The world is n-dimensional where n is some value greater than 4 but less than infinity(?). It is hard to imagine an infinite dimensional space, but it might be possible I do not know. As mentioned previously, humans do not perceive all of these dimensions. So how do humans perceive all of these dimensions? A better first question is what is a dimension. A dimension is a duality. It is most easily thought of as a line.
Tentative dimension properties:
(1) There is an origin, or a neutral position. (what that means in all dimension it is hard to say)
(2) Going one way on the line increases the value of the dimension, while going the other way decreases the value of the dimension.
(3) If from the origin you go the same distance from center in both directions, then two "values" negate each other. (kind of a corollary of 2)

Think of a number line for example. Going one way increases the numerical value while going the other way decreases it. However, dimensions do not have to be numerical. Love-hate is a dimension. There can be a neutral position ie indifference. I don't know how to prove the theory that x amount of hate cancels out x amount of love. but I think that it is true. (which has always been enough for me, belief is more important than reality anyway)

But anyway so that is what a dimension is. The real world is some number of dimensions n and humans perceive some number of dimensions k that is less than n. The brain is a filter that maps the n dimensional world into the k dimensional world that we perceive. Information is lost in this process. Mapping from a higher dimension to a lower dimension causes an irrevocable loss of information. (always) Thus it is probably not possible to know everything about the real world. Good questions are what is the value of k and n. K is probably computable to a clever person, but thats a good topic for next time.

Next time: bases (base-eez)