Which clock or observer conclude that time dilation has occurred? Is it the stationary clock/observer or the moving one? (Please bear in mind that each observer/clock independently concludes that one second has lasped according to their lightclock)
The stationary observer concludes that Event A and B occured simultaneously. The moving observer concludes that Event B occured first. Who then concludes that Simultaneity is Relative?
My question is therefore: which observer concludes that ''each observer concludes that the other observer's clock is running slowly''?
Alice observes that Bob's light clock runs slower than hers and Bob observes that Alice's light clock runs slower than his.
Alice will explain to Bob that the fact that Bob observes her clock to run slow is because Bob's clocks are not synchronized.
Bob will explain to Alice that the fact that Alice observes his clock to run slow is because Alice's clocks are not synchronized.
That relatively moving observers don't agree on whether two events are simultaneous is known as the relativity of simultaneity.
See this answer for a spacetime diagram complete with arguing observers.
