<prompt> Qedela le nkulumo elandelayo: Ngo-1913, u-Ejnar Hertzsprung wazama ukuthola amabanga ama-Cephid angu-13 esebenzisa ukunyakaza esibhakabhakeni. Nokho, ucwaningo lwakhe lwaluzodinga ukubuyekezwa kamuva. Ngo-1918, uHarlow Shapley wasebenzisa i - Cepheid ukuze abeke imingcele yokuqala ngosayizi nokuma komthala i - Milky Way, kanye nokuma kweLanga lethu kuwo. Ngo-1924, u-Edwin Hubble wasungula ibanga eliya eziguquguqukayo ze-Cepheid zakudala emthaleni i-Andromeda, kuze kube yileso sikhathi eyaziwa ngokuthi i- Andromeda Nebula, futhi wabonisa ukuthi lezi ziguquguqukayo zazingeyona ingxenye ye-Milky Way. Ukuthola kukaHubble kwaxazulula umbuzo owaphakanyiswa  <response>: I-Great Debate yokuthi iMilky Way yayimelela yonke indawo yonke noma yayimane nje ingenye yezinkanyezi eziningi ezikhona endaweni yonke. 