How could two observers measure a different speed for the same moving object?

Special Relativity. Velocity Addition: If observers in two different frames of reference (that are in motion relative to each other) are observing motion of the same object, they will both measure it to be traveling at different speeds.

Why is speed of light same for all observers?

The speed of light in vacuum is the same in all inertial reference frames. According to Special Relativity, as a frame goes faster, it shortens more in the direction of motion, relative to the stationary observer. In the limit that it travels at exactly the speed of light, it contracts down to zero length.

Would the speed of light differ when measured from different observers?

It is a basic postulate of the theory of relativity that the speed of light is the same in all inertial frames. This can be broken down into two parts: The speed of light is independent of the motion of the observer. The speed of light does not vary with time or place.

Why does time slow down for the observer who is moving at light speed compared to the standing observer?

Time slows down for an observer moving arbitrarily close to the speed of light because the subatomic particles that make up the atoms in the body of the observer are also limited to light speed.

Why does time slow down at the speed of light?

As light is spread out by the observer moving away from the source of the light time is decreased. The faster the observer moves the more light is spread out and time slows down. Time slows down as you travel faster because momentum bends the fabric of spacetime causing time to pass slower.

Why is the speed of light different in different mediums?

When light enters a denser medium (like from air to glass) the speed and wavelength of the light wave decrease while the frequency stays the same. How much light slows down depends on the new medium’s index of refraction, n. Light moves slower through denser media because more particles get in its way.

Why is light speed invariant?

Originally Answered: What makes the speed of light an invariant quantity? By Einstein theory of relativity the speed of light is invariant. Speed of light is not depends upon the motion of observer. And it does not vary with time or place.

Will two events that occur at the same place and same time?

Is it possible for two events happen at the exact same time? No. Even at any one event itself there can be several (or in though-experimental principle even arbitrarily many) distinct participants (encountering and passing each other, momentarily).

Do any two observers always agree on simultaneity of events Why?

Never since they are both moving. Always only if they occur at the same time. Always only if they occur at the same place and time. Simultaneity is impossible in Relativity.