Gregrrr wrote:Is it possible that different parts of the universe expand at different rates?
Well, that's a tricky question. The Universe is four-dimensional (spacetime), which is why we essentially see back in time when we view more distant objects. And the evidence is quite strong that the part of the Universe we see far away is expanding at a different rate than what we see nearby. But in just the three spatial dimensions? There is no observational evidence to suggest that different regions are expanding at different rates (except to the extent that expansion is reduced or eliminated by gravity- the spacetime that contains galaxies, for example, isn't expanding because gravity is holding it together). And current theory doesn't suggest different regions will expand at different rates, either.
So is it possible? Yes. Does anything support the hypothesis? No.