The Aspect experiment showed that the photons do not have a well-defined value for the measurable property prior to the measurement being made so I don't see why you think this solves the problem. How can the second photon be forced to be "left" if the first doesn't take a value of "right" until the experiment is performed "at the other end of the galaxy".

Dear George, so two particles entangled with no well-define value. If this is so, they could be left-left; left-right and right-right. Right?

Dear Omar

We know that there is no consensus among physicists about the different interpretations of quantum mechanics. Of course we also know that there exists a central core of "interpretation" related to the probabilities of outcomes of experiments performed on systems subjected to certain state preparation procedures. The different "interpretations" are (sometimes this word is unapropriate), for instance hidden-variables theories, collapse theories, quantum nonlocality of spacetime structure and causality, aspects of the ontological character of quantum states and are all well know. If you consider for example two disjoint physical systems, 1 and 2, and associate Hilbert spaces H1 and H2 to those systems, you can define an associated Hilbert space to the composite system which is defined as the tensor product space, denoted H1⊗H2. Now if you consider that the two systems are independently prepared in pure states |1⟩ and |2⟩, the state of the composite system may be given as the product state |1⟩⊗|2⟩. A pure state of the composite system represented by a state that is not a product vector is an entangled state: i.e. a composite system consisting of spatially separated parts, so that, even when the state of the system is a pure state, the state is not determined by the reduced states of its component parts, ie, the quantum states exhibit a form of nonseparability. Let's be practical. Consider as an example a quantum system that can be prepared in at least two distinguishable states: |A> and |B>. You have to consider in the following the coupling of the system with the experimental apparatus, described by |Eap>, with at least two different results, which will modify the original states |A> and |B>, in the form |A>|EapA> and |B>|EapB>. If you write a linear combination of the states, before and after the measurement, and ask about eigenstates of the system and eigenstates associated to the apparatus, the instrument reading state and the system state are entangled with each other, resulting in a “measurement problem”. Now the interpretation of the results is strongly dependent on the interpretation line followed by you. I do not know if my answer is fine for you, but I give some of the possible interpretations on this problem and you can apply in the case of two photons (should remember that the mass of a particle mix states of different helicities; since the photon has no rest mass, you have states with a well defined helicity). Here it goes: there are approaches

a) that involve a denial that a quantum wave function (or any other way of representing a quantum state) yields a complete description of a physical system.

b) that involve modification of the dynamics to produce a collapse of the wave function in appropriate circumstances.

c) that reject Bell’s dilemma, and hold that quantum states undergo unitary evolution at all times and that a quantum state-description is, in principle, complete.

Dear All, photons and electrons can be in two places at the same time. This is observed in self-interference and partial reflection. The requirement in both experiments is that the two places should be at multiples of wavelength distances. If this is so, entanglement have both particles witnessing each other at all times. Once the measurement is done, one particle is randomly collapsed. The other will collapse to the complementary property. But that means that those complementary properties were like that since the beginning. Thus, they cannot be left-left and right-right. They started left-right and that is entanglement. Therefore, should I still think that he initial entanglement state does not have defined features?

Thank you very much for your arguments. Those help me think!

Dear Omar

I do not get your arguments and how does your arguments fit in mine. I do not get what you mean by "photons and electrons can be in two places at the same time."

Dear Cesar, I wrote "Matter and Light in Flatland" on 2004. I used Mikio Kaku ideas of extra-dimensions. I figure a particle model which uses those ideas. In a nutshell, I am proposing that the electron and the photon are spinors built as hypertoruses. All our quantum weirdness comes from our inability to see a four dimensional object. We are constricted to observe only its intersection in a 3-D plane. Imagine that you have an object that can be in two different places at the same time. Can you explain correlation experiment results with this quality?

Dear Omar

Thanks for your explanation.