Jun 11, 2020 08:35 PM
(This post was last modified: Jun 11, 2020 08:56 PM by C C.)
https://aeon.co/essays/heres-why-so-many...-free-will
EXCERPTS (George Ellis): The French mathematician Pierre-Simon Laplace (1749-1827) believed that the Universe was a piece of machinery, and that physics determines everything. Napoleon, who had read up on Laplace’s work, confronted him about the conspicuous absence of a creator in his theory. ‘I had no need of that hypothesis,’ came the reply. Laplace might have said the same thing about free will, which his mechanistic universe rendered superfluous.
Since Laplace’s day, scientists, philosophers and even neuroscientists have followed his lead in denying the possibility of free will. This reflects a widespread belief among theoretical physicists that if you know the initial values of the variables that characterise a physical system, together with the equations that explain how these variables change over time, then you can calculate the state of the system at all later times. For example, if you know the positions and velocities of all the particles that make up a gas in a container, you can determine the positions and velocities of all those particles at all later times. This means that there should be no freedom for any deviation from this physically determined trajectory.
[...] At very small scales, quantum theory underlies what’s happening in the world. Heisenberg’s uncertainty principle introduces an unavoidable fuzziness and an irreducible uncertainty in quantum outcomes. You might know the value of one variable, such as a particle’s momentum, but that means you can’t accurately detect another, such as its position. This seems to fundamentally undermine the allegedly iron-clad link between initial data and physical results.
[...] One of the most astounding discoveries of the previous century was that biological activity at the micro level is literally grounded in the physical shape of biological molecules [...] This means that, to link physics and biology, we need to look at the theory that underlies molecular shape. And that theory is quantum chemistry, based in the fundamental equation of quantum physics: the Schrödinger equation. In quantum theory, the state of a system is described by what’s known as its wave function, which determines the probabilities of different outcomes when events take place. The Schrödinger equation governs how the wave function changes with time. ... I will take for granted the validity of the Schrödinger equation, which is one of the best-tested equations in physics. To link this to the functioning of life, we need to apply the Schrödinger equation to the wave function of the relevant molecules – in this case, proteins – so as to determine how their shape will change with time.
[...] The confounding thing for free-will skeptics is that all outcomes don’t depend only on the equations and the initial data. They also depend on constraints. ... when constraints vary, outcomes are not determined by initial conditions; they depend on the way that the constraints change with time.
In the case of the biomolecules that underlie the existence of life, it’s the shape of the molecule that acts as a constraint on what happens. These molecules are quite flexible, bending around joints rather like hinges. The distances between the atomic nuclei in the molecules determine what bending is possible. Any particular such molecular ‘conformation’ (a specific state of folding) constrains the motions of ions and electrons at the underlying physical level. This can happen in a time-dependent fashion, according to biological needs. In this way, biology can reach down to shape physical outcomes. It changes constraints in the applicable Schrödinger equation.
[...] Ion channels are proteins imbedded in the cell wall, controlling the flow of ions in and out of the cell. They can be open or closed, depending on the position of their hinged parts. They thereby either allow movement of ions into or out of the cell (depending on their type), or prevent it. This gating plays a crucial role in brain functioning. ... It is these changes of molecular shape, rather than initial conditions, that determine which specific solutions of the molecular Schrödinger equation will occur in your brain when you’re thinking. They underlie the possibility of thought.
So what determines which messages are conveyed to your synapses by signalling molecules? They are signals determined by thinking processes that can’t be described at any lower level because they involve concepts, cognition and emotions in an essential way. Psychological experiences drive what happens. Your thoughts and feelings reach ‘down’ to shape lower-level processes in the brain by altering the constraints on ion and electron flows in a way that changes with time.
For example, suppose you’re walking down the street, and just in front of you a terrible accident happens – smashed-up cars, people injured, blood everywhere. You react with horror: sympathy for those who’ve been hurt, fear that they will die, a guilty sense of relief that it didn’t happen to you. These are all mental events that take place because of the way your brain functions at the psychological level, based on some combination of past experience and innate responses. None of those qualities – sympathy, fear, guilt – occur at the ion or synapse level. These high-level mental operations act down to alter the shape of ion channels, and so change the motions of billions of ions and electrons in your brain. In an intricate causal dance between levels in your brain, those thoughts are able to occur because of the underlying spike chains, but it’s their essentially psychological nature – what it means to recognise an accident, which thoughts flow through your mind as you decide what to do, what it feels like to experience the shock of seeing the event – that causes what happens. Physics enabled what took place in your head and body, but didn’t determine it; your mental interpretation of the event did.
Learning and memory offer another example of how downward causal effect shapes the underlying physics. [...] What these instances show is that psychological understandings reach down to shape the motions of ions and electrons by altering constraints at the physics-level over time. That is, mental states change the shape of proteins because the brain has real logical powers. This downward causation trumps the power of initial conditions. Logical implications determine the outcomes at the macro level in our thoughts, and at the micro level in terms of flows of electrons and ions.
[...] Free-will skeptics ignore the kind of time-dependent constraints that I discuss here, which enable downwards causation in biology in general and brain function in particular. Of course, nothing about molecular biology contradicts the physics that underlies all material existence. Rather, it provides an extraordinarily complex context where things work out according to that context. Even though our brains are indeed made up of fundamental particles, high-level function emerges through the interaction of upward and downward causal processes.
But still a nagging thought occurs: if the initial data were known for the entire Universe, then why can’t it determine all these lower-level dynamics in a mechanistic way? After all, aren’t they just smallscale details in this larger picture, where one can claim that no constraints occur? The Universe is by definition all that there is, so it can’t be constrained by effects from a larger environment. Might physics not be deterministic in that case, and my argument fall apart?
The response is twofold. First, there’s a major element of randomness in what happens both in cosmology at large scales and in molecular biology at small scales. At the large scales, in cosmology we have difficulty in getting the details of what happens right, even at galactic scales; we work only with statistical likelihoods. There are significant unsolved problems, such as how dark matter clumps around galaxies at scales hugely greater than that of the solar system. We can’t realistically determine from studies based in the initial conditions in cosmology what happens at smaller scales such as that of the Sun or Earth. There’s no hope whatsoever of predicting details down to the scale of the human body.
However, skeptics still say that it’s just a matter of lacking enough data and computing power. In principle, it could work. But actually, it won’t, because of what happens at the microscale. At molecular scales, the processes at work forget initial data due to billions on billions of collisions between molecules every second. Biology thrives on that disorder – a ‘molecular storm’, as Peter Hoffman calls it in his book Life’s Ratchet (2012). Molecular machines do work, such as kinesin moving cargos from one place to another in the cell, extracting order out of the chaos. Far from physics having the determinate nature envisaged by Laplace, all the molecules’ argy-bargy every microsecond means that the details of their initial state of motion are irretrievably lost. It’s this molecular-level chaotic motion that prevents micro-determinism in practice.
But how can order emerge out of this chaos? As explained by Denis Noble and Raymond Noble in their paper for the journal Chaos in 2018, molecular randomness gives cellular mechanisms the option of choosing the outcomes they want, and discarding those they don’t. This power of choice enables physiological systems such as the heart and brain to function in a way that isn’t enslaved by the lower-level interactions, but rather choosing the outcomes of the preferred interactions from a multitude of options. In this way, a layer of order can emerge from the disorder – and micro data – at the lower level. This isn’t conclusive proof that free will exists, but at least it opens up a way for it to exist.
For the sake of argument, let’s suppose I’m wrong. Let’s ignore all these issues and take the deterministic view seriously. It implies that the words of every book ever written – the Encyclopaedia Britannica, Das Kapital, the Harry Potter series – were encoded into the initial state of the Universe, whatever that was. No logical thinking by a human played a causal role in the specific words of these books: they were determined by physics alone.
It’s unclear how any words could have been encoded into the Universe, which led to apparently random fluctuations at the time when matter and radiation decoupled from each other. How would they have been represented in those fluctuations? It’s virtually impossible that they could have affected the detailed brain-state of the authors when they wrote their books. The issue of quantum uncertainty adds another layer of implausibility to these claims.
[...] Physics has made huge strides since the days of Laplace; indeed, it would be completely unrecognisable to him. Yet there are still physicists today who confidently proclaim that we can’t have free will because physics determines everything, including brain functioning – entirely ignoring the complex context and the power of constraints... (MORE - details)
EXCERPTS (George Ellis): The French mathematician Pierre-Simon Laplace (1749-1827) believed that the Universe was a piece of machinery, and that physics determines everything. Napoleon, who had read up on Laplace’s work, confronted him about the conspicuous absence of a creator in his theory. ‘I had no need of that hypothesis,’ came the reply. Laplace might have said the same thing about free will, which his mechanistic universe rendered superfluous.
Since Laplace’s day, scientists, philosophers and even neuroscientists have followed his lead in denying the possibility of free will. This reflects a widespread belief among theoretical physicists that if you know the initial values of the variables that characterise a physical system, together with the equations that explain how these variables change over time, then you can calculate the state of the system at all later times. For example, if you know the positions and velocities of all the particles that make up a gas in a container, you can determine the positions and velocities of all those particles at all later times. This means that there should be no freedom for any deviation from this physically determined trajectory.
[...] At very small scales, quantum theory underlies what’s happening in the world. Heisenberg’s uncertainty principle introduces an unavoidable fuzziness and an irreducible uncertainty in quantum outcomes. You might know the value of one variable, such as a particle’s momentum, but that means you can’t accurately detect another, such as its position. This seems to fundamentally undermine the allegedly iron-clad link between initial data and physical results.
[...] One of the most astounding discoveries of the previous century was that biological activity at the micro level is literally grounded in the physical shape of biological molecules [...] This means that, to link physics and biology, we need to look at the theory that underlies molecular shape. And that theory is quantum chemistry, based in the fundamental equation of quantum physics: the Schrödinger equation. In quantum theory, the state of a system is described by what’s known as its wave function, which determines the probabilities of different outcomes when events take place. The Schrödinger equation governs how the wave function changes with time. ... I will take for granted the validity of the Schrödinger equation, which is one of the best-tested equations in physics. To link this to the functioning of life, we need to apply the Schrödinger equation to the wave function of the relevant molecules – in this case, proteins – so as to determine how their shape will change with time.
[...] The confounding thing for free-will skeptics is that all outcomes don’t depend only on the equations and the initial data. They also depend on constraints. ... when constraints vary, outcomes are not determined by initial conditions; they depend on the way that the constraints change with time.
In the case of the biomolecules that underlie the existence of life, it’s the shape of the molecule that acts as a constraint on what happens. These molecules are quite flexible, bending around joints rather like hinges. The distances between the atomic nuclei in the molecules determine what bending is possible. Any particular such molecular ‘conformation’ (a specific state of folding) constrains the motions of ions and electrons at the underlying physical level. This can happen in a time-dependent fashion, according to biological needs. In this way, biology can reach down to shape physical outcomes. It changes constraints in the applicable Schrödinger equation.
[...] Ion channels are proteins imbedded in the cell wall, controlling the flow of ions in and out of the cell. They can be open or closed, depending on the position of their hinged parts. They thereby either allow movement of ions into or out of the cell (depending on their type), or prevent it. This gating plays a crucial role in brain functioning. ... It is these changes of molecular shape, rather than initial conditions, that determine which specific solutions of the molecular Schrödinger equation will occur in your brain when you’re thinking. They underlie the possibility of thought.
So what determines which messages are conveyed to your synapses by signalling molecules? They are signals determined by thinking processes that can’t be described at any lower level because they involve concepts, cognition and emotions in an essential way. Psychological experiences drive what happens. Your thoughts and feelings reach ‘down’ to shape lower-level processes in the brain by altering the constraints on ion and electron flows in a way that changes with time.
For example, suppose you’re walking down the street, and just in front of you a terrible accident happens – smashed-up cars, people injured, blood everywhere. You react with horror: sympathy for those who’ve been hurt, fear that they will die, a guilty sense of relief that it didn’t happen to you. These are all mental events that take place because of the way your brain functions at the psychological level, based on some combination of past experience and innate responses. None of those qualities – sympathy, fear, guilt – occur at the ion or synapse level. These high-level mental operations act down to alter the shape of ion channels, and so change the motions of billions of ions and electrons in your brain. In an intricate causal dance between levels in your brain, those thoughts are able to occur because of the underlying spike chains, but it’s their essentially psychological nature – what it means to recognise an accident, which thoughts flow through your mind as you decide what to do, what it feels like to experience the shock of seeing the event – that causes what happens. Physics enabled what took place in your head and body, but didn’t determine it; your mental interpretation of the event did.
Learning and memory offer another example of how downward causal effect shapes the underlying physics. [...] What these instances show is that psychological understandings reach down to shape the motions of ions and electrons by altering constraints at the physics-level over time. That is, mental states change the shape of proteins because the brain has real logical powers. This downward causation trumps the power of initial conditions. Logical implications determine the outcomes at the macro level in our thoughts, and at the micro level in terms of flows of electrons and ions.
[...] Free-will skeptics ignore the kind of time-dependent constraints that I discuss here, which enable downwards causation in biology in general and brain function in particular. Of course, nothing about molecular biology contradicts the physics that underlies all material existence. Rather, it provides an extraordinarily complex context where things work out according to that context. Even though our brains are indeed made up of fundamental particles, high-level function emerges through the interaction of upward and downward causal processes.
But still a nagging thought occurs: if the initial data were known for the entire Universe, then why can’t it determine all these lower-level dynamics in a mechanistic way? After all, aren’t they just smallscale details in this larger picture, where one can claim that no constraints occur? The Universe is by definition all that there is, so it can’t be constrained by effects from a larger environment. Might physics not be deterministic in that case, and my argument fall apart?
The response is twofold. First, there’s a major element of randomness in what happens both in cosmology at large scales and in molecular biology at small scales. At the large scales, in cosmology we have difficulty in getting the details of what happens right, even at galactic scales; we work only with statistical likelihoods. There are significant unsolved problems, such as how dark matter clumps around galaxies at scales hugely greater than that of the solar system. We can’t realistically determine from studies based in the initial conditions in cosmology what happens at smaller scales such as that of the Sun or Earth. There’s no hope whatsoever of predicting details down to the scale of the human body.
However, skeptics still say that it’s just a matter of lacking enough data and computing power. In principle, it could work. But actually, it won’t, because of what happens at the microscale. At molecular scales, the processes at work forget initial data due to billions on billions of collisions between molecules every second. Biology thrives on that disorder – a ‘molecular storm’, as Peter Hoffman calls it in his book Life’s Ratchet (2012). Molecular machines do work, such as kinesin moving cargos from one place to another in the cell, extracting order out of the chaos. Far from physics having the determinate nature envisaged by Laplace, all the molecules’ argy-bargy every microsecond means that the details of their initial state of motion are irretrievably lost. It’s this molecular-level chaotic motion that prevents micro-determinism in practice.
But how can order emerge out of this chaos? As explained by Denis Noble and Raymond Noble in their paper for the journal Chaos in 2018, molecular randomness gives cellular mechanisms the option of choosing the outcomes they want, and discarding those they don’t. This power of choice enables physiological systems such as the heart and brain to function in a way that isn’t enslaved by the lower-level interactions, but rather choosing the outcomes of the preferred interactions from a multitude of options. In this way, a layer of order can emerge from the disorder – and micro data – at the lower level. This isn’t conclusive proof that free will exists, but at least it opens up a way for it to exist.
For the sake of argument, let’s suppose I’m wrong. Let’s ignore all these issues and take the deterministic view seriously. It implies that the words of every book ever written – the Encyclopaedia Britannica, Das Kapital, the Harry Potter series – were encoded into the initial state of the Universe, whatever that was. No logical thinking by a human played a causal role in the specific words of these books: they were determined by physics alone.
It’s unclear how any words could have been encoded into the Universe, which led to apparently random fluctuations at the time when matter and radiation decoupled from each other. How would they have been represented in those fluctuations? It’s virtually impossible that they could have affected the detailed brain-state of the authors when they wrote their books. The issue of quantum uncertainty adds another layer of implausibility to these claims.
[...] Physics has made huge strides since the days of Laplace; indeed, it would be completely unrecognisable to him. Yet there are still physicists today who confidently proclaim that we can’t have free will because physics determines everything, including brain functioning – entirely ignoring the complex context and the power of constraints... (MORE - details)
