For robrecht: Aristotle, Aquinas, Newton and Einstein

[robertb]

The purpose of this thread is to examine Aristotilian metaphysics, specifically those which are relevant to the "god of classical theism" and the first three of Aquinas's Five Ways (for starters) in light of the discoveries of Newton and Einstein with respect to gravity.

My position is simply that what Aristotilian metaphysics points to with regards to change, causality and contingency may in fact be what we call gravity.

[robertb]

From where we left off in the other thread:

Within this universe, certainly the parameters of this universe are contingent upon gravity. But I'm wondering about larger cosmological perspectives, eg, the multiverse, or inflation prior to the Big Bang, or other theoretical physics perspectives on quantum gravity. I'm going to see what I can find in a couple of books I have at home (away for the weekend). Nor is it my purpose to argue for God, that would seem very presumptious! But I am fascinated by your use of Aristotelian-Thomistic metaphysics to describe more modern theories of gravity. Good stuff.

Perhaps we can go through this systematically using Aquinas's Five Ways (or at least the first 3 ways and the supporting metaphysical principles) as a guide to provide some order for our discussion. Though the larger cosmological perspectives are an interesting topic, I think that getting into them might detract from the more specific investigation I am proposing.

What do you think?

[robrecht]

Thanks, Robert, for starting this thread.

I think your idea is very interesting indeed. I'm inclined to accept it, but have some questions and reservations that I will raise to the best of my ability, but, of course, I am not trained in theoretical physics (but very interested) and all of my philosophy courses were many years ago in college so whatever introductory material you would like to produce would be most welcome. Likewise, I hope others will also participate and correct my deficiencies and contribute where I am not able to.

One idea about how Thomas (as a rather good Augustinian) might approach the Einsteinian idea of gravity as curved space, is that he might conisder it, in part, a privation, not an actualization. Ultimately, however, I think he would easily see and affirm how gravity is the engine that drives the universe and therefore not a privation.

More interesting, I think, is how we understand gravity in inextricable relation to mass, ie, the emerging Higgs boson. Since mass is responsible for the curvature of space, I think Thomas might see mass as the true immanent driver of the engine of the universe. I've read that Newton at times may have spoken of gravity as a spiritual, nonmaterial force, but this is not an option today. This is where my lack of understanding of theoretical (and now experimental) physics comes in. I play with these ideas in my attempt to better understand them but am especially interested in people who can teach me more about this. How are theories of quantum gravity related to either the Higgs boson or perhaps more nonstandard models of theoretical physics? I also think that Thomas might appreciate the highly theoretical idea of the multiverse, or at least I do. To whatever extent gravity is linked to the nature of our universe and many similar ones may be tempered by different ways in which mass and gravity may manifests themselves in less similar universes.

Finally, I am not inclined to agree that Thomas would see gravity as actus purus, which I think he reserves to God as he 'understands' him. I put this in quotation marks, because of course Thomas does not think that humans can comprehend God's essence. I think the idea of Pure Act is more like the modern idea of a singularity as a cipher for what we can at best only point to at the limits and beyond of what we believe we understand.

But note that none of these questions and reservations detract from my appreciation of your fundamental idea. I find it rather exciting and would primarily like to see it fleshed out some more. Is the idea original to you?

Thanks, Robrecht

[robertb]

Hi Robrecht,

I doubt that the idea of equating the "god of classical theism" to something like gravity is orginal to me, though I have not seen a formulation of such an idea myself. It actually occured to me while reading Edward Feser's book 'Aquinas'. I couldn't help but to notice that the arguments Aquinas/Aristotle based their metaphisical concepts on seemed to, in my mind at least, point towards what we would consider fundamental forces of nature, eg. gravity.

Yes, Aquinas does reserve the idea of Actus Purus to God, but I am more interested in actus purus as applied to god with a small 'g', indeed the god of classical theism. It is there, in the doctrines of divine simplicity and divine conservation, that I see what can be interpreted to be a pre-Newtonian description of the fundamental forces of nature, specifically gravity.

Consider the following implication of divine simplicity; immutability, impassibility, eternal, not as distinct parts of a whole, but as the whole itself. Now consider gravity. Gravity is immutable, it is changeless. Gravity is impassible, as it is not effected by anything else. Gravity, in a sense, exists outside of space and time, it is eternal.

Next consider divine conservation, in that gravity sustains everything and that apart from the continuous sustaining action of gravity the world could not exist, nor would it have ever come into existence, even for a second (as Feser puts it).

Interesting point about privation. I had not considered that but I think you are correct in stating that privation doesn't really work in this case. In fact, one could say that for our world to exist, gravity must act exactly as it does, therefore and in that respect, perfect. I'll give this some more thought regardless.

Finally, I agree that the possibilities of how things might be beyond our own universe are very interesting and am under no illusion that our current understanding of things is anything more than quite limited and, perhaps, mistaken. Regarding your point about mass, I would counter that mass has the potential to curve spacetime, though it is gravity that actualizes that potential.

[robrecht]

I don't know if gravity exists outside of space and time and therefore do not know in what sense it is eternal. Is not gravity, in a very real sense, the curature of space? And, insofar as it seems to be inextribably linked to mass (and space) in this universe, I am also not sure that we can speak of it as simple rather than composite. I think we could just as easily say that mass actualizes space in curving it through gravity. Within this universe, at the current time, ie, for the last 13.7 billion years, I do think gravity (in conjunction with mass and space) acts as something comparable to a prime mover, which is why I like your idea, but I'm not sure if this would apply in a period of inflation prior to the big bang, when it may have acted as a kind of opposite repellant force. I'm also not sure that gravity, within our current spae-time frame, fully encompasses the full Aristotelian sense of the prime mover as thought thinking itself, which is I believe is a final cause but not an efficient cause. As for Thomas, I am reluctant to speak of him as a representative of classical theism as there are some pretty radical ideas among paleo-thomists that are completely lost on neothomists and other classical theists. Namely, a very strong appreciation of apophatic theology being fundamental to all theology. I think Thomas' sense of divine simplicity is, like Pure Act, something that points beyond what I consider to be an immanent force like gravity. There is a brief discussion of Thomas' idea of divine simplicity in this thread that you might enjoy. In addition to the idea of noncomposite simplicity, I would place more emphasis on the articles 4 & 5 of the divine simplicity Questio of Thomas, especially the idea that God is not composed of genus and difference, ie, as a species or privation within a genus. This is much more profound than merely saying that God is not composite, but actually means that there can be no definition of God. To use a modern term, it's as if God is a singularity within Thomas' system of thought. This is a simplicity that eludes our ability to conceive of him with our minds that only perceive of composite material and concepts.

Unfortunately, I will not be available to respond again today but I very much enjoy this discussion. Thanks, Robrecht

[robertb]

I don't know if gravity exists outside of space and time and therefore do not know in what sense it is eternal. Is not gravity, in a very real sense, the curature of space? And, insofar as it seems to be inextribably linked to mass (and space) in this universe, I am also not sure that we can speak of it as simple rather than composite. I think we could just as easily say that mass actualizes space in curving it through gravity. Within this universe, at the current time, ie, for the last 13.7 billion years, I do think gravity (in conjunction with mass and space) acts as something comparable to a prime mover, which is why I like your idea, but not necessarily in the full Aristotelian sense of the prime mover of thought thinking itself, which is I believe is a final cause but not an efficient cause. As for Thomas, I am reluctant to speak of him as a representative of classical theism as there are some pretty radical ideas among paleo-thomists that are completely lost on neothomists and other classical theists. Namely, a very strong appreciation of apophatic theology being fundamental to all theology. I think Thomas' sense of divine simplicity is, like Pure Act, something that points beyond what I consider to be an immanent force like gravity. There is a brief discussion of Thomas' idea of divine simplicity in this threadhttp://www.theologyweb.com/campus/showthread.php?141703-Is-God-Simple that you might enjoy. In addition to the idea of noncomposite simplicity, I would place more emphasis on the articles 4 & 5 of the divine simplicity Questio of Thomas, especially the idea that God is not composed of genus and difference, ie, as a species or privation within a genus. This is much more profound than merely saying that God is not composite, but actually means that there can be no definition of God. To use a modern term, it's as if God is a singularity within Thomas' system of thought. This is a simplicity that eludes our ability to conceive of him with our minds that only perceive of composite material and concepts.

Unfortunately, I will not be available to respond again today but I very much enjoy this discussion. Thanks, Robrecht

Hi Robrecht, there is quite a bit here and some interesting points. I'll try to address these as best I can and see if my idea holds up.

Eternal, for my purpose, means something like always existing though not simply in a temporal sense.

So, firstly, there was never a time when gravity was not because time is contingent upon gravity as gravity is necessary for inflation. It would seem to me that gravity must therefore precede inflation in order to explain the seeming fact that spacetime resulted from inflation. In that sense gravity precedes spacetime, it is, therefore, pretty much eternal by definition as any distinction, (eg. coming into existence), prior to the existence of spacetime would require the existence of time in order to be a distinguishable event (if that is clear).

Is not gravity, in a very real sense, the curature of space?

I think that it is more correct to say that the effect of gravity acting upon mass results in the curvature of spacetime.

I disagree, (pretty much for the reasons stated above), with viewing gravity as being linked as part of mass and space and that gravity is not simple but composite. Though it is true that gravity can only be observed through interaction with mass and spacetime, it seems to me that gravity exists apart from mass and spacetime.

Let's set aside the specific theology of Aquinas and the idea of directedness for the moment and see if we can, at least, agree on a concept of gravity. I think the theology might only serve to cloud the discussion, if you don't mind. For now, let's just assume that we can understand the concept of simplicity.

[robrecht]

Hi Robrecht, there is quite a bit here and some interesting points. I'll try to address these as best I can and see if my idea holds up.

Eternal, for my purpose, means something like always existing though not simply in a temporal sense.

So, firstly, there was never a time when gravity was not because time is contingent upon gravity as gravity is necessary for inflation. It would seem to me that gravity must therefore precede inflation in order to explain the seeming fact that spacetime resulted from inflation. In that sense gravity precedes spacetime, it is, therefore, pretty much eternal by definition as any distinction, (eg. coming into existence), prior to the existence of spacetime would require the existence of time in order to be a distinguishable event (if that is clear).

I think that it is more correct to say that the effect of gravity acting upon mass results in the curvature of spacetime.

I disagree, (pretty much for the reasons stated above), with viewing gravity as being linked as part of mass and space and that gravity is not simple but composite. Though it is true that gravity can only be observed through interaction with mass and spacetime, it seems to me that gravity exists apart from mass and spacetime.

Let's set aside the specific theology of Aquinas and the idea of directedness for the moment and see if we can, at least, agree on a concept of gravity. I think the theology might only serve to cloud the discussion, if you don't mind. For now, let's just assume that we can understand the concept of simplicity.

Gravity may be necessary for inflation, but, if I understand correctly, at least in some theories of inflation gravity is repuslive not attractive during inflationary conditions. Hence not immutable. And not necessarily eternal, depending upon whether one attributes inflation to this universe, prior to the so-called big bang, or to the multiverse, 'prior' to the formation of each universe.

Why do you think it is more correct to say that the effect of gravity acting upon mass results in the curvature of spacetime? Are you speaking as a physicist, philosopher, or with some other expertise? I've heard of gravity being described as itself the curvature of space, not necessarily a force producing the curvature of space. Is that wrong?

Why does it seem to you that gravity exists apart from mass and spacetime? This sounds more akin to Newton supposedly at times speaking of gravity as a spiritual, nonmaterial force than Einstein. Does Einstein speak of gravity existing apart from mass and spacetime?

I don't know if we should agree on a concept of gravity insofar as it is unclear if and how theoretical physicists will succeed in developing a Theory of Everything, which would give a unified account of how gravity is related to the other fundamental forces. It seems like gravity's story has not yet been fully told perhaps. Or perhaps you can explain it in a way that I can understand.

[shunyadragon]

So, firstly, there was never a time when gravity was not because time is contingent upon gravity as gravity is necessary for inflation. It would seem to me that gravity must therefore precede inflation in order to explain the seeming fact that spacetime resulted from inflation. In that sense gravity precedes spacetime, it is, therefore, pretty much eternal by definition as any distinction, (eg. coming into existence), prior to the existence of spacetime would require the existence of time in order to be a distinguishable event (if that is clear).

I would propose that the natural conditions that include what we call gravity exist in 'absolute time-independent' of the greater cosmos, irrespective of the relative time-space relationship that began with the expansion of our universe. I believe ultimately what is described as possible called Quantum Gravity and time is akin to the absolute time-independent zero-state field that our universe likely began expanding from. This is described by one source here . . .

http://www.voting.ukscientists.com/barbour3.html

Shrödinger's stationary wave equation.

Julian Barbour's idea of a timeless universe has to do with turning Scrödinger's quantum mechanics into a quantum cosmology. But to do that, he first has to relativise the remaining classical absolute time and space frame-work, within which Schrödinger's equation is expressed. Barbour's popular explanation of all this gives non-physicists a new insight into these mysteries.

. . .
The Schrödinger equation comes in a time-dependent and a time-independent form. Barbour suggests, contrary to conventional wisdom, that the latter is the more fundamental. The wave equation, that finds all the possible stationary states of a system, hints at a universal state of affairs in which super-positions of stationary waves create a variation in time of the probability density.

© source where applicable

I think that it is more correct to say that the effect of gravity acting upon mass results in the curvature of space/time.

Yes, within our universe, but not in a zero-state field.

[robertb]

Gravity may be necessary for inflation, but, if I understand correctly, at least in some theories of inflation gravity is repuslive not attractive during inflationary conditions. Hence not immutable. And not necessarily eternal, depending upon whether one attributes inflation to this universe, prior to the so-called big bang, or to the multiverse, 'prior' to the formation of each universe.

Why do you think it is more correct to say that the effect of gravity acting upon mass results in the curvature of spacetime? Are you speaking as a physicist, philosopher, or with some other expertise? I've heard of gravity being described as itself the curvature of space, not necessarily a force producing the curvature of space. Is that wrong?

Why does it seem to you that gravity exists apart from mass and spacetime? This sounds more akin to Newton supposedly at times speaking of gravity as a spiritual, nonmaterial force than Einstein. Does Einstein speak of gravity existing apart from mass and spacetime?

I don't know if we should agree on a concept of gravity insofar as it is unclear if and how theoretical physicists will succeed in developing a Theory of Everything, which would give a unified account of how gravity is related to the other fundamental forces. It seems like gravity's story has not yet been fully told perhaps. Or perhaps you can explain it in a way that I can understand.

Gravity actually remains the same, what is repelled by gravity is dark energy, (a density of something like 2 hydrogen atoms per cubic meter that is extremely weak over small scales relative to the scale of the universe). Whatever dark energy actually is it makes up over 70% of the expanding universe which, perhaps, actually results in the generation of spacetime itself (with mass(energy) being the universal free lunch, (as Guth says), created by the negative energy of the gravitational force "pushing" against the dark energy. So, yes gravity is immutable. I actually do not see what difference a "prior to the so-called big bang" or a multiverse, etc. would make to gravity itself.

Remember, we are relating the immaterial prime mover of Aristotilian metaphysics to gravity. In other words, what is it that Aristotle's metaphysical conclusions actually describe. What gravity in fact is is almost besides the point. It is only metaphysically relevant as far as the concept of gravity is concerned related to the Aristotilian metaphysical concept of the prime mover.

[robrecht]

I think it is essentially correct to describe gravity as a prime mover (as an efficient cause) in the sensible world as we know it. Thanks for the explanation of repellant gravity during inflation. That goes a long way toward positing the same gravity driving inflation in a multiverse or omniverse and might eliminate my reservation about the speculative existence of gravity independent of space time and matter.

Before I would describe gravity as the prime mover, however, I would also want to see further consideration of matter and energy (you've already hinted at space and time). Do you consider them to be prime movers as well? Theory of everything?

Of course, none of this relates to Aristotle's notion of final causality, which distinguishes the why question from the how question, and which is perhaps the heart and soul of all metaphysical speculation.

[shunyadragon]

I would consider the nature of gravity as a potential factor in the prime mover, but whatever unifying unifying principle of all the forces and/or the underlying Natural Laws and constants represents the prime mover(s) in nature.

What we see in our relative time/space universe is the relationship of cause and effect with what we observe as gravity as well as the weak and strong electromagnetic forces. I am not willing to label gravity itself as the 'underlying prime mover' of our physical existence.

[robertb]

I think it is essentially correct to describe gravity as a prime mover (as an efficient cause) in the sensible world as we know it. Thanks for the explanation of repellant gravity during inflation. That goes a long way toward positing the same gravity driving inflation in a multiverse or omniverse and might eliminate my reservation about the speculative existence of gravity independent of space time and matter.

Before I would describe gravity as the prime mover, however, I would also want to see further consideration of matter and energy (you've already hinted at space and time). Do you consider them to be prime movers as well? Theory of everything?

Of course, none of this relates to Aristotle's notion of final causality, which distinguishes the why question from the how question, and which is perhaps the heart and soul of all metaphysical speculation.

I see matter/energy, dark matter and dark energy (whatever those two are...) as "created" potential relevant to the metaphysical concept we are playing with, (perhaps something akin to Aristotle's prime matter I suppose). "Created" in the sense that, if Guth is correct, matter/energy etc. results from the action, ("free lunch" energy moving the total energy towards 0), of gravity (negative energy) in the expansion (this, for the most part and sorry but I am trying to keep this really really simple both for my own sake and so that we do not get too distracted by really cool theory).

I did not address the other fundamental forces, EM and the nuclear forces so we can stay away from QM, but I do think a Grand Unification Theory would probably fit as well, perhaps more so in that such a theory should explain everything and we could then include QM, or so they say.

Yes, final causality and how to deal with it. We can get to this bit, I have some ideas we can discuss once we can see if the concept of gravity clears the hurdle with regards to the other relevant parts of the metaphysics. For now, I suppose, we could say that all naturally occuring and inorganic things tend to form due to gravity, at least at the most fundamental level, (actually I think this may cover organic things as well, but we can explore it along with some other ideas).

[David Hayward]

Here is a quote from the opening of an essay by an also-ran for the theoretical research funding that Julian Barbour won. As you will see, he argues that if time is considered fundamental it is possible to dispense with space, geometry and gravity:

It is often said that in general relativity time does not exist. This is because the Einstein equations generate motion in time that is a symmetry of the theory, not true time evolution. In quantum gravity, the timelessness of general relativity clashes with time in quantum theory and leads to the \problem of time" which, in its various forms, is the main obstacle to a successful quantum theory of gravity. I argue that the problem of time is a paradox, stemming from an unstated faulty premise. Our faulty assumption is that space is real. I propose that what does not fundamentally exist is not time but space, geometry and gravity.

I quote this to show that it is at least conceivable that gravity is not fundamental.

David

[robertb]

Here is a quote from the opening of an essay by an also-ran for the theoretical research funding that Julian Barbour won. As you will see, he argues that if time is considered fundamental it is possible to dispense with space, geometry and gravity:



I quote this to show that it is at least conceivable that gravity is not fundamental.

David

Facinating. If true, one day people may perform the same exercise with Einstein and Newton that we are doing with Aristotle. Cool!

[robrecht]

Why do you want to stay away from QM?