Tuhia he tomokanga mō tēnei wāhanga - I te tau 1912, i kitea e Vesto Slipher he whero te marama mai i ngā aorangi tawhiti, i muri mai
i whakamāramatia hei aorangi e neke atu ana i te Ao. I te tau 1922, i whakamahia e Alexander Friedmann ngā whārite āpure a Einstein hei whakarato i ngā taunakitanga ā-ariā e whakanuia ana te ao. I te tau 1927, i tae motuhake a Georges Lemaître ki te whakatau rite ki a Friedmann i runga i te kaupapa ariā, a, i whakaatuhia hoki te whakaaturanga kitenga tuatahi mo te hononga raina i waenga i te tawhiti ki nga tupuni me to raatau tere tere. I whakapumautia e Edwin Hubble nga kitenga a Lemaître e rua tau i muri mai. Ki te whakaaro ki te kaupapa o te ao, ko ēnei kitenga e tohu ana kei te neke atu ngā aorangi katoa i a rātou anō.