Yintoni uthuli olukhanyayo?

Ukukhanya okuzenzekelayo kunye kwezi zinto zikhulu eziphuhliswe ngumntu. Isenza sisebenze, sihambe kwaye sihlangane emva kobusuku, isenza ukuba izitrato zizive zikhuselekile. Kodwa ininzi yelanga elingaphandle lilungiswe kakubi: libeka ukukhanya apho akukho namnye ofuna khona. I-efekthi yi i-light pollution, kwaye kwixesha elinye lempilo icima isibhakabhaka sakusasa kubaninzi babantu beplanethi.

Iindlela ezine zokukhanya okubi

• Isibhakabhaka. I-oranje okanye i-dome emhlophe ngaphezulu kweedolophu nemimandla, ebangela ukusatshalaliswa kokukhanya kwimozulu. Ibonakala kumawaka eekhilomitha kude.
• Ukukhanya okugqithisileyo. Ukukhanya okugqithisileyo obangela ukungakhululeki kokujongwa kwaye, ngokuchaseneyo, kunyusa ukubonwa, ngakumbi kumathambo adala nakumaqhubi.
• Ukungena kwelanga. Ukukhanya okuwela apho akunqweneli khona okanye kufuneka khona, njengokuba kwifestile yegumbi lokuhlambela okanye kwindawo ekhuselekileyo yobume bendalo.
• Isilumkiso. Iiqela ezikhanyayo, ezichaphazelayo zemithombo yelanga, eziqhelekileyo kwiindawo zorhwebo ezikhanya kakhulu.

Isizathu sokuba kubaluleke

Isayensi yelanga nembali. Isibhakabhaka sakusasa siyilifa elidala kakhulu eliya kudibana nalo lonke uluntu. Iindawo zokujongwa kufuneka zibekwe kwindawo ezikufutshane zeentaba, kwaye omnye kubantu abathathu akakwazi ukuqhubeka ebona iNkqubo yeMnyama ukusuka ekhaya.

Ubomi obumnyama. Ubomi buguquke ngobusuku nobusuku. Iintaka ezininzi ezihambayo zibaleka ngobusuku kwaye ziqhuba ngee-stars; iimigodi ekhanyayo zitsala kwaye ziyiphazamise, kunye nokungqubana kwemigodi kubulala amawaka eezigidi zeekati ngonyaka eUnited States kuphela. Iintaka ezitshatileyo zesiqu selwandle zijolise kwindawo ekhanyayo yokukhanya ukuze zifumane ulwandle; ilanga elinomtsalane lizikhokelele kwindawo engafanelekanga. Izityalo eziphilayo zijikeleza iilampu de zife, zinceda ukuhla kweentyatyambo. Iintaka ezidumileyo, iintaka kunye nemifuno zonke zitshintsha ukuziphatha kwabo phantsi kwelanga eliyenziweyo.

Ubuhle bempilo yomntu. Ukukhanya kwemini, ngakumbi ukukhanya okuluhlaza okwesibhakabhaka, kuthintela imelatonin, i-homoni elawula ukuphumla, kwaye kuguqula iyure yengqondo. Uvavanyo ludibanisa ukungqubana okuqhubekayo kweyure yengqondo nokuhlala uphumle kakubi kunye nezinye iziphumo ezichaphazela impilo; iimvavanyo zomhlaza othile zihlala ziphuhliswa kwaye sizilandela ngaphandle kokwenza izigqibo ezingaxhaswanga.

Ingxolo nemali. Ilanga elikhanyayo phezulu alikhanyisi nto. Yonke ilanga elingakhuselwanga lilahla inxalenye yombane oyisebenzisayo, kunye nokukhishwa okuvela kuyo.

Ukhuseleko. Iilanga ezininzi azithethi ngokuzenzekelayo ukuba zikhuselekile ngakumbi. Ukukhanya okuqaqambileyo kwenza izithunzi apho iliso lingabonakaliyo, kwaye uvavanyo lwesibane sendlela kunye nobugebengu lunika iziphumo ezixutyiweyo.

Ubusuku buyintliziyo yobomi beplanethi. Siyikhanyela njenge ukuba akukho mntu uhlala khona.

Ukulungisa kulula

Iingxaki ezininzi zendalo zinzima kwaye zihamba ngokukhawuleza. Le nto ayiyiyo: iinkqubo zibiza kakhulu, zifumaneka namhlanje, kwaye zisebenza xa zifakiwe. Funda ukuba usebenzise ukukhanya kwangaphandle ngokufanelekileyo.

Iinkqubo eziqinisekisiweyo

Ukukhanya kokutshatyalaliswa kwezinto kunye lweempawu ezincinci zokutshatyalaliswa kwezinto ezilahleka xa isiqwenga sayo simiselwe, kwaye amadolophu asemthethweni, amazwe kunye neendawo zokuhlambela sele zibonise ukuba zingaphi izinto ezinokubuyiselwa.

• Flagstaff, Arizona: umzi ogcine ii-stars zakhe. Ukhuseleko lwesibhakabhaka sasemini seFlagstaff luya kutshatyalaliswa ngo-1958, xa umzi waqala ukuphatha ukukhanya kwangaphandle, kwaye ngo-2001 waba ngumzi wokuqala wehlabathi weSibhakabhaka esimnyama samazwe ngamazwe. Imithetho yayo ihlala kwizinto ezintathu: ukukhanya okumnyama kweendawo ezininzi zangaphandle, ukukhuselwa ngokupheleleyo, kunye nesigqubuthelo kubungakanani bokukhanya obukhulu kwishishini nakwezinye iindawo ezingahlaliyo. Calibrated measurements made in 2016 and presented to the American Astronomical Society in 2017 found that the light dome over Flagstaff, a city of about 80,000 people, was about 90 percent fainter than the one over Cheyenne, Wyoming, a city of similar size (Flagstaff Dark Skies Coalition).
• Tucson, Arizona: iinkuni ezintsha zesitrato, ezimnyama ngobusuku obuphakathi. Ngo-2016 no-2017 iTucson yatshintsha iindonga zayo zesitrato ngee-LEDs ezimhlophe ezishushu ezikhuselwe ngokupheleleyo ze-3000 K, kwaye ngaphezulu kwe-19,000 zazo zingamnyama ukusuka kwinkqubo esembindini. Ezininzi zivalwa ziye kwi-60% ye power ngobusuku obuphakathi busuku bonke. In a 2019 test that dimmed them further, to 30 percent, the sky overhead in the city centre grew about 5 percent darker as soon as the lights dimmed. Uvavanyo olufanayo luqikelele ukuba iinkuni zesitrato zomzi zivelisa kuphela malunga neepesenti ezingama-14 zokukhanya ngasemva kwe-skyglow yeTucson; okuseleyo kuvela kwezinye iindawo, ezinjengeekhabhathi eziqhutywa ngamadolophu angaphandle kunye nabanini bendawo, izibonakaliso, iipaki zokupaka iimoto kunye neesakhiwo (Barentine et al., 2020). Isifundo: iinkuni zendlela ziqala kakuhle, kodwa isibhakabhaka sibuyela ngokupheleleyo xa zonke iintlobo zezinto ezikhanyayo zangaphandle zilandela imigaqo elungileyo.
• France: a national switch-off. Since a government order of December 2018, shop windows in France must be dark by 1 am, or one hour after closing if later, and car-park lighting must go off two hours after the car park closes. Iilanga ezintsha kufuneka zithumele ngaphantsi kweepesenti ezili-1 zesibane sazo phezulu kwaye, kwiindawo ezininzi, azikho zibanda kakhulu kune-3000 K, nge-2400 K kwiindidi zobume bendalo (Ngomhla we-27 kuDisemba 2018). Iidolophu ezingaphezu kwe-1,000 zaseFransi kunye neelali ngoku zinesiphawulo sokukhanya okulungileyo ngexesha lobusuku (bona amaqela angaphantsi).
• Iindawo ezijikelezayo zonke zigcinwe zimnyama. Ngo-2011 isiQithi seChannel saseSark saqala ukuba yiSiqithi esimnyama sezulu, sibonisa ukuba iqela elipheleleyo elinabantu liyakwazi ukunika ukukhanya abantu kwaye ligcina iiplanethi zayo (Sark). I-Pic du Midi eFransi i-Pyrenees, indawo yokujonga imbali, yayiyiNdlu yeSibhakabhaka esiMnyama saseHlabathi ngo-2013 (Pic du Midi).

• Chicago: iifestile ezikhanyayo ezincinci, iintlanzi ezifileyo ezincinci kakhulu. Iminyaka emibini yobalo lwansuku zonke kwisakhiwo esikhulu esiselwandle eChicago yabonisa ukuba ukunyuka kweepesenti ezimbini komhlaba weefestile ezikhanyayo kuthintela ukungqubana kwezityalo malunga ne 11-ixesha lonyaka omtsha kunye ne6-ixesha lonyaka omtsha. Ukugcina iinkuni kwinqanaba eliphantsi kakhulu elalirekhodwe linokuthi lithintele malunga neepesenti ezingama-60 zeengozi zokufa (Van Doren et al., 2021).

IiNkonzo

ezingenanzuzo zineempumelelo ezinokuqikelelwa kwaye zipapasha izinto ezizenzayo. Ukuba eli phepha likuqhubele phambili, nceda ujonge umsebenzi wabo kwaye ucinge ngokubonelela kubo ngokuthe ngqo, ngewebhu yabo. I Local Solar System Foundation ayihambelani nanye yazo kwaye ayifumananga nto kuzo. Phambi kokuba unikezele, funda iingxelo zeminyaka yonke kunye neeakhawunti zolawulo ngalunye.

• DarkSky International (i-United States, inkampani engasebenziyo engekho phantsi kwetyala ukusukela ngo-1988). Isungulwe eTucson, iqhuba inkqubo yehlabathi yendawo ezimnyama zezulu eziqinisekisiweyo kwiFlagstaff, Sark nePic du Midi, kunye neDarkSky Approved scheme yeefestile ezihlangabezana nemigangatho yayo yokukhanya. Isebenza kunye nemimandla neentlanganiso kwikhowudi zokukhanya.
• Iqela leFlagstaff Dark Skies (i-United States, elingenako ukuhlawula iirhafu) Isungulwe ngo-2000, yacebisa inkqubo yendawo ezimnyama zesibhakabhaka ngo-2001 kwaye ngoku ishicilela “iFlagstaff Solution” ukuze ezinye iindawo zikwazi ukuyikopa.
• ANPCEN I-National Association for the Protection of Night Sky and Environment (i-NASA) Iqhuba inkqubo yokukhanya kwemithetho yaseFransi kwaye iqhuba “Villes et Villages étoilés” uphawu: ngoSeptemba 2025, amadolophu angama-1,062 kunye neelali zazigcina zijikeleze phantsi, zikhusele okanye zivale iiglasi zabo.
• CPRE, iqela lokwenza inzuzo edolophini (iEngland, iqela lokwenza inzuzo elibhalisiweyo 1089685). Iqhuba ubalo lweeNkwenkwezi ngonyaka apho amawaka abantu abala iinkwenkwezi endlwini, kwaye ishicilela imaphu yokukhanya okubi nokumnyama kwezulu jikelele eNgilani ukukunceda iikomiti zikhusele.

Uncedo olufumanekayo

• Qhuba ngaphandle izinto ongazifunayo, ngakumbi iikhabhathi ezihombisayo kunye nelanga lonke.
• Gcina ukhuselo kwaye ujonge ezantsi yonke ilanga elingenanto onayo; khetha ii-bulbs ezishushu ze-3000 K okanye ngaphantsi.
• Vala iimilo ngobusuku ukuze ukukhanya okungaphakathi kuhlale ngaphakathi.
• Ukuthetha nabahlobo malunga nelanga elikhanyayo, ngento esebenzayo yokuyilungisa.
• Umbuzo wekomiti yakho kunye neenkampani zasekhaya malunga nokukhuselwa, ubushushu, ukutywina ukukhanya kunye nophawu lokuvala emva kwexesha lokuvala.
• Gcina iintaka ezihambayo: ebusika nasebusika, shiya ii-lights ezingafunekiyo kwizindlu ezinde ngemini.
• Bala iinkwenkwezi ngeGlobe ngoMhla kwaye uqale iqela lezulu elimnyama lisebenzisa i ibhodi yonikezelo.

IiNkonzo zoLuntu

• I-DarkSky International, Uthuli olukhanyayo
• U-Falchi nokunye (2016), I-atlas entsha yehlabathi yokukhanya kwelanga, Uphuhliso lweSayensi
• I-Kyba et al. (2023), Abaphandi abavela kumaziko olwazi lwamazwe ngamazwe baxela ukuncipha okukhawulezayo kokubonakala kweenkwenkwezi, Ubunzululwazi
• Ilahleko et al. (2014), Iintshukumo zokuyila iintaka eMzantsi Melika, The Condor
• I-Flagstaff Dark Skies Coalition, The Flagstaff Solution ne International Dark Sky City
• I-Barentine et al. (2020), Ukubuyisela umngcipheko wokukhanya kwendlela yomzi-mveliso ovela kuvavanyo lokufumanisa ubushushu belanga kwimeko yovavanyo olukhulu lokunciphisa ukukhanya komzi-mveliso, Iphephandaba leSpektroskopy yeNkqubo kunye noTshintshiso lweRadiation 253 (iprinta esimahla)
• I-Republic of the Congo, Arrêté du 27 décembre 2018 relatif à la prévention, à la réduction et à la limitation des nuisances lumineuses
• Gooley et al. (2011), Ukukhanya kwegumbi phambi kokuba ufike ebhedini kuthintela ukuqalisa kwemelatonin kwaye kufutshane nokuhlala kwemelatonin kubantu, Incwadi yezonyango lweentsonkothi nemetabolism 96
• Brainard et al. (2001), Ispectrum yokusebenza yokulawulwa kwemelatonin kubantu: iimvavanyo zokufumana umfanekiso omtsha wexesha lokuphumla, Journal of Neuroscience 21
• U-Chang nokunye (2015), Ukusetyenziswa kweencwadi ezifundayo ze-eReaders ezinika ukukhanya ngemini kunegalelo elibi ekuphumleni, kwixesha lokujikeleza kwelanga, kunye nokuzimela ekuseni, PNAS 112
• Van Doren et al. (2021), Abaqhubi beengozi ezibulalayo zeentaka ekufumaneni indawo yokuhlala, PNAS 118
• Izixeko neziXeko eziNkwenkwezi
• CPRE, Izulu elimnyama
• Iinkcukacha zeNkqubo yoBulungisa esuka ku IKomiti yeNkqubo yoBulungisa yaseNgilani naseWales kunye nemeko engasebenziyo yaseMelika evela ku ProPublica Nonprofit Explorer
• Uninzi lwezifundo zidweliswe kwiphepha lethu iincwadi zesayensi.