Yini ubuthi bokukhanya?

Ukukhanya okungenziwa kwenziwa yisinye sezidalwa ezidumile zomuntu. Sisebenza, sihamba futhi sihlangana ngemuva kobusuku obumnyama, futhi kwenza iziteshi zihlale ziphephile. Kodwa-ke, ukushayela okuningi kwangaphandle kufakwe kahle: ikhipha ukukhanya lapho akukho muntu ofuna khona. Imiphumela i ukukhishwa kwelanga, futhi ngesikhathi sokuphila esisodwa sisuse izulu lemini kubaningi babantu beplanethi.

Indlela ezine ukukhanya kudlula ngendlela engalungile

Isibhakabhaka. I-oranje noma i-dome emhlophe phezu kwezifunda kanye nezifunda, ezibangela ukusakazeka kwelanga ngaphakathi kwe-atmosphere. Ingabonakala emakhilomitha angamakhulu.
Isikhashana. Ukukhanya okuningi okubangela ukukhathazeka kokubukeka futhi, ngokungemthetho, kunciphisa ukubonakala, ikakhulukazi kumazinyo adala nabagibeli.
Isikhashana sokukhanya. Ukukhanya okuwela lapho akudingeki noma kudingeka khona, njengokungena efenisha yegumbi lokuphumula noma endaweni yokugcina izinto eziphilayo.
Isikhala. Isikhashana, amaqembu athakazelisayo emithonjeni yokukhanya, avame kakhulu ezimbonini ezikhanyayo kakhulu.

Kungani kubaluleke

Isayensi yezinkanyezi nesiko. Isibhakabhaka sakusihlwa yinto edala kakhulu yomlando ohlukaniswe abantu. Izindawo zokubhekana nazo zidinga ukukhiwa eziphezulu zemifula engaphandle, futhi umuntu ngamunye kumuntu wesithathu akakwazi ukubona i-Milky Way kusuka ekhaya.

Impilo eluhlaza. Ukuphila kwaqala ngemini nemini. Izilwane eziningi ezihamba ngezinyawo zindiza ekuseni futhi zihamba ngezinkanyezi; amafulethi akhanyayo athakazela futhi akhohlisa, futhi ukungqubuzana kwamafulethi kubulala izilwane ezizigidi ezingamakhulu ngayinye ngonyaka e-United States kuphela. Izinkomo ze-sea-turtle ezincane zihamba phambili ezindaweni ezikhanyayo ukuze zithole ilwandle; amalambu angaphakathi mhlaba aholela ngendlela engalungile. Izilwane ezifuywayo zihamba ngazo zonke izinhlamvu kuze kuphele, zisiza ukuncipha kwezilwane ezifuywayo. Izintaka, izimvu kanye nezitshalo zonke zishintsha indlela eziphila ngayo ngaphansi kwelanga elikhiqizwe.

Izinsana ze-Loggerhead sea turtle zihamba phezu kwebhishi elinqwaba yeqhwa lisuka emagwadini emini. — I-Loggerhead sea turtle hatchlings ihamba elwandle eCape Hatteras National Seashore, North Carolina. Ebhishi elimnyama ngokwemvelo, i-horizon ekhanyayo kakhulu yilwandle, ngakho-ke amalambu angaphansi kwedune angabaholela ekuhambeni. Photo: Cape Hatteras National Seashore, US National Park Service, public domain

Ukunakekelwa kwempilo. Ukukhanya kwelanga, ikakhulukazi ukukhanya okuluhlaza okwesibhakabhaka, kuvimbela i-melatonin, i-hormon elawula ukuphumula, futhi kuguqule ihora lesikhumba. Ucwaningo luxhuma ukungqubuzana okuqhubekayo kwe-body clock nokuhlala ekuseni kakhulu kanye nezinye izinzuzo zempilo; izimpawu zokugula okuthile ziqhubeka nokuthuthukiswa, futhi silandela lokhu ngaphandle kokwenza iziphetho ezingaxhasi.

Energy and money. Ukukhanya okukhanyayo phezulu akukhazimuli lutho. Yonke ilanga elingagcini ngokuzivikela lilahla inqwaba ye-electricity elisebenzisayo, kanye ne-emission evela kuyo.

Ukuphepha. Ukukhanya okuningi akuyona into eholela ekubeni kungabikho ukuphepha okuningi. Ukukhanya kwenza izithunzi lapho imehlo alikwazi ukuzibona, futhi ucwaningo lwesibani sendlela kanye nobugebengu lunikeza izimpendulo ezihlukahlukene.

80%abantu abaphila ngaphansi kwelanga elingcolile (U-Falchi nokunye, 2016)

9.6%unyaka okhanyayo wezulu olubonakalisa abacwaningi base-U-Kyba nokunye, 2023)

365 kuya ku-988 millionizilwane ezifa ngenxa yokuhlaselwa kwesakhiwo ngonyaka e-US (Ukulimala nokunye, 2014)

Ubusuku buyingxenye yokuphila kweplanethi. Siyikhanya njengoba kungenjalo.

I-Nile delta neCairo ngobusuku kusuka esiteshini sendawo yangaphandle yezwekazi. — Izifunda zibonakala kusuka e-orbit ngenxa yokukhanya okuphuma phezulu futhi kulahlekile. Credit: NASA

Ukuxazulula kulula

Izinkinga eziningi zesimo sezulu zinzima futhi zihamba kancane. Lenye ayiyona: izixazululo zibiza kakhulu, zikhona namhlanje, futhi zisebenza ngokushesha lapho zifakwe. Funda ukuthi ungawakha kanjani amafasitela ngaphandle ngokuzimela.

Izixazululo eziqinisekisiwe

Ukulimala kwelanga kuyinye yezimo ezincane zokulahlekelwa yimvelo ezingenayo lapho ikhona khona, futhi izifundazwe, amazwe kanye nezindlu zangempela zibonise ukuthi zingatholakali kanjani.

Flagstaff, Arizona: isixeko esigcina izinkanyezi zayo. Ukuvimbela i-sky yasebusuku kweFlagstaff kubuyela emuva ngo-1958, lapho isixeko saqala ukuphatha ukukhanya kwangaphandle, futhi ngo-2001 yashintsha yaba yidolobha lokuqala le-International Dark Sky City. Izimiso zayo zihlala ezizinto ezintathu: ukukhanya kwe-amber kuzo zonke izindawo zangaphandle, ukuvimbela okugcwele, kanye ne-cap kuleyo ngxenye yokukhanya ebhizinisini nakwezinye izifunda ezingahlali. Ukulinganiselwa okuhlobene kwenziwa ngo-2016 futhi kwanikezwa iSociety yaseMelika ye-Astronomical ngo-2017 kwathola ukuthi i-dome ekhanyayo ngaphezulu kweFlagstaff, umzi oneminyaka engama-80,000 abantu, yayiyi- 90 percent fainter kunaleyo eCheyenne, Wyoming, idolobhana elinobubanzi obufanayo (I-Flagstaff Dark Skies Coalition).
Tucson, Arizona: amalambu e-street amasha, amnyama ngobusuku obuphakathi. Ku-2016 no-2017 i-Tucson yashintsha amalambu ayo e-street nge-LEDs amhlophe apholile agcwele angaphansi kwe-3000 K, futhi ngaphezulu kuka-19,000 kwazo kungancipha kusuka kuhlelo oluphakathi. Amanye afakwa ngaphansi kwephesenti le-60 lokusebenza ekuseni ngaso sonke isikhathi. Ngo-2019 ukuhlolwa ukuthi wavala nabo ngaphezu, ku-30 percent, izulu phezu kwekhanda ezindaweni zedolobha Ingxenye engu-5 emnyama njengoba amalambu amnyama. Ucwaningo olufanayo lulinganisela ukuthi amalambu esitezi sedolobha akhiqiza kuphela cishe i-14% yokukhanya eduze kwe-skyglow yeTucson; okushiwo kuvela kwezinye izifunda, ezinjengezibani eziqhutshwa ngamadolobhana asogwini kanye nabasebenzi abasemthethweni, izinhlamvu, izindawo zokupaka izimoto nezindlu (Barentine et al., 2020). Isifundo: amalambu esitezi yisiqalo esihle, kodwa izulu libuyela ngokuphelele lapho wonke uhlobo lwesibani esingaphandle silandela izimiso ezinhle.
France: i-national switch-off. Ngomyalo wesifundazwe ngoDisemba 2018, amafasitela esitolo aseFrance kufanele amnyama kuze kube ngu-1 am, noma isigamu sehora ngemuva kokuvula uma kudlule isikhathi, futhi ukukhanya kwemoto kumele kuvale amahora amabili ngemuva kokuvala indawo yokupaka. Izibani ezintsha kufanele zithumele ngaphansi kuka 1 ngekhulu lezibani zabo eziphezulu futhi, ezindaweni eziningi, zingabi zimbi kune-3000 K, ne-2400 K ezindleleni zobuciko (Arrêté du 27 décembre 2018). Okungaphezu kuka-1,000 amadolobhana namadolobhana aseFrance amanje anesitifiketi sokukhanya okuhle kwesikhathi sebusuku (bona izinhlangano ngezansi).
Indawo egcwele igcinwe imnyama. Ngo-2011 iChannel Island yaseSark yaqala njengendawo yokuqala yezulu elimnyama, libonisa ukuthi inhlanganiso ephelele ehlala abantu ingakha ukukhanya kwabanye futhi igcine izinkanyezi zayo (Sark). I-Pic du Midi eFrench Pyrenees, indawo yokubuka imbali, yashintsha yaba yi-International Dark Sky Reserve ngo-2013 (Pic du Midi).

Abaphathi bepaki ababini esithombeni esibhekene ne-telescope enkulu eduze kwelanga eliluhlaza okwesibhakabhaka. — I-Rangers ibeke ama-telescopes empilweni yeqembu le-star elihlonipha isitifiketi sepaki labo njenge International Dark Sky Park e-United States. Photo: Chris Wonderly, US National Park Service, public domain

IChicago: amafasitela ancane, izinhlanzi ezifile zincane kakhulu. Izinkulungwane ezimbili zokubala ngosuku esitezi esisodwa esikhulu se-lakeside eChicago kubonisa ukuthi ukuncipha kwengxenye yendawo yefenisha ekhanyayo kunomthelela ekuhlaselweni kwezilwane. 11-ukuphindaphindwa ebusika no-6-ukuphindaphindwa ehlobo. Ukugcina amalambu emazingeni aphansi kakhulu arekhodwe khona kungavimbela cishe i-60% yamagciwane (Van Doren et al., 2021).

Izinhlangano ezisebenza kulolu msebenzi

Lezi qembu ezingatholakali zithola imiphumela elinganiselwa futhi zishicilela lokho ezikwenzayo. Uma lekhasi likushintshile, bheka umsebenzi wabo bese ucabanga ukunikela kubo ngokuqondile, nge-webusayithi yabo. I Local Solar System Foundation ayisebenzisi noma iyiphi yazo futhi ayitholanga lutho kuzo. Phambi kokuba ukhokhe, funda izibalo zeminyaka kanye nezimali zohlelo ngalunye.

DarkSky International (i-United States, inkampani engatholakali ngezimali kusukela ngo-1988). Isungulwe eTucson, iqhuba uhlelo lwezizinda zesibhakabhaka esimnyama sezwekazi eliqinisekisile iFlagstaff, iSark nePic du Midi, kanye ne-DarkSky Approved scheme yezinto ezibonakalayo ezihlangabezana nemibandela yayo yokushaja. Isebenza namadolobha nezinhlangano ezilawula ukufakwa kwezinhlelo zokushayela.
Flagstaff Dark Skies Coalition (i-United States, engatholakali ngezimali). Isungulwe ngo-2000, yamemezela iphrojekthi yezindawo zesibhakabhaka esimnyama ngo-2001 futhi manje ishicilela “iFlagstaff Solution” ukuze ezinye izifundazwe zikwazi ukuyikophola.
ANPCEN I-National Association for the Protection of Night Sky and Environment (i-NAOS) Isebenzisana nemithetho yokukhanya yaseFrance futhi isebenza nge- “Villes et Villages étoilés” label: ngoSepthemba 2025, amadolobhana namadolobhana angama-1,062 abambe iqhaza ekushintsheni, ukuvimbela noma ukumisa ukukhanya kwabo.
CPRE, inhlangano yosizo ezweni (I-England, inhlangano yosizo ebhalisiwe 1089685). It runs the annual Star Count, in which thousands of people count stars from home, and publishes maps of light pollution and dark skies across England to help councils protect them.

Ukukhanya kwelanga ledolobha ezindaweni ezingaphansi komhlaba eduze kwezindlu ze-Kitt Peak National Observatory ngaphansi kwesibhakabhaka esikhanyayo. — Ama-lights eTucson, Arizona, akhanya emgwaqweni odlula ama-telescopes eKitt Peak National Observatory. I-Tucson's shielded, dimmable street lights isiza, kodwa njengoba ukuhlolwa kwe-2019 kukhombisa, wonke uhlobo lwesibani sangaphandle sinengxenye yokudlala. Photo: KPNO/NOIRLab/NSF/AURA/P. Marenfeld, CC BY 4.0

Ungasiza kanjani

Qhafaza konke ongakudingayo, ikakhulukazi izibani ezihlobisa kanye nezibani zesikhathi sonke.
Isilinda bese ubeka inhloso kuwo wonke umshayeli ongaphandle ongawuthola; khetha ama-bulbs apholile angama-3000 K noma ngezansi.
Vala amafasitela ngemini ngakho ukukhanya kwegumbi lihlala ngaphakathi.
Xhumana nabangane mayelana nezibani ezikhanyayo, ngesinqumo esisebenzayo esisemandleni.
Buza ikomiti lakho kanye nezinkampani zasendaweni ukuthi zinikeze ukukhanya okugqwala, okupholile, nokuncane futhi zinikeze izibonakaliso zokuvala ngemuva kosuku lokuvala.
Khusela izinhlanzi ezihamba: ehlobo nasebusika, vala amalambu angadingekile emigodini ephakeme ngemini.
Bala amakilasi ngeGlobe Night futhi uqale iqembu lezulu elimnyama kusetshenziswa ibhodi yosizo.

Izinsizakusebenza

I-DarkSky International, Isikhashana sokulimala
I-Falchi et al. (2016), I-atlas entsha yezwe lelanga elikhanyayo, Science Advances
I-Kyba et al. (2023), Abacwaningi abavela emphakathini babike ukuncipha okukhawulelwe emhlabeni jikelele kokubukeka kwezinkanyezi, Ulwazi
Ukulimala (2014), Izingqimba zokuthuthukiswa kwezilwane e-United States, The Condor
I-Flagstaff Dark Skies Coalition, The Flagstaff Solution ne International Dark Sky City
I-Barentine et al. (2020), Ukubuyisela umngcele wokukhanya kwedolobha kusuka ekulinganiseni kwe-skyglow kucwaningo olukhulu lokugcoba idolobha, *Incwadi yeSpektroskopy eningi neTransfer Radiative * 253 (iphrinta yamahhala)
République française, Arrêté du 27 décembre 2018 relatif à la prévention, à la réduction et à la limitation des nuisances lumineuses
U-Gooley nokunye (2011), Ukukhanya kwegumbi ngaphambi kokuhlala ekuseni kuvimbela ukukhishwa kwemelatonin futhi kunciphise isikhathi sokuthatha i-melatonin kubantu, Incwadi ye-Clinical Endocrinology neMetabolism 96
Brainard et al. (2001), Isizinda semisebenzi yokulawulwa kwemelatonin kubantu: isivivinyo sohlelo olusha lwe-circadian photoreceptor, Journal of Neuroscience 21
U-Chang nokunye (2015), Ukusetshenziswa kwe-eReaders ekhipha ukukhanya ekuseni kuthinta ngokubi ukuphumula, isikhathi sesikhathi sosuku, kanye nokuzivikela kokuqala, PNAS 112
U-Van Doren nokunye (2021), Abaqhubi bezilwane ezibulalayo ezingqubuzana ezindaweni zomphakathi, PNAS 118
ANPCEN, Villes et Villages étoilés results
CPRE, Izulu elimnyama
Imininingwane ye-charity kusuka ku- Charity Commission for England and Wales register kanye nesimo se-US esingasebenziyo kusuka ku- ProPublica Nonprofit Explorer
Ucwaningo oluningi lutholakala kukhasi lethu izindaba zesayensi.