I thought there were already some posts about this, but I can't find them. In this article of Anton Zeilinger et al. they perform an experiment which suggests FTL or retrocausal influence. Alice and Bob both produce their own polarisation-entangled photon pair, both send one photon of the pair to Victor, and measure the polarisation of the other themselves. Victor performs one of two measurements of the photons he receives from Alice and Bob: a separate measurement, or a Bell state measurement, the latter of which has the effect of entangling the photons, which causes entanglement swapping, thus entangling the photons Alice and Bob measure. Victor measures after Alice and Bob have measured their photons. As I understand it, when Victor makes a separate measurement, after investigation Alice's and Bob's photons are not correlated, and when Victor makes a Bell-state measurement, thus entangling Alices's and Bob's photons, those photons are correlated after investigation. Now, I understand that strictly speaking this does not imply retrocausality or FTL influence. But the fact that Victor's decision to make a Bell-state measurement or a seperate measurement determines whether Alice's and Bob's measurements are correlated, while being done prior to Victor's decision makes me wonder! For how to explain that Alice's and Bob's photons are correlated, if not for the fact that Victor is going to make a Bell-state measurement? There is in my eyes no reason for a strict correlation between Alice and Bob other than a future decision by Victor! In my eyes this suggests retrocausality! Is this really possible?