Entanglement is a solidly established fact for interacting particles in the laboratory. When we talk about entanglement in the whole universe we are straining our neck quite a bit. But, on the other hand, there is at present no reason to suppose that what we observe on a limited scale should cease to operate on a larger scale. The only problem is that it quickly becomes so complex that it far transcends our ability to describe it in detail. But again, as technique progresses we keep finding that entanglement shows up in larger and larger domains: so it is not unreasonable to think it is a general state of affairs, rather than a quirky feature of our experiments with the microworld.
Having said that, we won't really understand what entanglement means until we reach an understanding of the quantum process of observation, which I believe is the paradigm of our contact with the world in general. It is something utterly basic that has been with us for almost a century, yet there is no general consensus on how to understand it.
The quantum measurement process is not something special that only happens in the laboratory: it is the paradigm of experiencing in general. All perception can be described in the language we use to describe a quantum observation, as a von Neumann chain of interacting systems that undergo changes in a correlated way. When, say, I am watching the moon, photons from the sun bounce off the surface of the moon and strike my retina, which undergoes changes correlated with the state of the impinging photons and sends signals correlated with those changes up the optic nerve, which in turn causes some neurons to fire in a manner correlated with the signals. Eventually, somehow somewhere there is 'someone' who has an experience: ohmygod, I see the moon!
So simple. Yet we are still far from understanding this very basic process. It is important to understand in which sense we don't understand it. The naive reductionist believes that if we just understood the biology a little bit better, if we understood the software of the brain a little bit better, we would understand the experience of seeing the moon. That's a misplaced hope: it is not a matter of degrees, As it has been eloquently argued by the Australian philosopher David Chalmers, the inner experience and the physical phenomenon are things of a different nature, irreducible to each other: qualia and quanta don't mix, a color is not the same as an electromagnetic frequency, the sensation of butterflies in one's stomach is not the same as a set of hormonal reactions.
And yet, inner experiences and physical phenomena mirror each very closely. So closely as to suggest that there are not actually two things, matter and mind, but one substance, that appears as mind 'when experienced from the inside' and appears as matter 'when experienced from the outside'.
Coming back to entanglement. We won't understand entanglement until we reach an understanding of the quantum process of observation, and we won't understand the quantum process of observation until we include mind or consciousness in our description of the physical universe. The universe is one, but it has an 'inside' and an 'outside'. So far in science we have assumed that we can understand the whole of reality just looking at the outside. Quantum physics is forcing us to realize it does not work like that: it forces us to include mind or consciousness in our description of the physical universe.
That does not mean that we should make consciousness another object of study, that we should treat it as another 'outside'. It is quite a bit more subtle. We should rather understand the role of mind in the way we construct a world.
Quantum physics prompts us to see that the world we ordinarily assume, the solid world of objects surrounding us is a construct. It is a necessary construct, an inevitable one, arising within the process of experience itself.
The tricky question here is: what is real? At the most basic level there is experience. That's the rock bottom ground. Of course we never have it pure: experience always comes colored with some degree of interpretation. One level of interpretation is the notion of a solid world of objects surrounding us. Classical physics stops there. It considers the objective world the ultimate reality. Quantum physics goes farther: it introduces another level, underlying the objective world, the quantum level, the level we can call for short 'of the wavefunction'. At this level we encounter that peculiar inseparability of phenomena we call 'entanglement'.
The objective world arises from the entangled totality in the process we call quantum observation or quantum measurement. But we have already seen that this process is not something special that happens in the physics lab: it is the process of experience in general. Therefore the objective world arises in the process of experience. The crucial task is describing the process of experience in a way consistent with quantum physics.
The 'persistence of information' theorem is only the first step in seeking to describe the process of experience in a way consistent with quantum physics. It is the only step, I believe, in which we get some guidance from math. But the task of interpreting the result still needs to be tackled. Interpreting the result means understanding the role of mind or consciousness in how we construct a world.
Let's try to set some solid points in this shifty ground. First of all, consciousness emerges in the world, not looking in from the outside, but being in it, being part of it. That means consciousness has a body, it happens in a body. What a body has to be in order to be the body of an experience, in order to 'house consciousness', is an important question that we will put aside for now. Let me just stay with this fact: experience happens in a body, it is the 'inside' of some body event (of a 'trace'!).
As a consequence of that, the entangled level, the level of the wavefunction, remains hidden from the experiencing consciousness. The world necessarily appears to it as either/or, as an objective world. This is the essential implication of the 'persistence of information' theorem. But that's not the whole story: in experience the world does not just appear to consciousness as either this or that; it appears as THIS, or it appears as THAT. This or that are indifferent at the wavefunction level, the wavefunction embraces them both. But in the actual world a choice appears.
If quantum theory is correct, that choice appears out of nothing, out of the blue. That's the notion that was so repugnant to Einstein. But all the evidence so far is against Einstein and in favor of quantum physics. The wavefunction is a broad container, the container of all that is possible. But within the container there is freedom.
The hypothesis I want to explore is that consciousness exists right there where there is that margin of freedom. It appears in coincidence with the unpredictable. When 'this or that' can happen, and THIS actually happens, an atom of consciousness is present. Notice, by the way, that this is also the definition of a bit of information. The information is recorded in the trace.
Most scientists would probably shrug off this strange notion as nonsense. What? The electron going through slit one or slit two in the interference experiment corresponds to an atom of consciousness? Yes. Of course that elementary consciousness is so far from ours that we have no idea what it may be like. By contrast, the consciousness belonging to a highly evolved organism, e.g., to a human being is associated with an incomparably vaster array of traces: the highly organized system that is a human body, and particularly - but not exclusively - a human brain and nervous system.
While this notion does not fit with the prevailing materialistic notion of the relation between matter and consciousness, it doesn't fit with the prevailing spiritualistic notions either. These view consciousness as existing independently of matter. A metaphor which is frequently used to describe the relationship between consciousness and matter from the spiritualistic point of view is that of the radio waves and the radio receiver. The body (or the brain) is like a receiver through which consciousness manifests in a specific way, but consciousness exists independently of the receiver, just like the radio waves exist independently of the radio set.
The notion I am proposing assumes a much closer relationship between consciousness and its embodiment, between mind and matter. It does not assume that consciousness can exist separately from material form. On the other hand, it does not assume that matter exists independently of consciousness either. The quantum wavefunction does not describe matter in any ordinary sense of the word: it is only a reservoir of potential events. We can speak of an actual event (and therefore of matter) only in a trace-forming interaction. But that is also when we can speak of consciousness.
Wavefunction: coded info about a certain source preparation procedure, a certain reproducible initial circumstance
Trace forming interaction: coded info about a 'measuring apparatus', an outcome checking device (let's assume a yes/no outcome, 0/1)
When we have these two, we have a series of events, 001011101...
In each event a 'fact' is born together with its trace
The fact is an atom of world
The trace is the outer manifestation of an atom of consciousness (of an experience)
The world is the collection of all facts
Consciousness is the collection of all experiences
A fact is (generally) unpredictable: it is a manifestation of the creative nature of reality
The statistics of series of events conforms to the laws of quamtum physics (the creativity of reality operates within the boundaries of quantum physics)
The coherence of all experiences is guaranteed by the trace requirement (Wigner's friend's argument)
Facts and traces can form complex organic systems (you and I are examples)
Some such systems include self-referential symbols (you and I are examples)
Although consciousness is one, a complex organic system (particularly one that includes a self-referential symbol) may have a sense of existing as an autonomous entity (you and I are examples)
I identify a specific portion of the world as my own body and sense the creativity manifesting in unpredictable facts connected with my body as my own free choice