Monday, May 15, 2006
Free Will and the Quantum
I have taken the, for me, unusual step of putting my latest Sunday Times article straight on to the Selected Articles on this web site. I have done this because of the intelligent and curious responses that the piece has already inspired. I shall add these as comments to this entry as I get permission from the authors to do so. What is apparent is that the issues raised by the furthest reaches of speculative physics have a special urgency to certain types - either scientific or philosophical - of imagination. People want to know if they are free or want to be sure they are not. As I say in the article, this is the theology of our time.
Subscribe to:
Post Comments (Atom)
A blog about, among other things, imaginary ideas - What ifs? and Imagine thats. What if photographs looked nothing like what we see with our eyes? Imagine that the Berlin Wall had never come down. What if we were the punchline of an interminable joke? All contributions welcome.
Dear Bryan:
ReplyDeleteI read with much interest your columns in today's Sunday Times.
Had you been across the breakfast table I would have raised what I think is an interesting topic with the title above. I would have started with: Natural Radioactive Decay
For example, the mildly-radioactive Uranium-238 goes through a series of 13 predetermined steps of radioactive decay that culminate in Lead-206, yet the fate of each atom at each step is random, or indeterminate (i.e. whether it stays as that element, for the time being, or changes to the next in the series). The two features are not contradictory, or in conflict. It is just the way things are.
The first step, with a half-life of 4.5 billion years, is the random loss of an alpha-particle which converts that atom of U-238 into an atom of Thorium-234. The particular atom which happens to decay in a particular interval of time is entirely random, or indeterminate. Yet the outcome is absolutely predictable, in that the particular Uranium-238 atom that is affected is inescapably converted into an atom of Thorium-234.
There are then 12 subsequent steps, taking the Thorium-234 to Protoactinium-234, then to Uranium-234, then to Thorium-230, then to Radium-226, and so on down to Lead-206. The half-lives for each of these steps range from 250,000 years down to milliseconds. Each of these steps is characterised by randomness, coupled to both a particular rapidity (as reflected in the half-life) and a predetermined outcome.
Philosophically, this may have application in other fields where indeterminacy and predestination seem to contradict eachother. Perhaps there is a component of this in the mechanism of Evolution of Life on our planet?
Another elementary example would be the boiling of water in a kettle. The fate of individual molecules of water is indeterminate, in that you can't predict which will escape to the atmosphere in a particular time-interval. Yet, inevitably, if heating is continued the kettle will eventually boil dry.
I won't ramble on!
Kind regards,
Alastair
Alastair C.Wardlaw
(Scientist, retired)
Two small comments on your ST article:
ReplyDeleteThe sentence "But, in another sense, it matters a great deal. If I am persuaded of the absolute determinacy of the world, then I could decide to start behaving very oddly indeed" is completely inconsistent. If the world is deterministic I cannot "decide" anything. When you discover that free will does not exist you also discover that that discovery has no impact on your actions.
If you assume that quantum mechanics is indeterministic there is a theory that could explain Free Will as we know it. I believe was Roger Penrose that proposed a Quantum computer model of the brain. Quantum physics produces random options, and a determinisic machine (our brain) chooses one of those options. This would allow randomeness to produce choice. Of course, it needs God to play dice....
?On Freedom?
ReplyDeleteChris Nunn
?Free will?, defined as a capacity of consciousness to influence its own future evolution, follows from two intuitively acceptable ?axioms? of neuroscience:-
(a) any unique conscious state is associated with an unique neural state.
(b) consciousness is entangled with the memory process.
The first ?axiom? is entailed by any monistic world-view (i.e. any that reject Cartesian dualism). The ?unique? neural states can be thought of as possessing the same sort of identity as that belonging to a reef knot, for example; it doesn?t matter whether it?s tied in a rope or a piece of string, it?s still a reef knot if tied properly.
There?s lots of experimental evidence for ?b?. Consciousness takes around a third of a second to get going and therefore has to be part of the early stages of the memory process. Moreover its content is closely related to that of so-called ?working? memory.
The neural activity that either is, or at least is closely associated with, consciousness is thus poised at the point where the content of longer term memory is selected and edited. But what?s in memory constrains our choices and actions, and thus what we shall experience in future. So consciousness does affect its own evolution.
These circumstances, I suggest, by-pass psychologist Daniel Wegner?s argument for the illusoriness of free choice (see his book The Illusion of Conscious Will. MIT Press, 2002). He shows that the feeling of choosing is down to the output of a brain ?I did it? module. Like all conscious experience, the feeling is a latecomer on the scene and thus cannot cause the actions it claims responsibility for ? as Wegner rightly points out. However, the actuality of free choice is mediated by conscious influences on memory and has nothing directly to do with the feeling.
The freedom from (unconscious) neural determinism comes at a price, for it entails social determinism. Memories can be regarded as equivalent to stories. Most of the stories that get into our memories originate in our cultures and reach us via family example, education, the media, etc. Once in memory, they can determine our actions via the mechanisms outlined above, sometimes against our individual conscious wishes. However, the ability of consciousness to select (to some extent) what shall get remembered, and to edit and modify stored memories, still leaves a loophole for individual freedom of choice.
This picture of ?free will? involves regarding consciousness as indistinguishable for all practical purposes from neural activity of some sort. Thus one might be led to conclude that the determinism (or randomness) of the underlying physics and chemistry of nerve cells is still basically in control. But conscious choices can affect neurons via a whole range of mechanisms. Choosing to have beer, for instance, affects them; choosing to learn to dance modifies the anatomy of the brain. If consciousness can affect its own physical basis, any physical determinism must operate at so many removes as to be not very meaningful. Furthermore, one can make a speculative argument that all consciousness related goings-on can be pictured in terms of attractor dynamics. And attractors are more like natural laws than like physical causes. There may be a sense in which consciousness can influence the laws which determine its own behaviour ? a possibility that removes any lingering suspicion that physical determinism (or chance) could be all there is.
A full account of this can be found in my De la Mettrie?s Ghost; the story of decisions. Palgrave MacMillan. (2005).
River,
ReplyDeleteThere is no inconsistency. I started the sentence "If I am persuaded...." Makes all the difference
Bryan
Dear Bryan -
ReplyDeleteThe problem of freedom (free will) is still obscure and unresolved. This is mainly because no one realized that the opposite of necessity (causal determination) is not freedom but contingency. William S. Haas rightly remarks: ?? the opposite of causal necessity is not simply absence of necessity which has been erroneously identified with an ill-defined idea of freedom, but contingency. And contingency is both a positive and tangible datum in thought no less than in experience. Freedom is the true opposite of compulsion by instinct. If there be anything which survives the elimination of instinct it must be freedom. But it is not the empty idea of freedom which the West philosophy opposes to necessity, a pseudo-freedom which must be saved by such formal terms as self-determination and the like.?
No, thought I would had like to come with this, nothing of the above is mine ? it is from one of the book I refer each morning for my meditative reading; The Life and Teaching of N?ropa by Herbert V. Guenther (ISBN 0-19-501473-1 for those interested).
Pierre Misson
Note: in () mine!
Do we choose our own destiny?
ReplyDeleteThe answer to this question seems obvious. Of course we are responsible for our choices. When we make the ?right? ones we feel a sense of achievement; when we make the ?wrong? ones, we feel we have failed. However, some of our behaviour, such as yawning or blinking, is largely beyond our control. Also, we often perform many routine activities without thinking much about them at all. Moreover, our emotions seem to unwittingly affect much of our behaviour, so counselling is often more helpful than rational enquiry. Although choice does not seem to play much part in reflex or habitual actions, what about those actions that appear to be intentionally or consciously performed? All attempts at identifying some kind of ?ghost in the machine? that might be responsible for the decisions we make has lead nowhere. Nothing like a pilot at the controls has ever been found. Our brains contains more than 100 billion nerve cells, many of which communicate with one other by a network of fibres that send signals across any one of several thousand connections and they are firing and altering in response to ever-changing sense data and memory all the time ? even in our sleep. Our brains are the most complex things in the known universe, so it is hardly surprising we know so little about how we think and act.
Determinists believe there is a cause for every effect. In other words, there can be one and only one possible outcome from any set of circumstances. If we knew enough about a person?s genetic make-up, their acquired experiences and their situation, it would be possible, theoretically at least, to predict their behaviour. Until recently, such an approach has been the starting point for all scientific enquiry, not just that of the human condition. And, it has to be admitted, this belief has helped us make sense of the world. On the face of it then, this seems a reasonable starting point for attempting to understanding the workings of the human mind but there is a problem: if any thought is an inevitable consequence of its antecedents, those antecedents themselves must be a consequence of their antecedents and so on ad infinitium, leading to the uncomfortable conclusion that all our present thoughts must have been pre-programmed from the beginning of time. If this mechanistic view of the world is correct, it leaves no room for personal choice, so free will must be a delusion.
How then has determinism and traditional science been so successful in discovering laws from which predictions can be made? Actually, outside the laboratory, they are less successful and applicable only under certain conditions: when two variables are dominant, when the time scale is limited and particularly with respect to the macro. In fact, at a sub-atomic level the deterministic relationship between ?cause? and ?effect? breaks down completely and is replaced by uncertainty. As J B S Haldane said: ?the world is not only stranger than we think but probably stranger than we can think?. And the same sort of uncertainty seems to be contained within the evolution of life itself. After all, chance is the only way of explaining the diversity of life-forms that have evolved over countless generations from their humblest beginnings. In fact, the characteristics of all plants and animals deviate from their parental norms, usually only slightly but in indeterminate ways that can never be precisely predicted. Nature does not ?choose? to change over time, it does so by chance variation about its parental norms and according to its compatibility to the environment. So all patterns in nature come about by a kind of ?trial and error-elimination? process, repeated over countless generations.
And our own neural networks may have evolved in much the same ?trial and error-elimination? way, even though the time frames involved are usually measured in milliseconds rather than years. In some interesting experiments, B. Libet, (1979) et al, found that subjects were aware, only retrospectively, that their brains were preparing to act but still before they actually did so. In other words, they were not actually conscious of an intention until after it had been triggered in their brain. In practice, this allowed a very brief interval of time for their conscious minds to veto the subconscious intention, if they wanted to. If, therefore, we are at all able to consciously control our behaviour, we do so by vetoing our subconscious intentions, not by initiating them. Preparing to act is like an intended ?trial? and if vetoed, it is like an ?error-elimination?.
But this begs the question though: is this conscious ability to approve or veto a subconsciously evoked thought really an exercise of free will? Presumably, the criteria by which a thought is evoked or not, is by reference to remembered norms of behaviour and these norms must themselves have become established as unacceptable or acceptable in the memory by the same process of trial and error-elimination. Thus, the brain seams to learn from experience by modifying future expectations in the light of past experiences [R C Schank, 1999]. To approve or veto an act by reference to acquired standards of convention, habit or taste, whether spontaneously or after consideration, must inevitably be subject to personal and cultural bias, which can hardly be a judgement of free and impartial will. On the other hand, the nature of this on-going process of modification can never be rigidly determined either because past experience and future expectation are never quite the same. Since ?free will?, at least in its impartial and rational sense, remains elusive to human thought, so too does our moral right to judge anyone as ?good? or ?bad?. After all, the standards by which we make these judgements are based on the belief that people really are able to free themselves from their emotions and prejudices. Even the International Court of Human Rights probably never achieves such ideals of impartiality.
It is probably only about 10,000 years ago, when Homo sapiens began to consciously veto or approve his own subconscious thoughts, that he started exercising moral judgement over his fellow men. Previously he had no conception of morality as we know it today. Established norms of behaviour were principally maintained simply by acceptance or rejection of one another, not by labelling them as ?good? or ?bad?. Being an accepted member of a band community in Palaeolithic times increased one?s chances of survival, whereas rejection reduced them, so this control mechanism must have been a very effective way of keeping behavioural deviance in check. It was only after the birth of the city-state that this simple practice became ineffectual. Instead, order and conformity was controlled by the growth of spiritual and temporal justice systems, prescribed by state and church but the fact that these had to be accompanied by strict penal systems of compliance indicated the difficulties involved. It is probably no coincidence that at about this same time too, modelling the world along rational scientific lines began to dominate man?s consciousness and lead to the ubiquitous belief that we too are rational creatures with a free and independent will to choose between ?right? and ?wrong?.
In conclusion then, there is a fundamental divide between the two interpretations of how nature changes over time and in particular of human thought and action: either determinism inextricably links ?cause? and ?effect? or it does not. In other words, either there is only one possible outcome from every event or there are an indeterminate number of outcomes and since each excludes the other, there is no room for compatibility. On the face of it determinism and the scientific method wins hands down because they creates order out of chaos and fulfils many of our materialistic needs. If, however, the profit and loss account is measured by inner peace and harmony with our natural environment, then the deterministic model looks more like a terminal cancer. The inescapable question we are now faced with is: how soon will Gaia have its revenge?
John Faupel
Truro, Cornwall.
15th May, 2006
Choice requires the execution of a decision-making process. A deterministic universe is consistent with the existence of choice if the decision-making process is a part of the overall deterministic process. The choice made is uniquely determined prior to the occurrence of the decision-making process, but the choice made is, nevertheless, dependent upon the decision-making process taking place.
ReplyDeleteNow, introduce the distinction between epistemological concepts and ontological concepts. Epistemological concepts are concepts of what we can know or understand; ontological concepts are concepts of what actually exists or occurs. With this distinction, one can define choice as an epistemological concept. Even if the outcome of a decision-making process is uniquely determined, ontologically speaking, because we cannot know the choice prior to making it, we must execute the decision-making process.
Dear Mr. Appleyard,
ReplyDeleteLet me first declare myself a huge fan not only of your writing but also of your range ? from physics to philosophy to art and architecture. To a certain extent this reflects, in part, my own long journey from academic scientist (I quit academia in 1988) to spare-time writer on aspects of physics and philosophy.
The purpose of this note is to suggest that the determinacy-indeterminacy argument is not, in fact, about language (unless you happen to accept Wittgenstein?s arguments that all philosophical problems are merely problems of language). Indeterminacy is a fundamental building block of the Copenhagen interpretation and is tied very closely to Bohr?s original version of complementarity ? we can only ever experience the wave or particle shadows on Plato?s cave wall but we can never directly experience what causes them. The mechanism (if that?s the right word) by which chance exerts its influence in quantum physics that Einstein so abhorred is hidden beneath a veil. We can never penetrate beneath this veil because it lies beyond our ability to experience, including experiencing the results of any measurements we make.
That there are many physicists like Gerard t?Hooft who are not happy about this is well known. All attempts to resolve the discomfort of indeterminacy resort either to local hidden variables (now pretty well ruled out by Aspect-type experiments), non-local hidden variables (which Einstein always thought of as ?too cheap?), many worlds or consistent histories (which bring with them a whole new set of problems) or by somehow tying quantum physical events to the workings of human consciousness (which simply tries to resolve one philosophical conundrum by substituting another).
Given your continued interest in this subject, you might also be interested in a book of mine published a couple of years ago by Oxford University Press: Beyond Measure: Physics, Philosophy and the Meaning of Quantum Theory. This is an attempt to survey recent experimental work and provide an overview of all the different interpretations without grinding any particular axe in favour of one or another. It is not intended as a popular text, but I tucked all the maths to the back and hope to have achieved a degree of accessibility in the main text. It has attracted some flattering reviews from physicists (all the more heartening for me, as I was actually a chemist and have long ceased to be involved in academic study).
In your latest article "Loading the dice against free will" you mentioned Conway-Kochen Free Will Theorem, which I think is of paramount importance - http://www.god-does-not-play-dice.net/Kochen.html
ReplyDeleteI hesitate to comment on the way you've presented Gerard 't Hooft's "hidden variable" speculations and uncountable "dancing angels". Instead, I will offer you my understanding of CK Theorem.
There is a remnant from the elusive master/cosmological time arrow, which is being displayed as a fundamental INdecisiveness in the physical world.Mathematically, the physical world is time-symmetric [Ref. 1], hence this remnant shows up as a genuine lack of *total* predictability (please see the link above). Thus, there is indeed a "window" for Free Will, as demonstrated by CK Theorem.I've tried to elaborate on this remnant from the master/cosmological time arrow, in the context of singularity theorems and the 'finite infinity'
proposal of George Ellis, at http://www.god-does-not-play-dice.net/Senovilla.html
It all boils down to the nature of the phenomenon that carries physical interactions from one "point" to the nearest "point" with a speed that cannot exceed the speed of light in vacuum, http://www.god-does-not-play-dice.net/Weinstein.html#F2
http://www.god-does-not-play-dice.net/Weinstein.html#miracle
We cannot pinpoint this phenomenon in a time-symmetric physical world, but instead of speculating about some "hidden variables" a la Gerard 't Hooft (or uncountable blond sexy dancing angels, which is basically the same), I believe we should try to understand the implications from Kochen-Specker and Conway-Kochen Theorems.
I'm sure that you will have received quite a few 'cranky'
ReplyDeletee mails regarding your article in the ST and you might potentially regard this as just another one, but, as it may prove interesting, I do hope that you can take some time to read it. So let me cut to the chase immediately. From a general scientific perspective your article in the ST was very good and well researched, however, have you carried out any investigation on a more individualistic personal level.
The reason I am asking, and you will probably feel that this e mail is from someone who needs some sort of medical help, is that I appear, on an individual basis, to be living through a period that has a factor of pre-determinacy about it. Whether it is to the extreme that you wrote of 'absolute determinacy is potentially one of the most dangerous ideas imaginable etc etc', is open to conjecture. As a person who has always had strong views on my personal responsibility to myself and my family, I am quite perturbed by this inability on my own part to change what is happening.
As I said, you will probably evaluate this e mail as coming from a deranged person and at certain times I certainly feel so, but I know that what I am saying has a foundation of truth in it, that I believe I can substantiate.
It was a relief to read your article and as you put it 'including me writing this article and you reading it' gives me an indication that the phenomenon that I am experiencing, personally, is happening in a far wider sense, otherwise why would respected academics be investigating it.
As again you said in your article, 'it is beyond solution by the human mind', it is certainly beyond the solution and understanding of my mind. On my own behalf, I am a fairly well educated (2 degrees) and rational individual who has climbed the corporate ladder with some success. However, what I seem to have become aware of and had experience of, over the past 3 years, has certainly turned my head inside out. The prognosis in your article gave a certain sense to what has been occurring, but as I said for myself, not on a scientific or philosophical basis, but on an individually experienced basis.
I can assure you that this is not an e mail from someone, who, over the 50 years of his life, has thought hypothetically or deeply about such things. From what has happened personally and relatively recently, and from what, quite separately, I have been told, there is a lot of substance to the text in your article.
I know that you and the scientists involved are looking at this in a general, probably global sense, but when it happens on an individual basis, it is quite unsettling and this is from someone, who seriously, would have been very happy to have simply plodded on in my chosen, reasonably, unexciting path. In case you mis-interpret, there is nothing exciting whatsoever, about my life currently, but there are aspects that closely correlate with the text in your article.
One last thing that I would mention, and this seems somewhat coincidental, but I have just finished writing a management book, the manuscript is with my literary agent, and the first chapter is entitled 'Deal the cards and roll the dice' and I can assure you, prior to your article, I had never heard Luke Rhinehart's novel, The Dice Man, which I will now read.
If there is any body or organisation carrying out research into this phenomenon, I would be grateful to know of them, as I said, I was relieved to read the content of your article.