4D, facts, not fiction
This is not for the faint of heart! If you havent had your cup of joe yet or feel you lack the science geek in you to comprehend it, dont continue!! 
Anywho, I have some interesting theories on extradimensions, mainly the 4th… maybe the “teeming millions” or the godly Cecil himself could provide some input on this… but this is how my theory goes.
Mathematical proof of 4D (and 5D, 6D, etc…)
First, I look at this from almost a totally mathematical viewpoint. By doing it this way, I can back my statements with mathematical truths, instead of scientifically theorizing. My definition of a “dimension” is the space created by an axis. The 1st “dimension” is the space created by a single (x) axis. The 2nd “dimension” is the space created by the x and y axes. 3rd dimensional space is x, y, and z. Now, for the 4th dimension, ive coined the variable “k” to stand for the 4th axis. Now im not going to deal at all with 5th, 6th, and so on and so forth, because we first need to comprehend number four.
What bothers me alot is how people try to place measurements on the dimensions. Lots of people think (and sadly, some are taught) that the 1st dimension is length, 2nd is width, 3rd is depth, and so on… then in the theory time comes up, and then “time” is incorrectly coined as the “4th dimension”. I cant stress enough that measurements and dimensions are not the same thing. Measurements measure things, Dimensions define the objects that are measured.
Now, before I get into good ol’ numeral 4, we must fully understand 3, and how our dimensions interact mathematically.
Say I have a point on a 1 axis graph (x)… say… X=1. One a 1 axis graph, this defines a single point. Hopefully, you should know this. And you should also know that on a 2 axis graph (x,y), that X=1 would create a line made of infinite points. Now, on a 3 axis graph (x,y,z), X=1 creates a plane (a mathematical “surface” that extends infinitively directions and has no thickness).
Now, its almost impossible to visualize what X=1 would look like 4 dimensionally, but I could attempt to explain it. It would create an infinitely expanding “solid” at X=1, but yet these solids could parallel each other, or intersect each other. Like X=1 and X=-1.5 would be parallel solids on a 4 dimensional graph. These solids are infinitive, yet are parallel; see what I mean? Dont visualize it, you will explode, trust me… 
Now er… to try to visualize 4D a little easier, we take the point (3,-2)… that would be totally undefined 1D, a point 2D, a line 3D, and… viola, a plane 4D !
Same with (1,0,4)… it would be undefined at 1D and 2D, would be a point 3D, and a line 4D (consequently, a plane 5D and a infinitive solid 6D, etc…)
You define a point with 4 values (1,4,-2,5), and its undefined 1D-3D, and creates a point 4D.
If you dont understand what at all im saying, please re-read it, it should make sense after a few times… (sorry I dont have pictures to explain this… 
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Now I’ve heard about a “string theory” or “superstring” or something, and have heard it consists of 11 universal dimensions… now, I think, WTF… why is it limited to 11D ? I mean, if what I just explained to you made sense, why should the amount of dimensions be limited to 11? Why should they even be limitied positively?? (Yes, I knew someone that attempted to prove negative dimensions… either he was mentally retarded, intoxicated, or the greatest genious i know ) I think that the 11D limit is false mainly because of the mathematical evidence… I mean, what happens if I defnise a point at (1,2,3,4,5,6,7,8,9,10,11,12)… thats a 12 dimensional point… and I just defined it… see what i mean?
4D in reality
Lets warp back to 1000 AD…
wooooooooohoooooooo…
poof
Okay… everyone thinks the earth is flat… and really, I wouldnt slam the poor fools for it either, they have good reason… How does the earth seem round at all? It is really hard to determine the earth is round… mainly because we cant see the curvature easily. But the main evidence for it is pretty easy… you keep moving in one direction, you end up back where you started… odd… and if you (theoretically) drilled a whole at any degree into the earth, you would end up somewhere else… its like, WTF… and thus it was explained that the earth is 3D, and no longer was the earth a circle or a flat rectangle, but was a full fledged sphere.
Unfortunately, we now take this to the next level… hehe
Look at Space… seems 3D… there doesnt seem to be a “curvature”… but you have to look really closely to understand that the universe is a 4D object… mainly to do with the issue of gravity.
Now, the same rules apply in Space as they did with our 1000AD friends… we move in one direction long enough, we end up back where we started… we make a whole at any degree (such as hint hint a black hole ) and it will end up somewhere completely different… now we think, WTF… but, it can be explained relatively easily.
The universe, in its entirity, is a 4D sphere. This sphere is expanding from its center (space is only on the surface of this sphere, such as what we know of earth is only on the surface of the planet… get it? :)). Now this expansion leads the the “red-shift” effect, the infrared visibility of everything moving apart from each other…
Its easy to try to visualize the universe as a perfectly spherical balloon… magically being inflated from the center. All the pretty galaxies and the earth and stars are on the surface of this baloon… They started off really really really close to each other, but as the baloon inflates, the surface stretches, and these objects moved further and further apart from each other.
Now, gravity is one of the 4 universal forces (electromagnetisism, gravity, weak & strong nuclear force). Gravity is a “dip” in this 4D balloon.
Everything on the surface of this balloon causes a dip into the balloon… some obviously quite larger than others. Now the sun makes a relatively large dip compared to our earth, so the earth falls into this dip, and revolves around this dips curves down… either spinning toward the bottom or accelerating out of it, or trying to maintain a near-perfect equalibrium with its revolving around the bottom of the dip… thats gravity… i know its hard to understand but thats as best as I can describe it…
Now a particularly massive object can cause a dip so large it actually goes through the entire ballon and on to the other side, effectively creating a tunnel straight through the balloon. These massive objects are called black holes. Thats why mass goes into and out of a black hole (visit space.com for photographic proof of this). And that is also how black holes conform to the laws of physics… Nothing in a black hole is going faster than C (light)… its just that its taking a different path to get there… Like, if you dug a whole from NYC to Bejiing, and traveled at 100 KM/H through it, it would take you faster to get there than someone traveling 100 KM/H the ‘conventional’ way… but you are still going the same speed. Like, say there is matter going from Galaxy A to Galaxy B moving at .5C (half the speed of light)… it would take the matter a time to get there. Now if the matter goes through a black hole at Galaxy A to Galaxy B, it would take the matter less time to get there, but it would still be moving the same speed… get it?
The Glorius End
My wrists are starting to hurt really bad and I cant type for a few minutes… ill wait for some responses and for my Carpal Tunnel to die down before I continue… lol