Observer in Einstein's Train thought experiment

Observer is an integral part of motion. Without observer there is no motion. We cannot forget observer in motion. Einstein’s thought experiment regarding simultaneity. Two light signals are emitted at the two ends of a moving train.

 

A- The two light signals are emitted simultaneously at both ends of the train.

F - Stationary observer receives both light signals simultaneously.

B- The moving observer in the train sees the light coming from front of the train at first.

C – Then after a while the moving observer sees the light coming from the back of the train.

D – The scenario that both light signals reach the traveling observer simultaneously contrary to Einstein’s 

       prediction.

Why Einstein’s prediction in the thought experiment is wrong:

F – is correct, both light signals reach stationary observer simultaneously.

D – is also correct, both light signals reach the traveling observer simultaneously- light travels at constant   

        velocity.

B & C – are wrong. How does the stationary observer know that the light signal is received by the traveling observer? The only way it can be achieved is, the traveling observer gives some sign that he received the signal coming from the front. The assumption by the stationary observer that light coming from the front reach the traveling observer first since train travels forward and signal travels backwards is wrong. The stationary observer has know way of knowing this. He needs to rely on the sign given by the traveling observer. Since velocity of light is same in all reference frames the traveling observer will give the sign exactly when both light signals reach him simultaneously

The above diagram further explains the final position the two observers stand when both light signals are received by them. Lets assume time t lapses for the light to reach observers, v is velocity of train and c is velocity of light. One important factor is the time t is same to both observers. Therefore the light signals will be received by both observers simultaneously. It can be seen that in respect of both observers light signal has traveled ct distance to reach them. Further, the moving observer has moved a distance of vt forward when he received the light signal.

More explanation regarding the Mirror Example
The problem of how light behave when light oscillates between two moving parallel mirrors, originated from Michelson Morley experiment. Practically this scenario can be visualized if such a setup is made on earth since the earth is moving — same as what Michelson Morley did.
A  frame consisting with two parallel mirrors that has a light source directed up, will be moving forward at velocity v.

 

The observer stationed with mirrors will see light photons go up and come down. And he can observe this by setting up a a lesser beam that directed up and a light detector along it's side.

The main contentious point here, is how will the stationary observer see this moving arrangement as a whole. And in particular how the moving photons behave in respect to him. Einstein's thought experiment used light signals. This is wrong since a light signal is a bunch of photons. To be more accurate we need to consider how a single photon behave. Further, it was assumed that the light signals reach the lower mirror simultaneously for both observers. This assumption was made with no arguments how it can happen. I am examining it whether it is correct.

It is impossible to verify this argument directly, because a single photon cannot be detected by two different observers. Though a light signal can be broken into two, a single photon cannot. Even when it is possible to split a photon by polarization, in observing, multiple observers cannot detect it. Single photon can be detected only by a single observer.

First if we forget the time dilation and space contractions and assume that velocity of light is constant, the stationary observer will receive the light signal after the moving observer received it, since it has to travel more to reach the stationary observer — moving observe will see photon go vertically up and come down, while, stationary observer see photon travel diagonally up and down.

Is there any evidence that of two photons that are emitted simultaneously, one seen by the moving observer and the other by the stationary observer, will reach simultaneously the lower detector. Only way of finding out is, one observer will give out a signal to the other, exactly when he received the photon. This signal will also be another photon. However, it may not matter much in this case since both observers are at the same location when they receive the photons — it may not be the case if they receive photons at different times.

Special Relativity assumes that these two photons are received simultaneously and builds the theory on it.

However, there is an argument in favor that these two photons are received at the same time. If it is stated that these two photons are received at different times, each such photon needs to have knowledge when it is emitted originally by the beam which detector it is going to strike! If such knowledge is lacking, either photon might hit one of the two detectors. Therefore they both should hit the detectors simultaneously.

Once again in quantum theory where spliting of the same electrion having knowledge through wich s