Whakaotihia te rerenga e whai ake nei: I te wā kotahi ki tēnei huarahi pūmau ki te mātauranga o te ao, ka mutu te tautohetohe roa e pā ana ki te hanganga o te ao nui. Ko te tohunga whetu o Mount Wilson a Harlow Shapley i tautoko i te tauira o te ao i hangaia e te punaha whetu o te Milky Way anake; i te mea i tohe a Heber D. Curtis mo te whakaaro ko nga nebulae porohita he punaha whetu i roto i a raatau ano hei ao moutere. Ko tēnei rerekētanga o ngā whakaaro i eke ki te taumata ki te whakahaere o te
He tautohetohe nui i te 26 o Paenga-whāwhā 1920 i te hui o te U.S. National Academy of Sciences i Washington, DC. I whakatauhia te tautohetohe i te wa i kitea ai e Edwin Hubble nga Cepheid Variables i te Andromeda Galaxy i te 1923 me te 1924. I whakatūria e rātau he pūngāwerewere i tua atu i te pito o te Milky Way.