vol III Development:
Chapter 4: Physics
page 3: Action
God is pure act
A common theme in ancient thought is the belief that there is an invisible reality which is more real than visible reality. In the history of western philosophy, this idea was introduced by Parmenides who proposed the existence of an eternal complete being behind the world of appearances. This idea was taken up by Plato and found a place in Christian doctrine. Parmenides - Wikipedia, Richard Kraut - Plato, Neoplatonism and Christianity - Wikipedia
Plato's student Aristotle broke away from this tradition, and may be considered among the first empirical scientists. Aristotle appears to have been a voracious collector of data. He studied and commented on many of his philosophical predecessors, and wrote on many subjects from physics and cosmology to poetics, ethics, politics and metaphysics. Aristotle - Wikipedia
Aristotle developed a model of the world which comprised two principles: potency and act; and one axiom: no potency can actualize itself. He used this model to argue for the existence of an unmoved mover that motivated the world. Thomas used the same argument to establish the existence of God. Potentiality and actuality - Wikipedia, Aristotle: Metaphysics XII, xii, Aquinas 13: Does God exist?
This model enabled Aristotle to construct an ordered sequence of causality running from the unmoved mover to the simplest physical realities. This ladder bridged the ancient dichotomy between the visible and the invisible and opened the way for a theory of everything. The axiom that no potency can actualize itself, given the existence of actual beings, implies the existence a pure actuality.
The history of the universe suggests that it began very simple and gradually became more complex as further layers of process are added to existing structure. Such development, for instance, carries the biosphere from simple chemical molecules to hugely complex forms of life.
In Thomas' theology, act is the primordial entity from which all else flows, the creator. Act, as a general synonym for any event or thing, is fundamentally just an existing unit with no particular identity. Identity is conferred on particular acts by their place in larger processes. We can agree with Thomas that in the primordial act essence and existence are identical. The essential feature of an act is that it exists.
Modern physics
Aristotle realized that all knowledge comes through the senses, so science is based on observable events, that is actions. This is consistent with Landauer's idea that all information is physical. Even spiritual, theological and metaphysical documents and mathematical proofs are recorded and transmitted in physical text, be it made of paper and ink or little magnets. Aristotle - On the Soul, Rolf Landauer: Information is a physical entity
We understand the term action to cover everything that happens in the world. Some events, like a world war or the collapse of a star, are very large. Others are exceedingly small, but all events are equally actions. Action is a very general and abstract term that covers everything that happens. A theology or theory of everything seeks to understand the system whose output is all the actions or events we observe, both within ourselves and outside.
The modern history of action begins with the idea developed by Maupertuis and others that the creator made the Universe as efficient as possible. He felt that we might expect that natural events occur with minimum action. Maupertuis' principle - Wikipedia
This idea eventually evolved into Hamilton's principle, the principle of stationary action. Hamilton saw the action is a functional defined as a the time integral of the Lagrangian function. The Lagrangian L is the difference between the kinetic energy and the potential energy of the particle whose trajectory or path is being studied. Hamilton's principle - Wikipedia
We find the path of stationary action using variational methods. Such methods are the mathematical equivalent of evolution, selecting a particular outcome from a set of variations. An advantage of the Hamilton's approach is that it works for both classical and quantum mechanics. The quantum mechanical version of the Hamiltonian method is realized by Feynman's path integral formulation of quantum mechanics. Calculus of variations - Wikipedia, Path integral formulation - Wikipedia, Feynman: QED
Quantum mechanics
Quantum mechanics reveals that there is a smallest action, whose size is measured by Planck's quantum of action. The observable universe is pixellated at this scale. We understand all large actions to comprise many smaller actions, ultimately of quanta of action. Quantum - Wikipedia
Thomas, following Aristotle, define God as pure action. For Thomas action is consistent with the eternity of God. It contains no time component. So here, although we think of action as involving motion, we make no assumptions about the time rate of motion, so my whole life may be considered as one action, as may 'events' like the existence of the universe, which may be considered to go on forever. In general, we may consider a 'life' as an action.
Quantum mechanics is a mathematical model of the world (theory of everything?) built in Hilbert space. Information is stored as vectors in this space and processed by differential operators. Hilbert space - Wikipedia, Quantum mechanics - Wikipedia
We may see quantum mechanics as a description of a network.The fundamental event in a network is an act of communication. An event occurs when two sources in the network make a connection, exchange information and disconnect. Quantum mechanics predicts the rate of traffic flow between sources, which is represented by the probability of a transformation between the states of the sources which are encoded as state vectors in Hilbert space. .
The quantum formalism predicts the probability of these transformations, but it cannot predict when they will actually happen. The transformation from the continuous formalism to discrete observed states is often called 'the collapse of the wave function'. Here we understand that such a quantum event, regardless of the complexity of states involved, is realized with one quantum of action. Wave function collapse - Wikipedia
Taking the network view, we interpret a quantum interaction as a description of the computation involved in transmitting a message. We interpret eigenfunctions as Turing machines, and eigenvalues as the halted states of these computers, the fixed poinst or particles that we actually observe.
Action is conserved
When a photon is exchanged between two atoms, a quantum of action is exchanged. Given that this happens at every interaction, we can see the quantum network as a conserved flow of quanta of action. We can use the network model to extrapolate to any level of complexity in the Universe. Because of the universality of action, we may see our own lives as a flow of actions, at our scale, each involving huge numbers of actions at the physical quantum scale.
In classical physics, the dimensions of action are ML2T-1, which are the same as the dimensions of angular momentum. This dimensional similarity enables us to understand action in terms of spin and orbital angular momentum. The dimensions of energy are ML2T-2, so that we understand energy to be the time rate of action. The energy in a communication channel is therefore a measure of the rate of action or information transfer.
A consequence of this analogy is that in physics, action, like angular momentum, has direction, a spin axis. Although we observe quantum events in space-time, we consider space and time as emergent properties of the Universe. From this point of view, action is a feature of a layer beneath space-time. As a consequence, the axis of action has no preferred direction. Action is the fundamental symmetry of the universe, as the exchange of a message is the fundamental symmetry of a network. In the following pages we will record some more guesses about the evolution of our complex universe within a dynamically simple divinity. Spin (physics) - Wikipedia, Richard Feynman: Symmetry and Conservation Laws
Action unites physics and theology
In languages, the more general a term, the greater the number of instances it applies to. My name applies only to me, whereas the term mammal applies to me and a large number of other creatures. I have long had the feeling that action is so primordial that it has no measure: there is nothing else to compare it to, it covers everything. Its essence is in fact its existence. Michael Nelson: Existence
From the most abstract point of view an action is simply an event or state which can be counted and is (in itself) nothing more. From this point of view, we might compare an action to a set, a definite and separate entity. This is action seen from the outside. But if the universe is divine we are inside the divine action, where we see the concrete complexity of the divinity, each of us seeing the fixed points in the divine activity from our own point of view.
A completed action becomes part of history and forever static. Physics sees physical process as the creation and annihilation of fundamental particles. In general, a particle is created, has a certain lifetime and is then annihilated, releasing its energy for the creation of further particles. The lifetime is the static phase of its existence. I can see myself as a particle, created seventy years ago and existing in a state of life until I die.
Although classical Newtonian dynamics attributes no direction to time until we come to statistical physics, and physicists use time reversal in modelling anti-particles, our common experience is that time moves inevitably forward. We are carried along by time, leaving the past behind and moving into the future. An action (ie a completed transformation) marks the boundary between past and future. An action done remains done until undone by some agent. An important agent is time itself. Since quantum systems are always in motion things change with the passage of time.
So time is the Universal system clock. Time is measured as a count of action, and there is no measure of action. It is the ubiquitous, primordial undifferentiated unit. Aristotle's definition of time: the number of motion according to before and after seems consistent with this idea. Aristotle: time
(revised 16 May 2016)
|
Copyright:
You may copy this material freely provided only that you quote fairly and provide a link (or reference) to your source.
Further reading
Books
Click on the "Amazon" link below each book entry to see details of a book (and possibly buy it!)
Feynman, Richard, QED: The Strange Story of Light and Matter, Princeton UP 1988 Jacket: 'Quantum electrodynamics - or QED for short - is the 'strange theory' that explains how light and electrons interact. Thanks to Richard Feynmann and his colleagues, it is also one of the rare parts of physics that is known for sure, a theory that has stood the test of time. . . . In this beautifully lucid set of lectures he provides a definitive introduction to QED.'
Amazon
back |
Links
| Aquinas 13, Summa: I 2 3: Whether God exists?, I answer that the existence of God can be proved in five ways. The first and more manifest way is the argument from motion. . . . The second way is from the nature of the efficient cause. . . . The third way is taken from possibility and necessity . . . The fourth way is taken from the gradation to be found in things. . . . The fifth way is taken from the governance of the world. back |
| Aristotle, Metaphysics, Book XII, vii, 'But since there is something which moves while itself unmoved, existing actually, this can in no way be otherwise than as it is. For motion in space is the first of the kinds of change, and motion in a circle the first kind of spatial motion; and this the first mover produces. The first mover, then, exists of necessity; and in so far as it exists by necessity, its mode of being is good, and it is in this sense a first principle.' 1072b3 sqq back |
| Aristotle - On the Soul, On the Soul - The Internet Classics Archive, 'Holding as we do that, while knowledge of any kind is a thing to be honoured and prized, one kind of it may, either by reason of its greater exactness or of a higher dignity and greater wonderfulness in its objects, be more honourable and precious than another, on both accounts we should naturally be led to place in the front rank the study of the soul. The knowledge of the soul admittedly contributes greatly to the advance of truth in general, and, above all, to our understanding of Nature, for the soul is in some sense the principle of animal life. Our aim is to grasp and understand, first its essential nature, and secondly its properties; of these some are taught to be affections proper to the soul itself, while others are considered to attach to the animal owing to the presence within it of soul.' back |
| Aristotle - Wikipedia, Aristotle - Wikipedia, the free encyclopedia, 'Aristotle (Ancient Greek: Ἀριστοτέλης, Aristotélēs) (384 BC – 322 BC) was a Greek philosopher and polymath, a student of Plato and teacher of Alexander the Great. His writings cover many subjects, including physics, metaphysics, poetry, theater, music, logic, rhetoric, linguistics, politics, government, ethics, biology, and zoology. Together with Plato and Socrates (Plato's teacher), Aristotle is one of the most important founding figures in Western philosophy. Aristotle's writings were the first to create a comprehensive system of Western philosophy, encompassing morality, aesthetics, logic, science, politics, and metaphysics.' back |
| Aristotle: time, Physics, VIII, 1 (251b12), 'Further, how can there be any 'before' and 'after' without the existence of time? Or how can there be any time without the existence of motion? If, then, time is the number of motion or itself a kind of motion, it follows that, if there is always time, motion must also be eternal.' back |
| Calculus of variations - Wikipedia, Calculus of variations - Wikipedia, the free encylopedia, 'Calculus of variations is a field of mathematical analysis that deals with maximizing or minimizing functionals, which are mappings from a set of functions to the real numbers. Functionals are often expressed as definite integrals involving functions and their derivatives. The interest is in extremal functions that make the functional attain a maximum or minimum value – or stationary functions – those where the rate of change of the functional is zero.' back |
| Computability theory - Wikipedia, Computability theory - Wikipedia, the free encyclopedia, 'Computability theory, also called recursion theory, is a branch of mathematical logic that originated in the 1930s with the study of computable functions and Turing degrees. The field has grown to include the study of generalized computability and definability. In these areas, recursion theory overlaps with proof theory and effective descriptive set theory.
The basic questions addressed by recursion theory are "What does it mean for a function from the natural numbers to themselves to be computable?" and "How can noncomputable functions be classified into a hierarchy based on their level of noncomputability?". The answers to these questions have led to a rich theory that is still being actively researched.' back |
| Einstein, Podolsky and Rosen, Can the Quantum Mechanical Description of Physical Reality be Considered Complete?, A PDF of the classic paper. 'In a complete theory there is an element corresponding to each element of reality. A sufficient condition for the reality of a physical quantity is the possibility of predicting it with certainty, without disturbing the system. In quantum mechanics in the case of two physical quantities described by non-commuting operators, the knowledge of one precludes the knowledge of the other. Then either (1) the description of reality given by the wave function in quantum mechanics is not complete or (2) these two quantities cannot have simultaneous reality. Consideration of the problem of making predictions concerning a system on the basis of measurements made on another system that had previously interacted with it leads to the result that if (1) is false then (2) is also false, One is thus led to conclude that the description of reality given by the wave function is not complete.' back |
| Hamilton's principle - Wikipedia, Hamilton's principle - Wikipedia, the free encyclopedia, 'IIn physics, Hamilton's principle is William Rowan Hamilton's formulation of the principle of stationary action (see that article for historical formulations). It states that the dynamics of a physical system is determined by a variational problem for a functional based on a single function, the Lagrangian, which contains all physical information concerning the system and the forces acting on it. The variational problem is equivalent to and allows for the derivation of the differential equations of motion of the physical system. Although formulated originally for classical mechanics, Hamilton's principle also applies to classical fields such as the electromagnetic and gravitational fields, and has even been extended to quantum mechanics, quantum field theory and criticality theories.' back |
| Hilbert space - Wikipedia, Hilbert space - Wikipedia, the free encyclopedia, 'The mathematical concept of a Hilbert space, named after David Hilbert, generalizes the notion of Euclidean space. It extends the methods of vector algebra and calculus from the two-dimensional Euclidean plane and three-dimensional space to spaces with any finite or infinite number of dimensions. A Hilbert space is an abstract vector space possessing the structure of an inner product that allows length and angle to be measured. Furthermore, Hilbert spaces are complete: there are enough limits in the space to allow the techniques of calculus to be used.' back |
| Juan Yin et al, Bounding the speed of 'spooky action at a distance', 'In the well-known EPR paper, Einstein et al. called the nonlocal correlation in quantum entanglement as `spooky action at a distance'. If the spooky action does exist, what is its speed? All previous experiments along this direction have locality loopholes and thus can be explained without having to invoke any `spooky action' at all. Here, we strictly closed the locality loopholes by observing a 12-hour continuous violation of Bell inequality and concluded that the lower bound speed of `spooky action' was four orders of magnitude of the speed of light if the Earth's speed in any inertial reference frame was less than 10^(-3) times of the speed of light.' back |
| Maupertuis' principle - Wikipedia, Maupertuis' principle - Wikipedia, the free encyclopedia, 'In classical mechanics, Maupertuis' principle (named after Pierre Louis Maupertuis) is an integral equation that determines the path followed by a physical system without specifying the time parameterization of that path. It is a special case of the more generally stated principle of least action. More precisely, it is a formulation of the equations of motion for a physical system not as differential equations, but as an integral equation, using the calculus of variations.' back |
| Michael Nelson, Existence (Stanford Encyclopedia of Philosophy), 'Existence raises deep and important problems in metaphysics, philosophy of language, and philosophical logic. Many of the issues can be organized around the following two questions: Is existence a property of individuals? and Assuming that existence is a property of individuals, are there individuals that lack it? back |
| Neoplatonism and Christianity - Wikipedia, Neoplatonism and Christianity - Wikipedia, the free encyclopedia, 'Neoplatonism was a major influence on Christian theology throughout Late Antiquity and the Middle Ages in the West due to St. Augustine of Hippo, who was influenced by the early Neoplatonists Plotinus and Porphyry, and the works of the Christian writer Dionysius the Pseudo-Areopagite, who was influenced by later Neoplatonists, such as Proclus and Damascius.' back |
| Parmenides - Wikipedia, Parmenides - Wikipedia, the free encyclopedia, 'Parmenides of Elea (early 5th century BC) was an ancient Greek philosopher born in Elea, a Greek city on the southern coast of Italy. He was the founder of the Eleatic school of philosophy, his only known work is a poem which has survived only in fragmentary form. In it, Parmenides describes two views of reality. In the Way of Truth, he explained how reality is one; change is impossible; and existence is timeless, uniform, and unchanging. In the Way of Opinion, he explained the world of appearances, which is false and deceitful. These thoughts strongly influenced Plato, and through him, the whole of western philosophy.' back |
| Path integral formulation - Wikipedia, Path integral formulation - Wikipedia, the free encyclopedia, 'The path integral formulation of quantum mechanics is a description of quantum theory which generalizes the action principle of classical mechanics. It replaces the classical notion of a single, unique trajectory for a system with a sum, or functional integral, over an infinity of possible trajectories to compute a quantum amplitude. . . . This formulation has proved crucial to the subsequent development of theoretical physics, since it provided the basis for the grand synthesis of the 1970s which unified quantum field theory with statistical mechanics. . . . ' back |
| Potentiality and actuality - Wikipedia, Potentiality and actuality - Wikipedia, the free encyclopedia, 'In philosophy, Potentiality and Actualit are principles of a dichotomy which Aristotle used to analyze motion, causality, ethics, and physiology in his Physics, Metaphysics, Ethics and De Anima (which is about the human psyche).
The concept of potentiality, in this context, generally refers to any "possibility" that a thing can be said to have. Aristotle did not consider all possibilities the same, and emphasized the importance of those that become real of their own accord when conditions are right and nothing stops them.[3] Actuality, in contrast to potentiality, is the motion, change or activity that represents an exercise or fulfillment of a possibility, when a possibility becomes real in the fullest sense. back |
| Quantum - Wikipedia, Quantum - Wikipedia, the free encyclopedia, 'In physics, a quantum (plural: quanta) is an indivisible entity of a quantity that has the same units as the Planck constant and is related to both energy and momentum of elementary particles of matter (called fermions) and of photons and other bosons. The word comes from the Latin "quantus," for "how much." Behind this, one finds the fundamental notion that a physical property may be "quantized", referred to as "quantization". This means that the magnitude can take on only certain discrete numerical values, rather than any value, at least within a range.' back |
| Quantum mechanics - Wikipedia, Quantum mechanics - Wikipedia, the free encyclopedia, 'Quantum mechanics, also known as quantum physics or quantum theory, is a theory of physics providing a mathematical description of the interaction of matter and energy.' back |
| Richard Feynman, Lctures on Physics III,17: Symmetry and Conservation Laws, 'The most beautiful thing of quantum mechanics is that the conservation theorems can, in a sense, be derived from something else, whereas in classical mechanics they are practically the starting points of the laws. . . . In quantum mechanics, however, the conservation laws are very deeply related to the principle of superposition of amplitudes, and to the symmetry of physical systems under various changes. This is the subject of the present chapter. Although we will apply these ideas mostly to the conservation of angular momentum, the essential point is that the theorems about the conservation of all kinds of quantities are—in the quantum mechanics—related to the symmetries of the system.' back |
| Richard Kraut - Plato, Plato (Stanford Encyclopedia of Philosophy), First published Sat Mar 20, 2004; substantive revision Thu Sep 17, 2009
'Plato (429–347 B.C.E.) is, by any reckoning, one of the most dazzling writers in the Western literary tradition and one of the most penetrating, wide-ranging, and influential authors in the history of philosophy. . . . Few other authors in the history of philosophy approximate him in depth and range: perhaps only Aristotle (who studied with him), Aquinas, and Kant would be generally agreed to be of the same rank.' back |
| Rolf Landauer, Information is a Physical Entity, 'Abstract: This paper, associated with a broader conference talk on the fundamental physical limits of information handling, emphasizes the aspects still least appreciated. Information is not an abstract entity but exists only through a physical representation, thus tying it to all the restrictions and possibilities of our real physical universe. The mathematician's vision of an unlimited sequence of totally reliable operations is unlikely to be implementable in this real universe. Speculative remarks about the possible impact of that, on the ultimate nature of the laws of physics are included.' back |
Spin (physics) - Wikipedia, Spin (physics) - Wikipedia, the free encyclopedia, 'In quantum mechanics and particle physics, spin is an intrinsic form of angular momentum carried by elementary particles, composite particles (hadrons), and atomic nuclei.
Spin is one of two types of angular momentum in quantum mechanics, the other being orbital angular momentum. Orbital angular momentum is the quantum-mechanical counterpart to the classical notion of angular momentum: it arises when a particle executes a rotating or twisting trajectory (such as when an electron orbits a nucleus). The existence of spin angular momentum is inferred from experiments, such as the Stern–Gerlach experiment, in which particles are observed to possess angular momentum that cannot be accounted for by orbital angular momentum alone.' back |
| Wave function collapse - Wikipedia, Wave function collapse - Wikipedia, the free encyclopedia, 'In quantum mechanics, wave function collapse is the phenomenon in which a wave function—initially in a superposition of several eigenstates—appears to reduce to a single eigenstate (by "observation"). It is the essence of measurement in quantum mechanics, and connects the wave function with classical observables like position and momentum. Collapse is one of two processes by which quantum systems evolve in time; the other is continuous evolution via the Schrödinger equation.' back |
|
