<prompt> Ukudlulisa: Ukudlulisa i-HI nge-radio telescope kuyindlela esetshenziselwa ukunquma ukwakheka kwemithala ye-spiral. Iphinde isetshenziselwe ukudweba ukuphazamiseka kwamandla adonsela phansi phakathi kwemithala. Lapho imithala emibili ihlangana, impahla idonswa ngemicu, ivumela izazi zezinkanyezi ukuthi zinqume ukuthi imithala ihamba ngayiphi indlela. Umbuzo: Kuyini ukudweba i-HI?  <response>: inqubo esetshenziselwa ukunquma isakhiwo semithala emise okhalweni 