuneka zifane nekhephu.
Ngaloo ndlela uboya bebhere emhlophe buzinyamekela kakuhle gqitha iintswelo ezimbini zesi silwanyana: ukukhangeleka simhlophe nokuhlala sisithile. Ngoko, ayimangalisi kangako into yokuba isazinzulu ngezinto zemvelo uGrojean sabuncoma uboya baso sisithi “sisakhono sobunjineli esimangalisayo.” Lilonke, esi sidalwa singaqhelekanga nesimangalisayo singqinela ubulumko boMdali waso.