
162 Chapter 3 The Universe Was Born With a Big Bang
Hubble’s Theory of the Expansion of the Universe Was
Imperfect
Although Hubble discovered that the universe is expanding, it seems highly likely that he
would have encountered fierce opposition from people around him, especially from his fel-
low researchers in the astronomical community. In fact, many accounts say that Hubble very
prudently kept his ideas to himself.
The value that determines the expansion velocity of the universe is called Hubble’s
constant, and it is represented by H
0
. Hubble obtained a value of 500 km/sec/Mpc for this
velocity; this is approximately seven times the curr