About dark matter and the limits of the universe.

[WindScars]

1. Is the universe finite?

2. Could it be just the surface of a higher dimensional object?

3. If something travels across the universe will it reach the same point?

4. Could the effects of the accelerating universe, that scientist credit dark matter to, be just a side effect of some higher-dimensional twist that we weren't able to calculate yet?

 

[Parlyne]

This should be in the Cosmology forum; but, here goes.

1) Unknown.

2) It could be (this usually goes under the name of "brane theories"); but, there's no evidence to point one way or the other on this.

3) No. Even if the universe is finite and closed, the accelerating expansion will prevent anything from making it all the way around.

4) I think you mean "that scientists accredit to dark energy." And, again, that might be possible; but, nothing we know necessarily points to it.

 

[WindScars]

But if the universe is the surface of a higher dimensional space would not you end up in the some point?

 

[DrGreg]

But if the universe is the surface of a higher dimensional space would not you end up in the some point?

The surface is expanding (at an accelerating rate) and you'd have to go faster than light (which is impossible) to complete a circuit.