Why physics still matters
Part 4 of 5: The mythology of physics
The logic of the last installment leads to the conclusion that physics can provide no direct information about the intrinsic nature of its objects. This noncommittal ontological attitude follows directly from the formal object of this science, which examines material objects only insofar as they are subject to measurement, abstracting from all their other features. But physicists do in fact make ontological claims and give causal explanations for phenomena rooted in those claims. Indeed, they sometimes are regarded as the only ones qualified to provide such explanations. To properly evaluate and defend the value of physics, and describe the kind of knowledge that it gives us, we need to probe more deeply into what these claims mean. In this segment, I argue that the standard explanations of phenomena given by physicists, relying on notions of mechanistic reduction and laws of nature, are a form of verified mythology. They are valid explanations, and often the only kind of explanations accessible to human intelligence, but a close analysis of their origin will caution us against taking them too literally.
The Oxford English Dictionary defines a myth as “a traditional story, especially one concerning the early history of a people or explaining some natural or social phenomenon, and typically involving supernatural beings or events.” Sometimes these stories are the only available framework for organizing our experiences about things that are beyond human comprehension. Physics, particularly in the 20th century, deals with many things that are far beyond human comprehension, and requires mythological narrative for scientists to communicate with each other or with the public at all. Even in things that are closer at hand, the myth gives a universal language in which all scientists can communicate clearly with one another.
The need for mythological narrative in physics arises from the very nature of a formally quantitative science. Once the concrete material objects of the science have been abstracted into a set of quantities, they no longer possess any properties that could lead them to do one thing rather than another. Strictly speaking, the most this science can do on its own is mathematically describe the stable relationships among measured quantities in the nomological machines. But it is very difficult for humans to think and especially to exercise creativity at such a distant level of abstraction. The demands of human psychology require us to employ an imaginatively accessible language of entities with properties and powers. Physics therefore requires myth-making, and the theorist is given a wide latitude for the construction of the myth, with the only requirements being the recovery of the quantitative relationships and the elimination of irrelevant features.1
The core myth of physics is the myth of the laws of nature. This concept solves the basic problem mentioned above, that the abstracted objects of physics no longer contain any properties or tendencies that would lead them to do one thing rather than another. What is left after the process of abstraction is nothing but an inert bundle of potential measurement results. The concept of law allows the physicist to give these bundles a reason for action, in a maximally flexible way. Whenever stable regularities are established in a broad enough class of nomological machines, they can be elevated to the status of a law, which decrees the obedience of the entities within its domain.
To apply these laws to natural phenomena, one must mentally analyze the object into a composite of simpler objects that each approximates the relevant nomological machine. This process gives rise to another central element of the mythology: mechanistic explanation. Any complex phenomenon is explained in terms of the interactions among its component parts, each of which acts in accordance with the relevant physical law. There is no other relationship between parts and wholes that can be described within the framework of a formally quantitative science. The only narrative that fits the process for generating predictions of such phenomena within physics (without any extraneous content) is that of a complex machine built from simpler machines.2
A mythological language of laws of nature and mechanistic reduction thus arises necessarily from the very structure of physics. Even someone who does not believe in the independent existence of laws of physics, and who rejects the thesis that macroscopic things are literally built from atoms, would have to speak in these terms in order to do physics. This necessity leads to two important consequences. First of all, despite the limitations of mechanistic language, it would be a mistake to attempt to translate physics into a supposedly more suitable “holistic” language. Formally quantitative science is the only possible science of phenomena, as argued in the second installment, and this science can only be conducted with the help of a reductionist mythological narrative.3 At the same time, the fact that physicists use this language has no bearing on whether the world is really mechanistic or governed by laws. The nature of the discipline requires them to speak this way in any case.
Physicists implicitly acknowledge this point by taking their own ontology lightly, easily switching from one description to another depending on what is most useful for the application at hand. This is nowhere more apparent than in the descriptions of quantum phenomena, where the limitations of the mechanistic narrative become apparent even at the purely quantitative level. As theoretical physicist Sabine Hossenfelder puts it in a recent popular book: “The subjects of my research area, then, are particles that move through space and time, occasionally hitting each other and forming composites. Don’t think of them as little balls; they are not, because of quantum mechanics (more about that later). Better think of them as clouds that can take on any shape.”4 It turns out that the spectacularly well-confirmed mathematical theory of quantum mechanics is ultimately inconsistent with any one mental image of these “particles” — including the image of a “cloud.” For this reason, proficiency in quantum mechanics requires years of training, which eventually enables one to spontaneously reach for the appropriate mental image for a given context, in order to keep one’s imagination in line with the mathematics of the theory.
See Jacques Maritain, The Degrees of Knowledge (1959), pp. 162-164.
See Jacques Maritain, The Degrees of Knowledge (1959), p. 184.
This position does not fit neatly into the realist/instrumentalist taxonomy in philosophy of science. On the one hand, all the entities proposed by a physical theory are meant to be taken seriously in the context of the narrative, as real agents with causal powers, and the resulting explanation may well be the only one humans will ever have for a given phenomenon. On the other hand, the use of these entities and concepts within the narrative has no immediate ontological implications. Philosophical reflection on the existence and properties of various beings should make contact with physics primarily through the observed (or predicted) experimental observations themselves, without giving undue weight to the mythological representation currently in use by working scientists.
Wow, really enjoyed the explanation on the necessity of mythological narratives for sense-making in Physics. Thanks!