I buy the hypothesis that the universe is 3-dimensional space warped into a 4-dimensional object--analagous to a sphere, which is a 2-dimensional space warped into a 3-dimensional object. If true, the theory goes, if the universe is perfectly symmetrical, you could take off in a straight-line direction and end up coming back to the same spot you left from...going the same direction, from behind you.
The obvious question is, what's "outside" of this 4-dimensional object, and what even does a 4-dimensional object "look" like? And are there more or multiple such objects?
Interesting Bad Gopher. I think the dimensions are mathematical products, where any number of dimensions are possible. Not only can't I envision 4 dimensions, I certainly can't envision 12 dimensions, but math can.
I can envision 2 dimensions, which what this message is, and even 3 dimensions which is what surrounds us every day-- just add an up-down axis (or Z axis) to a flat world of XY axis and voila -- 3 dimensions.