Whakakiia te rerenga e whai ake nei: I whakawhanakehia te ariā o te Big Bang mai i ngā kitenga o te hanganga o te ao nui, mai i ngā whakaaro ariā. I te tau 1912, i whangangahia e Vesto Slipher te nekehanga Doppler tuatahi o te "nebula porohita" (ko te nebula porohita te kupu tawhito mo nga aorangi porohita), ana ka kitea e tata ana ki te katoa o aua nebula e neke atu ana i te Ao. E kore ia i hopu i te pānga cosmological o tenei meka, a pono i te wa i reira
He tautohetohe nui mehemea he "ao motu" enei nebulae i waho atu o to tatou Milky Way. Tekau tau i muri mai, Alexander Friedmann, he Russian cosmologist me te kaikauwhau, i ahu mai i nga whārite Friedmann mai i nga whārite āpure Einstein, e whakaatu ana kei te whanui pea te ao i te rereketanga ki te tauira o te ao pumau i taunakitia e Albert Einstein i taua wa.