Is the universe really expanding?

[phinds]

... as Michio Kaku likes to call it ...

Just so you are aware, there are numerous threads on this forum which point out that Kaku is a basically full of kaka when it comes to this stuff. He is a popularize of the worst sort and will say anything to sell books. He USED to be a real physicist but that ended years ago.

 

[phinds]

Yes, if our universe is one of many than yes, it makes sense that it is spinning in relation to other universes.

And just what do you think that MEANS? Even if there ARE other universes (an idea that I think is nonsense but I know it is believed to be possible by some serious physicists) and even IF our universe were in some sense rotating about other "bubbles" (again, almost certainly a nonsensical metaphor even if there ARE other universes), it is irrelevant to the OP's question because it obviously has not effect in our universe. If it did there would be a preferred frame of reference in our universe and there is not.

Do you not understand this concept of no preferred frame?

 

[phinds]

Sorry Chronos, but I have to reply to this.

There are several theories nowadays that support the Multiverse hypothesis. If our Universe is one of many, then it makes sense to say that it is spinning. It is spinning in relation to other universes or the hyperspace, as if it was a bubble, as Michio Kaku likes to call it. The difference is that a bubble has air in it and the Universe has space in it (and it is also much much bigger, needless to say)

See the post directly above.

 

[Stuart]

We can't be certain. There are many ways to interpret what we've observed. It's assumed that space-time itself and the laws of physics are generally consistent throughout the universe. If that's true then our observations support expansion. That doesn't make expansion true. In fact, it's certainly not the entire truth. Simply thinking about expansion may give you some sense of how much of the truth we still need to work out. Our data does give us great confidence though.

If the universe is not generally consistent things get interesting. That possibility is very upsetting to many people. Change is always upsetting.

Personally, I think it's typically egocentrics of us to assume that the entire universe is the same as the bit we live in. I guess well have to wait and see. In the mean time, here's a paper with a fun thought experiment which is reasonably approachable.
http://arxiv.org/pdf/1305.4630.pdf