@Rath: Actually earth is moving away from the sun. Of course, before earth falls off from the orbit, sun has lost so much of it's mass, that the nuclear reactions expands further and burns everything on earth before anything else happens (and let's note that the sun is too small star to explode as supernova).

@Soriku: That's because it takes years to get funding and even longer before all the equipment are ready to be launched. Finding suppliers for the tech, designing, manufacturing and testing takes a lot of resources, especially when everything you send to space, are used in exceptional conditions.

I get that space is distorted by space time, and that a less dense area would alter it.  However, shouldn't it be altering it in constant way throughout all eternity?  Maybe everything's in a different spot, but I don't see how position can constantly change as a result of a constant amount of less density.  Glass can bend (sort of) light, but it doesn't make it looks like things are moving, it just makes the object emitting or reflecting the light look like it's somewhere it's not.

@Vlad: I took AP Physics B last year.  I aced the class and got a 5 on the AP.  Is the calculus portion of Physics C that much worse?  I'm 1/5 through the year and all it is is a repeat of Physics B so far.  I recognize that the stuff we're talking about is well beyond Physics C, but I just included it to show I did have some form of a physics foundation.

What if you imagine looking through a lense that makes objects appear more distant than they are. At close distances the difference between actual distance and perceived distance would be small and the difference would increase the further the object was away from you. Thus an object moving away from you would appear to be moving away at a higher speed than it really was. I believe thats the kind of distortion we're talking about here.

Not to nitpick but space-time is warped by mass(you could say distorted but warped is a bit more accurate). 

In regards to your question I'm not entirely sure I know what you're asking but to I wanted clarify a few points:

The amount of mass in an area determines how warped the space-time of that area is.  Since the mass can move the warping effect doesn't have to stay static for a given location in space-time.

On the issue of the way the light is affected it is literally moving along the curvature of space-time, this isn't a refraction, but rather the space the light moves "through" is curved and thus the path the light takes is curved.  Technically it is only curved to those thinking of it in an euclidean sense (which all of you are), but in other geometric terms such as hyperbolic or elliptical geometry an observer might consider it to simply be a straight line.  But the underlying point is that the light takes a geodesic path through space and is not refracted by medium, it is simply going straight ahead.  Something of note is that the difference between euclidian and hyperbolic geometry, for example, on small scales is negligible, and indeed there is dissent as to whether we live in a euclidean or hyperbolic world, luckily in our day to day lives these two geometric worldviews have identical practical implications and only on larger scales does it truly matter.  It makes a great deal of sense though when you realize the difference between these two actually boils down to the very mundane parallel postulate.

In any cases I'm way off my point, so I'll leave it here and hope this info helps at least a little.

I meant to write light is distorted by space time. -_-;

Wouldn't that still mean that the amount of mass could only change in one direction.  It looks like everything is moving away, right?  That would mean the change would have to be constantly positive or negative if I'm understanding that right.

@Rath: I was under the impression nothing was moving away from us, the void just makes it look like it is.  Are we going from static to moving or moving to moving faster?  If it's the latter, that makes perfect sense.

@Tarheel. I think what's confusing physicists is not that the entire universe is moving away from us (which was expected) but that it appears to be accelerating outwards. So we aren't talking about static things looking like they are moving, we are talking about moving things looking like they're accelerating.

So the Copernican Principle is the idea that Earth isn't special.

So nothing wil EVER happen to Earth that doesn't happen anywhere else. We're just not special.

So ANY extraordinary event will NEVER EEEVVVEEERR happen in our Solar System because we're not special.


My god. Who is the moron who came up with that principle?

The way you just stated it? That would be you =P

A better definition would be that nothing extraordinary can happen here if it cannot happen somewhere else as well. It doesn't have to happen somewhere else first, it just can't be something that can only happen here.

We can have the most astronomically improbable event  imaginable happen here and it won't break the Copernican Principle unless it could only ever happen here.  If it could happen somewhere else then the principle holds.

Ah I think perhaps you are missing a bit of the "how" in the moving away process, and I'll be honest this point is something that makes it very hard to visualize the implications of this new discovery.

Part of the reason other universes are moving away from us is because of how the universe expands.  The universe expands from within itself not simply on the outside edges.  So literally the distance between two galaxies can grow even if they are both stationary relative to each other.  To be more specific the rate of this expansion has been measured to be about 70-72km per second per million parsecs. Gravity being what it is holds the planets, solar systems, and galaxies close together despite this but it does throw a bit of a wrench into the way you have to think about this issue.  There is still the actual motion of these systems to consider as well but I think this expansion is the constant you were looking for if I understood your question correctly.

Not everything looks like it is moving away though, as an example we are set to collide with the Andromeda galaxy in some ~4.5 Billion years (iirc, might be off on that number).

It is the latter.  We see the universe as not just expanding, but that expansion is accelerating, rather than decelerating as one would expect.  When scientists set out to see how and if the universe was moving, the found that, as expected, it was expanding, from the force of the big bang.  They then decided to find out how much that expansion was slowing down, but found the exact opposite of what anyone expected.

If the void bubble theory is correct, though, it may explain why the expansion appears to be accelerating.