Kuyini Ukuzwa Kude?
Ukuzwa okukude kuwukuthola ulwazi ngento ethile noma into ethile ngaphandle kokuthi uthintane nayo ngokoqobo, ngokungafani nokubona in situ noma endaweni. Leli gama lisetshenziswa ngokukhethekile ekutholeni ukwaziswa okuphathelene noMhlaba namanye amaplanethi. Ukuzwa okukude kusetshenziswa emikhakheni eminingi, kufaka phakathi i-geophysics, i-geography, i-land surveying kanye nemikhakha eminingi yesayensi yomhlaba (isib. i-geophysics yokuhlola, i-hydrology, i-ecology, i-meteorology, i-oceanography, i-glaciology, i-geology); futhi inezicelo zempi, ubuhlakani, ezentengiselwano, ezomnotho, zokuhlela, nezokusiza abantu, phakathi kwabanye.  Ukusetshenziswa kwamanje, igama elithi ukuzwa okukude ngokuvamile libhekisela ekusetshenzisweni kobuchwepheshe bezinzwa ezisekelwe kusathelayithi noma endizeni ukuthola nokuhlukanisa izinto eMhlabeni. Ihlanganisa indawo nomoya nezilwandle, ngokusekelwe kumasignali asakazwayo (isib. imisebe kagesi). Ingase ihlukaniswe ibe "ukusebenza" kokuzwa okukude (lapho isignali ikhishwa isathelayithi noma indiza iye entweni futhi ukubonakaliswa kwayo kutholakala yinzwa) kanye nokuzwa okukude "okungenayo" (lapho ukubonakaliswa kokukhanya kwelanga kutholakala yinzwa).