my take on the question:
3 dimensional atoms have their length width and height, but are basically still life models of an atom, where nothing moves or changes. you add in the dimension of time, the axis on which change occurs... and you have atoms as they are commonly observed in 4d.
think of observable 3d space as sort of a cut of time, like the "visible man" program, where you could display a portion of a corpse, as it moves down the length (reclining, head to foot) you see all the insides of him within the boundries of his width and heigth. A constant movement along the length makes his insides appear to expand and flow as if they are moving, shrinking, growing, along the two visible axes.
time is the same, but the cut is moving down the axis of time and we are observing the axes of length width and heigth of the frozen corpse of the universe one slide at a time. one should then question weather or not the future is malleable or if it is set in stone (as the past is) and we just lack enough data about the current state of the world and possible changes to determine which route in that "future cone" that is going to be followed.