Please pardon my english.
Here is my simple thought experiment.
In universe, there are two clocks A, B.
B moved outward at the speed of light for 1 second at 00:00"
From clock A, I think it will say "00:01" and clock B will say "00:00". But, if the motion is relative, from clock B, the clock A probably moved outward at the speed of light so that after 1 second, clock B would say "00:01" and clock A would say "00:00". This contradicts the first guess.
I am sure I misunderstood the theory. Could someone help on this? Thanks.