RE: Time
Time is not the fourth dimension. Duration is the fourth dimension (I'll explain the difference later). If you think about it, duration seen by us is similar to the way a 2D person would see the 3rd dimension. Imagine a 2D person on the surface of a water tank. Imagine the suface of the water as a 2D plane (not aeroplane).
Now imagine you passing your 3D arm through the water. What would the 2D person on the surface see? He'd see a cross section of your hand as it passes through the water. First he'd see a cross section of your finger tips, then they'd merge into the cross section of your hand, and finally your arm.
To the 2D character, it'd look as if there starts off as 5 lines (2D characters can only see lines), and then they merge into 1. It looks as if it's changing shape. Time allows the 2D person to see the effects of the 3rd dimension (if it wasn't for time, the object would just look like an every day 2D object).
With us 3D people, there's a similar idea with duration. If you take a still image of a person, they look like a 3D object. But with time, just as the 3D hand appeared to change shape to the 2D person, to us 3D people, it appears that people change shape. They start off really small, and eventually get bigger. What if we're 4 dimensional objects in a 3D world. We're slowly moving through a 3D plane and so to 3D people, it seems like were moving and changing shape. Time allows us to see the changes just like it allowed 2D people to see the 3D changes.
I don't think i believe any of that stuff, but i have fun thinking about it.