We are surrounded by gender lore from the time we are very small. It is ever-present in conversation, humor, and conflict, and it is called upon to explain everything from driving styles to food preferences. Gender is embedded so thoroughly in our institutions, our actions, our beliefs, and our desires, that it appears to us to be completely natural. The world swarms with ideas about gender – and these ideas are so commonplace that we take it for granted that they are true, accepting common adage as scientific fact. As scholars and researchers, though, it is our job to look beyond what appears to be common sense to find not simply what truth might be behind it, but how it came to be common sense. It is precisely because gender seems natural, and beliefs about gender seem to be obvious truths, that we need to step back and examine gender from a new perspective. Doing this requires that we suspend what we are used to and what feels comfortable, and question some of our most fundamental beliefs. This is not easy, for gender is so central to our understanding of ourselves and of the world that it is difficult to pull back and examine it from new perspectives. But it is precisely the fact that gender seems self-evident that makes the study of gender interesting. It brings the challenge to uncover the process of construction that creates what we have so long thought of as natural and inexorable – to study gender not as given, but as an accomplishment; not simply as cause, but as effect; and not just as individual, but as social. The results of failure to recognize this challenge are manifest not only in the popular media, but in academic work on language and gender as well. As a result, some gender scholarship does as much to reify and support existing beliefs as to promote more reflective and informed thinking about gender.

Introduction

A language is a highly structured system of signs, or combinations of form and meaning. Gender is embedded in these signs and in their use in communicative practice in a variety of ways. Gender can be the actual content of a linguistic sign. For example, English third-person singular pronouns distinguish so-called neuter (it) from masculine and feminine (she/her/her; he/him/his). The neuter pronoun is mainly used for inanimates, but we will see later that it is occasionally used for animals and even people. Perhaps more surprisingly, the masculine and feminine forms are sometimes used for inanimates (Curzan 2003) and sometimes masculine is used for a female person or animal, feminine for a male (see McConnell-Ginet [forthcoming]). The suffix -ess transforms a male or generic noun into a female one (heir; heiress). Lexical items, as well, refer directly to male and female (as in the case of male and female; girl and boy). In other cases, the relation between a linguistic sign and social gender can be secondary. For example, the adjectives pretty and handsome both mean something like ‘good-looking,’ but have background meanings corresponding to cultural ideals of good looks for females and males respectively, and are generally used gender-specifically, or to invoke male- or female-associated properties. Consider, for example, what pretty and handsome suggest when used with objects such as houses or flowers. And although it is positive to describe someone as a handsome woman (it seems to accord her a little extra class) the description a pretty boy is generally not considered a compliment. There are many means by which we color topics with gender – by which we invoke gender and discourses of gender even when we are ostensibly talking about something else. At the same time, the resources that the language offers constrain us to some extent in how gender figures in our talk. English obliges us to specify whether a person is male or female when we use a third person singular pronoun (he, she, it), whereas Chinese does not.

Up until now, we have talked separately about different aspects of linguistic practice, all of which can be thought of as constituting a conventional toolbox for constructing gendered personae. In this, the final chapter, we will consider how people assemble the various resources in this linguistic toolbox to fashion selves. Each person uses the toolbox in their own way, mixing and matching linguistic resources. Some of this may be automatic – the product of long-ingrained habit – and some may be quite consciously strategic. The outcome is a communicative style, which combines with other components of style such as dress, ways of walking, hairdo, and patterns of consumption to constitute the presentation of a persona. It is in this process of fashioning selves that we do gender, and that we bring about change.

What is style?

Style is sometimes thought of as the external wrapping inside which the meaningful substance is found. People think that how it is said is distinct from what is said. But style is a combination of what we do and how we do it. You hear of people with “pushy” or “passive,” “friendly” or “obsequious” styles. What doctors say in the course of treating patients contributes as much to making them seem like doctors as the white coat and casually draped stethoscope. A tough guy's talk about his exploits is as much of his style – as big a part of his threatening demeanor – as his studded leather jacket. Of course, it's easier to buy the jacket or put on the lab coat than it is to treat patients or beat people up, and one could make those sartorial moves in order to give the impression that the other actions follow. But the sartorial moves will only work to the extent that (1) the social types already exist so that people know how to make the connection between the clothing and the activity, and (2) the performer can convince the audience that the content matches the form. Styles do not stand alone but signal social distinctions – the tough guy's persona distinguishes him from a “sissy” and a doctor's style distinguishes her from a patient, a nurse, an orderly. And the debutante is not a doctor, a tough guy, or her maid.

Gender is built into the very fabric of nations, even when it is not formally embedded in documents of nationhood. The fact that a society's gender order is often an important part of its patrimony is dramatically illustrated in current struggles between Western nations and conservative Islamic nations, as each points to the other's gender order as evidence of depravity. In this chapter, we will discuss how gender ideologies are recruited so that language and gender interact in the building of national, regional, and local communities and boundaries. We will begin with a discussion of how power accrues to particular language varieties, then move on to specific instances of the construction of boundaries through the gendering of language.

Language varieties in contact

Pierre Bourdieu pointed out (e.g., Bourdieu 1991) that the value of a person's utterances in the marketplace of ideas lies in the fate of those utterances – in whether they are picked up, attended to, acted upon, repeated. And he emphasized that this fate depends crucially on the language variety in which the utterances are framed. The right linguistic variety can transform an otherwise “worthless” utterance into one that may command attention in powerful circles. Like the right friends, clothes, manners, haircuts and automobiles, the “right” linguistic variety can facilitate access to positions and situations of societal power and the “wrong” variety can block such access. At the same time, although people who speak like Queen Elizabeth or like a US network newscaster may be helped thereby to gain access to the halls of global power, they will have trouble gaining access and trust in a poor community, or participating in a group of hip-hoppers, gang-bangers, or cheerleaders. And while these latter communities may not command global power, prestige or wealth, they command a variety of social and material resources that may be of greater value to many.

Overview

The existence of this book is owed (both figuratively and literally) to the fact that the building blocks of matter possess a quality called charge. Two important aspects of charge are conservation and quantization. The electric force between two charges is given by Coulomb’s law. Like the gravitational force, the electric force falls off like 1/r 2. It is conservative, so we can talk about the potential energy of a system of charges (the work done in assembling them). A very useful concept is the electric field, which is defined as the force per unit charge. Every point in space has a unique electric field associated with it. We can define the flux of the electric field through a given surface. This leads us to Gauss’s law, which is an alternative way of stating Coulomb’s law. In cases involving sufficient symmetry, it is much quicker to calculate the electric field via Gauss’s law than via Coulomb’s law and direct integration. Finally, we discuss the energy density in the electric field, which provides another way of calculating the potential energy of a system.

Electric charge

Electricity appeared to its early investigators as an extraordinary phenomenon. To draw from bodies the “subtle fire,” as it was sometimes called, to bring an object into a highly electrified state, to produce a steady flow of current, called for skillful contrivance. Except for the spectacle of lightning, the ordinary manifestations of nature, from the freezing of water to the growth of a tree, seemed to have no relation to the curious behavior of electrified objects. We know now that electrical forces largely determine the physical and chemical properties of matter over the whole range from atom to living cell. For this understanding we have to thank the scientists of the nineteenth century, Ampère, Faraday, Maxwell, and many others, who discovered the nature of electromagnetism, as well as the physicists and chemists of the twentieth century who unraveled the atomic structure of matter.

Preface to the first edition of Volume 2

The subject of this volume of the Berkeley Physics Course is electricity and magnetism. The sequence of topics, in rough outline, is not unusual: electrostatics; steady currents; magnetic field; electromagnetic induction; electric and magnetic polarization in matter. However, our approach is different from the traditional one. The difference is most conspicuous in Chaps. 5 and 6 where, building on the work of Vol. I, we treat the electric and magnetic fields of moving charges as manifestations of relativity and the invariance of electric charge. This approach focuses attention on some fundamental questions, such as: charge conservation, charge invariance, the meaning of field. The only formal apparatus of special relativity that is really necessary is the Lorentz transformation of coordinates and the velocity-addition formula. It is essential, though, that the student bring to this part of the course some of the ideas and attitudes Vol. I sought to develop—among them a readiness to look at things from different frames of reference, an appreciation of invariance, and a respect for symmetry arguments. We make much use also, in Vol. II, of arguments based on superposition.

Our approach to electric and magnetic phenomena in matter is primarily “microscopic,” with emphasis on the nature of atomic and molecular dipoles, both electric and magnetic. Electric conduction, also, is described microscopically in the terms of a Drude-Lorentz model. Naturally some questions have to be left open until the student takes up quantum physics in Vol. IV. But we freely talk in a matter-of-fact way about molecules and atoms as electrical structures with size, shape, and stiffness, about electron orbits, and spin. We try to treat carefully a question that is sometimes avoided and sometimes beclouded in introductory texts, the meaning of the macroscopic fields E and B inside a material.

Overview

The first half of this chapter deals mainly with the potential associated with an electric field. The second half covers a number of mathematical topics that will be critical in our treatment of electromagnetism. The potential difference between two points is defined to be the negative line integral of the electric field. Equivalently, the electric field equals the negative gradient of the potential. Just as the electric field is the force per unit charge, the potential is the potential energy per unit charge. We give a number of examples involving the calculation of the potential due to a given charge distribution. One important example is the dipole, which consists of two equal and opposite charges. We will have much more to say about the applications of dipoles in Chapter 10.

Turning to mathematics, we introduce the divergence, which gives a measure of the flux of a vector field out of a small volume. We prove Gauss’s theorem (or the divergence theorem) and then use it to write Gauss’s law in differential form. The result is the first of the four equations known as Maxwell’s equations (the subject of Chapter 9). We explicitly calculate the divergence in Cartesian coordinates. The divergence of the gradient is known as the Laplacian operator. Functions whose Laplacian equals zero have many important properties, one of which leads to Earnshaw’s theorem, which states that it is impossible to construct a stable electrostatic equilibrium in empty space. We introduce the curl, which gives a measure of the line integral of a vector field around a small closed curve. We prove Stokes’ theorem and explicitly calculate the curl in Cartesian coordinates. The conservative nature of a static electric field implies that its curl is zero. See Appendix F for a discussion of the various vector operators in different coordinate systems.

Overview

In this chapter we study how electric fields affect, and are affected by, matter. We concern ourselves with insulators, or dielectrics, characterized by a dielectric constant. The study of electric fields in matter is largely the study of dipoles. We discussed these earlier in Chapter 2, but we will derive their properties in more generality here, showing in detail how the multipole expansion comes about. The net dipole moment induced in matter by an electric field can come about in two ways. In some cases the electric field polarizes the molecules; the atomic polarizability quantifies this effect. In other cases a molecule has an inherent dipole moment, and the external field serves to align these moments. In any case, a material can be described by a polarization density P. The electric susceptibility gives (up to a factor of ϵ0) the ratio of P to the electric field. The effect of the polarization density is to create a surface charge density on a dielectric material. This explains why the capacitance of a capacitor is increased when it is filled with a dielectric; the surface charge on the dielectric partially cancels the free charge on the capacitor plates.

We study the special case of a uniformly polarized sphere, which interestingly has a uniform electric field in its interior. We then extend this result to the case of a dielectric sphere placed in a uniform electric field. By considering separately the free charge and bound charge, we are led to the electric displacement vector D, whose divergence involves only the free charge (unlike the electric field, whose divergence involves all the charge, by Gauss’s law). We look at the effects of temperature on the polarization density, how the polarization responds to rapidly changing fields, and how the bound-charge current affects the “curl B” Maxwell equation. Finally, we consider an electromagnetic wave in a dielectric. We find that only a slight modification to the vacuum case is needed.

Overview

Magnetic fields in matter are a bit more involved than electric fields in matter. Our main goal in this chapter is to understand the three types of magnetic materials: diamagnetic materials, which are weakly repelled by a solenoid; paramagnetic materials, which are somewhat strongly attracted; and ferromagnetic materials, which are very strongly attracted. As was the case in Chapter 10, we will need to understand dipoles. The far field of a magnetic dipole has the same form as that of an electric dipole, with the magnetic dipole moment replacing the electric dipole moment. However, the near fields are fundamentally different due to the absence of magnetic charge. We will find that diamagnetism is due to the fact that an applied magnetic field causes the magnetic dipole moment arising from the orbital motion of electrons in atoms to pick up a contribution pointing opposite to the applied field. In contrast, in the case of paramagnetism, the spin dipole moment is the relevant one, and it picks up a contribution pointing in the same direction as the applied field. Ferromagnetism is similar to paramagnetism, although a certain quantum phenomenon makes the overall effect much larger; a ferromagnetic dipole moment can exist in the absence of an external magnetic field. Magnetized materials can be described by the magnetization M, the curl of which gives the bound currents (which arise from both orbital motion and spin). By considering separately the free and bound currents, we are led to the field H (also called the “magnetic field”) whose curl involves only the free current (unlike the magnetic field B, whose curl involves all the current, by Ampère’s law).

The metal lead is a moderately good conductor at room temperature. Its resistivity, like that of other pure metals, varies approximately in proportion to the absolute temperature. As a lead wire is cooled to 15 K its resistance falls to about 1 ∕ 20 of its value at room temperature, and the resistance continues to decrease as the temperature is lowered further. But as the temperature 7.22 K is passed, there occurs without forewarning a startling change: the electrical resistance of the lead wire vanishes! So small does it become that a current flowing in a closed ring of lead wire colder than 7.22 K – a current that would ordinarily die out in much less than a microsecond – will flow for years without measurably decreasing. This phenomenon has been directly demonstrated. Other experiments indicate that such a current could persist for billions of years. One can hardly quibble with the flat statement that the resistivity is zero. Evidently something quite different from ordinary electrical conduction occurs in lead below 7.22 K. We call it superconductivity.

Superconductivity was discovered in 1911 by the great Dutch low-temperature experimenter Kamerlingh Onnes. He observed it first in mercury, for which the critical temperature is 4.16 K. Since then hundreds of elements, alloys, and compounds have been found to become superconductors. Their individual critical temperatures range from roughly a millikelvin up to the highest yet discovered, 138 K. Curiously, among the elements that do not become superconducting are some of the best normal conductors such as silver, copper, and the alkali metals.