Every motion in space is also a motion in time.
The speed of light is the upper limit of the spacetime rate.
— Me@2012-04-28 12:42:08 PM
An object cannot change this position without changing its time coordinate.
In short, there is no instantaneous motion.
— Me@2020-08-12 05:26:20 PM
2020.08.12 Wednesday (c) All rights reserved by ACHK