Rubuta ci gaba ga wannan sakin layi - Kimanin shekaru goma bayan haka, a tsakiyar abin da aka kira "Babban Muhawarar
", Hubble da Slipher sun gano fadada sararin samaniya a cikin 1920s ta hanyar auna hasken redshifts na Doppler spectra daga galactic nebula. 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.