[The Cajun]

Shouldn't your top reflector be moving at the same speed as your clock in order to be considered part of the clock?

[ETL]

Shouldn't your top reflector be moving at the same speed as your clock in order to be considered part of the clock?

http://galileo.phys.virginia.edu/classes/252/srelwhat.html

The following is with respect to the stationary outside observer watching the light clock apparatus move past him from left to right:

When the light pulse leaves the bottom reflector/emitter, the clock is at position 1. When it reaches the upper, it is at position 2. When it returns to the lower, it is at position 3. The movement of the apparatus is left to right with respect to the outside stationary observer.