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Re: Cosmology

Oh cosmologists, I need tutoring:

1) Our galaxy is expanding -- whirling out into the Universe. And the
Universe is expanding and making our galaxy bigger in the process.

Is this correct?

There is no evidence that our galaxy is expanding. The universe is
expanding according to evidence of a couple of kinds, but none of
that evidence arises from observation of objects within our galaxy.
No external galaxy is seen to be expanding, either.

How does one tell the difference between the two causes of change in size?

2) During the first few minutes of the existence of the Universe, it's
rate of change in size was enormous.

There is a crazy belief in something called "inflation". Particle
physicists often believe in it, but they change their religions
more often than the Vicar of Bray.

What is the current rate of change in size? In reasonable units? In

Something of the order of 75 km/s/Mpc. If you work that out you
will get the change in percent per year. It's the same exact
number, but I consider the units I quoted reasonable.

3) If the Universe is increasing in size due to a metric increase, doesn't
each part of the Universe change size as well? The distance to
alpha-Centauri is getting bigger? The size of the Solar System is getting
bigger? The diameter of the Earth is getting bigger? The diameter of a
neutron is getting bigger? The diameter of me is getting bigger? My
current excuse for not dieting. <g>