Ka cika wannan magana: "Kusan shekaru goma bayan haka, a tsakiyar abin da aka kira "
Babban Muhawara", Hubble da Slipher sun gano fadada sararin samaniya a cikin 1920s da auna redshifts na Doppler spectra daga galactic nebulae. Ta wajen yin amfani da ka'idar da ake kira general relativity na Einstein, Lemaître da Gamow sun tsara abin da aka sani da ka'idar babban fashewa. Wani abokin hamayya, wanda ake kira ka'idar daidaitacciyar ka'idar ta Hoyle, Gold, Narlikar da Bondi.