In the words of my
Astrophysics Professor:
"
Cosmology is the science of the Really Big Picture.
" -
(Prof. Ken Ragan at McGill University) If you treat
stars as
atoms, then the
molecules that they make are
Galaxies, and the
Universe the whole object, one that we can barely
comprehend.
The questions that any intro course in Cosmology will bring up are
vast in
scale; things like "What are the
characteristics of the Universe?" "Why is it the way it is?" "How big is the universe?" "Where did it come from?" and, of course, "Where is it going?"
As opposed to
Astronomy, Cosmology generally doesn't deal with as much
observation, rather, it concentrates on
stellar motion and
interactions between galaxies. No serious
cosmologist would bother with anything closer to
home than
Andromeda.