Quote Originally Posted by ksst View Post
What I wonder is how can the universe actually be expanding. Like a lot of physics, this makes no sense to me. Our data comes from the red shift of distant objects, right? So what if there is some other explanation for this apparent red shift that we just haven't discovered yet? The universe may not be expanding at all.
Believe me, there's a lot of physics that doesn't make sense to me, either. There's a lot of physics that doesn't always make sense to physicists, too, which is why they keep studying it. But as for the red shift, scientists have searched for any and all possible causes of it, including gravity and dust, and they try to take all of that into account, but there is still shifting which occurs. There may, of course, be something which they haven't discovered yet, which may change their measurements, and it could show that the expansion of the universe is slowing rather than speeding up, but the expansion itself, as of right now, is pretty much solid science. A lot of the doubt comes from the discovery of "dark matter" and "dark energy", horribly named by some publicist no doubt. All it means is matter and energy which has been detected but which they have yet to learn anything about.

Even the term "Big Bang" is misleading, since it really wasn't an explosion so much as an expansion. Which is still going on.