Rubuta ci gaba ga wannan sakin layi - Ka'idar Big Bang ta samo asali ne daga lura da tsarin sararin samaniya da kuma la'akari da ka'idoji. A shekara ta 1912, Vesto Slipher ya auna na farko na Doppler na "nebula mai juyawa" (nebula mai juyawa shine tsohuwar kalma don galaxies masu juyawa), kuma ba da daɗewa ba ya gano cewa kusan dukkanin waɗannan nebulae suna janyewa daga Duniya. Bai fahimci tasirin sararin samaniya na wannan gaskiyar ba, kuma hakika a lokacin ya kasance mai rikitarwa sosai
ko wadannan nebulae sun kasance "tsibirin halittu" a waje da Milky Way. Shekaru goma bayan haka, Alexander Friedmann, masanin kimiyyar sararin samaniya na Rasha kuma masanin lissafi, ya samo lissafin Friedmann daga lissafin filin Einstein, yana nuna cewa sararin samaniya na iya fadada akasin tsarin sararin samaniya wanda Albert Einstein ya bayar da shawarar a wancan lokacin.