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

You sound surprised that I asked a good question (for a change)... :-}

> 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.

So, basically, it's the same as the parallax effect, but on a much grander scale?

> 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.

The only way it makes sense to me is if time moves in waves. Four-demensional waves, perhaps - but waves nonetheless.

> 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.

Just out of curiosity (and I know I'm going to regret asking this) - the ToR is a consideration of what relative to what? Or just in general? If the latter, I would assume perception to be of primary importance, as that is our relation to what takes place. But, since you say it is not a perceptional thing, then what is relative, and to what?

dkd1