I hit send before pasting this in:
Before I continue onwards, I should make clear what I mean by contextual and noncontextual. Contextual means that reality assigned to a quantum system is only found through a measurement, "within the context of the eigenbasis established by the observer." Hidden variable theories often claim there is some reality which exists independent of this contextuality, and are often referred to as hidden variable theories with some reality that is noncontexual. What I mean by noncontextuality of QM is that there is no such reality that can be assigned in a noncontextual basis, or at least no reality as understood in a classical setting.
The contextuality of QM is what we observe through experiments, which may involve incommensurate and commensurate sets of detections. In other words the context of the apparatus (whether we measure momentum or position) or the orientation of a Stern-Gerlach apparatus is what determines the outcome, and a succession or ensemble of such measurements will demonstrate nonlocal properties and the incommensurability of measurements between conjugate observables. So the interpretation of quantum mechanics can only be inferred through the types of measurements we perform. These measurements are in the Copenhagen interpretation performed by perfectly classical systems and the outcomes determined by an infinite number of observations. This is an idealization. A perfectly macroscopic or classical system has an infinite mass, and a finite mass has some quantum wave spreading. The CI means context is made within a classical setting, where the world has a duality between quantum and classical physics. In the Many World Interpretation the contextual aspect of QM involves the basis of state vectors the world splits off into. The MWI entangles pointer states to a wave function super-position and the various pointer states that are observed correspond to a particular world-path. Decoherence indicates that wave function reduction is due to such entanglements which become spread into a vast reservoir of states, and the direct observation is a coarse grained result.
In all of these interpretations there is a ways that the context of the measurement produces its outcome: classical-quantum dichotomy, many world eigen-vectors splitting off, entanglement phase or pointer states that grows irreversibly in a coarse graining and so forth. With all of these there is a bit of "fuzz" that is introduced, where this fuzz is something imposed = the "machinery" behind the context. Quantum physics in its pure setting has no such context, and no reality hidden beneath any context = noncontextual quantum waves. The funny issue comes in if we do consider the world as fully quantum mechanical on all scales. The context from which quantum observables are detected must originate then from something which is ultimately noncontextual, and that "something" has no local reality.
The ordering of a Hilbert space is permitted by the AC, and any such ordering in a commutative basis of commensurate observables is what gives the context. However, if reality is quantum mechanical "all the way," then how do we get contextuality from nonlocal noncontextual waves that have no local or classical reality? This noncontextuality means there is nothing which orders eigen-vectors in the Hilbert space. So we may think of QM in this setting as having not-AC. As such we might have ultimately a duality which involves set theory and undecidable propositions underlying quantum mechanics.
I don't worry too much about the moon not being there if I am not looking at it. For one thing the separable states (eg thermal states) of photons from the sun interact with the moon and remove what little bit of coherent phase it might have. So this is a sort of Zeno measurement process where the wave function of the moon is constantly jolted away from being in any quantum superposition of position. So I am sure this holds for the entire macroscopic world. So I sure that 120 million years ago the photons reflecting off the moon formed an image in the retina of an Allosaurus, without any conscious awareness of what was being observed --- I doubt dinosaurs had any sense of the moon outside of being a "light."
Cheers LC