(some ideas here are mine, and I'm really not an expert about these dimensions, so please, please take them with a grain of salt)
For a 2-dimensional world, take away the height. (but a 2-D world doesn't exist, for now.)
1-dimensional only has the length. For a 0-dimension, well, take away the length.
In other words,
Get the idea?
1,2,3-D... then comes the 4-D. We can't see a 4-D world fully, if there really is one.
To get the idea...
If there really was a 2-D world and there was a creature living in it, we'll be able to pick up something in that world, right? (theoretically, at least) And the 2-D creature doesn't know of a new dimension- height- where the hand comes from, so it won't realize it's been abducted from its world till the hand actually picks it up. The creature can only see 2 dimensions, so when it comes to our 3-D world he'll instead see slices of it, like a CT scan I guess.
So, if a 4-D creature finds us and snatches a person(let's call him Joe ), Joe won't know when it's coming and when he's taken away(poor Joe), the people with him can't see the 4th dimension (like the 2-D creature can't see heights), so to them it'll look like Joe just disappeared. And to Joe, the 4-D world will flash past him in 3-D form, which will most likely give you a headache.
I looked up on Wikipedia about the 4th dimension, and I got this really confusing video.
some browsers might show this as a still image.
I decided that thinking of 4-D as an image will be close to impossible, at least for me, so I looked at the number of vertexes, sides and surfaces in a dot, line, square and a cube and I found a rule to it!
I'll write about it in the next post about dimensions.