shouldn't time be considered the pre 0 dimension and not the ..........?

Good point: "can anything exist if time doesn't"

Without time there would be no interactions, therefore no way for anything to test if anything else exists, nor to even test; full stop. So would anything exist?

I'm not too keen on time being considered another dimension, somehow on a par with the spatial dimensions. It certainly makes for elegant mathematics. But then again you can consider colour to be a three dimensional entity if you like (3 intensities RBG), it makes nice maths and any colour can then be positioned in a 3 dimensional "space", but noone seriously believes that colour is in any way an actual space that you could walk into.

Also note the imaginary factor in the definition of time in relativity. It is really quite different to the spatial dimensions.

I think that the real meaning of time is lurking in the quantum world, and what we perceive as time is just as illusional as the concept of a surface; a surface originates at the quantum level even though it does not exist there, and the vast assemblage of "particles" involved gives the illusion of a flat surface to our senses.

Happy pondering,

&Cheers!

nope -its taken 0 dimension is a universe without time,and negative 1 is a dimension without space but time

so it must stay the 4th

Space and time can't be separated, that's why Einstein called them Spacetime. You need all of them to clearly define one event. You need to know where it took place and when it took place. Miss any of that information and it's pointless.

you could write it that way if you wanted, I don't think it would affect the results of any calculations. in relativity time usually _is_ the first dimension listed.

Time is not needed for a vertice in space, but it is for a point in space-time. You can have an x-coordinate, a y-coordinate, and a z-coordinate, but how do you describe something that is in motion? You need a fouth coordinate, which is time.

Time is called the fourth dimension because it was the fourth to be discovered

Well, you could probably debate that with Einstein if he were alive. But unfortunately for us, he's dead, so we just have to go along with what he wrote.