Aquinas and Modern Physics

[Veritas6]

What do you make of this short video that states the First Way works with Aristotle’s physics and cosmology, but is now invalidated by modern physics? One objection mentions physical changes resulting from gravity, nuclear forces, and electromagnetism do not come about from continual action of an external moving agent, but from intrinsic capacities identified as “fundamental forces”.

Another objection mentions no individual changes observed nor the motion of the universe is essentially subordinated chains. They are “temporally successive transfers of [kinetic] energy”. Physical change and motion result from intrinsic forces and not from continuous action of per se causes. I would appreciate any assistance. The written transcript is the second link, thank you.

http://www.aquinasonline.com/Topics/firstway-assess.pdf

 

[rom]

What do you make of this short video that states the First Way works with Aristotle’s physics and cosmology, but is now invalidated by modern physics?

Strictly speaking St. Thomas philosophy of nature is not based on Aristotle’s scientific cosmology (although he sometimes illustrated his teachings with examples based on that cosmology), but on Aristotle’s philosophical treatises on physics and metaphysics. So St. Thomas’ philosophy was not invalidated by modern physics.

One objection mentions physical changes resulting from gravity, nuclear forces, and electromagnetism do not come about from continual action of an external moving agent, but from intrinsic capacities identified as “fundamental forces”.

Many of the concepts of modern physics today are mere models of reality, or “vehicles for calculation,” and do not necessarily represent real physical elements. Take “force,” for example. For the physicist, the force, F, acting on a body of mass m moving with an acceleration a, is given by F = ma^2. It is the mathematical product of the mass of the moving body and the square of its acceleration. But a mathematical product is a concept, it is not the real cause of a body’s motion. It is a concept useful for describing the motion of a moving body, but is not itself something real. I am not saying that the body’s motion does not have a real cause. It does, but it is not the “force” of the physicist. The “force” of the physicist is just a conceptual tool, a vehicle for quantifying the observable action of the cause. When a bat hits a ball, the force F calculated by the physicist helps to describe (by means of additional equations, of course) the projectile and trajectory of the ball’s motion as it moves in space. But F is not the cause of the ball’s motion. The bat is.

As a philosopher St. Thomas dealt with issues of cause and effect, because he was interested in the causes of being and becoming. He was interested in the bat, not in the force F. For St. Thomas, the motion of the ball was brought about by the action of the bat, independent of how you, as a physicist, describe the motion of the ball mathematically. The philosopher is interested in the real causes of being and becoming, not in the mathematical description of physical phenomena.

To be continued … (This will be a long one… sorry. But you asked for it.)

 

[rom]

Continued from Post #2

What I will say next applies as well to the other “fundamental forces” of nature, but I will only talk of gravity for now because everybody is quite familiar with it. What exactly is “gravity”? Using Newtonian mechanics, gravity is a force calculated as F = Gm1m2 /s^2, where G is the gravitational constant. Given two bodies of masses m1 and m2, at a distance s apart, the force of attraction between them can be calculated. Again, notice that “gravity” is just a mathematical product, a concept, but it is useful for describing the behavior of bodies in space, such as the planets around the sun.

Now, question: why do bodies attract in the first place? Does the physicist have an answer? No, because the real cause is invisible and cannot be observed. Actually, the physicist hasn’t got a clue. He does not know the nature of the cause of attraction between bodies, but he knows it is there, and calls it gravity. Even though he does not know the exact nature of this unseen cause, nothing stops him from sharpening his tools and inventing more concepts to be able to describe gravity better, especially in the scale of quantum reality. Do you know what he does? He postulates the existence of a subatomic particle, known as the graviton, and then imagine the gravitational force as being equivalent to the exchange of gravitons between particles. Is the graviton a real particle then? NO! But it is a useful concept or model for describing gravitational forces among subatomic particles.

Now let me digress a little to talk about models. Foundation engineers often design the concrete foundation of a vibrating machine foundation that is resting on earth. Do you know how they do it? They model the soil-foundation system as a spring mass system with some damping. By experiment they make some measurements to determine the equivalent spring constant and damping of the soil. Then they set up the second-order differential equation of the spring-mass system to describe the motion of the vibrating mass. The predictions made on this model are not exact, because the soil is not a perfectly elastic material like a spring. But it gives good results when the amplitudes of vibration are small. Now, will you say that the soil is really a spring because the foundation engineer was successful in describing and designing his foundation by using this model? Of course, not. The spring is just a model, a conceptual tool he used to study the reaction of the soil subject to vibratory loads. The same is true of the various elementary particles and force particles of nature. They are models used by a physicist for predicting physical reality. They are not real particles, and the waves of quantum mechanics are not real waves. This does not mean there is nothing real in physics. There is, and it is what physicists are trying to describe. But the true essence and nature of material reality remain hidden and concealed from them!

To be continued… I told you, this is going be a long one.

 

[CaptainPrudeman]

Now, question: why do bodies attract in the first place? Does the physicist have an answer? No, because the real cause is invisible and cannot be observed. Actually, the physicist hasn’t got a clue.

The Detection of Gravitational Waves Was a Scientific Breakthrough, but What’s Next? | Smithsonian

Just gonna leave this here.

 

[CTBcin]

First Way works with Aristotle’s physics and cosmology, but is now invalidated by modern physics

I’m not philosophical expert, but I’m pretty sure that Thomas’ argument relies more on an Aristotelian metaphysics, not so much his physics or cosmology. So it doesn’t necessarily invalidate the argument.

Plus, I’m also pretty sure that Thomas’ understanding of “motion” is different from the modern empiricist understanding of “motion,” which might affect things as well.

Again, I’m no expert. So somebody correct me if I’m wrong.

 

[rom]

Continued from Post #3…

Now, what about the electron? The same. It is a model. There is a reality being modeled by it, but it itself is not real. That is why it can have strange properties. It can be a particle, or a wave. Sometimes, the electron is not even a particle or a wave, but an equation. And in Schroedinger’s equation, it is not the electron that travels like a wave, but the probability of finding an electron that spreads out like a wave. See what I mean?

So, to answer the first objection, let me say that reality and real physical changes do have a real cause. The concepts we use to mathematically describe them may not be real, but things in nature are real and have real causes. The dictum of St. Thomas, quidquid movetur ab alio movetur (“whatever is moved, is moved by another”) is true because it is a law of being. Motion is the transition from potency to act, and nothing in potency is reduced to act except by something already actual. It applies to real causes, not to conceptual models. Therefore, even when we do not exactly know or see the forces at play in quantum reality, the truth is, that the laws of being are still there.

We should be careful when building up a philosophy based on the changing theories of modern physics. Modern physics is becoming less and less real. In Newtonian mechanics “mass” began to represent, not a real stuff of bodily substance, but only a measure of a body to generate a gravitational force-field. Careless thinkers then thought that a force-field was real, until Einstein had a concept of “mass,” not as generating a force-field but as generating a “curved space-time continuum.” But hey, the warped space-time continuum of Einstein is also not a real continuum. It is just a model! Luckily, St. Thomas philosophy of nature was not based on Newtonian principles, or it would have been thrown away by every change in the models used by the physicist. The philosophy of St. Thomas is not based on the validity of gravity, relativity or quantum physics. It is a philosophy of being, not a science of phenomena.

 

[Veritas6]

Strictly speaking St. Thomas philosophy of nature is not based on Aristotle’s scientific cosmology (although he sometimes illustrated his teachings with examples based on that cosmology), but on Aristotle’s philosophical treatises on physics and metaphysics. So St. Thomas’ philosophy was not invalidated by modern physics.

I definitely agree. I’m more puzzled as to why this website has a video like this. The website seems to come from a Thomistic philosopher, but he has apparently weak objections. He seems to support everything else on St. Thomas at his website: www.aquinasonline.com.

I think the first objection wouldn’t invalidate the First Way, it seems these fundamental forces would support potentiality and actuality in metaphysics. If one were to “pull away the curtain” of the universe and its observed forces, there God would be. The second objection might be a little more difficult to prove: to find an actual essentially ordered causal chain. Read the PDF or watch the video for his full argument.

This discussion seemed interesting:

No such thing as a hierarchical causal series in the real world Philosophy

Metaphysicists emphasize the difference between a temporal causal series, and a hierarchical causal series. The most commonly used example of a temporal causal series is falling dominoes. While the most commonly used example of a hierarchical causal series is a hand pushing a stick, pushing a rock. But in fact these two causal series are identical, and they’re both temporal. In the example of the falling dominoes a force is applied to the first domino and this force then passes in order from on…

 

[rom]

I will continue tomorrow. I have to rest now.

 

[AlNg]

For the physicist, the force, F, acting on a body of mass m moving with an acceleration a , is given by F = ma^2. It is the mathematical product of the mass of the moving body and the square of its acceleration.

Not true. Force is the rate at which momentum is changing with time. So if the mass is constant, F = ma.

Now, question: why do bodies attract in the first place? Does the physicist have an answer? No, because the real cause is invisible and cannot be observed. Actually, the physicist hasn’t got a clue. He does not know the nature of the cause of attraction between bodies, but he knows it is there, and calls it gravity.

Not true. Gravity is a consequence of the curvature of spacetime.

Now, what about the electron? The same. It is a model. There is a reality being modeled by it, but it itself is not real.

Not true. The electron is a real subatomic particle. Since it is real, it can generate an electric field or when it is in motion it generates a magnetic field. An electric motor is a real object which is driven by the magnetic field induced according to the Ampere-Maxwell law. Not too many people will deny the reality of the electric motor.

 

[IWantGod]

What do you make of this short video that states the First Way works with Aristotle’s physics and cosmology, but is now invalidated by modern physics?

I would say that it misunderstands the concepts used and the context in which they are used. This is why there are constant efforts by Thomists to make Aquinas understandable to a modern audience. Whether or not Aquinas succeeds in proving God, the first hurdle is understanding that Aquinas is making a metaphysical argument and not a scientific one, and certain words used take on a different level of significance that has very little relevance to how those same words are used in a scientific context. The word motion in a metaphysical context for example has nothing to do with what physicists mean when they use that word. A person might appeal to science and say that it’s possible for there to be a movement or effect without a traditional notion of a cause. But this would completely misunderstand the argument since it has no relevance to what Aquinas would mean by cause and effect or motion. To gain a better understanding one would have to learn metaphysics and not just judge the five-ways by themselves.

So what happens, as it often does, we end up with straw-men of what Aquinas attempted to signify.

 

[AlNg]

The word motion in a metaphysical context for example has nothing to do with what physicists mean

OK. What does motion mean?

 

[rom]

Not true. Force is the rate at which momentum is changing with time. So if the mass is constant, F = ma.

Oops, you’re right. It was a slip. It should be F=ma. I cannot edit the post anymore, but the argument is unaffected. Thank you!

Not true. Gravity is a consequence of the curvature of spacetime.

Einstein’s theory of relativity replaced Newtonian mechanics. So, instead of thinking of the mass as generating a gravitational force field, physicists now think of the mass as generating a curved spacetime. But this still betrays the ignorance of the physicist regarding the nature of gravitation. For, physicists have no clue why (using general relativity) masses warp spacetime, just as they do not know (using Newtonian mechanics) why bodies attract each other.

Not true. The electron is a real subatomic particle.

You can think of the electrons as particles, and set up your equations assuming that they are particles. I italicized the word “think” to remind you that you are in the conceptual order and that your so-called “particle” is nothing but a conceptual model. Using this model you can succeed in predicting the effect of the electrons when you let them pass through a single slit and strike a screen behind it. But if you make the electrons pass through a double slit and let them strike a screen behind it, then the particle model fails to account for the interference pattern of bright and dark bands on the screen (This is the famous “double-slit experiment” in physics). For this interference pattern you need to revise your model and start thinking of the electron as a wave.

Remember the example I gave in my previous post (Post #3 above)? Soil is not really a spring just because you modeled it as a spring to describe the motion of a vibrating concrete foundation. In the same manner, an electron is not necessarily a particle just because you modeled it as a particle. This does not mean that the electron is not real. It is your model of the electron that is not real.

All the other elementary particles of modern physics – the fermions and the bosons – are models of subatomic reality. They are not real anymore than the “particle” used to model the electron is real.

 

[Magnanimity]

I would say that it misunderstands the concepts used and the context in which they are used. This is why there are constant efforts by Thomists to make Aquinas understandable to a modern audience

You ain’t lyin! These correctives occur ad nauseam.

OK. What does motion mean?

For the metaphysician, there are at least three distinct senses of the term motion. But first, a definition of “change” is necessary, since that is what St Thomas (and Aristotle) are addressing.

”Change is the process of becoming different or other than something was.
Motion in the strict sense (local motion) is change of place or position.
Motion in the wide sense is any change which can be directly measured by time, any change which is continuous or gradual in character.
Motion is the widest (or transferred sense) is any change.“ -Klubertanz, George, S.J. Introduction to the Philosophy of Being. (p.87).

So the metaphysician is wondering about change, period. It’s an analysis of what would have to be antecedentally true for any change whatsoever to be possible, since we note by constant observation of local motion that change is regularly occurring (change is actual, not merely possible).

 

[AlNg]

They are not real

Is the electric motor real? Since the electron is not real, how do you suppose the electric motor works? Is your computer real? Are you real?

 

[Annie]

Wow, I am totally impressed by your posts! That’s alotta larnin’ thar!

 

[rom]

Is the electric motor real? Since the electron is not real, how do you suppose the electric motor works?

Yes, the electric motor is real. But the model (electron particles) that we use to describe how it works, is not real. This does not mean there is no electricity that makes the motor runs. The electricity is very real. If you want to think of them as being made of electron particles, you are free to do so. However, thinking of them as particles does not make them particles. A better model of the electron is that it is neither a particle only nor a wave alone, but both. Some called it a “wavicle.”

 

[rom]

Wow, I am totally impressed by your posts! That’s alotta larnin’ thar!

Thank you, Annie.

Just gonna leave this here.

You left an article on the detection of gravitational waves. Let me give you some comments on that.

These gravitational waves are ripples in the spacetime model due to moving material bodies in space. They are just models. Physicists do not explain why the model bends near masses because physicists still do not know the nature of gravitation. They simply shrug their shoulders and say, “Well, it is what it is.” That’s OK, because the essence of matter is hidden from us. But we should not start claiming more than we know.

The spacetime model is useful for predicting the motion of large bodies of matter. But note: this does not mean that spacetime is real. It is a concept and, therefore, it is only in our minds. And, no matter how useful the spacetime model is in describing the universe, our world is still a 3D world; real space does not bend nor warp; and real time does not dilate nor contract. Now, if we want to make calculations, measurements, or make predictions about our world, then we should use our conceptual tools.

Plus, I’m also pretty sure that Thomas’ understanding of “motion” is different from the modern empiricist understanding of “motion,” which might affect things as well.

Yes, there is some difference. Because the philosopher, like St. Thomas, would want an explanation of motion. And he can only explain something by giving its causes: material, formal, efficient and final cause. In addition, he is interested in finding the ultimate cause of motion, which is how he arrives at the existence of God, the Prime Mover. On the other hand, a scientist only wants to be able to give, not an explanation, but a description of motion. And he wants a mathematical description, if possible. If you ask him to describe the motion of a rocket, he will describe it by calculating its position, velocity and acceleration at any time t. As a scientist, he could be interested in the proximate cause of motion, or what triggered the rocket to move. But he is not interested in tracing the ultimate cause of that motion to a Prime Mover.

 

[AlNg]

The electricity is very real.

What is electricity in your view?

 

[Dovekin]

no matter how useful the spacetime model is in describing the universe, our world is still a 3D world; real space does not bend nor warp; and real time does not dilate nor contract.

The “3D world” is as much of a model as spacetime is. It seeks to adapt our observations into a rational system. There are better ways of understanding our world.

Space most certainly does bend and warp. If it did not, our observations of light from other stars would not be comprehensible. Both models, with bending and without, are based on our observations.

Time dilation is also the simplest explanation of observations. Much simpler than a model that does not have time dilation.

The dictum of St. Thomas, quidquid movetur ab alio movetur (“whatever is moved, is moved by another”) is true because it is a law of being. Motion is the transition from potency to act, and nothing in potency is reduced to act except by something already actual.

This is, as conventionally understood, false. If you want to restate it, as Newton’s first law does, that is one thing. Using it as true by redefining motion is quite a different thing. You need to avoid the impression that “whatever moves is moved by another.”

 

[rom]

What is electricity in your view?

Electricity is the movement or flow of electrons.

The “3D world” is as much of a model as spacetime is.

Sure, the “3D world” is also a model, because it can be conceptualized. But the 3D world exists in reality; the spacetime world does not. Any world with a number of dimensions greater than 3, exists only in the mind. Hence, they are “beings of reason,” not real beings.

Space most certainly does bend and warp. If it did not, our observations of light from other stars would not be comprehensible.

It is not space that bends or warps. It is the path of light that bends and warps as it propagates through space. And the way that physicists predict this behavior is by modeling the path of light in a curved spacetime model.

Time dilation is also the simplest explanation of observations. Much simpler than a model that does not have time dilation.

Real time has nothing to do with mathematical time but the name. Real time is the duration of mobile or material beings, and it is absolute. Time dilation applies to measured time, or time referred to moving frames of reference. There is here a relativity of measurement, not a relativity of things. That by which we measure is relative, but not that which we measure.

This is, as conventionally understood, false. If you want to restate it, as Newton’s first law does, that is one thing. Using it as true by redefining motion is quite a different thing. You need to avoid the impression that “whatever moves is moved by another.”

I never redefined motion. I only translated into English an old Latin formula. Also, I never said that “whatever moves is moved by another.” What I said was “Whatever is moved is moved by another.” That means, whatever is moved, is never moved by itself, but by something other than itself.

There is a difference between a thing that moves, and a thing that is moved.

A thing “that moves” is a thing already in a state of actuality. A thing “that is moved” is a thing that transitions from potentiality to actuality.