MEMoirist said:
If the universe itself is a sentient creature, then there is an observer to everything. We are the universe observing itself
Now that's a "way out there" idea. But, honestly, it's not that far away from considering the Universe as a giant quantum computer running the program we call "reality".
The experimental evidence is clear, but not logical. On a quantum scale, until something is observed, it is a probability distribution. It simply does not exist in the definite sense of either being there or not being there. The experimental evidence for this is irrefutable. But on the macro scale, we see no evidence of reality being a probability distribution. The most careful measurements of classical reality, such as GR, show no probability distributions at all on the macro scale. Therefore, there must be a transition from quantum to classical reality at some small scale, call it decoherence or whatever you like, and that transition must be governed by definable physical laws.
Experiments seem to indicate that decoherence is a continuous process rather than a discrete one as one might expect. Something along the lines of quantum states becoming entangled with the classical states of the surrounding environment, essentially drawing the quantum reality into classical reality particle by particle.
Another equally valid way to look at this is the pure quantum states have very low entropy (high information content) and as the decoherence occurs, information is lost to the environment like mixing a few drops of yellow paint into a bucket of blue paint. The problem with this analogy is that even though the bucket of blue paint might seem just as blue to the eye, sophisticated measurements could detect the the slight difference in absorption of different wavelengths of light caused by the addition of just a few drops of yellow to a bucket of blue. Measurements of classical macro objects do not show just a slight probabilistic nature, they show none at all. As someone said, it's either a mixture of states, or it's not. Almost being a mixture isn't an explanation.
But this way of looking at it, with classical reality being of very high entropy and quantum states being of very low entropy and decoherence being the process of information transfer from quantum to classical reality is at least an approach that is subject experiential investigation. Of course, being part of the macro world, any time we observe a quantum object, we must logically be transferring information from the quantum to classical environments, therefore requiring decoherence. This gives the silly impression that a photon knows if we are observing it or not. This thermodynamic interpretation would simply say that that by observing the photon and gathering information about it, or from it, we are forcing decoherence as defined by an information transfer from the quantum states to the classical environment. If that is the case, the special position of the conscious observer can be removed from the process and the Copernican principle remains intact.
Does this answer all our questions? I believe so. If a tree falls in the woods, and no one observes it, does it make a sound? Yes, because the tree and surrounding air are already classical macro objects and behave as such. Does the moon exist if we aren't looking at it? Yes, by the same logic. Does the observation of a distant star by a bug in Copenhagen instantly collapse the waveform of every particle in that star? No, because the bug passes away peacefully in it's sleep one night, never having transferred any information to the environment. But if a human makes the same observation, does the waveform collapse?
If the human acts as a transfer function to transfer information from a quantum reality, say a photon emitted by an excited hydrogen atom, to a classical environment, say a star chart. Then by this definition, yes, at least some decoherence is forced by the information transfer. That decoherence may represent a very tiny percent of the total mass of the star, as someone noted earlier, but the math says some tiny amount of decoherence must occur nonetheless.
I believe this thermodynamic interpretation is the only one that is logically consistent and passes the test of reasonableness. You can look at it as though the human consciousness possesses some special power to crystallize quantum probabilities into classical reality if you like. That math works fine, but the concept leads away from the truth as we know it that we really aren't that special in the Universe. You can look at the many worlds interpretation, and believe that every time a leaf falls from a tree face up or face down, the entire universe splits into two separate and complete universes, one with the leaf up and one with the leaf down. The math works just as well, but the concept is silly.
As far as dedoherence appearing to be a continious process, rather than a discrete one, if the smallest amount of information that can be transferred is smaller than our ability to measure it (I leave definition up to the reader, but a very small bit), the transition may appear to be continious to the best of our measurement ability, when in fact it is a discrete process.
I propose we accept the thermodynamic interpretation of QM as the only interpretation that is logically consistent and subject to scientific investigation, and proceed with that investigation with all due haste. This is of course just my opinion. Others may have reasonable differences, and I'd be happy to hear from them.
