Medium 9780253006073

Doing Physics, Second Edition: How Physicists Take Hold of the World

Views: 723
Ratings: (0)

Doing Physics makes concepts of physics easier to grasp by relating them to everyday knowledge. Addressing some of the models and metaphors that physicists use to explain the physical world, Martin H. Krieger describes the conceptual world of physics by means of analogies to economics, anthropology, theater, carpentry, mechanisms such as clockworks, and machine tool design. The interaction of elementary particles or chemical species, for example, can be related to the theory of kinship—who can marry whom is like what can interact with what. Likewise, the description of physical situations in terms of interdependent particles and fields is analogous to the design of a factory with its division of labor among specialists. For the new edition, Krieger has revised the text and added a chapter on the role of mathematics and formal models in physics. Doing Physics will be of special interest to economists, political theorists, anthropologists, and sociologists as well as philosophers of science.

List price: $21.99

Your Price: $17.59

You Save: 20%

Remix
Remove
 

7 Chapters

Format Buy Remix

1 The Division of Labor: The Factory

ePub

Nature as a Factory; Handles and Stories. What Everyday Walls Must Do; Walls for a Factory; Walls as Providential. Particles, Objects, and Workers; What Particles Must Be Like; Intuitions of Walls and Particles. What Fields Must Be Like.

THE ARGUMENT IS: THE WORKINGS OF NATURE ARE ANALOGIZED to a factory with its division of labor. But here the laborers are of three sorts: walls, particles, and fields. Walls are in effect the possibility of shielding and separation; particles are the possibility of sources and localization; and fields allow for conservation laws and path dependence. Different kinds of degrees of freedom are associated with each type of laborer, and the laborers naturally restrict each other’s degrees of freedom – if the Factory of Nature is to be as productive as it is. Corresponding to the efficiency of the division of labor in a factory or an economy is the comparative richness, elegance, economy, and wide applicability of a physical mechanism or theory or model. Technically, Maxwell’s equations for electromagnetism are one realization of this political economy of a transcendental aesthetic, to honor both Adam Smith and Immanuel Kant in one phrase.1 (We discuss other mechanisms of production in subsequent chapters, for example ones in which exchange and the extent of the market are crucial features.) My claim is that physicists take Nature in this sense of manufacture; of course that sense being interpreted in terms of empirical “peculiarities,” as Smith employs the term.

 

2 Taking Apart and Putting Together: The Clockworks, The Calculus, and the Computer

ePub

The Right Degrees of Freedom; The Clockworks and The Calculus. Parts Are Strategies; Independence and Randomness; Dependence, Spreadsheets, and Differential Equations; Additivity and The Calculus; Disjoint Functionality and Interpretability: Bureaucracy, Flow Processing Plants, and Object-Oriented Programming; Sequence and Procedure. Parts Are Commitments.

THE ARGUMENT IS: PARTS ARE DEGREES OF FREEDOM, THEY ARE strategies, and they are commitments. In the first chapter the operative model was the division of labor in manufacture and in political economy. Now we ask just what kinds of individuals are suitable for a factory or for an economy of Nature. The operative model is a mechanism such as a clockworks, or anything composed of systematically associated or interdigitated parts, parts being the generic term that implies that individuals make up or compose something. (Note that the factory is now such a mechanism.) We shall be concerned with the process of building or making such a mechanism and, in chapter 5, the ways of an artisanal craftsmanship employed in discovering the mechanism’s workings. In this mode of thinking, if we can find good analytic units – parts – then we hope that their mode of composition will be manifest, or almost so. And if we can put the world together out of those parts, those parts should be good handles onto the world; namely, they are or they possess good degrees of freedom. (Of course, the mechanism may possess good degrees of freedom not readily reducible to the parts’ degrees of freedom.)

 

3 Freedom and Necessity: Family and Kinship

ePub

Recapitulation and Prospect; Kinship, Exchange, and Plenitude; Systematics in the Field; The Problem of “Quite Rarely”; Markets and Fetishes; Taking the Rules Seriously; Structure and System.

THE ARGUMENT IS: THERE IS A REMARKABLE ANALOGY BETWEEN kinship systems, particle physics, chemistry, and market economies. All may be accounted for by stories of fair exchange: of women, elementary particles, electrons, and currency and goods, respectively. Actual social systems and Nature are taken as the consequence of the necessary occurrence of all exchanges that are not forbidden (“plenitude”) and also the fact that names or labels on objects fully characterize them, both in their interaction with other objects and in their classification into groups of like objects (“fetishism” and “nondegeneracy”). Once we take on the world as a system of exchange, it seems we are also committed not only to plenitude and nondegeneracy, but also to rules of exchange that balance or conserve the flows of exchanged objects, the set of exchanges being the glue which ties the system together – at least if we are physicists. Here, the degrees of freedom are those nondegenerate fetishized labels (particle properties, for example) interpreted by the rules of forbiddenness, rules which reflect the orderlinesses or symmetries of the system. And the conservation of flow (say in balancing goods and money, or charge, or energy that is exchanged) also implies that we treat the exchanged materials as fully commensurable with each other.

 

4 The Vacuum and The Creation: Setting a Stage

ePub

So Far, an Epitome; Sweeping Up the Vacuum; Symmetry and Order. The Empty Stage; Of Nothing, Something, and the Vacuum. Setting Up the Stage; Ideologies for a Vacuum; The Dialectic of Finding a Good Vacuum; The Analogy of Substance, Once More. Fluctuations in a Vacuum. Annealing the World.

THE ARGUMENT IS: THIS CHAPTER DESCRIBES A SET OF STRATEGIES employed by physicists for achieving a comparatively simple world: They find an orderly emptiness – a “vacuum” that is much like our everyday notions of an empty space, properly understood. And in that vacuum, degrees of freedom that are in accord with that orderliness show themselves most effectively. Other degrees of freedom are tamed or repressed, and so they are hidden, and it is just in this sense that the space is empty. That is how the vacuum can both be empty and exhibit simple, orderly phenomena. (For physicists, a model for this vacuum is an orderly crystal.) This strategy might be called theatrical, a matter of setting a stage on which only certain actors and actions may appear. Along the way, an account is given of how Something that is in accord with this orderliness arises out of Nothing, an account of creation.* And that arising is an abrupt or discontinuous or fairly sharp transformation, much like freezing.

 

5 Handles, Probes, and Tools: A Rhetoric of Nature

ePub

A Craft of Science; Some Handles onto the World (Particles, Crystals, Gasses; Analogy; Phase Transitions; Knowledge Is Handling). Probes; Objectivity and Inelasticity; Probes and Handles. Tools and Toolkits; A Physicist’s Toolkit; So Far.

THE ARGUMENT IS: PHILOSOPHY HAS OFTEN PROJECTED A VISUAL analogy of knowledge – the knower as spectator – into its discussions of science. But physicists speak of what they are doing in terms of an Archimedean, haptic, and instrumental analogy. They sensitively get hold of the world (the Archimedean fulcrum) and so get a feel for it; and they craft explanations by employing as concepts just those instruments or tools they use to take hold of the world. Knowledge is handling, and Kantian transcendental conditions are actual experimental setups and theoretical models. The Archimedean analogy not only describes the physicist’s research work itself, but also the physicist’s theoretical structures – handles being degrees of freedom, probing modeling our interaction with Nature, and tools often being physical models and mathematics as well as experimental equipment. In earlier chapters we have been describing some components of such a toolkit. Here we review those descriptions in terms of handles, probes, and tools. Then we explore the technical and rhetorical structure of the toolkit, both in terms of mathematical and diagrammatic tools and in terms of a rhetoric for addressing Nature. The story of craft and handles is a commonplace for the physicist. It is the way physicists describe their work, just how it is actually done, as Maxwell described (p. xi).

 

6 Production Machinery: Mathematics for Analysis and Description

ePub

Philosophical Analysis and Phenomenological Description; Machinery and Production Processes; Naming and Modeling the World; Demonstrations and Proofs as Strategies of Explanation; Understanding “The Physics”; Analogy and Syzygy; The Mathematics and The Physics.

THE ARGUMENT IS: MATHEMATICS PROVIDES MACHINERY FOR modeling Nature, physicists customizing that mathematics so that it does the work of physics and of Nature, and along the way that machinery allows us to analyze and understand physical phenomena. So, for example, in mathematically modeling and so giving specific meaning to or “naming” freezing, or diffusion, or fluid flow, physicists discover better what they mean by those notions. In viewing Ising matter from many different mathematical points of view, physicists discover that Ising matter accommodates many modes of conception. The deep question then becomes how can Nature accommodate so many points of view (much as an everyday object accommodates many aspects and uses). Correspondingly, we are led to ask how are the different mathematical conceptions related to each other – what accommodates all of them. So there is an analogy between a physical analogy and a mathematical analogy, an analogy of analogies, what is called a syzygy.

 

7 An Epitome

ePub

PHYSICISTS’ THEORIES AND PICTURES OF NATURE ARE ANALOGIES with everyday phenomena and objects (hereafter, “objects”) such as a factory, a mechanism, or family relationships. How physicists get hold of the world through those analogies is the way Nature is for them. They understand each analogy in a highly stylized and particular way, and to so understand Nature is to be trained as a physicist.1 When understood in one of those highly stylized ways, the physics, the everyday objects, and the grammar or language overlap nicely. Nature would seem to accommodate many perspectives or many such analogies, and a particular object or phenomenon may be adequately described by more than one.

What physicists want is a deeper understanding of what is going on. The analogies allow them to name features of Nature and analyze them. Getting hold of an object in multiple ways, leading perhaps to analogies of analogies, can lead to that deeper understanding. In order to name and understand an object by analogy, physicists isolate features of both the physical object and the analogized everyday object, each at an appropriate scale or size of energy or length, while they ignore most other features. In other words, parts represent the whole: in rhetoric called a synecdoche, in anthropology called fetishism. Such fetishism, modeling Nature, has proved to be an effective strategy.

 

Details

Print Book
E-Books
Chapters

Format name
ePub
Encrypted
No
Sku
B000000031734
Isbn
9780253006080
File size
1.06 MB
Printing
Allowed
Copying
Allowed
Read aloud
Allowed
Format name
ePub
Encrypted
No
Printing
Allowed
Copying
Allowed
Read aloud
Allowed
Sku
In metadata
Isbn
In metadata
File size
In metadata