Ukuphosa Iliso Kwizinto Ezingabonakaliyo—Yintoni Okuyityhilayo?

YINTONI efezwayo xa abantu besebenzisa izinto ezintsha abazivelisileyo ukuze ngokungathi kunjalo batyhile umdiya-diya, baze babone izinto ababengenakuzibona ngaphambili? Ukwenza oko kunokusinceda ngokomlinganiselo othile sibone izinto esasingenakuzibona ngaphambili.—Bona ibhokisi engasezantsi.

Kwakha kwacingwa ukuba umhlaba usesizikithini sendalo. Kodwa kwathi kwakusetyenziswa iteleskopu kwabonakala ukuba izijikelezi-langa, kuquka umhlaba, zimi ngolungelelwano yaye zijikeleza ilanga. Kutshanje, kuthe kwakuveliswa iimikroskopu ezinamandla, abantu bakwazi ukuhlolisisa iathom baza babona ukuba iiathom zidibana njani nezinye ukuze zenze iimolekyuli.

Khawucinge nje ngokubunjwa kwemolekyuli yamanzi, into ebalulekileyo ebomini. Ngenxa yendlela ezenziwe ngayo, iiathom ezimbini zehydrogen zidibana ngendlela ekhethekileyo neathom enye yeoksijin ukuze zenze imolekyuli yamanzi—ekukho amawaka ezigidi zazo kwithontsi ngalinye! Sinokufunda ntoni ngokuhlolisisa imolekyuli yamanzi nokuhlola indlela eba yiyo kwiimeko ezahlukeneyo?

Ummangaliso Wamanzi

Nangona amathontsi amanzi ebonakala eyinto eqhelekileyo, amanzi ayeyona nto intsonkothileyo. Enyanisweni, uGqr. John Emsley, ongumbhali ngezenzululwazi eImperial College, eLondon, eNgilani, wathi “alelona chiza lihlolisiswa ngokubanzi, kodwa kuphela kwalo elingaqondwayo.” Iphephancwadi iNew Scientist lathi: “Amanzi lolona lwelo luqhelekileyo eMhlabeni, kodwa lolona lungumnqa.”

UGqr. Emsley wathi nangona amanzi ebonakala eqhelekile, “ayikho into entsonkothe njengawo.” Wathi ngokomzekelo: “IH₂0 ibifanele ibe yigesi, . . . kodwa lulwelo. Ngaphezu koko xa iqina . . . , iba ngumkhenkce ize ihlale ngaphezulu emanzini kunasezantsi,” njengokuba ngokuqhelekileyo bekuya kulindeleka ukuba kube njalo. Ngokuphathelele le nto ingaqhelekanga, uGqr. Paul E. Klopsteg, owayekhe wangumongameli weAmerican Association for the Advancement of Science, wathi:

“Le ibonakala iyindlela emangalisayo yokunyamekela izinto eziphila emanzini njengeentlanzi. Khawucinge nje ngento ebiya kwenzeka ukuba amanzi, njengoko eya ekhenkceka, ebengabi njengoko echazwa. Ebeya kuqhubeka esiba ngumkhenkce ozalisa lonke ichibi, ubulale zonke izinto eziphila emanzini.” UGqr. Klopsteg wathi oku kungaqheleki kwamanzi “kubonisa ingqondo enamandla nenenjongo ekhoyo kwindalo iphela.”

Ngokutsho kweNew Scientist, ngoku abaphengululi bacinga ukuba bayasazi isizathu sokuba amanzi angaqheleki. Baye benza indlela yokukubona kakuhle ukwanda kwamanzi. Abaphengululi bayaqonda ukuba “lo mnqa ubonakala kwisithuba esikhoyo phakathi kweeathom zeoksijin nezi zinto zimbini.”

Ngaba oko akumangalisi? Imolekyuli ebonakala ilula idida amandla omntu okuqonda. Yaye eyona nto ininzi emzimbeni wethu ngamanzi! Ngaba nawe ubona “ubungqina bengqondo enamandla nenenjongo” xa ubona imolekyuli eneeathom ezintathu kuphela nezinto ezimbini? Kodwa imolekyuli yamanzi incinane gqitha yaye ayintsonkothanga kakhulu kunezinye iimolekyuli.

Iimolekyuli Ezintsonkothe Gqitha

Ezinye iimolekyuli zibunjwe ngamawakawaka eeathom ezikwizinto ezingama-88 ezikho ngokwemvelo emhlabeni. Ngokomzekelo, imolekyuli yeDNA (isishunqulelo sedeoxyribonucleic acid), enoludwe lwenkcazelo yemizila yemfuza yazo zonke izinto eziphilayo, inokuba nezigidi ngezigidi zeeathom ezinezinto ezahlukeneyo!

Phezu kwako nje ukuntsonkotha kwayo ngendlela engakholelekiyo, imolekyuli yeDNA ilisuntswana nje elincinane kangangeemilimitha ezili-0,0000025, incinane gqitha ukuba ingabonwa ngaphandle kokuncediswa yimikroskopu enamandla. Kwathi ngowe-1944 izazinzulu zafumanisa ukuba iDNA inenkcazelo yemizila yemfuza yomntu. Oko kwafunyaniswayo kwaba yintshayelelo yophando olunenyameko ngale molekyuli intsonkothe gqitha.

Kodwa iDNA namanzi ziimolekyuli nje ezimbini kwiindidi ezininzi ezakha izinto. Yaye ekubeni kukho iimolekyuli ezininzi ezifumaneka kwizinto eziphilayo nezingaphiliyo, ngaba sifanele sigqibe kwelokuba ngandlel’ ithile kukho umchankcatho phakathi kwento ephilayo nengaphiliyo?

Kangangethuba elide, abantu abaninzi babecinga ukuba kunjalo. UMichael Denton, osisazi ngebhayoloji yezinto ezingenakubonwa ngeliso lenyama wathi: “Ithemba lokuba ulwazi olungakumbi ngamachiza lwaluya kuwuvala umsantsa lakhutshwa ngokukhethekileyo ngamagunya amaninzi ngeminyaka yee-1920 neyee-1930.” Kodwa ekuhambeni kwexesha kwafunyaniswa ntoni?

Ubomi Bukhethekile Yaye Buhamba Bodwa

Nangona izazinzulu zazilindele ukufumana amanqanaba atshintshatshintshayo, okanye uthotho lwamanyathelo athe ngcembe, phakathi kwezinto eziphilayo nezingaphiliyo, uDenton wathi lo msantsa “wafunyaniswa ekugqibeleni emva kokuba kufunyaniswe ibhayoloji yeemolekyuli ebutsheni beminyaka yee-1950.” Ebalisa ngesibakala esimangalisayo ngoku esiye sabonwa zizazinzulu, uDenton waqhubeka esithi:

“Ngoku asazi nje kuphela ukuba kukho umsantsa phakathi kwezinto eziphilayo nezingaphiliyo, kodwa sazi nokuba umela ezona zinto zichukumisayo nezisisiseko kweziqhubeka kwindalo. Phakathi kweseli ephilayo neyona nkqubo intsonkothileyo ingaphiliyo, njengekristale okanye ihlwantsi lekhephu, kukho umsantsa omkhulu nopheleleyo nekunzima ukuwuthelekelela.”

Oku akuthethi ukuba kulula ukwenza imolekyuli. Incwadi ethi Molecules to Living Cells ithi, “umxube wezinto ezibumba imolekyuli encinane untsonkothe wona kuqala.” Noko ke, yongezelela ngelithi, ukwenza iimolekyuli “akuyonto xa kuthelekiswa noko kusenokuba kwalandela ukuze kwenziwe iseli yokuqala ephilayo.”

Iiseli zinokuziphilela, njengeentsholongwane, okanye zinokusebenza njengenxalenye yezidalwa ezineeseli ezininzi, njengasemntwini. Bekuya kufuneka iiseli eziqhelekileyo ezingama-500 ukuze wenze isingxi esisekupheleni kwesivakalisi. Ngoko akumangalisi ukuba imisebenzi yeseli ingabonakali kwiliso nje lilodwa. Ngoko, yintoni ebonakalayo xa usebenzisa imikroskopu ukuze ubone iseli enye esemzimbeni womntu?

Iseli—Ngaba Yenzeka Ngamabona-ndenzile Okanye Yadalwa?

Okokuqala, umntu akakwazi kungamangaliswa yindlela ezintsonkothe ngayo iiseli eziphilayo. Omnye umbhali ngezenzululwazi wathi: “Ukukhula okuqhelekileyo kweyona seli iqhelekileyo ephilayo kufuna amashumi amawaka okusebenza kwamachiza ngendlela elungeleleneyo.” Wabuza: “Kunokulawulwa njani ngexesha elinye ukusebenza okungama-20 000 kwiseli enye encinane?”

UMichael Denton wathelekisa nezona seli zincinane ziphilayo “nomzi-mveliso wezinto ezincinane ngokwenene onamawakawaka amasuntswana ayilwe kakuhle enkqubo enobugocigoci yeemolekyuli, ebunjwe likhulu lamawaka ezigidi zeeathom, entsonkothe ngakumbi kunawo nawuphi na umatshini owenziwe ngumntu nengenakuthelekiswa nanto ngokupheleleyo kwizinto ezingaphiliyo.”

Izazinzulu zisadidwa kukuntsonkotha kweseli, njengoko iThe New York Times kaFebruwari 15, 2000, yathi: “Okukhona izazi ngendalo zisazi ngeseli ephilayo, kokukhona kubonakala kutyhafisa ukufumanisa yonke into eziyenzayo. Iseli eqhelekileyo yomntu incinane gqitha ukuba ingabonwa, kodwa nangawuphi na umzuzu, imizila yemfuza esusela kuma-30 000 kweli-100 000 isenokuba ixakekile inceda iseli okanye isabela imiyalezo evela kwezinye iiseli.”

ITimes yabuza: “Kunokwenzeka njani ukuba umatshini omncinane noxhakaxhaka ngolu hlobo ukwazi ukugocagocwa? Kwanokuba abantu bebenokuzimisela ukwazi kakuhle iseli yomntu enye, kukho ubuncinane ezingama-200 ezahlukeneyo emzimbeni womntu.”

Iphephancwadi iNature, kwinqaku layo elithi “Iinjini Zokwenene Zendalo,” lanikela ingxelo ngeenjini ezincinane ezingaphakathi kwiseli nganye yomzimba. Ezi ziyajikeleza ukuze zenze iadenosine triphosphate, engumthombo wamandla eeseli. Esinye isazinzulu saqiqa ngelithi: “Yintoni ebesinokuyenza xa kusithiwa masiyile size sakhe oomatshini benkqubo yeemolekyuli abafana nenkqubo yeemolekyuli esiyifumana kwiiseli?”

Khawucinge nje ngamandla okuyila eseli! Umlinganiselo wenkcazelo ekwiDNA yeseli nje enye yomzimba wethu ibiya kuzalisa malunga nesigidi samaphepha alingana neli ngobukhulu! Ngaphezu koko, sihlandlo ngasinye iseli iqhekeka phakathi ukuze yenze enye entsha, kwale nkcazelo inye idluliselwa kule seli intsha. Ucinga ukuba seli nganye—kwiiseli ezili-100 lamawaka ezigidi ezisemzimbeni wakho—yayifakelwa njani le nkcazelo? Ngaba yonke le nto yenzeka ngamabona-ndenzile, okanye yenziwa nguMyili Omkhulu?

Mhlawumbi nawe uye wafikelela kwisigqibo esifanayo neso safikelela kuso isazi ngendalo uRussell Charles Artist. Sathi: “Sijamelene nobunzima obupheleleyo nobungaphaya kwengqondo bokuzama ukuchaza isiqalo [seseli] nokuqhubeka kwayo isebenza, ngaphandle kokuba ngokusengqiqweni siyavuma ukuba kukho ingqondo ekrelekrele eyibangele ukuba ibekho.”

Ulungelelwano Olumangalisayo Lwezinto

Kwiminyaka eyadlulayo, uKirtley F. Mather, ngelo xesha owayengunjingalwazi kwizifundo ngokuma komhlaba kwiHarvard University, wafikelela kwesi sigqibo: “Siphila kwihlabathi, elingavelanga ngamabona-ndenzile okanye lizenzekele, kodwa eloMthetho noCwangco. Lowo ulilawulayo unengqiqo yaye ufanelwe yimbeko epheleleyo. Khawucinge nje ngale nkqubo imangalisayo yokubala yendalo esenza sikwazi ukunika izinto amanani eathom.”

Kancinane nje makhe siqwalasele “le nkqubo imangalisayo yokubala yendalo.” Phakathi kwezintoa ezazisaziwa ngabantu bamandulo yayiyigolide, isilivere, ubhedu, inkcenkce nentsimbi. Iarsenic, ibismuth, neantimony zafunyaniswa ngamagcisa emichiza ngamaXesha Aphakathi, yaye kamva ebudeni beminyaka yee-1700, kwafunyaniswa izinto ezingakumbi. Ngowe-1863 ispectroscope, esikwaziyo ukwahlula umbala wento nganye, sasetyenziselwa ukubona i-indium, eyinto yama-63 eyafunyaniswayo.

Ngelo xesha isazi ngemichiza uDmitry Ivanovich Mendeleyev wagqiba kwelokuba izinto azizange zenziwe ngokungalungelelananga. Ekugqibeleni, ngoMatshi 18, 1869, kwafundwa inqaku lakhe elithi “Ukwandlalwa Kwenkqubo Yezinto” kwiRussian Chemical Society. Kulo wathi: “Ndifuna ukuvelisa enye inkqubo engenziwa ngamabona-ndenzile kodwa ngendlela eyiyo nechanileyo.”

Kwiphepha lakhe elidumileyo, uMendeleyev wenza olu qikelelo: “Sifanele silindele ukufumana izinto ezininzi ezingaziwayo; ngokomzekelo, ezo zifana ne-aluminium ne-silicon, izinto ezinobunzima beathom obungama-65 ukuya kutsho kuma-75.” UMendeleyev washiya izikhewu ezingenanto esenzela izinto ezintsha ezili-16. Xa wacelwa ukuba anikele ubungqina ngoqikelelo lwakhe, waphendula wathi: “Akuyomfuneko ukuba ndinikele ubungqina. Imithetho yendalo kungekhona imithetho yegrama, ayindivumeli ukuba ndenjenjalo.” Wongezelela ngelithi: “Ndicinga ukuba xa izinto zam ezingaziwayo zifunyaniswa, abantu abaninzi baya kunikela ingqalelo.”

Kwenzeka loo nto kanye! IEncyclopedia Americana ithi: “Kwiminyaka eli-15 eyalandelayo, ukufunyaniswa kwe-gallium, i-scandium ne-germanium, ezenziwe zizinto ezikufutshane kwezo zaqikelelwa nguMendeleyev, kwangqina ukunyaniseka kolungelelwano lwazo nodumo lwalowo wazifumanisayo.” Kwinxalenye yokuqala yenkulungwane yama-20, kwafunyaniswa izinto ezikhoyo ngoku.

Ngokucacileyo, ngokutsho kongumphengululi wemichiza, uElmer W. Maurer, “eli lungiselelo lihle alingombandela nje wamabona-ndenzile.” Ethetha ngesibakala sokuba kunokwenzeka ukuba ulungelelwano lwezinto lungumbandela wamabona-ndenzile, unjingalwazi wemichiza uJohn Cleveland Cothran wathi: “Ukuqikelelwa kusengaphambili kokufunyaniswa kwezinto zonke ezaqikelelwa [nguMendeleyev], nokuba neempawu ezifana kanye nezo waziqikelelayo, kwasichitha sonke eso sikrokro. Oko wakuthethayo akuze kubizwe ngokuba ‘Ngamabona-ndenzile.’ Kunoko kubizwa ngokuba ‘Ngumthetho.’”

Uhlolisiso olunenyameko lwezinto nendlela ezidibana ngayo ukuze zenze izinto ezikhoyo kwindalo iphela, lwabangela ukuba ingcali edumileyo yamachiza uP. A. M. Dirac, owayengunjingalwazi wezibalo eCambridge University, athi: “Unokuthi xa uchaza le meko uThixo uyingcaphephe yezibalo ehamba yodwa yaye wasebenzisa izibalo ezikumgangatho ophezulu ekubumbeni indalo iphela.”

Enyanisweni kubangel’ umdla ukuphosa iliso kwizinto ezingabonakaliyo ezibunjwe ziiathom ezincinane gqitha, iimolekyuli, neeseli eziphilayo neminyele emikhulu gqitha yeenkwenkwezi engenakubonwa liliso nje lilodwa! Loo nto ikwenza uzive uphantsi. Ikuchaphazela njani? Ubona ntoni kwezi zinto? Ngaba ubona ngaphezu kokuba iliso lakho lenyama linokubona?

[Umbhalo osemazantsi]

[Ibhokisi/Imifanekiso ekwiphepha 5]

Ikhawuleza Gqitha Ukuba Ingabonwa Liliso

Ekubeni ihashe ligqabadula ngokukhawuleza, abantu benkulungwane ye-19 babezibuza enoba kukhe kwenzeke na ukuba iimpuphu zalo zincothuke emhlabeni ngaxeshanye. Ekugqibeleni, ngowe-1872, uEadweard Muybridge waqalisa ukwenza ulingelo lokuthabatha imifanekiso nto leyo eyathi kamva yayizinzisa le mbambano. Wavelisa indlela yokuthabatha imifanekiso eshukumayo enesantya esiphezulu.

UMuybridge wadwelisa uthotho lweekhamera ezingama-24 zaqelelana kancinane. Ukusuka kwiqhosha lokufota lekhamera nganye, wabopha umtya onqumla kwindawo yomdyarho, ukuze xa ihashe ligqabadula, linyathele lo mtya, uze wona ucinezele iqhosha lokufota. Xa kukhangelwa imifanekiso ephumileyo, kwafunyaniswa ukuba ihashe lalikhe liwushiye kancinane umhlaba.

[Inkcazelo]

Courtesy George Eastman House

[Umfanekiso okwiphepha 7]

Kutheni umkhenkce undanda phezulu kunokuba utshone ezantsi?

[Umfanekiso okwiphepha 7]

Imolekyuli yeDNA iziimilimitha ezili-0,0000025 kodwa inkcazelo enayo inokuzalisa izigidi zamaphepha

[Inkcazelo]

Computerized model of DNA: Donald Struthers/Tony Stone Images

[Umfanekiso okwiphepha 8]

Kwiseli nganye esemzimbeni—kwezili-100 lamawaka ezigidi—amashumi amawaka eentshukumo zemichiza enzeka ngolungelelwano

[Inkcazelo]

Copyright Dennis Kunkel, University of Hawaii

[Imifanekiso ekwiphepha 9]

Isazi ngemichiza saseRashiya, uMendeleyev wagqiba kwelokuba izinto azizange zenziwe ngokungalungelelananga

[Inkcazelo]

Courtesy National Library of Medicine