The spin states of the entangled photons could have been pre-determined from the beginning of the experiment, it requires that certain assumptions on which quantum physics is based are either untrue or misleading. The first assumption I discuss is one of <PERSON>'s. In his introduction to his theory of the Principles of Quantum Mechanics (Fourth Edition revised) he states that “Only questions about the results of experiments have real significance for the physicist.” and then “ The foregoing discussion about the result of an experiment with a single obliquely polarized photon incident on a crystal of tourmaline answers all that can be legitimately be asked about what happens to an obliquely polarised photon when it reaches the tourmaline. Questions about what decides whether the photon is to go through or not and how it changes its direction of polarisation when it goes through cannot be investigated by experiment and should be regarded as outside the domain of science.... Nevertheless some further description is necessary in order to correlate the results of this experiment with the results of other experiments that might be performed with photons and to fit them into a general scheme. Such further description should be regarded, not as an attempt to answer questions outside the domain of science, but as an aid to the formulation of rules for expressing concisely the results of large numbers of experiments.” Obviously when <PERSON> was formulating these statistical rules he was deeply concerned about the practicalities of making precise measurements on individual particles although he explicitly accepted that there may well be deterministic rules guiding things. All of quantum mechanics is now based on <PERSON>'s derivation of statistical rules based on the idea that determinism is impossible to prove so we must adopt a statistical approach. When we interpret the sayings of physicists then, we should bear in mind that QM is only statistical because we do not have the fineness and gentleness of experiment to be able to conduct the experiment deterministically.
To then come to the issue of <PERSON>'s inequality which has been mentioned. <PERSON> himself made the statement in a 1985 radio interview (from wiki) “There is a way to escape the inference of superluminal speeds and spooky action at a distance. But it involves absolute determinism in the universe, the complete absence of free will. 682
Suppose the world is super-deterministic, with not just inanimate nature running on behind-the-scenes clockwork, but with our behavior, including our belief that we are free to choose to do one experiment rather than another, absolutely predetermined, including the ‘decision’ by the experimenter to carry out one set of measurements rather than another, the difficulty disappears. There is no need for a faster-than-light signal to tell particle A what measurement has been carried out on particle B, because the universe, including particle A, already “knows” what that measurement, and its outcome, will be.”. I suggest that this super-determinism is excessive and that only each individual photon transfer needs to be pre-determined, which would be the strict answer to what you ask, but it then begs follow on questions such as how such a 'local' pre-determinism maybe achieved in isolation from a more general non-deterministic environment and this is answered as follows:
There is no example of a photon existing independently and outside of an exchange between two atoms. The only way we can detect a photon is through its acceptance and incorporation into the structure of a receiving atom. Therefore we may consider a photon to be a singular exchange of an indivisible quantum of energy between two atoms. Over a large number of photons the pattern of distribution of those exchanges is then determined to fit a statistical pattern as described by what we know as electromagnetic waves. An exchange is a transaction or an instantaneous moment in time occurring between a giver and a receiver. I would suggest that at the moment of exchange of any photon its destination atom is known and 'agreed' with that destination.
But then if this transaction is instantaneous the question then arises as to how the time-delay appears which gives rise to a speed associated with the photon's time of flight from source atom to destination atom. This question also has a complete answer but which is too big for here.
In conclusion I would say that it is possible for the spin of entangled photons to be pre-determined,there is no experiment or theory which precludes this possibility. In <PERSON>'s words what you ask is “outside the domain of science”! What we should really be asking is how the illusion of 'time' occurs in photon transfers. 795