Hubble’s law states that galaxies are moving away from each other and the further apart
they are the faster they moving away. The acceleration that has been determined be 74.2
km/s/Mpc. That means for every Mega parsec(1million*3.26 light-years) between galaxies they
are moving apart at 74.2 km/s.
How was Hubble’s law found and used?
About ninety years ago there was an astronomer named Edwin Hubble. He took many images of
what were known as nebula. Some of these nebulas contained stars and some had Cepheid
variables. Cepheid variables are stars the change their brightness of a period of time. The
relationship between brightness and period is well known so if take images over an extended
amount of time you can figure out the period, after that you can figure out the maximum
brightness and figure out how far the galaxy is away. Hubble came to the conclusion that some of
the nebula were further away then what could be in our galaxy. At the same time there was a
group measuring the red shift of these nebula, Hubble compared the distances with red shifts and
found that further away the galaxies the faster they were travelling away from us. Since Hubble’s
time there have been at least one other way of finding distances that is type 1a supernovae. Type
1a supernova are large explosions created when enough mass is deposited onto a white dwarf.
After a while the white dwarf becomes unstable and there is a large explosion. The amount of
light decreases at predictable rate so they can be used similar to Cepheids.
The electric universe theorists claim there is no evidence support that the further a galaxy it is
however there is plenty of evidence to support it.
Kauffman(1995),Universe,4th edition, pages 396-385, 483-485
Carrol and Ostlie, An Introduction to Modern Astrophysics pages 1112