Fourth Dimension

Four-dimensional space (4D) refers to a universal expanse that can be perceived through the fourth spatial axis. Virtually all known living organisms, including humans, exist within the 'standard' three dimensional space (3D), and perceive the environment around them in two dimensions only (2D), therefore it is impossible to visualise the fourth dimension. However, three-dimensional matter is able to be moved through the fourth dimension by the means of any higher dimensional force or entity - this results in the matter entering a different three-dimensional space. 
Four-dimensional space is sometimes additionally used as an analogy to describe the concept of third-dimensional spacetime - in other words, time in reference to space. To avoid confusion however, scientists generally refer to the “dimension of time” as n-dimensional spacetime. For example, fourth-dimensional spacetime is the concept of time within four physical dimensions, which Sakura has likened to recording a third-dimensional space onto video tape.
4D space can be described as the medium in which every 3D space exists. From a 3D observer it would appear that they all occupy the same space, however in reality this is incorrect. For example, a 2D being occupying a hypothetical 2D surface can only move and look in four directions across 2 dimensions: up, down, left, and right. From a 3D observer, the 2D being is incapable of moving in the third dimension, i.e. moving "forwards" and "backwards" from the observer's perspective. However, the 3D being does have the ability to do so, and can move the 2D being accordingly. As a result, moving the 2D being in the third dimension introduces them to a new 2D space in which they can still only move in 2D. In principle, this is analogous to the idea of moving in 4D space. If a 3D observer were to be nudged in 4D space, they would translate across the fourth spatial axis into a new 3D space, but would not possess the means to return.
4D space is, in theory, infiniteIt is currently unknown if the phenomena of "Unreality" also appears at some point within it.. Referring back to the 2D-3D analogy, it can be inferred that, since a 2D plane has a thickness of zero (i.e. it does not extend at all on the three-dimensional axis), any 3D space must consist of an infinite amount of 2D planes - by principle, any number divided by zero must return infinity (except zero, which returns zero.) 3D and 4D space are analogous to this, so logically there are an infinite amount of 3D spaces. It is yet unknown whether other dimensions (not to be confused with spatial dimensions, referring to the axes upon which space exists) are merely locations within unique 4D coordinates (x,y,z,w, where 'w' refers to the fourth spatial axis upon which unique 3D spaces exist) or if they exist outside of spacetime entirely.
Category:Dimensions and Timelines
Category:Mathematical Dimensions
Category:Locational Dimensions