Take the 2-minute tour ×  Is there a physical reason why not to
think that instead of space expanding, all physical constants
and parameters are shrinking (including of course the
instruments we use to measure the constants) and space is
static, or is it a case of Occam's razor?  share|improve this
question add comment  2 Answers  up vote 3 down vote accepted
The expansion of the universe is happening at large-scales. This
means that, if you choose two galaxies, they are moving away
from each other at a speed proportional to their distance. The
space between the Sun and the Earth, for instance, is not
expanding. In fact, some galaxies close to us appear blue-
shifted due to their peculiar velocities. The physical constants
must be very complicated functions of space and time to mimic
such a phenomenon. The almost-FRW universe yields the expansion
quite naturally. So, in a sense, you are right that it is
because of Occam's razor, but, isn't all of "established"
physics due to Occam's razor? :)  share|improve t