Amazuba

Amazuba (noma ugesi) ayisimongotho sendalo esiyamaniswa nobukhona kanye nomdiki woTho onobuzuba. Amazuba ahlobene nobuwonga, zombili eziyingxenye yesimongotho senzubawonga, njengoba ichazwa izilinganiso zikaMaxwell. Kunezinhlobonhlobo zezimongotho ezihlobene namazuba, ezihlanganisa umbani, umzuba (static electric), umsikizo wamazuba (electric discharge), ukuchadameza ngamazuba, phakathi kwezinye.

Ukuba khona komlelesa (electric charge), okungaba okuvumayo (positive) noma okuphikayo (negative), kukhiqiza umzuba (electric field). Umdiki womlelesa wona uwuluzuba (electric current)  futhi ukhiqiza ubuwonga (magnetic field).

Lapho umlelesa usendaweni engenawo umzuba, kunesiphoqi esizosebenza kuwo. Ubukhulu balesiphoqi sibuthola emthethweni ka-Coulomb. Uma umlelesa udikiza, kusho ukuthi umzuba uzobe wenza umsebenzi kuwo umlelesa. Kanjalo siyakwazi ukukhuluma ngamazuba akhona (electric potential) endaweni ethile, alingana nomsebenzi owenziwa isenzi esingaphandle ekuthwaleni umuvo womlelesa ovumayo kusuka endaweni ehlofuzile kuya kuleyo ndawo ngaphandle kokuphangisa futhi kulinganiswa ngezivuve (volts).

Amazuba awumnyombo wezinto eziningi zobuchwepheshe banamuhla, njengoba asetshenziswa kulokhu: Amandla wamazuba lapho uluzuba lusetshenziswa khona ukudlakalisa amathuluzi; Kwezezingabuzuba eziphathelene nezintandelo zamazuba ezibandakanya izigcoyi zamazuba eziqebethayo ezifana namathumbu elinya (vacuum tubes), transistors, diodes, nezintandelo ezihlayiziwe (integrated circuits), kanye nobuchwepheshe boxhakaxhumano obuyamaniswa nakho.

Isimongotho samazuba sasilokhu sicwaningwa kusuka endulo, nakuba ukuqombola ekuqondeni lowombono kwakulusilili kwaze kwaba semakhulwini e-17 ne-18. Umbono wobuwonga benzuba wathuthukiswa ekhulwini le-19, futhi ekupheleni kwalelo khulu amazuba ayesefakwa ezindaweni zezimboni nezokuhlala osonjiniyela bamazuba. Ukwanda okusheshayo kobuchwepheshe bamazuba ngaleso sikhathathi kwaguquka izimboni nomphakathi, okwaba isiphoqi esifuqela phambili INguquko yeziMboni yesibili. Ukusebenziseka kwamazuba ndawozonke okumangazayo kusho ukuthi ingasetshenziswa ezintweni eziningi ezihlanganisa ezokuthutha, ukuchadameza, ukukhanyisa, ukuxhumana, nokucikiza. Isidlakalasi samazuba kuyimanje siwumgogodla womphakathi wezimboni wanamuhla.

Kudala ngaphambi kokuba kube nanoma iluphi ulwazi olukhona ngamazuba, abantu babelumuka ubuzaze bezinhlanzi zamazuba. Imibhalo yaseGibhithe lasendulo eqala ngonyaka wezi-2750 BCE ibhekisela kulezinhlanzi ngokuthi "umbani weNayili", futhi izichazisa ngokuthi "abavikeli" bezinye izinhlanzi. Izinhlanzi zamazuba zaphinde zabikwa ngemuva kwenkulungwaneni yeminyaka ngabosomvelo nabelaphi baseGrisi, eRoma nase-Arabiya. Ababhali basendulo abambalwa, abafana no-Pliny oMdala no-Scribonius Largus, bafakazela uzenzane lwamazuba oluba khona emva kokuzazwa izinhlanzi zamazuba nayizinzaza, futhi babenolwazi lokuthi ubuzaze obunjalo bungahamba ngezinto ezibuhambisayo. Iziguli ezinezigulo ezifana ne-gout noma ikhanda elinkenkethayo zzaziqobdiswa ukuba ziyothinta izinhlanzi zamazuba ngethemba lokuthi inhlukuzo enamandla izozilapha.

Amasiko wasendulo asoLwandle olukhulu iMedithera ayenolwazi lokuthi izinto ezithile, ezifana nezinduku (rods of amber), zazingahlukuhlwa kanye noboya bengobe ukuheha izinto ezilula njengezimpaphe. UThalesi waseMiletu wenza uhide lwezingqaphelo zobuzuba ngonyaka ka+600 BCE, ezamenza wakholwa ukuthi umshikisho wenza umhluzi (amber) ube nobuwonga, okuphambene nezimbiwa ezifana netshewonga (magnetite), elingadingi ukuhlukuhlwa. UThalesi wayegeja ngokukholwa ukuthi umheho wenzeka ngenxa yobuwonga, kodwa kamuva inzululwazi yafakazela ukhongco phakathi kobuwonga namazuba. Ngokombono odala impikiswano, abantu base-Parth kungenzeka babenolwazi lwe-electroplating.