The proper time between two events is measured by clocks at rest in a reference frame in which the two events:
A) occur at the same time
B) occur at the same coordinates
C) are separated by the distance a light signal can travel during the time interval
D) occur in Boston
E) satisfy none of the above

Question

Quizplus · Accepted Answer

Proper time is measured in the reference frame where the two events occur at the same spatial coordinates, meaning the observer is at rest relative to the events.

The Proper Time Between Two Events Is Measured by Clocks