>
> > Not that this has anything to do with the
> > original discussion.
>
> Relevance is for wimps, anyway. :-}
>
> Now that that's done with, I need some help with
>my understanding of the theory of relativity (ToR
>for short from now on)... Specifically, does it
>not assume, then, that time is a physical force,
>akin to light and sound? In order for the
>velocity at which we travel to have any effect on
>time, would it not have to be some type of
>partcle and/or wave substance? Or is it not time
>itself that changes, but rather our perception of
>time? Or am I just spaced out?

That's actually a good question. I'll see if I can answer it.

The thing we're really talking about when we talk about "time" in Relativity is "space-time". Time is considered another dimension beyond the three physical dimensions we are used to.

This leads right into the Lorentz-Fitzgerald contraction, which is also figured by using gamma (since space and time are really "the same"). I'm still fuzzy on how this works, but this is what I understand: An object in motion reletive to a viewer will contract by a factor of 1/gamma in the frame of reference of the viewer and in the direction of the motion.

Short version: I see a meter stick pass me at .6c. It doesn't look a meter long to me, however--it only looks to be 80 centimeters long (1/gamma = .8 for an object moving at .6c). As I said, I'm still fuzzy on this--from what I understand, this is a measurable yet *frame dependant* contraction, meaning that as far as the meter stick is concerned, it's still a meter long.

Confused yet? Join the club. This doesn't answer the question of *why* time dilation and the Lorentz-Fitzgerald contraction takes place (I'm not sure *anybody* really knows why that happens) but I hope it explains your question about the nature of time. Short version: time is the fourth dimension.

It is most definitely not just "our perception" of time or anything else that is changing in Relativity. The biggest trap you can fall into when trying to learn Relativity is saying "this is just an illusion" to thinks like time dilation and length contraction.