I was always told it's the stuff between my ears!
But on reflection, I think it's what every thing else fits in.
It's not anything. There is stuff "in" space, like matter and radiation, but space is not anything. At all.
Think big bang (one theory). You've got everything in the universe tightly packed into this little, little bundle of joy. Outside that is space, nothing, nada. Then kaboom or whatever and matter spreads out.
Space is used to describe the holes that are now between stuff.
I think though, that the term "space" can mean different things to different people.
What freaks me out though is that when you look very, very closely at an object it is mostly, by far, empty space. As in the space between the electrons. When two object touch do they really touch? <puts reefer down>
Satan - A circle has no begining or end. Eternity has no end.
Space is a lack of windsurfing gear - a void waiting to be filled.
JB
I think some of you guys are wrong, out side the big bang there was nothing, agreed, but that includes space!!!!
As I understand it, space-time doesn't exist out side the expanding bubble produced by the big bang.
There is a boundary to this universe, inside it is space, outside doesn't exist, not even space
Doesn't it wrap around Pac-man style? So if you reached the end you'd pop into existence on the other side?
Or if it doesn't wrap around then if you hit the edge you wouldn't be able to exist outside... sort of like trying to drag your mouse outside the computer screen, with no pixels to display it the cursor doesn't exist.
That God bloke is a clever fellow 
AS Neb's says.
Don't think you can ever find the boundary, you just end up back where you started.
After all, how can you come to something that doesn't exist?
it could be time that has no beginning or end but i thought space has been around as long as time has been around.
our universe may increase and decrease over time but space and time will continue????
well in terms of art and architecture space has no beginning and end and is what defines the objects within it.
does the end of the universe define the limit of space? i would say no as the universe is expanding into space.
No No No No.
I think I was wrong to talk about boundaries, on second thoughts I don't think there are any.
But the universe is finite, without a boundary. (That's why you end up where you started from and can't fall of the edge, there isn't one)
It's expanding but not into anything!
There's nothing outside it, not even space!!!!
Space is something!
It's part of space-time and the universe.
Since there is no up or down Space must be 2D as you can only move in two directions - towards something and away from something
Space is a Higgs field with 12 dimensions plus one time dimension.
We perceive time as only going forward due to the second law of thermodynamics.
Before the Big Bang there were 13 space dimensions and no time dimension, which is why there was "nothing" before the Big Bang because there was no "before".
Early in the Big Bang one of the space dimensions morphed into a time dimension.
Jeez, someone might even think that I know what I'm talking about. Almost.
Space is impossible to enter in this forum, because you just keep getting an error message that "You must enter a message"
^^^
i thought that the universe was part of space. so space is the universe and the areas outside the boundary called the universe. ie. the universe is expanding into space. if space is finite then we have a problem on our hands.
