Originally Posted by edgeprod

The best way I can explain it is this: imagine a 1D world (a single line), where you can only move forward or backward. This is "one dimension": length. Now imagine a 2D world (a grid/graph), where you can move forward and backward, but also side to side: length and width. Next, imagine a 3D world, where you can move forward or backward, side to side, and also up and down. This would be akin to giving three-dimensional coordinates (x, y, z) as in "3 miles west, 5 miles south, and 50 feet in the air".

Now, let's expand it to 4D, by adding time. If you gave me a place in three dimensions to meet you, you might say:

Meet me in the building at the corner of 31st street (width) and 5th avenue (length), on the 12th floor (height)

I'd arrive there, but who knows when? I'd have to wait indefinitely for you to arrive, or vice versa. Now, let's add a FOURTH dimension (time):

Meet me in the building at the corner of 31st street (width) and 5th avenue (length), on the 12th floor (height), at 3:00pm (time).

Now I know exactly WHERE and WHEN to meet you.

Originally Posted by **********

Hi Mutt,

The 4th dimension is sometimes considered to be time. So for example, let's say you want to meet a friend on a street corner. You might specify a location of a building which is on the corner of Street X (1) + the corner of Street Y (2) + the floor of the building Z (3), and then finally the date and time of the meeting (T). X+Y+Z+T = the location of the meeting.

However, more modern theory combines space and time into a single unit, called Spacetime. There is a really go primer on the subject at this URL : http://en.wikipedia.org/wiki/Spacetime

Originally Posted by EddyTheDog

I understand that our universe is not infinite - Its the thought there are infinite universes - Think about statistics and infinity - Not only does everything possible exist there must be infinite number of them...

There are an infinite number of universes with us having this conversation on infinite GFYs - That's where my head starts hurting.....