Umbono Oyisisekelo Wamagagasi E-Electromagnetic
Amagagasi kagesi ayisisekelo ezicini eziningi zesayensi nobuchwepheshe banamuhla. Lawa magagasi awabalulekile nje kuphela ekuqondeni indawo yonke kodwa futhi anezisetshenziswa ezingokoqobo emikhakheni ehlukahlukene, njengokuxhumana, ezokwelapha, kanye nobunjiniyela. Emongweni wawo, amagagasi kagesi awukubonakaliswa kobudlelwano obuguquguqukayo phakathi kwamagagasi kagesi namagnetic, asakazeka emkhathini. Ukuqonda imibono eyisisekelo yamagagasi kagesi kwenza umuntu akwazi ukuqonda izimiso eziyisisekelo ezilawula ukuziphatha kwawo kanye nokusetshenziswa kwawo.
Umlando
Ucwaningo lwamaza kagesi lwaqala ngokuzimisela ngomsebenzi kaJames Clerk Maxwell ngekhulu le-19. Izibalo zikaMaxwell, ezakhiwa ngawo-1860, ziyitshe lesisekelo senkolelo-mbono kagesi. Lezi zibalo zichaza indlela amasimu kagesi namagnetic asakazeka futhi asebenzisana ngayo. Umsebenzi kaMaxwell wahlanganisa imibono ehlukene ngaphambilini kagesi kanye ne-magnetism futhi wabikezela ukuba khona kwamaza kagesi. Kamuva uHeinrich Hertz waqinisekisa izibikezelo zikaMaxwell ngokuhlola ngawo-1880, enikeza ubufakazi obubonakalayo bokuba khona kwamaza.
Izilinganiso zikaMaxwell
Izibalo zikaMaxwell ziqukethe izilinganiso ezine ezihlukile ezingaphelele ezichaza indlela amasimu kagesi (E) kanye namasimu kazibuthe (B) akhiqizwa futhi aguqulwa ngayo omunye nomunye kanye nangamashaji kanye nemisinga:
1. Umthetho kaGauss Kagesi: Lo mthetho uthi ukugeleza kukagesi endaweni evaliwe kuhambisana nokushaja okuvalelwe yileyo ndawo. Ngokwezibalo, kuvezwa kanje:
\[
\nabla \cdot \mathbf{E} = \frac{\rho}{\epsilon_0}
\]
lapho \(\rho\) kungubuningi beshaja, kanye \(\epsilon_0\) kungukuvumela isikhala esikhululekile.
2. Umthetho kaGauss we-Magneticism: Lo mthetho uthi ukugeleza kukazibuthe endaweni evaliwe kungu-zero, okubonisa ukuthi azikho 'izindleko zikazibuthe' ezifana nezindleko zikagesi. Umelelwa kanje:
\[
\nabla \cdot \mathbf{B} = 0
\]
3. Umthetho KaFaraday Wokungenisa: Lo mthetho uchaza ukuthi insimu kazibuthe eshintshashintshayo ngesikhathi idala kanjani insimu kagesi. Ifomu lezibalo lithi:
\[
\nabla \izikhathi \mathbf{E} = -\frac{\partial \mathbf{B}}{\partial t}
\]
4. UMthetho ka-Ampère (ngokulungiswa kukaMaxwell): Lo mthetho uthi amasimu kazibuthe akhiqizwa yiziphethu zikagesi kanye nezinguquko ensimini kagesi. Unikezwa ngu:
\[
\nabla \izikhathi \mathbf{B} = \mu_0 \mathbf{J} + \mu_0 \epsilon_0 \frac{\partial \mathbf{E}}{\partial t}
\]
lapho \(\mathbf{J}\) kungubuningi bamanje, kanye \(\mu_0\) kungukuvuleka kwesikhala esikhululekile.
Ukususwa kwe-Wave Equation
Kusukela kuzibalo zikaMaxwell, umuntu angathola i-electromagnetic wave equation. Ngokuthatha i-curl yoMthetho kaFaraday bese uyifaka kuMthetho ka-Ampère, ngenkathi sicabanga ukuthi akukho zindleko zamahhala kanye nemisinga, sithola:
\[
\nabla \izikhathi (\nabla \izikhathi \mathbf{E}) = – \frac{\partial (\nabla \izikhathi \mathbf{B})}{\partial t}
\]
Ukusebenzisa i-vector identity \(\nabla \izikhathi (\nabla \izikhathi \mathbf{E}) = \nabla (\nabla \cdot \mathbf{E}) - \nabla^2 \mathbf{E}\) kanye nomthetho we-Gauss wogesi (\(\nabla \cdot \cdot \mathbf{E}) = singayenza lula
\[
\nabla^2 \mathbf{E} = \mu_0 \epsilon_0 \frac{\partial^2 \mathbf{E}}{\partial t^2}
\]
Lesi yisibalo samagagasi sensimu kagesi. Inqubo efanayo ingasetshenziswa ukuthola isibalo samagagasi sensimu yamagnetic, \(\mathbf{B}\). Lezi zibalo zamagagasi zichaza indlela amagagasi kagesi asakazeka ngayo emkhathini.
Uhlobo Lwamagagasi Kagesi
Igagasi likagesi liqukethe amasimu kagesi namagnetic ajikelezayo aqonde komunye nomunye futhi aqonde lapho kusabalala khona amagagasi. Insimu kagesi (E) kanye nensimu yamagnetic (B) yegagasi zisesigabeni futhi zijikeleza ngokungaqondile. Lolu hlobo oluqondile lwamasimu e-E kanye ne-B lusho ukuthi amagagasi kagesi angamagagasi ajikelezayo.
Ijubane lamagagasi kagesi endaweni engenalutho, elikhonjiswe ngu-\(c\), linikezwa ngu:
\[
c = \frac{1}{\sqrt{\mu_0 \epsilon_0}}
\]
Lo mphumela ophawulekayo ubonisa ukuthi ijubane lokukhanya ku-vacuum liyisici esiyisisekelo se-medium, esixhunywe ekuvumeleni nasekungeneni kwesikhala esikhululekile. Ku-vacuum, u-c cishe u-\(3 \times 10^8 \text{m/s}\).
I-Spectrum yamagagasi kagesi
Amagagasi kagesi ahlanganisa ububanzi obukhulu bamaza kanye namaza okuphakama, akha i-spectrum kagesi. Le spectrum ihlanganisa izinhlobo ezahlukene zamaza, kusukela kumaza omsakazo anemvamisa ephansi kuya emisebeni ye-gamma enemvamisa ephezulu. I-spectrum ivame ukuhlukaniswa ngezifunda ngokusekelwe ku-wavelength kanye nemvamisa, okuhlanganisa (ngokulandelana kwemvamisa ekhulayo): amagagasi omsakazo, ama-microwave, imisebe ye-infrared, ukukhanya okubonakalayo, imisebe ye-ultraviolet, ama-X-ray, kanye nemisebe ye-gamma.
Isifunda ngasinye se-spectrum sinezakhiwo kanye nezinhlelo zokusebenza ezihlukile. Isibonelo, amagagasi omsakazo asetshenziselwa ukuxhumana, ama-microwave e-radar nokupheka, i-infrared yezithombe ezishisayo, ukukhanya okubonakalayo kokubona komuntu, ukukhanya kwe-ultraviolet kokubulala amagciwane, ama-X-ray ezithombe zezokwelapha, kanye nemisebe ye-gamma yokwelapha umdlavuza.
I-Polarization
I-Polarization ibhekisela ekuqondisweni kwe-vector yensimu kagesi yegagasi le-electromagnetic. Kugagasi elihlukaniswe ngomugqa, insimu kagesi iyashintshashintsha endaweni eyodwa. I-polarization eyindilinga yenzeka lapho insimu kagesi ijikeleza ngokunyakaza okujikelezayo njengoba igagasi lisakazeka. I-polarization eyindilinga iyisimo esijwayelekile lapho insimu kagesi ilandela khona i-ellipse.
I-Polarization ingumqondo obalulekile kuma-optics kanye nokuxhumana. Isibonelo, izibuko zelanga ezi-polarized zivimba ukuqondiswa okuthile kwamagagasi okukhanya ukuze kuncishiswe ukukhanya, futhi ama-antenna aklanyelwe ukuhambisana ne-polarization yezibonakaliso ezidluliswayo nezamukelwe ukuze kuxhumane kahle.
Ukuzindla, Ukuphinda Ukwahlukaniseka, kanye Nokuphambuka
Amagagasi kagesi asebenzisana nezinto ngokusebenzisa izinqubo ezifana nokuzindla, ukujikijela, kanye nokusabalalisa. Ukuzindla kwenzeka lapho igagasi lihlangana nomngcele bese libuyela emuva. Ukuphindaphinda kuwukugoba kwegagasi njengoba lidlula lisuka kwenye indawo liye kwenye elinezakhiwo ezahlukene, ezichazwa uMthetho kaSnell. Ukuhlukanisa kuhilela ukusabalala kwamagagasi azungeze izithiyo kanye nokuvuleka, okubonakala kakhulu kumagagasi amade.
Isiphetho
Ithiyori eyisisekelo yamaza kagesi, egxile ezibalweni zikaMaxwell, inikeza isisekelo sokuqonda ukuziphatha nokusetshenziswa kwala maza. Le thiyori ichaza ukusabalala kwamaza kagesi kagesi, isivinini sawo, kanye nokusebenzisana kwawo nezinto, phakathi kwezinye izakhiwo. Ukwazi kahle le mibono eyisisekelo kubalulekile ekuthuthukiseni ubuchwepheshe kanye nokuthuthukisa ukuqonda kwethu umhlaba wemvelo.
