The Quantum Thomist

Musings about quantum physics, classical philosophy, and the connection between the two.
Why Is There Something, Rather Than Nothing? (Part 4)


Why Is There Something, Rather Than Nothing? (Part 5)
Last modified on Sat Jan 12 23:08:40 2019


I have been sporadically writing a series on a recent article by Sean Carroll. This is taking me several posts to respond to it fully, so I am going one section at a time. My first post gave an introduction to the topic, and covered Carroll's own introduction. My second post discussed his first main section, where he established his definitions and described the scope of his discussion. My third post discussed the definitions of "something" and "nothing". Carroll was a bit more reasonable here than many of his fellow atheists, who managed to get something out of nothing only by redefining the word "Nothing" to mean "Something." The fourth post discussed whether the universe could come into existence without something causing it, or could continue indefinitely. Carroll argued that both were plausible, and this is where his article started going wrong.

Now we come to the next section, entitled "Why this particular universe?" Even if we conclude that the universe could simply be, we are still tempted to ask why the universe is arranged as it is. Why this set of laws rather than another? Why this particular distribution of matter, anti-matter, and dark matter? This is probably at the heart of the current debate between those who argue that contemporary physics supports religious views, and those who say that it doesn't necessarily do so. I'm thinking in particular of the fine-tuning of the various physical constants.

Our current knowledge of fundamental physics can be reduced to a small number of underlying principles:

  1. It is a quantum field theory.
  2. It is constrained by various discrete features, such as the number of space and time dimensions and the geometry and topology of space/time.
  3. It is further constrained by various symmetries.
  4. It is constrained by a number of continuous parameters, which control (for example) the masses of the particles and the strength of the forces.

The first three of these conditions are of a different nature to the last. Firstly because they relate to the structure of the laws, while the last point to the finer details. Secondly, because these points are in principle easier to justify. One senses that one could explain them (or at least some of them) from general philosophical principles. The constants, however, as real quantities, and thus it is much harder to see how they could be predicted from first principles. They can only be induced from experiment.

There is no obvious logical reason (to the scientist with no interest in metaphysics) why any of these should be the case. The only guide he has is the demand for self-consistency. Experiment can show which theory is correct, but not explain why it is that way. Classical theories are just as self-consistent as quantum theories, and there might well be other options which are neither classical nor quantum. It is just as easy to construct theories which have different symmetries from the standard model, or which lack (for example) local gauge invariance. There is no logical reason why there has to be three space and one time dimensions (and obviously some candidate quantum gravity theories claim that there aren't). Or why it isn't represented by the Euclidean geometry used by Galileo and Newton rather than the Reimann geometry recognised since Einstein. These questions, are, I think very important, and I will discuss them again shortly.

Fine Tuning

But the biggest interest in recent times has been over these parameters. We are not discussing dimensional parameters such as the speed of light, whose numerical value will depend on whether you measure it in meters per second or furlongs per Jovian year. Instead these refer to dimensionless parameters, which have the same values no matter which units you use. One example is the fine structure constant, which controls the strength of the electromagnetic force. Another is the coupling between the scalar field and first family of lepton fields, which controls the electron mass. So we keep the quantum nature, symmetries, and geometry as they are in our universe, and start fiddling around with the values of these parameters.

There are about thirty of these numbers in total, most from the standard model of particle physics, and a few from cosmology. I say about thirty, because there is still some uncertainty. There might be a few more if (for example) there are some additional particles whose masses are too large or couplings to the currently known particles too small to have been measured in the experiments so far. There might be fewer if some of them are actually dependent on the others, for example if some of the cosmological parameters in practice can be deduced from the standard model parameters, or the standard model parameters are linked together through some unified theory we don't yet know about. Scientists deduce the values of these parameters through a process of deduction and comparison. They generally can't be measured directly, but we can calculate the values of quantities we can measure which depend on them. So we take an observable, calculate its value as a function of these parameters, measure what value it actually is, and use that to constrain the parameters. The system is very much over-determined, since there about thirty parameters, and a vast number of possible measurements that could be made.

So we have the ability to calculate many of the observable properties of the universe based on the basic theoretical structure (the symmetries and so on) and the values of these constants. That's why we are so confident in the theory. Thirty measurements are needed to constrain the parameters. Predicting the results of the tens of thousands of experiments after that is some considerable achievement. But just as we can calculate what the universe is like given the actual values of these parameters, we can also calculate what the universe would be like if they were slightly different.

And what we find is that the universe would be vastly different. Tweak one parameter a bit, and stars immediately collapse. Tweak another parameter, and atoms don't form. Tweak another parameter, and the most exciting molecule you can get is hydrogen. There are thirty parameters, but over a hundred conditions that need to be satisfied for chemists to have anything more than a handful of molecules to play around with. Of course, there wouldn't be any chemists in that case. Life requires the storage and transmission of complex information. While I don't see why this has to be provided through the DNA and RNA molecules, you will still need something of similar potentiality if you are to have life. Good luck doing that if all you have to build it out of is the hydrogen atom.

The universe would be consistent if these parameters had any real number. Only a tiny region in that space prevents the catastrophe (for us). It so happens that we are right in the middle of that region. Change any of the parameters by a small amount, and you break at least one of the conditions. Try to compensate for this by changing another parameter and you break something else. Of course, it may be that we don't live on the only island of order in this vast sea of chaos, but if there are any other regions which might allow the complexity needed for life, they are just as unlikely as the one we find ourselves in, were we to select the parameters at random (according to some sensible distribution). These are known as the anthropic coincidences, a name which is a little too human centred for my taste and thus obscures the point. It's not about our existence. It is about the existence of carbon and thus complex chemistry.

The possibility for these parameters to be just right for us is too small for it to be chance, not when there is any other possible option. And there are other options. The first is design, which those who accept God have immediately seized on. The second is large numbers; if we suppose that ours is not the only universe, but there is a vast number sampling every possible value of these constants, and we happen to be lucky enough to be in the one which has complex chemistry (although luck is the wrong word; we are in this universe because we couldn't be in any other). (A third option, which I have seen from some people such as Victor Stenger, is to try to deny the problem; but this is just wishful thinking and poor reasoning against an overwhelming weight of evidence.)

Carroll makes a couple of points in his discussion of this:

For other parameters, however, this anthropic expectation predicts something very different from the real universe. An obvious example is the low entropy of the early universe, which is many orders of magnitude smaller than what it would need to be in order for life to exist. More generally, the universe simply seems to have far more stuff in it than any reasonable anthropic criterion would imply; there are more than a trillion galaxies, with of order a hundred billion stars and planets in each of them, none of which is necessary for our existence here.

The first of these examples is clearly missing the point. True, the early universe was not suitable for life. But equally clearly, as the universe evolved under the second law, entropy increased until it became a value where life could be supported. God's need was for a universe that could support rational creatures. But God is timeless. If the time when those rational creatures exist is only a tiny interval when compared to the lifetime of the universe, then God has still achieved His goal; just as our planet (and the few others that might be like it) are only a tiny specks in the vastness of space; but that it exists at some point is nonetheless enough for God to achieve His goal. As for the vastness of space, even if it is true that this is independent of the fundamental parameters under consideration, it makes no difference to the argument. There is no obvious reason why God would prefer a small universe to a big one. God is not like a man who ought to conserve limited resources at every turn.

The second point he makes is more substantial. The problem is we don't know how to sample these parameters. We say that the chances of these parameters taking the values that they do is improbable because they could practically take any value from zero to infinity and lead to a self-consistent physics, but only a tiny region (or a number of tiny regions) are such that life can emerge. But to express this unlikelihood as a probability we need to know how probable it is that whatever mechanism it is that churns out these parameters would select one particular value. The value given to that probability distribution will depend on one's underlying model. All probability depends on one's assumptions. Those who believe in a God who wants to create a rational creature will peak the distribution around that region which supports life, because that's what their assumption demands. Those who deny God need an alternative way of predicting the distribution of parameters, one which isn't biased towards that small region. Which means that we need an atheistic theory of the origin, not of the universe, but of the emergence of physical law. Once we have that theory, then we can at least draw some ideas about how the parameters might be expected to be distributed if that version of atheism is true. But atheists don't have that to enough detail or certainty. In the lack of any certainty, we usually select a uniform distribution, but that doesn't work because a uniform distribution cannot be used over an infinite range. We can map the infinite range to a finite range by using, for example, an inverse tangent function, and select a uniform range over the inverse tangent of the parameters. That's now mathematically consistent, but why an inverse tangent rather than some other function? We have introduced a degree of arbitrariness such that whichever choice we make cannot be justified ahead of the other possibilities.

This problem is particular acute for those atheists such as Carroll who regard the universe as a brute fact -- something which could be otherwise but happens to be what it is, and it is impossible to give a further explanation. To calculate the chances of the parameters having the values that they do requires some theory generating them. But Carroll says that not only do we not know what that theory is but we cannot know what that theory is. His very philosophy denies us the possibility of getting philosophical guidance on how to sample the landscape of possible universes. Yet the question still remains: theism can explain why the parameters take the value that they do, while Carroll can't. Yet he still wants to maintain that his model has fewer assumptions (and is simpler) than theism. [Theists maintain that God is simple and thus cannot be other than what He is, and thus have just one constant to explain. Carroll has to pick one universe out of infinity without justification.]

The laws themselves

So that brings me to the other problem. Beyond the issue of these parameters, we have the further issue of whether we can explain the structure of physical law in terms of some more fundamental principle. This is, of course, of particular interest to me, since it is the topic of my book, where I argue that we can explain why modern physics is what it is if we assume classical theism. I claim that the axioms behind physics can be drawn from the conclusions of theism.

So the problem is that there is a vast (possibly infinite) number of different ways one can construct a self-consistent quantum theory, and many more if one also allows non-quantum theories. So why is the universe governed by this particular set of laws, rather than another? After correctly stating the problem, and saying that it seems hopeless, Carroll offers a thought. He presents the idea that the universe is governed the most simple or most elegant form of the laws.

One justification for this could be the trajectory of physics over the course of centuries. We started by considering a wide range of phenomena, astronomy, dynamics, gravity, electricity, light, heat, magnetism, fluids, gases, solids, hardness, brittleness, and so on. Gradually, starting from Newton's laws, these have been unified, and we are down to two theories, the standard model of particle physics (or some extension of it), and the standard model of cosmology. It is hoped soon that a theory of quantum gravity will be established unifying these.

However, this doesn't really answer the question. Many possible members of the landscape of laws equally reduce to a single principle. So we have no reason to prefer ours over those from a principle of simplicity. Are the laws that measure our universe simpler or more elegant than others? To answer this, we need to have an objective measure of simplicity and elegance, but such concepts are often used subjectively. What is elegant to one generation need not be to the next. If simplicity is to be defined in terms of the number of free fields, our universe couldn't be said to be that. Even within quantum field theory, one has the phi4 theory, the simplest possible field theory (in the sense that it has the fewest fields) or quantum electrodynamics, as the simplest gauge field theory. Even with the gauge structure we have, the weak interaction sector of the standard model is very messy, treating left and right handed particles differently. It would be far more elegant if it were an SU(2) version of QCD. Others might disagree: but that's my main point. The opinions of the last paragraph are just based on my own subjective ideas of simplicity and elegance. They don't count for anything in reality.

Or what about string theory? Could it be that our low energy messiness emerges from some elegant high energy theory? Calling string theory (or loop quantum gravity, or ...) elegant is a matter of opinion, not fact. And even if it was objectively elegant, why does that prove it to be true? There is no evidence, as Carroll states, for suggesting that the underlying laws are as simple as possible. And there is no known good reason that they should be.

Conclusion

So Carroll raises an important problem, but offers no real hope of a resolution in this section. The criteria of simplicity and elegance has no objective measure and no rational justification. The existence of intelligent observers is, to him, no more a solution.

The safest tentative conclusion to draw is that the properties of our particular universe cannot be solely attributed to the fact that intelligent observers exist within it, even if some particular properties may be.

This, statement of course, seems to have the direction of causality (in the sense of the sequence of explanation) the wrong way round. It is not the presence of intelligent observers that causes the universe to be what it is, but the nature of the universe that allows the possibility of intelligent observes. Unless, of course, we assign some purpose or design to the nature of the universe, which would mean going down the path towards God.

So what alternatives did Carroll miss? The most obvious one to me is that the structure of the universe can be deduced from underlying metaphysical principles. Indeed, I believe that philosophers should focus on doing this: figuring out what implications their philosophy has for physics, and then drawing up a list of physical axioms deduced from their philosophy which can be compared against our best theories. This would turn philosophy from random hand-waving to a genuine science. Of course, this might not resolve the underlying problem, but only push it down a level: why this philosophical system, rather than another? But at least then we move the question to the study where it belongs; and maybe here we might be able to reduce the number of degrees of freedom to just a handful, compared against the vast possibilities that physicists have to contend with. The problem Carroll faces is that we are reaching the limit of what can be explained through physics. But that doesn't mean that we have reached the limit of what it is possible to explain. It just means that we have to move beyond physics.

If physics had lead to a situation where we could say that that was the only self-consistent way in which the universe could work, then there would be (some, not complete) justification for seeking ultimate explanations in the natural science, as naturalists such as the new atheists demand. But that isn't what has happened. Instead, contemporary physics is demanding that we look beyond science for a more fundamental explanation. Atheists cannot argue that no explanation is possible, because theists have already provided one, which fits all the facts. The burden is on atheists to step up to the challenge.



Why Is There Something, Rather Than Nothing? (Part 6)


Reader Comments:

1. Scott Lynch
Posted at 04:51:49 Wednesday January 23 2019

Matrix and Inference vs. Deduction

Well it is interesting to note that many people in academia (e.g. Neil deGrasse Tyson) are moving towards the “universe as a computer simulation” or Matrix hypothesis. This obviously gets rid of the fine-tuning problem. Of course, as you (and other Scholastic philosophers) would argue, it still does not ultimately address the teleology of our universe. Clearly there must be a teleology of some sorts in the universe that our programming overlords live in (if this ridiculous hypothesis turned out to be true) in order for them to be able to impart any kind of order to our universe. The Matrix hypothesis can defeat fine-tuning, but it cannot defeat the Fifth Way which is just as valid for QFT as it is for a four element or a Newtonian mechanistic universe.

I would nit-pick on the last section of your post (while acknowledging that you were not trying to give a rigorous argument). You said that we should try to deduce physical axioms from our metaphysics (and presumably our natural theology). Unless you are going to adopt a rationalist philosophy that claims that our particular finite universe is absolutely necessary, that will not be possible. All that a Thomist could do is explain how certain physical axioms can be consistent with metaphysics. It is more of an inference than a deduction. Would you agree?

2. Nigel Cundy
Posted at 19:36:27 Wednesday January 23 2019



I'm rather sceptical of the idea that we are a computer simulation; it would have to be a very different computer that we have at the moment. For example, computer algorithms can't generate genuine random numbers (just a sequence that appears random to various tests but will eventually repeat itself). I'm not fully convinced that this defeats fine tuning -- the computer's universe would have to obey some physics, which would also have to be fine tuned. But I agree that the fifth way and similar arguments are stronger. After all, the fine tuning argument in its most common forms is an argument from design, an inductive argument, while the fifth way is a deductive argument.

With regards to your second point, I would disagree that I am adopting a rationalist approach. Maybe I didn't make this clear in my post, but I believe that metaphysical theories can considerably but not perfectly constrain the underlying physics. Some experimental input is still needed.

3. Christopher
Posted at 07:50:58 Monday January 28 2019



Hi Dr. Cundy,

Thank you very much for taking my suggestion so seriously. I have been loving this series of posts and it has really bolstered my confidence in these classical arguments. I never expected my request on your post about revisions would get this detailed of a response so thank you for replying in such length to my quick comment a couple posts back. So, three things - First, thank you for the detailed work. Second, I wanted to let you know that your work really does have an effect on bolstering people's faith. Third, this series has motivated me to decide on getting my physics degree in addition to my philosophy degree, so thank you for making the subject matter interesting enough to seal the deal. Keep up the great and inspiring work!

4. Nigel Cundy
Posted at 22:43:26 Monday January 28 2019



Thanks for the encouragement, Christopher. Just be aware while taking physics that it will be a while before you get to the material I discuss -- you have to get through classical and quantum mechanics first. But it is a great subject. And we do need more philosophically aware physicists, just as we need more physically aware philosophers.

I am working on what will be the last of this series at the moment. Hopefully it will be up in the next week.

5.
Posted at 01:22:05 Tuesday January 29 2019



Dr. Cundy,

First, I would like to thank you for writing this in-depth series of posts. It has been very informative for me.

You mention towards the end of your post that, because several different sets of laws are possible, physicists need an explanation as to why this set of laws operates as opposed to some other set of laws. Ed Feser makes this point as well. However, there have been several recent attempts to derive the laws of Quantum Mechanics from a set of axioms. If the laws of physics can be derived from a set of self-evident axioms, would the laws then be logically necessary, requiring no further explanation?

Here is an example: https://arxiv.org/abs/1011.6451

The axioms offered in the paper are not self evident (it seems to me), and the authors do not derive the entirety of physics from them. However, there is a possibility in the future that such a feat will be completed.

6. Christopher
Posted at 08:56:48 Tuesday January 29 2019



Hi Dr. Cundy,

Thanks for the advice. Luckily I am still an undergraduate so I have plenty of time to get into physics and study it going into grad-school. Quick questions about the direction to take it once I start studying it - what courses and things should I focus on at the bachelors level to direct me toward theoretical physics? Given that I am most interested in the philosophical and theoretical side of physics, are there certain math classes or physics classes in particular that I should concentrate on to get into the modern theory side of it? I know undergraduate degrees are general in terms of topics, but the university I am at allows a pretty good amount of student requested independent study and I am wondering how best to use that time. Finally, looking to the future, what are the most fundamental theories that I should prepare to study? I want my future work (PHD work) in philosophy to be interacting with the best current and most fundamental theories, so what should I plan for? Quantum field theory, string theory, loop quantum gravity etc?

7. ficino
Posted at 12:33:49 Tuesday January 29 2019



Aquinas writes in De Potentia 3.17 co, when we ask why the world came to be when it did, or why it is of its size or location, the answer is not in necessity or in some inherent“best” but simply in God’s will (“non potest huius ratio reddi nisi ex voluntate producentis”) and wisdom.

I do not see how this functionally different from saying “God did it.” When we get to God's will as an explanatory principle, we admit that our understanding of the world reaches a point beyond which is inscrutability, since God’s will is not known to us.

Theists maintain that an appeal to God (what I consider an appeal to God's will, which implies of course God's intellect) is different from saying that we arrive at brute fact. Because God exists necessarily and His essence is identical with His existence, etc., appeals to God are not appeals to brute fact.

Since we have no direct access to God's essence, being forever on the near side of the dividing line of analogical predication, it's not clear to me how God don't cash out as brute fact appeals.

Aristotle on the other hand accomplishes the same without needing to give his god a will. The upshot is that in Aristotle, the kind of necessity by which nature exists and operates is not the hypothetical necessity needed by Thomas, but absolute necessity: cf. Metaphysics Lambda 7 1072b10-13. More economical. A consequence down the road is that Aristotle does not need to distinguish between eternity, "aevum" (Aquinas' mode of measuring duration of existence of separated, immaterial substances) and time. Aristotle only needs time, which is eternal, the principle of prior-posterior, in a universe that is eternal and by necessity (and, for him, "best"). More economical!

But WHY is the universe this way and not some other way? One person says, "it is God's will." Another says, "it's brute fact." Maybe the focus of difference will turn out that at least on Aristotle's picture (and in most of ancient dogmatic philosophy except possibly Plato), there is no possibility in reality, only in imagination, that there could have been a different universe, even if on a day to day level there can be automatic events here and there. The Thomist on the other hand seems to be able to allow that in reality, not only in imagination, there could have been a different universe. I'm not sure whether it's an interesting gain to preserve for God the option of having created different universes than this one, since this one is the only one we have. It doesn't seem to further scientific inquiry to maintain that God could have created a different universe - it only serves theological ends. But if we're debating whether God exists, then we can't take it as given that the principle subject of theology exists.

Anyway, I get the feeling that what motivates ultimate "but WHY is reality this way?" questions is not a conviction that we need theology in order to do science as much as it is a desire to preserve religion. "The universe is how it is because God willed it so." "But WHY did God will this universe and not some other one?" ... ?? The answer to us is indistinguishable from an appeal to brute fact, as far as I can see.

8. Nigel Cundy
Posted at 21:30:36 Tuesday January 29 2019



Dear Christopher,

Firstly take as much math as you can. You will need calculus, geometry, linear algebra, complex analysis, and statistics for the basic stuff. More advanced courses in all of those areas (except perhaps statistics) plus group theory, topology, tensor analysis and differential geometry are needed for theoretical physics. Even though you are aiming for theoretical physics, you should also do some practical physics. I'm a theoretician myself, and never really liked doing the practicals as an undergraduate, but it is where the heart of physics lies, and you need some experience at it. If you haven't done any computing before, this would also be a good opportunity to pick up the basics. It's a very useful skill no matter where you end up. You will, of course, do the basics in any case: classical physics, waves, classical electromagnetism and optics, special relativity and basic quantum mechanics (Schroedinger equation, perturbation theory both time dependent and time independent; try to find someone who teaches the Dirac notation as well as the more standard wave notation -- I was fortunate enough to have a tutor who used it from the beginning). Thermodynamics and especially statistical mechanics are hugely important. These are the basics which every physicist needs, and which should be covered in the first couple of years of the course.

After that, I would focus on general relativity, relativistic quantum mechanics and scattering theory, condensed matter theory (the physics of solids), and particle physics. Condensed matter theory is important. Firstly the underlying mathematics is very similar to particle theory, and there has been ideas moved from one side to the other. Secondly, the theory of solids is something philosophers debate about (and in particular the relationship between predicates and the underlying substance). As a philosopher, you have probably encountered bundle theory, trope theory, substratum theory and other similar ideas. Modern physics has gone a long way in this area since it parted with philosophy, and the progress in condensed matter physics has been startling; and the philosophy textbooks I have read seem to have no knowledge of what has been happening down the corridor in the physics department. I don't discuss it much in my book, but I think there is plenty of room for a philosopher of physics to make a mark here. Obviously, there are other areas of physics, electronics, fluid dynamics, and so on, which are interesting but not so relevant for fundamental physics.

That will take you to the end of your undergraduate studies. Note that you haven't yet reached the topics I tend to discuss: be prepared, as a Thomist, for many dark moments as you go through years of mechanistic physics before things start changing (I only started studying Thomistic philosophy during my first post-doc). But it is still essential to master it.

If you survive all that still wanting more, then if you want to go into theoretical particle or condensed matter physics, you will study quantum field theory first of all in your postgraduate degree. After that, there are four basic options: cosmology, quantum gravity, standard model particle physics (which is where I went) and condensed matter theory. I can't offer you advice here: it is too far in the future. By then, you would have your own ideas of which areas you are most interested in. I'm personally skeptical of string theory (and if the LHC doesn't find supersymmetry by the time you get to that stage it is in big trouble anyway), and wouldn't recommend it to someone starting a postgraduate study today: there are far too many exceptionally bright people working on it and making no progress (but then, if the LHC does find supersymmetry, string theory will start to look very favourable). The big questions at the moment are quantum gravity, dark matter, dark energy, and neutrino physics. But things might change in four or five years.

9. Nigel Cundy
Posted at 21:54:29 Tuesday January 29 2019

To #5

Thanks for bringing that article to my attention.

I agree that fundamental physics will ultimately be reduced to a small number of axioms, and I also think that that is the limit of how far physics can take us. I only glanced at the paper, and I am not sure that the axioms it lists are sufficient (maybe when I read it in more detail, I will change my mind there) to imply the standard models of particle physics and cosmology (which is what we ultimately are after). But the basic approach is right. So axioms, yes. Of course, there might be several competing sets of axioms which have the same implications, so just because someone lists some axioms doesn't mean that they are right.

Self-evident axioms, on the other hand, are more problematic. I don't think that is possible for us to say that the axioms are self-evident and thus the laws of physics are necessary without needing any metaphysical explanation. The problem is that it is very difficult to get people to agree what is and isn't self evident. On one hand, we have Godel's theorem, saying that no theoretical framework can be complete. You need some data or some being outside the theoretical structure to make sense of it. Secondly, Newtonian physics (for example) is a perfectly good, self consistent theory. It too can be reduced to a small set of axioms. The only definite guide that we have to which set of axioms to choose is mathematical and logical consistency. But all of Newtonian physics, Schroedinger wave mechanics, and Quantum Electrodynamics (a QFT) satisfy this even though they are based on different axioms. Why then should we say that the axioms behind quantum theory are correct and those behind Newtonian physics are wrong? We need to bring in something else; either experimental data or some philosophical principle (such as God) supported by revelatory data. In which case, they are not self-evident.

So I don't think that this approach is going to explain physics. It is an essential step in constraining physics, and getting it to a state where the philosophers and theologians can take over, but at the end of the day it just leaves us with a set of principles which don't and can't explain themselves (unless, like Carroll, we go down the brute fact route).

10. Nigel Cundy
Posted at 21:57:54 Tuesday January 29 2019

To Ficino

Good question, but I think the best time to discuss it will be after my next post, where I discuss brute facts in more detail.

11. Ficino
Posted at 15:29:25 Thursday January 31 2019



Nigel, in an earlier post, you wrote: "Now the "stage that is last" is a physical state, having the same standing as the stage that was first, meaning that final causality once again links one substance with another. So I took this idea in my adaptation of Aristotelian philosophy to quantum physics. The only thing I have added to this is the idea of indeterminacy (and I'm not sure that it is an addition to Thomistic thought): that a single object can have many possible ends. If the end marks the end effects of a possible physical process, then clearly the ends or final causes of a down quark include the up quark, electron and anti-neutrino."

You are saying that a subatomic particle is a substance in the Aristotelian sense, in that it has an end/final cause? And yet, that its end is not determinate but can be one among a number of possible ends? If that is so, then on A-T principles its substantial form is not determinate, since form and end are one in extension in A-T. But substantial forms in A-T are determinate, as are ends. You seem to have allowed for A-T metaphysics to be dismantled on the micro level. And if that's so, then we seem to have no reason to retain it on the macro level. It seems to me, though I am no physicist, that what you allow for quantum indeterminacy problematizes A-T metaphysics. I don't know of any passage in Aristotle or Aquinas where entities without will operate, not toward a determinate end state, but only toward a multiplicity of possible end states.

12. Nigel Cundy
Posted at 21:45:56 Thursday January 31 2019

Reply to Ficino

Thanks again for your comment, which is certainly thought provoking.

Firstly, I have no desire to slavishly follow Aristotle and Aquinas. My aim is to develop a workable philosophy of physics. I find Aristotle's philosophy and categories a useful starting point, but feel free to extend it if necessary. Aquinas, after all, didn't accept everything in Aristotle, but extended it and also brought in aspects of neo-Platonic thought. But he is still, unquestionable, in the Aristotelian tradition.

I agree that form and finality are closely linked. I see the eigenstates of the Hamiltonian operator as a at least partial representation of the form, and the Hamiltonian is constructed from creation and annihilation operators that describe the various interactions and decay channels of the particle, or its final causes. So finality and formality are closely linked.

Now, I regard the final cause as a list of possible outcomes. That list is not infinite, but has a relatively small size, but it is greater than one. Which one of those outcomes will happen in practice is indeterminate. But the list itself is determined; for every particle of a particular form, it has the same list of possible outcomes.

I think that even in Aristotelian philosophy the final cause of an object can be frustrated or there can be multiple ends. In part what happens depends on the circumstances. Put a cube of sugar in a flame and you will get one outcome; put it in some tea and you will get another. Both of these changes have to be described in terms of the final causes of the sugar lump. Or an acorn will, under the right circumstances, grow into an oak tree, but precisely where each branch of the tree is only partially determined by the genetics of the acorn and partly by external circumstance. Obviously, this is not the same as what I discuss, where the different possible outcomes aren't so much dependent on circumstance (although external circumstances such as a external magnetic field or high temperature can change the amplitudes), but more intrinsic to the particles.

We also need to be careful about what we mean by determinate and indeterminate. There are several different definitions around. For example, there is a philosophical sense where determinate means that the meaning of something is clear, and indeterminate "that no collection of physical facts, and indeed not even the entirety of physical facts, entails any particular meaning rather than another." (http://edwardfeser.blogspot.com/2013/10/oerter-and-indeterminacy-of-physical.html) What I mean, however, is something different, namely that it is not possible to predict an outcome from a complete knowledge of the state of the universe at a previous time and the laws of physics. The form and and final cause of a substance is determinate in the philosophical sense; while the outcomes are indeterminate in the physical sense. When I discuss determinism I mean physical determinism (after all, I am a physicist), so when I say that the final causes are indeterminate I don't mean that they are in some way vague or undefined.

So form and finality are determinate in the philosophical sense, and this is what is needed by Aquinas and Aristotle. However, that doesn't preclude that there is also physical indeterminism.

[Of course, I'm just guessing what you mean by the term in the question; if you mean the same thing as me, then I apologise].

So I wouldn't say that I have dismantled A-T metaphysics at the micro level. I have, perhaps, extended it (mostly in my conception of space/time, but perhaps also in allowing more than one possible outcome from a state). My main argument is that the concepts of form, finality, efficient, material causality, potentiality and so on fit in very well with what is happening at the micro level, and therefore they should also apply at the macroscopic level.

13. Ficino
Posted at 17:38:32 Friday February 1 2019



Nigel, what you say above seems to violate the PSR, which Thomists say is a necessary metaphysical principle and a linchpin of their system. Cf. Dennis Bonnette on Strange Notions just today: "There must be a sufficient reason, and that is not a mere figment of the mind, but a real existential state of affairs which accounts for this particular outcome coming to be as opposed to all other possible outcomes... But if there is real causation at work in the agent which will account for this and only this particular outcome, then this establishes a real relation between the before and the after, in which the after is not mere possibility, but also that which the agent is really being "aimed" at... once you realize that the agency is really acting toward a specific outcome -- an outcome that is not mere possibility, but a state of reality that the agent is actively moving and determined toward , that outcome then has some real influence on its coming to be as opposed to any other possible outcome."

If there is not a rigid final causality at work, I don't see how Thomistic arguments from governance for God's existence will go through, nor arguments for God's providence. It seems to me the Thomist has to hold that end states on the quantum level, like other end states in nature, are determined by hypothetical necessity (in the classical sense of that term). Or else the Thomist has to deny that subatomic particles are agents, or has to bundle them as aggregates upon which to impose rigid determinate final causality.

I'm all in favor of whatever physicists can do to push forward the boundaries of our knowledge. I'm just not seeing their results as consistent with the Thomist system. For example, I think you'll find it hard to cite textual evidence that the final cause as formulated in A-T is "a list of possible outcomes." (A-T explains anomalies either as relatively rare cases of defect due to the matter, or as cases where some other substance interferes as that substance actualizes ITS own form/end.) I speak in a friendly way when I wonder whether your blog ought to be called "The Quantum Thomist-lite" or something like that, heh heh. But it is great to see someone trying to think about the Aristotelian-Thomistic contribution more creatively than to treat it simply as a system of necessary truths hammered out in the 13th century, any difference with which is to be branded simply as an instance of intellectual decline.

And though I know more Aquinas than most, my academic specialty is not scholastic philosophy, and certainly not physics.

14. Ficino
Posted at 18:19:42 Friday February 1 2019



OK, I think I see better what you mean. But then it sounds as though we have a sort of two truths picture, where something is asserted as necessarily true on the metaphysical/ philosophical level but not on the physical level. That split is quite foreign to both Aristotle and Aquinas, since they worked with a physics from which was derived their conception of Act-Potency and the rest, and with which that conception was consistent. Is the metaphysics tied to the world that scientists can observe or is it a self-consistent system of notions that fails to capture what happens in nature?

Sorry to take up extra time: I'm wondering again whether in the end, one person will be satisfied with brute fact explanation, another will want to posit God but with seeming little or no payoff for investigating the universe any better than the first person could do.

15. Nigel Cundy
Posted at 18:03:10 Saturday February 2 2019

Rigid Final Causality.

Actually, I see the indeterminism of physics as further bolstering the conclusions of the teological argument.

I see physics as ultimately a description of God's sustaining the universe. God works through secondary causes, so the chain of efficient causes is maintained, and also God respects the final causes of matter (God is ultimately the author of the final causes, so this doesn't undermine God's soveriegnty). In other words, each individual decay of a particle arises as a result of God's will.

I define a free will in a similar way to how I define physical determinism; namely that it is impossible to predict the outcomes even with a complete knowledge of the circumstances in which the decision was made. (In this way, we can both say that Marcus Brutus had free will in deciding whether to join the conspiracy against Caesar, but we still know for certain what his decision was.) So the fact that there are multiple possibilities and God can select one of them is a reflection that God's will is not constrained to a single option, which would be the case if each being had only one possible final cause. So I find the indeterminacy of physics as a key piece of evidence that God's will is free. (Of course, to get to this point, one needs to accept a lot of prior ideas including my interpretation of physics; I don't want to argue all that here).

I do agree with the PSR (everything needs a sufficient explanation), but perhaps disagree in what constitutes a sufficient explanation. [I also believe that the common formulation of the PSR originated with Leibniz, after the major Aristotelian philosophers, even though it has been adopted by many Thomists. We have to be careful about what we mean by the PSR if we are to make it a linchpin of Aristotelian thought.] For example, consider the decay of an electron from an excited state of hydrogen to the ground state, emitting a photon. We need to think of the different types of explanation. The initial state of the electron is sufficient as an efficient cause of the final state, one type of explanation. It is not sufficient as an explanation for the decay itself (and the process of actualisation), although it is part of the explanation. To fully explain that, we need both the electron in its initial state, and the freely chosen decision of God to actualise that potential at that moment. Together, these provide a sufficient reason for the decay.

Obviously, not every philosopher is going to agree with me here. I'll take your word for Aristotle's definition of final causality. I don't recall any passage that contradicts you, and I don't have time right now to thumb through my copy to find one (if it exists). I'll just say that my definition is a bit more general; obviously the list of possible outcomes could have just one member, so if Aristotle was right, I can still cope with it in my framework. The question is whether any of the key Thomist arguments (particularly the teleological argument) depend on there only being one possible outcome given an initial state. I think that they can be modified to allow for this, but am open to correction.

Also, I don't see a clear distinction between the world described by metaphysics and a the world described by physics; they both refer to the same thing (albeit that what we study in physics is a mathematical representation that contains aspects which are in a one-to-one mapping with reality. So ψ isn't the electron itself, but merely a representation of the electron. We can map from the physical object to the representation, do our calculations, and then map back to the physical object). My discussion about philosophical and physical determinism is simply that the word determinate has had at least two distinct meanings attached to it, one by philosophers and another by physicists. When we use the word, we need to specify which of those definitions we use, and be consistent in our use of it. Using one definition the final causes are determined. With the other definition, they are indeterminate. It's no different from saying the word "bat" could mean a flying mammal or an instrument for hitting a ball. There is no contradiction in saying "The bat I used to hit the ball wasn't a flying mammal." But both the bat, ball, and flying mammal are all part of the same reality. The difference is that the two definitions of "determinate" have similar meanings (probably both evolved from the same original concept, but in different directions), so it is easier to confuse them.

But thanks for your contribution. I appreciate it. Obviously, I'm not a philosopher myself. I'm confident about my physics; but aware that there is much of philosophy I'm unaware of. So it is good when a genuine philosopher forces me to think things through more carefully.

16. Ficino
Posted at 19:54:31 Saturday February 2 2019



Thanks for the further thoughts, Nigel. I of course have some as well of my own, but I'll wait for your next article.

cheers, F

17.
Posted at 13:18:20 Sunday February 3 2019

Is Information Fundamental?

Dr. Cundy,

As you may know, a spate of recent publications in popular science outlets have claimed certain theories of quantum gravity show information is "fundamental," and space-time is an "emergent" concept. What they seem to say is the physical world is not composed of matter or energy, but of "information" out of which space-time "emerges". Do you believe these theories to have any merit?

Secondly, I am wondering how this may affect James Ross' argument. Perhaps the "information" these theories speak of is determinate in content, or if changes in information states could be determinate in form (the form being the relevant "law of nature"). Even if the brain does not tap into thee fundamental information processes of nature, perhaps a computer could be built that did. What I'm most interested in is whether a thinking machine could exist in such an "information-based" universe.

18. Nigel Cundy
Posted at 23:21:50 Wednesday February 6 2019

To #17

Sorry for the delay in replying to you.

Firstly, I should say that I don't know so much on this topic, so treat what I am about to write with a healthy dose of scepticism.

With regards to the ideas on quantum gravity, we should be wary of taking any of them too seriously until they are firmly established either experimentally or through clear demonstration. In particular, I have always been uneasy about approaches which undermine the symmetries and ideas behind classical general relativity (which is what things like string theory and loop quantum gravity do). Theories which have an emergent space-time even usually violate the symmetry of special relativity, Lorentz invariance, which not only has been supported to a huge precision experimentally, but is also at the centre of the current successful theories of physics. So to my mind these ideas are a step in the wrong direction. (Which would explain why, after 30 years of intense investigation by some really smart people, we are no nearer showing them to be correct). But, of course, I could be mistaken about all of this. Be wary about my ideas on quantum gravity until they are proved as well.

Just to expand a little: we have in quantum physics something known as an effective theory. This is essentially a recasting of the theory in terms of other parameters. For example, the most fundamental theory that has been shown to be correct (or at least a good approximation of being correct) describes the interactions between quarks and gluons. However, it is possible to perform a mathematical transformation, average over redundant degrees of freedom, and we can turn it into a theory of protons and neutrons. It's a powerful tool describing how one level of physics can emerge from the previous one, and very useful in the right context.

The idea behind the emergent space time models is firstly that a quantum theory of gravity should be constructed in a similar way to a quantum theory of electromagnetism, and that our current best theory is an effective theory of something more fundamental. Since the field in classical gravity is the metric tensor which describes how one measures distances in space time, quantising the metric (albeit that this is over-simplifying what is done) and then treating it as an effective theory implies that space and time are not part of the fundamental theory, but only emerge after we coarse grain it. Turning the metric into a quantum particle destroys our notion of space and time.

I believe that many of

these ideas about emergent space time treat the building blocks of space-time as discrete rather than continuous (the spacing between points is just too small for us to notice). If it is discrete and the universe is finite in extent, then it is described by a finite number of data points. This

is the sort of thing that can be simulated on a computer (indeed, we construct similar computer simulations of parts of the standard model of particle physics, but with the priviso that we seek to recover the continuum limit -- which is done through the magic of renormalisation and the running coupling -- in order to compare against experiment).

The problem is if this is true in real life, then the symmetries behind special and general relativity are broken in the fundamental theory. Then it becomes much harder to justify why those symmetries emerge (the established effective field theories -- from quarks to protons -- are careful to preserve symmetries as much as possible). It also runs against common sense and the standard philosophy of physics, without providing a secure replacement.

The other issue about making the universe solely about information is that it isn't. We study the abstract structure of the universe in physics -- and that is part of reality -- but it cannot be the whole of reality. Statements in physics are conditional, and can only be conditional. We predict that if the universe is in state X at time t0 then the probability of it being in state Y at time t1 is p. But we need something outside the theory (or the information) to provide us with that initial state. Information doesn't mean anything unless you have something outside that informational system to interpret it. Equally, a purely informational and abstract system cannot be complete; there is always some axiom which cannot be proved from within the system. In traditional philosophy, where substances are made of a combination of information and an underlying matter, that underlying matter plays the role of the outside element, or gives us the initial state of the system. But without it, the universe would just be an undefined blob. There would be bits of information, but they wouldn't actually mean anything, because information only has meaning when it relates to something physical.

As for the universe being simulated on a computer, I'm sceptical of that as well. Firstly,

computers (as we know them) don't do randomness. They construct sequences of pseudo-random numbers, which pass various tests which we define but are ultimately mechanical and determined. This contrasts against the truly uncertain universe described by quantum physics. Secondly, no computer can be big enough to handle all the information that makes up the universe, without it being at least as big as the universe. Thirdly, such a computer would have to be instituted itself in some way which would mean it sits inside another universe (or something similar), leading to a regression.

With regards to James Ross' argument, do you mean the following?

Some thinking (judgement) is determinate in a way no physical process

can be. Consequently, such thinking cannot be (wholly) a physical pro-

cess. If all thinking, all judgement, is determinate in that way, no physical process can be (the whole of) any judgment at all. Furthermore,

"functions" among physical states cannot be determinate enough to be

such judgments,

either. Hence some judgments

can be neither wholly

physical processes nor wholly functions among physical processes.

</bockquote>

https://www3.nd.edu/~afreddos/courses/43151/ross-immateriality.pdf

By determinate he means here what I have been calling philosophical determinism, i.e. they have a clear meaning. Ross' argument is that our mental processes cannot be wholly physical; his conclusion seems to be that they are partly physical and partly immaterial (which I would agree with). I do not believe that a universe made solely of "information" can be (philosophically) indeterminate in the manner needed to undermine Ross' argument. A pattern of 1s and 0s (or whatever) doesn't carry any meaning by itself, and can't. It is only when we map it to something physical that we can interpret it.

Let's consider some information. Here it is:

1001100100011000101001001001110001100111100101011011101010101. By itself, it is a meaningless sequence of ones and zeros. However, if I tell you that each number refers to the occupation of a particular physical states, then it gains meaning. Or it might be a digitalised section of one of Beethoven's symphonies. Only when we map it to something physical does it get significance; and it is in the process of mapping from the informational to the physical that things become (philosophically) determinate. Without a code, the numbers mean nothing. But equally, lumps of matter following blind laws can't convey meaning by themselves. It is only the combination of information and matter which is meaningful.

Thus a purely informational universe would be no less (philosophically) indeterminate than a purely material universe. So even if these ideas are true (which I strongly doubt), they don't affect Ross' argument.



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