Okay, Sam, I've realized that your misunderstanding of SR is much more basic than I previously thought. So, let's start at the **very** beginning. Much of the next couple of paragraphs is real basic stuff, and I am not implying that you don't understand it. I just want to plainly set out what we're talking about.

First of all, take a plain piece of paper (not graph paper this time) and mark a point on it. Now, how can we define that point? We can use cartesian coordinates, and say it is (x,y). No two points on the paper will have the same x,y values, so those values uniquely identify that particular point . . . **except**: those numbers, by definition, only define that point **relative to another point**, (0,0). On a sheet of paper, we can easily identify a corner as (0,0), with the edges as the axes. However, if the paper were infinite in size, we would have to simply arbitrarily define an origin point (0,0) and arbitrarily define our x- and y-axes, and then we can define all other points relative to that point.

Now, to move into three-dimensional space, we need to add a third coordinate, z, with its own arbitrary axis. To locate an **event**, in space-time, we add a fourth coordinate, t, with its own axis. So, once we define our arbitrary origin point at (0,0,0,0), any other point can be defined relative to that origin by it's own coordinates (x,y,z,t).

Let's say you've got a light bulb sitting next to you. You turn the light bulb on. That's our first event, so we'll designate that as the origin and call it (0,0,0,0). Five minutes later, you turn off the light. That event occurs at (0,0,0,5) - our spatial coordinates stay the same. Five minutes after **that**, you smash the bulb. That event, then, is at (0,0,0,10).

Now, here's where SR gets a **little** complicated. Consider that under SR there is no absolute motion, only relative motion. That means that from a reference frame that is in relative motion to that light bulb, the spatial events would change for those events. For this discussion, we'll limit the movement to being along the x-axis. So, if our reference frame says the light bulb is moving to the left at 0.6*c*, then the light-bulb can't even be at (0,0,0,5) for that second event. At best, it would have to be at (-3,0,0,5). Now, keep in mind that we are not physically changing **anything**. All we are doing is changing the designation of that point in space-time. With me so far?

Now, here's where SR get's **really** complicated. The speed of light, *c*, must remain a constant. If we consider two events - a pulse of light being emitted at an emitter, and that light being received at a receiver - then, we can conclude that the values of x (in light-minutes) and t (in minutes) **must be the same**. So, if relative motion causes us to conclude that the value of x changes, then so too must the value of t change.

Now, again, we are **not** physically changing anything. All we're doing is saying that a point in space-time corresponding to (0,0,0,5) relative to the origin in one reference frame would correspond to (-3.75,0,0,6.25) relative to the same origin point but in the other reference frame. [NOTE: I had the numbers wrong in this last sentence and have corrected them]

Now, I think I'm just going to leave it at that for now and we'll make sure this is clear before we move on any further.

Sometimes you win, sometimes you learn