Yes, I tried to visualize that. Seems to me that all relativity requires the presence of at least two observers (objects of any kind in motion). I can understand that two objects approaching each other create an relative compression in spacetime and vice versa. But does that condition exist all the way between the two objects or is there a gradual increase of compression as two objects approach each other? An example is the gradual increase in pitch in a motorcycle's engine as it approaches and after passing, a gradual decrease in pitch as they recede from each other. Does distance have any effect on the compression or expansion of wavelengths (spacetime)?