The universe has 10 dimensions, duuuh. Or 26. No let's keep it "simple."
A right triangle that bisects a square is A squared plus B squared equals C squared.
A right triangle that bisects a cube is A squared plus B squared plus C squared equals D squared.
A ten dimentional triangle is A square plus B squared ... plus I squared equals J squared. That's one thing that makes sense, though it isn't visualizable. A 4D world (4 spatial dimensions, not counting time) is only fuzzily imaginable, and therefore is frustrating to try to draw, though it's productive to be frustrated, and better than being flat-minded. Mystical parallel world instead of Advanced Math think. Calculating machines are impressive but lack proper gravity, me thinks. Lacking communicative ability. But it's real oh yeah.
A tesseract is a four dimensional cube. It can't be visualized in 3D, but, as a cube's shadow can be thrown onto a screen, a 4D tesseract's 3D shadow can be thrown onto our space. A worthwhile picture of a rotating tesseract is here:
http://en.wikipedia.org/wiki/Image:Tesseract.gif
Though this is just one way to see it. 16 corners, 24 square faces, 32 edges. Now try to see that motion as being as perfectly symmetrical and pleasing as a cube rotating in 3D and then you've got it. Don't get bogged down in the details, try to concentrate on the boggling sensation. Pave the world.
The namer of the tesseract (in 1880), Charles Hinton, also invented the baseball pitching machine at Princeton, originally powered with gunpowder - which lead to him losing his job. He was also a convicted bigamist.
The six dimensions we can't see (including the tesseract) are folded up somewhere. Maybe in the back of your sock drawer. No, they are folded up individually, just like socks, in every speck of everything. But they also must spread out somewhere. Somewhere else. Is there a one-on-one correspondence between the matter there and the matter here? If so, it's motion and geometry must be entirely strange to us, but there must be some type of order, as it is connected to the order here. The 6D matter that "matches" my 4D matter, it must be locally anti-entropic the way I am. It must be "life." In fact, it must be me. It's fun to move myself around in ten dimensions and play jokes on my greater and unimaginable half.
It's like VALIS, but with less angina.
I'll do more research, but I won't do a good job.
It might be nice to have a car that eats bombs instead of gasoline.