Thread: Parallel Universe Dimension

Let's assume there is a parallel universe (or other kind of universe besides our own). Please do no dedicate this thread to whether or not there is another universe or not. Many people say or assume that another universe is across another dimension, or in another dimension. But wouldn't it be in the same dimensions we know now (three spacial and one time dimension), just another set of them? Just wondering. Please don't bash me for this.

If it's another universe, why would the laws of physics, as we know them, be the same? Your speculating another universe. Maybe there are 11 dimensions (oh wait, that's string theory in our universe). OK, maybe they have 47 dimensions.

Take a piece of paper. That's a 2D surface. Imagine it's infinitely big and contains an entire 2D universe. Now take another piece of paper with another universe on it. Where can you put the second sheet of paper? Either you put it in the same plane as the first, and if they were both infinitely big, they'd overlap and in fact be in exactly the same place, so that's not really a separate universe. Or you could put it above or below the first, but that's adding an extra dimension as you had to move the second sheet of paper in 3D space to separate it from the first.

So there are two possibilities when you extrapolate this to our universe. Either our universe is infinitely big (which it seems to be even if we can't see all of it) and any other universes must be separated by a 5th dimension. Or our universe isn't infinite and another universe could be in the same 4 dimensions as ours just too far away to count as part of our universe (though that raises the question as to what counts as a separate universe).

As PumaMan mentioned though, the other universes might not be limited to our 3+1 dimensions, so in the more general case, things get more complicated.

Originally Posted by MagiMaster

As PumaMan mentioned though, the other universes might not be limited to our 3+1 dimensions, so in the more general case, things get more complicated.

I figure that anything stated about other universes has to fall into the category of pure speculation. Maybe I'm wrong though and some cosmologists have done more than speculate. I admit I'm not on top of latest "other universe" studies.

I think there are some cosmologists out there that have done slightly more than speculate (doing some calculations to see what the existence of other universes might imply, for example), but I don't think anyone has anything like evidence for the existence of anything beyond our universe.

Originally Posted by MagiMaster

I think there are some cosmologists out there that have done slightly more than speculate (doing some calculations to see what the existence of other universes might imply, for example), but I don't think anyone has anything like evidence for the existence of anything beyond our universe.

If only one galaxy existed in our universe it would still be a universe. Galaxies are common and if that is all it takes to make a universe I would think universes are common. Our universe could be a multiverse visiting another galaxy is needed to prove otherwise.

Originally Posted by YangYin

Our universe could be a multiverse visiting another galaxy is needed to prove otherwise.

Arrant nonsense.

Originally Posted by YangYin

Originally Posted by MagiMaster

I think there are some cosmologists out there that have done slightly more than speculate (doing some calculations to see what the existence of other universes might imply, for example), but I don't think anyone has anything like evidence for the existence of anything beyond our universe.

If only one galaxy existed in our universe it would still be a universe. Galaxies are common and if that is all it takes to make a universe I would think universes are common. Our universe could be a multiverse visiting another galaxy is needed to prove otherwise.

Sorry, you don't get to redefine terms like that. A galaxy is a collection of stars. The visible universe is all the galaxies we can see. Since we can see more than one galaxy, the visible universe is not a galaxy.

multiverse discussion is pure speculating with out evidense. pure speculation is like sciencefiction more than science.

I am not sure what the point of speculating about multiverses is. (apart from the intellectual exercise of course).

But would it follow logically that if there is any possibility of connection between them then the same laws must apply -effectively making them all (as hypothesized) part of the same universe?

Originally Posted by geordief

I am not sure what the point of speculating about multiverses is. (apart from the intellectual exercise of course).

But would it follow logically that if there is any possibility of connection between them then the same laws must apply -effectively making them all (as hypothesized) part of the same universe?

Not if a galaxy is able to quantify and create its own prospective according to its total mass and momentum. Galaxies maybe producing their own space and the expansion of the multiverse is able to incorporate other galaxies (universes) as it encounters them.

Pure gibberish, stop it.