High School Expanding Universe - Could It Be Rotating?

[zuz]

Instead of expanding, could the universe be rotating? Everything rotates. Atoms, solar systems, galaxys. Could it be that we just can't see enough of the universe to see it's rotation?

 

[phinds]

Instead of expanding, could the universe be rotating? Everything rotates. Atoms, solar systems, galaxys. Could it be that we just can't see enough of the universe to see it's rotation?

And just what do you think it is rotating AROUND? Do you understand the implications of contending that the universe has a center?

 

[Drakkith]

Instead of expanding, could the universe be rotating? Everything rotates. Atoms, solar systems, galaxys. Could it be that we just can't see enough of the universe to see it's rotation?

That would not look the same as our present universe does. It would not generate the same redshifts, CMB patterns, galaxy distributions, etc.

 

[PeroK]

Instead of expanding, could the universe be rotating? Everything rotates. Atoms, solar systems, galaxys. Could it be that we just can't see enough of the universe to see it's rotation?

There's the Goedel "Rotating" universe. E.g.

https://en.wikipedia.org/wiki/Gödel_metric

 

[Drakkith]

@zuz it's important to understand that this is merely a valid solution to the equations of General Relativity, and not a realistic model. Per the wiki link given by PeroK:

Besides rotating, this model exhibits no Hubble expansion, so it is not a realistic model of the universe in which we live, but can be taken as illustrating an alternative universe, which would in principle be allowed by general relativity (if one admits the legitimacy of a nonzero cosmological constant).

 

[zuz]

I guess I don't understand the implications of a center of the universe. That's why I asked the question. What's the problem?

 

[phinds]

I guess I don't understand the implications of a center of the universe. That's why I asked the question. What's the problem?

Google "Cosmological Principle"

 

[Drakkith]

I guess I don't understand the implications of a center of the universe. That's why I asked the question. What's the problem?

I believe it would go against the idea that the universe is isotropic. That is, we currently believe that the universe is roughly the same in all directions. We don't find large variations in galactic densities or radiation just by looking at a different part of the universe (note that I'm referring to the universe at the largest scales. We obviously find extreme variations at the galactic scale and below). Observations so far have supported the view that the universe is isotropic and homogeneous at the largest scales, which goes against having a center.

Not only that, but I don't know if the universe can have a center and still obey General Relativity, or what it would look like if it can.