inertial observers

Inertial observers are those who are moving at a constant velocity—meaning they are not accelerating or changing direction. From their perspective, the laws of physics, such as the rules of motion and the speed of light, behave consistently and predictably. For example, if two inertial observers are moving at constant speeds relative to each other, they will agree on basic measurements like the time between events or the distance between objects, though they might differ in some details due to relative motion. Essentially, inertial observers are in steady, unchanging motion, providing a common framework for understanding physical phenomena.