The laws of motion of Isaac Newton (1643-1727), presented in his Principia1, are taught all over the world in high-school physics classes.
Law 1: Every body perseveres in its state of being at rest or of moving uniformly straight forward, except insofar as it is compelled to change its state by forces impressed. [p.416]
Law 2: A change in motion is proportional to the motive force impressed and takes place along the straight line in which that force is impressed. [p.416]
Law 3: To any action there is always an opposite and equal reaction; in other words, the actions of two bodies upon each other are always equal and always opposite in direction. [p.417]
I will discuss elsewhere the origin of these laws, to which, according to V.I.Arnol’d (1937-2010)2, “Newton himself did not pretend”.
The Third Law, which might seem obvious when first stated, has far-reaching implications, far beyond the typical discussions in a high-school class. In this post, I will present the implications of the Third Law, from my reading of the book Newton versus Einstein3, written by the father-and-son pair, Peter Graneau (1921-2014) and Neal Graneau (1963-). I have already mentioned the Graneaus in my post The Old Productive Research Programs Refuse to Die; therein I also presented André-Marie Ampère’s (1775-1836) defence of Newtonian physics when discussing electromagnetic and electrodynamic phenomena.
For the Graneaus, gravitational attraction between two bodies is a simultaneous phenomenon.
Since the magnitude of the gravitational attraction was a function of the size of both masses, and their distance of separation, it had to be an effect which both bodies experienced at the same time. To Newton the simultaneity of the gravitational force experienced by both bodies appears to have been self-evident. He lost no time discussing it. [p.35, my emphasis]
The Third Law begins thus: “To any action there is always an opposite and equal reaction”. It does not read “For any force there is always an opposite and equal force.” Yet, according to the Graneaus, that is exactly the manner in which gravitational attraction is presented today.
Today it is customary to draw diagrams of gravitational attraction by attaching an arrow of force on each body, the two forces being directed toward each other. This creates the false impression that gravitational attraction consists of two forces. It is then a small step to believing that the two forces may not act simultaneously. If the bodies are labeled A and B, the force on B could be due to something being sent from A to B. Similarly, A might receive a force from B. This kind of argument is found in all field-contact theories which have displaced Newtonian physics. Newton eliminated such speculations by insisting on a single force of attraction which could not be divided and had to be felt simultaneously by both interacting entities. To avoid confusion, the instantaneous nature of Newtonian attraction should have been spelled out in the universal law of gravitation by adding the sentence:
The force of gravitational attraction acts simultaneously on both interacting particles of bodies. [pp.35-36, my emphasis]
The Graneaus continue, explaining that this separation of gravitational attraction into two separate forces creates a false image, in which the words “instantaneous action at a distance” imply something physical moving at infinite speeds.
Mutual simultaneous far-action became instantaneous action at a distance. This choice of words was unfortunate because it hinted at something being transmitted at infinite velocity. Modern physics claims that nothing can travel faster than light. Therefore infinite velocities are not allowed. Hence, it is argued, instantaneous action at a distance must be wrong. But if nothing travels between the interacting bodies, as Newton's theory implies, the infinite velocity does not arise. [p.36]
Given that the words “instantaneous action at a distance” exist, I shall continue to use them. The above discussion leads one to ask, But what are the implications of action-at-a-distance, or far-action? Peter Graneau addresses this crucial question in the concluding paragraphs of his book Ampere-Neumann Electrodynamics of Metals4. He first refers to the book Forces and Fields5 by Mary B. Hesse (1924-2016), who explains that there are only two kinds of principles in science: far-actions or contact-actions.
Hesse … has written a beautiful account of action-at-a-distance in the history of science. It brings out the point that we human beings have been unable to think up more than two action principles. Far-actions, as they are called in the German literature, and the contact-actions of the aether and the field. The contact-action [philosophy] has been far more popular than that of far-actions. Yet for the most important single advance made in science, that by Newton, it was necessary to drop contact-actions in favor of far-actions. One gains the impression that far-actions lead to greater rigor. This was insufficient, however, to terminate the love affair of the human mind with something spiritual pervading all space. The unchallenged reign of newtonian physics lasted hardly more than two hundred years, which is half the age of quantitative physics. By the end of the twentieth century we are as totally immersed in ‘the field’ as Descartes was just before the rise of Newton. [p.296]
According to Peter Graneau, to get rid of far-actions, it was necessary to separate energy from matter, i.e., to introduce the concept of free energy, and ultimately the photon.
One of the cherished philosophical notions of modern physics is the flight of the photon through space. This ‘particle’ belongs to philosophy because there exists no experimental proof of its existence. The separation of energy from matter is essential when one wishes to do away with the other philosophical notion, that of far-actions. In Newton's cosmos we had only one substance which was matter. Now we have two substances, matter and energy, unification notwithstanding. They can co-exist in the same location or part company. Not always is energy a separate substance. A moving particle, for example, which possesses kinetic energy is only matter. [pp.296-297]
Graneau explains that the concept of free energy is the source of many problematic concepts in modern physics. For example, with no free energy, there would be no need to quantize energy. The reference to G. Burniston Brown (1902-1988) is to his book Science: Its Method and Its Philosophy6.
What would happen to physics if we were to do away with free energy? Well, to begin with, we would no longer have to quantize energy. This quantization was the perplexing aspect of Planck's discovery. The wave-particle duality would disappear, for we then would have to explain the wave-like behavior of the particle by far actions without a wave of energy. This has already been done quite successfully by Burniston Brown …. It would also mean, as mentioned before, that energy transmission time lags would have to be explained by simultaneous matter interactions depending on time derivatives. Abolishing free energy would spell the end of special and general relativity. So much hinges on choosing one of the only two available philosophical principles of far and contact action. [p.297, my emphasis]
Peter Graneau finishes with a paragraph stating that following the line of André-Marie Ampère and Franz Ernst Neumann (1798-1895) should be fruitful in the development of a causal quantum theory.
The Ampere-Neumann electrodynamics is utterly dependent on the quantization of matter and electric charge. It associates bound energy with the arrangement of material current elements and charges. It is compatible with the quantization underlying newtonian mechanics. It gave rise to the magnetic vector potential which has become so important in quantum mechanics. There is every indication that the Ampere-Neumann electrodynamics makes an ideal partner of quantum theory, albeit a causal quantum theory. [p.297, my emphasis]
To conclude, in my reading of these two works of Peter and Neal Graneau, Newton’s Third Law naturally leads one to accept action-at-a-distance, or far-action. Furthermore, embracing action-at-a-distance means the rejection of free energy, which implies that much of twentieth-century physics needs to be rethought.
Isaac Newton. The Principia: Mathematical Principles of Natural Philosophy. A New Translation by I. Bernard Cohen and Anne Whitman, assisted by Julia Budenz. Preceded by A Guide to Newton’s Principia, by I. Bernard Cohen. University of California Press, 1999.
V.I. Arnol’d. Huygens and Barrow, Newton and Hooke: Pioneers in mathematical analysis and catastrophe theory from evolvents to quasicrystals. Translated from the Russian by Eric J.F. Primrose. Birkhäuser Verlag, 1990. p.24.
Peter Graneau and Neal Graneau. Newton versus Einstein: How Matter Interacts with Matter. New York: Carlton Press, 1993.
Peter Graneau. Ampere-Neumann Electrodynamics of Metals. Second Edition. Palm Harbor, Florida: Hadronic Press, 1994.
Mary B. Hesse. Forces and Fields: The Concept of Action at a Distance in the History of Physics. Dover, 1962.
G. Burniston Brown. Science: Its Method and Its Philosophy. London: George Allen & Unwin, 1950.
This speed of gravity thing is such a noodle. Years ago I had someone walk me through the General Relativity explanation, he claimed we were assuming that the distortions in spacetime were propagating at the speed of light. When he got to the end though, it was "as if" the Sun n& Earth were feeling each other's instantaneous positions, not the 8 minute lagged positions. I have no idea if others would agree with that presentation. But it kind of contributed to me not wanting to pursue GR.