Since time
= R / V = d/v = 1 / H0,
t = 106 pc/72
km/s = 106 x 3.08 x 1013/ 72
= 4.3 x 1017 sec
= 14 x 109 yr
Hubble constant ® Expansion age of universe !!
Hubble Law
®v = H0 d
where v =
recessional velocity
d = distance to galaxy
H0 = Hubble constant
= slope of line
H0 = 72 km/s/Mpc (± 10%)
i.e. if distance to galaxy
increases by 106 pc, galaxy’s
recessional speed increases
by 72 km/s