Evidence for the big bang (AQA A-Level Physics): Flashcards

CMB radiation and H/He abundances

~300,000 years

$T = 2.725$ K

Isotropic (equal intensity from all directions)

~$10^{-5}$ K

$13.7 pm 0.2$ billion years

73% H, 25% He, 2% other

~100 seconds after Big Bang

~3 minutes

3:1 (hydrogen to helium)