4 ms·
The same way X direction can can be arbitrarily defined in space, the time can be arbitrarily defined in spacetime (so called "frame of reference"). Other 3 dir
by sheerun 6y ago
The same way X direction can can be arbitrarily defined in space, the time can be arbitrarily defined in spacetime (so called "frame of reference"). Other 3 directions parallel to time are called space.