Notes:
If we decide to have the photon after passage of the half transparent mirror go to Mars or to Venus then a measurement on Venus will collapse the state at Mars too. The spatial distance doesn’t matter and in the case of photons these two positions might fall outside the light cone (in other words if ‘information’ is transferred it has to go faster than light). These peculiar form of connectedness is called non-local correlation and shows that quantum information can be transcendental (not dependent) of space. (And as we will see later either from time).