# Dimension

One way of defining what a dimension is, is the minimum number of** co-ordinates** you'd need to give to **locate a certain point** in that dimension.

For example, in your everyday **2D co-ordinate graph**, you would need to give **two co-ordinates** to locate a point (generally, one each for the *x* and *y* axis). To locate something in a **3D space** would require three co-ordinates (e.g. a stationary helicopter): longitude, latitude and altitude (height).

## » The third dimension

Imagine that you are a flatlander (a 2D creature described on this page), walking across a piece of paper. Now imagine that a 3D creature (say, oh, a human, maybe?) picks up this piece of paper and folds it in such a way that **one edge of the paper meets up with the opposite edge**. Then you, the unknowing flatlander in your 2D world, could **walk across this fold and onto the opposite end of the paper**.

To you, the walking flatlander, this would be seemingly impossible, as you have now just **teleported** to the opposite end of your 2D world. Because you are **a part** of the piece of paper (the 2D world), you will have no knowledge of the fold that goes on in **the dimension above**.

So, another way of describing the third dimension is: **the dimension where you can fold through to jump from one place to another in the dimension below**.

## » String Theory

In string theory, there are **10 dimensions**, all of which are **stacked**, one on top of the lower one. If this is the case, then theoretically, time travel can be possible by** folding the fourth dimension through the fifth dimension**, just as the flatlander above has "teleported", in essence, from one point to another in the second dimension.