Originally posted by bbarr
Where did you get the idea that Planck's length delimits the physical domain? If anything, it merely delimits the classical or classically measurable (i.e., observable in principle) domain, but quantum effects are still physical effects.
(1) That brain processes instantiate conscious states does not entail that conscious states require brain proces l domain is not causally closed, and hence that the law of conservation of energy is false.
"Free Choice" is just mumbo-jumbo. Quantum effects aren't chosen, and they don't allow for choice.
On the contrary, the articles I've read suggest that quantum theory is unique precisely because it
does allow for free choice:
"The agent’s choice about how to act has been introduced into the scientific description at a basic level, and in a way that specifies, mathematically, how his or her choice about how to act affects the physical system being acted upon. The structure of quantum mechanics is such that, although the effect upon the observed system of the agent’s choice about how to act is mathematically specified, the manner in which this choice itself is determined is not specified. This means that, in the treatment of experimental data, the choices made by human agents must be treated as freely chosen input variables, rather than as mechanical consequences of any known laws of nature. Quantum theory thereby converts science’s conception of you from that of a mechanical automaton, whose conscious choices are mere cogs in a gigantic mechanical machine, to that of an agent whose conscious free choices affect the physically described world in a way specified by the theory."
http://www-physics.lbl.gov/~stapp/PTB6.pdf
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The free choice is posited by quantum theory, but quantum theory is prevented by the uncertainty principle from determining the
cause of the choice:
"Thus one is faced not merely with a practical unknowability of the causal origin of the “free choices,” but with an unknowability in principle that stems from the uncertainty principle itself, which lies at the base of quantum mechanics. There is thus a deep root in quantum theory for the idea that the origin of the “free choices” lies not in the physical description alone."
http://www-physics.lbl.gov/~stapp/PTB6.pdf
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Further, there
is a significant brain process which is subject to the influence of quantum effects due to its extremely small size. The trillions of links between nerve cells in the brain contain ion channels through which calcium ions pass in order cause a neighboring nerve cell to fire. The ion channel is less than a nanometer in diameter:
"The narrowness of the channel restricts the lateral spatial dimension. Consequently, the lateral velocity is forced by the quantum uncertainty principle to become large. This causes the quantum cloud of possibilities associated with the calcium ion to fan out over an increasing area as it moves away from the tiny channel to the target region where the ion will be absorbed as a whole, or not absorbed at all, on some small triggering site.
"Consequently, the quantum state of the brain has a part in which the neurotransmitter is released and a part in which the neurotransmitter is not released. This quantum splitting occurs at every one of the trillions of nerve terminals. This means that quantum state of the brain splits into vast host of classically conceived possibilities, one for each possible combination of the release-or-no-release options at each of the nerve terminals.
"This focus on the motions of calcium ions in nerve terminals is not meant to suggest that this particular effect is the only place where quantum effects enter into brain process, or that the quantum Process 1 acts locally at these sites. What is needed here is only the existence of some large quantum of effect. The focusing upon these calcium ions stems from the facts that (1) in this case the various sizes (dimensions) needed to estimate the magnitude of the quantum effects are empirically known, and (2) that the release of neurotransmitter into synaptic clefts is known to play a significant role in brain dynamics."
http://www-physics.lbl.gov/~stapp/PTB6.pdf
If the will is non-physical, and yet causally exerts itself on matter, then that means that the physical domain is not causally closed, and hence that the law of conservation of energy is false.
I don't know about that. From what I read the implication is that there is a potentially infinite amount of energy to draw upon. Whether that upsets the law of conservation of energy or not, I suppose, is debatable (by someone with way more expertise in this field than myself).
The main idea, as far as I can tell, is that classical physics is insufficient to describe the causal efficacy of mental effort. The standard way of conceptualizing what appears to be an "uncaused" act of will was to label it an "illusion". Quantum physics, as opposed to classical physics, introduces a subjectively free agent, to which can be attributed the observable effects of mental effort (heretofore only considered an illusion). "Our willful choices enter neither as redundant nor epiphenomenal effects, but rather as fundamental dynamical elements that have the causal efficacy that the objective data appear to assign to them."
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Further, quantum theory posits that at any given moment there are many possible futures, and if we were to adhere to the mathematics of the quantum wave function, we could no longer assume an objective, material universe - just potential versions of physical existence - and only one version perceived. Because only one version of material reality is ultimately perceived, the contention is that it can be mathematically proven that the conscious perceiving agent must be non-physical:
"That is, each of us must have a non-physical perceiving aspect that looks into physical reality and perceives just one of the quantum mechanical versions of physical reality. And since it is nonphysical, it is, of course, not located anywhere (such as in the brain) in physical three-dimensional space. It is this feature that distinguishes sentient beings from laboratory detectors."
https://bandura.sbs.arizona.edu/login/consciousness/pubreport.aspx?aid=2951
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At any rate, quantum theory
at least gives the immateriality and self-determination of the soul some plausibility. That's really the only reason I brought it up. Beyond the plausibility of all this, I have nothing invested in the particulars of quantum mechanics as it relates to neuroscience.
Here's what I see as plausible, which you, of course, are free to deny:
Quantum effects have influence upon brain function, on a large scale, splitting the brain's nerve cells into the trillion or so "Yes-No" possibilities defined by the mathematics of the quantum wave function, effectively allowing for a variety of possible realities. The focus of attention, or effort, being the primary vehicle for the assertion of the non-physical agent's will.
Life after Death
29 Jul '08 05:50
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