The History and Fate of the Universe
Primordial Era
t = -50: Planck epoch
t = -35: symmetry breaking,
inflation
t = -12: formation of “normal”
particles
t = -6 : production of helium
t = 4 : end of radiation domination
t = 5.5: atoms form, cosmic microwave
background
Stellar Era
t = 7 : first stars form
t = 9 : Milky Way, galaxies form
t = 9.5: formation of solar
system
t =10.2: Sun dies
t = 14 : end of star formation,
smallest stars die
Define time by “cosmic decade”: time=10 t years
(t is
decade)
