What exactly is hyperspace?

Question

Is it a nether region of existence where multiple universes float? Or is it region of the space-time continuum just beyond our perception? I'm curious.

Answer 1

Well your normal space, that we all know and love, has 3 dimensions.



Now if you assume that space has, say, 4, or 5, or 12 dimensions (or whatever), this extended space is called hyperspace.



Mathematicians can do geometry for space with pretty much any number of dimensions, so the term has real meaning for them. Which doesn't mean all that hyperspace actually exists, just that the math for it works perfectly well.



The idea of using hyperspace for interstellar space travel is an old sci fi standby. Typically it's explained by inviting you to imagine that our real space is represented by, say, a sheet of paper. If you want to travel from one side of the paper to the other, obviously you have to go through all the points between, on the paper. But suppose you bend or fold the paper, so that the two end points of your journey are right next to each other, then just hop across the gap? Now your trip takes no time at all.



That's like your "space warp" concept right there. Just as a 2D piece of paper can be warped through the 3rd dimension, maybe you can warp 3D space through a higher dimension, bring two distant points close together, then jump across through that higher dimension to get to the other side. And good luck with that.

Answer 2

On the other hand... hyperspace might be real even though we can't detect it.



There is a designed experiment, which to date can't be done because we lack the technology, that purports to find a hidden, extra dimension. [See source.] It goes something like this, but for a better more accurate account read the cited source.



We all know that gravity fields vary according to the inverse of the square of the distance from the source of the field. You know, g ~ M/r^2. But what you may not know is that the square in 1/r^2 is due to our 3 spatial dimensions. If we were in a 2D universe, for example, the relationship with g would have been g ~ M/r. Similarly, g ~ M/r^3 would have been true of a 4 spatial D universe. And that's the crux of the experiment.



What if there is a higher dimension that is so very very tiny that we cannot observe it and that it is everywhere "attached" to our 3 extended dimensions? Suppose we bring two massive plates to within some very very tiny gap of each other and measure the g between them. Suppose we find that g ~ M/r instead of ~ M/r^2 as in normal space.



That would indicate 2D space between the two plates. One of the extended dimensions has disappeared from the gravity field equation. And that would indicate some of the gravity field has "leaked" into another, hitherto-fore unknown higher dimension.



As I indicated; we can't do this experiment, except in our heads. But maybe some day, we'll have the technology to be that precise and to account for quantum effects at that precision. That would be so cool, to validate the existence of hyperspace.

Answer 3

1. Euclidean space of dimensions greater than three

2. Topological space whose elements are subsets of another topological space.