Wednesday, May 31, 2006

Free Will: All the Way Down

I really enjoyed this paper: The Free Will Theorem, by Princeton Mathematics Dept. luminaries John H. Conway and Simon B. Kochen (HT: Clark’s sidebar, which linked to this Garden post, which linked in turn to this Times article).

Using axioms which implement an idealized EPR-style quantum spin measurement experiment (and assuming relativity), the authors set out to prove that:

If the choice of directions in which to perform spin 1 experiments is not a function of the information accessible to the experimenters, then the responses of the particles are equally not functions of the information accessible to them.

They call this the Free Will theorem since we in practice assume experimenters are free to set up the experiment the way they wish. So, the authors are not proving free will exists, they are proving that if free will exists at the human level, then the outcome exhibited by elementary particles will also be free.

The proof seems fairly straightforward once one accepts the earlier Kochen-Specker theorem (it can’t be said that the spin values for each direction already exist prior to measurement).

Following the presentation of the proof, the authors show (by discussing a way to modify Bohm’s theory) that QM is logically consistent if one assumes the assumption of particles expressing free will in a relativistic framework. Next, they relax some of the idealized assumptions to establish the robustness of the result in a more real world context.

The next section discusses how this result furthers the process (earlier marked by the K-S theorem and Bell's Theorem) of making hidden variable theories unworkable. They also argue it is an obstacle for GRW-type collapse models.

Further tidbits:

The authors argue that it is incorrect to interpret EPR-style experiments as meaning there is faster-than-light communication between particles; the particles are entangled as a collective system, but one will not confirm the predicted correlation until the future measurement of the other member of the pair. This is congruent with the perspective of Smerlak and Rovelli’s recent paper which interprets EPR from the perspective of relational quantum mechanics (RQM).

In terms of interpreting quantum mechanics: the authors argue quantum states (between measurements) are merely predictors (with probabilities) of what will happen if various measurements are performed. It is a mistake to ascribe concrete reality to the quantum states. This again is consistent with RQM’s perspective that it is the measurement events which are concretely real. The authors also state briefly that they don’t believe a conscious human mind is needed for collapse, but they don’t discuss in detail what they think is necessary. They think a future physics will explain what sort of “texture” surrounding a system will cause collapse.

The authors offer some philosophical remarks on free will. First, they remind the reader that they don’t claim to prove free will. They say “determinism, like solipsism, is logically possible.” They themselves do subscribe, however, to what a philosopher would call a naïve folk conception of libertarian free will. They don’t see how science could be taken seriously if its practitioners weren’t free to investigate nature by choosing what experiments to perform.

In any case, the linking of free will at the human level to free or spontaneous outcomes at the level of elementary quantum systems is an important result. It is also an especially appealing idea to a panexperientialist like me. While I appreciate the substantial problems which afflict the folk conception of free will, the results of this paper fit with my view that the conscious experience, intentionality, and (at least limited) free agency of human beings are all sourced from fundamental and ubiquitous properties of the natural world.

I also want to comment on a section toward the end entitled “Free versus Random?” It is extremely common to interpret QM as meaning the universe contains a fundamental indeterminism, but it is unusual to say it implies the existence of a fundamental freedom. Here’s a point the authors make in favor of the latter:

“Although we find ourselves unable to give an operational definition of either “free” or “random,” we have managed to distinguish between them in our context, because free behavior can be twinned, while random behavior cannot (a remark that might also interest some philosophers of free will).”

“Twinned” here refers to the entanglement of two particles. The measurement of the first of the twinned pair enables us to predict the outcome of the measurement of the second, so they aren’t individually random events. But I’m not sure this is a good argument: are we conflating the idea of a particle’s randomness with its independence? I’ll have to give this more thought.

I’m very interested in arguments which support my contention that the worldview implied by QM is richer and much more interesting than just classical physics plus an overlay of randomness. It isn’t just that the measurement outcome is random vs. determined. The quantum measurement event has intrinsically more to it than a classical billiard-ball notion of a causal event. It is an interaction between two systems where one system’s propensity toward an outcome is actualized by the second (measuring) system. I believe this actualization event or process carries with it the raw material of agency (as well as experience).

Tuesday, May 23, 2006

The Intelligent Cell

A couple of correspondents have pointed me toward the work of Guenter Albrecht-Buehler, whose research and ideas are summarized on a website entitled Cell Intelligence.

The website is organized in a table of contents. In approaching it, one finds some radical claims in the first section, and I was at first put off by this. On second look, I found it useful to proceed a bit backwards in assessing the information on the site, much of which I found intriguing.

Section 3 of the contents includes what would seem to be an important research finding, where he shows that cells (“3T3” cells, which I gather are from a mouse embryo) detect and react to microscopic infra-red light sources at a distance. References on the site show that these experiments (as well as other Albrecht-Bueller results) have been published in mainstream journals. I do not know whether other researchers have replicated them.

It is interesting to think about how a cell might utilize light alongside its use of chemical-mechanical processes. There is a section discussing a proposal that a structure called the centriole detects the light, and one discussing microtubules as possibly the transmission mechanism for relaying this signal within the cell (of course, this triggered a memory of the role microtubles played in the Penrose Hameroff quantum brain proposal!).

Crucial to Albrecht-Buehler’s overall thesis is that the cells themselves are light sources: he thinks they scatter ambient radiation in a patterned way, with this radiation then utilized as a signal input by its neighbors (including at some distance). He shows some research which seems to indicate this scattered light is used in organizing “social” behavior among a group of cells.

This idea ties back into section 2 of the site, where intriguing behavioral properties of cells are discussed. Albrecht-Beuhler says that the data indicate that signals, rather than mechanisms, are being utilized in individual and group behaviors, and that the cell must be processing information in order to manifest such behaviors.

This is the basis for asserting that cells are worthy of being considered intelligent in the way characterized in the opening summary and in section 1, which now make more sense.

So, is there signal processing going on in cells? Do cells control and direct their processes in a top-down way, rather than being built strictly from bottom-up chemical processes? Do they utilize electro-magnetic signals specifically? I’m in a poor position to judge all this (knowing even less about biology than about other topics I blog here about). But I’m intrigued, and will keep these proposals in mind as I read more going forward.

Tuesday, May 16, 2006

The Coherent Organism

Following suggestions from Mike Wiest in his comment on this post, I’ve been reading more on efforts to invoke quantum physics in explaining life. Below are my thoughts following my reading of Mae-Wan Ho’s The Rainbow and The Worm: The Physics of Organisms.

This is an engaging and thought-provoking book, extremely dense with information and ideas running from accepted science through increasingly speculative extrapolations and concluding with some free-form philosophizing. This book was published in 1993, with the second edition I read coming in 1998. Ho, who was trained as a biochemist, has since been involved in leading an organization called the Institute of Science in Society, and her more recent writings tend toward public policy.

The early sections of Ho’s book discuss life in thermodynamic terms. I was broadly familiar with the idea that life utilizes energy flow to build and maintain high levels of structural organization far from equilibrium. In several steps, and citing work of other scientists, she builds a case that explaining life in detail strains the traditional thermodynamic picture (which assumes microscopic homogeneity). She says intricately organized living things utilize molecular systems which transfer energy without thermalization (zero entropy growth). Energy is stored and used at the electronic level, not the thermal level. But how can these micro-level energy exchanges operate across the macroscopic dimensions of the organism? Ho says stored energy can amplify weak signals across larger distances.

Throughout these early chapters, Ho uses the word “coherent” to describe the (non-thermal) energy storage and transfer within the organism (she says stored energy is by definition coherent energy). She will come back to this idea later in the book and explicitly argue that it must involve quantum coherence specifically.

The energy we’re talking about is electromagnetic. We know electrons move quickly and in organized fashion through crystals and super-cooled materials (superconductors). Could something like that be happening in the organism (despite the high temperature)? Ho uses the example of a solid state laser where energy flow induces a quantum phase transition which can take place very rapidly. She sketches how this might occur in living tissue and discusses the idea that cells could be solid state systems.

In a later chapter Ho leaves aside the solid state system model of the organism in favor of specifically identifying it as a liquid crystal system. She became convinced of this in part by examining fruit fly larva under a polarizing microscope. The title of the book comes from the colorful organized patterns she detected. She believes the type of organization seen is evidence that organisms are essentially liquid crystals.

What other evidence is there that organisms are coherent systems? A piece of possible evidence is in the analysis of the electro-magnetic fields emitted by organisms. It seems well supported that organisms do generate weak electromagnetic fields, and are in turn sensitive to external fields. Ho cites the work of Fritz Popp and colleagues who have analyzed the emission of light (“bio-photons”) from organisms such as fruit fly embryos. (A list of Popp’s publications can be found here). The pattern of photons issued in response to stimulus is said to be consistent with non-classical coherence. This may lend some credence to the idea that a coherent field may be providing organization to the organism.

Ho has a chapter toward the end of the book on quantum physics. She summarizes the familiar phenomena of quantum entanglement and coherence (2 slit experiment, EPR, etc.). Then she tries to convey why the ideas and arguments of the preceding chapters lead her to conclude it is indeed quantum coherence (superposition of states, non-local entanglement) which prevails in the organism. But has she made the case? In a key passage she says:

“I have been presenting heuristic arguments throughout many of the preceding Chapters on why the wholeness of organisms has to be understood as quantum coherence.”

This is followed by a brief summary of some of the earlier ideas; then:

“By far the most persuasive argument for quantum coherence, to my mind, is the nature of the coordination that is achieved in the organism, where every single part…is able to work autonomously while keeping in step and in tune with the whole.”

I think she is conceding that her case, which is admirably detailed and suggestive, is ultimately circumstantial. Now, criminals are convicted every day by circumstantial evidence, so I don’t mean to be dismissive here. But for the mainstream scientific community to get on board, we’ll need more.
As Paul Davies said, we need a secure experimental result which demonstrates a biological system clearly exploiting non-trivial quantum effects.

One area I do want to follow up on is this idea of an organism or cell as a liquid crystal. Saying something is a liquid crystal is not the same as saying it is coherent in the quantum sense. But liquid crystals and other phenomena of condensed matter physics demonstrate intriguing properties. And the scales at which these occur is small enough require quantum as well as classical theoretical tools to investigate. The emergent features found in some of these systems (some discussed in Robert Laughlin’s A Different Universe, which I discussed in this post) are mysterious in their own right, and if biological systems do exhibit characteristics of some of these, that would be very interesting to investigate.

Tuesday, May 02, 2006

Saving Reduction

Reductive explanations are at the heart of effective scientific investigation. And yet in the past I’ve argued that in the case of first-person experience (FPE), a normal approach to physical reduction will fail. A reduction of experience to wholly non-experiential parts will eliminate what we seek to explain. Equivalently, the ontological emergence of FPE from wholly non-experiential parts is incoherent. This argument was at the heart of the Galen Strawson paper linked to in the last post.

Now emergence and reduction are difficult topics. But it appears to me that attempts to give an account of genuine ontological emergence for any phenomenon must fail, given an assumption of physicalism.

This case is argued by William Seager in a recent paper appearing in the JCS (full text unfortunately not online). Seager argues that candidates for emergence, assuming a normal physicalist worldview, are really only epistemological or explanatory forms of emergence. For a contrasting view which defends a notion of “weak” ontological emergence consistent with physicalism, see this paper by Jessica Wilson in the new online philosophy conference. On my first read, my impression is that Wilson’s approach (which invokes reduced degrees of freedom as a way to define emergent structures) is of limited metaphysical help in terms of my interest in this topic (note she is not taking on the case of consciousness per se in this paper).

The problem is you can’t seem to get something ontologically brand-new in the macroscopic realm from mereological combinations of classical physical objects.

But what if we could reduce things to elementary entities which had a richer ontology? Could we then “save” reduction as an explanatory method for consciousness (and perhaps other difficult-to-explain phenomena)?

I’m going to cut this post short, because I know I’m repeating myself. I think the answer is yes, if we adopt an event ontology in which the fundamental entity is an actualization of a possibility. Science has already discovered these fundamental events in the form of quantum measurements. A network of such events offers a framework upon which the rich phenomena of the world, including conscious individuals, can be composed.