Originally Posted by
Bleve
The physics for describing motion in each is different.
Yes I poorly worded that statement. Physics is universal. What I meant to say is that the equations of motion are different. The classic example is the marble rolling across a frictionless rotating disc. Viewed from an inertial frame of reference it travels in a straight line at constant speed (Newton's First Law). But viewed from the non-inertial frame of reference (the rotating disc) it travels in a curved path. To describe the curved path a 'fictious' force (Coriolis) is invoked. Two very different equations of motion describing the same event.