Final answer:
Changing the origin of a coordinate system in a motion diagram does not affect the actual time interval, but observed time intervals can differ due to relative motion between observers, as per the theory of relativity. Time dilation signifies that time can be observed differently between moving and stationary frames, impacting the rate at which clocks are measured.
Step-by-step explanation:
The question addresses the concept of time dilation and simultaneity in Physics, specifically within the realm of special relativity. Changing the origin of the coordinate system in a motion diagram does not affect the actual physical time interval for a process. However, due to the principles of relativity, observed time intervals can differ between different inertial frames of reference. If an observer is in motion relative to the process they are observing, like the case of an astronaut in a spacecraft compared to an earthbound observer, the elapsed time can appear different because of the relative motion between them.
In practical terms, changing the coordinate origin is simply a shift in the point of reference and doesn't influence the actual time interval of the event itself. Yet, physical motion relative to a clock or event can indeed change the observed rate of that clock or duration of that event. This is due to the fact that the rate of a clock, or the measurement of time, can vary for observers in relative motion, which is demonstrated by the phenomenon of simultaneity and time dilation.