bluuebunny/crossref_metadata_2025 huggingface dataset:
Computational Principles
Authors: Pollock John L.
Published: November 2020

Much of the usefulness of probability derives from its rich logical and mathematical structure. That structure comprises the probability calculus. The classical probability calculus is familiar and well understood, but it will turn out that the calculus of nomic probabilities differs from the classical probability calculus in some interesting and important respects. The purpose of this chapter is to develop the calculus of nomic probabilities, and at the same time to investigate the logical and mathematical structure of nomic generalizations. The mathematical theory of nomic probability is formulated in terms of possible worlds. Possible worlds can be regarded as maximally specific possible ways things could have been. This notion can be filled out in various ways, but the details are not important for present purposes. I assume that a proposition is necessarily true iff it is true at all possible worlds, and I assume that the modal logic of necessary truth and necessary exemplification is a quantified version of S5. States of affairs are things like Mary’s baking pies, 2 being the square root of 4, Martha’s being smarter than John, and the like. For present purposes, a state of affairs can be identified with the set of all possible worlds at which it obtains. Thus if P is a state of affairs and w is a possible world, P obtains at w iff w∊P. Similarly, we can regard monadic properties as sets of ordered pairs ⧼w,x⧽ of possible worlds and possible objects. For example, the property of being red is the set of all pairs ⧼w,x⧽ such that w is a possible world and x is red at w. More generally, an n-place property will be taken to be a set of (n+l)-tuples ⧼w,x1...,xn⧽. Given any n-place concept α, the corresponding property of exemplifying a is the set of (n + l)-tuples ⧼w,x1,...,xn⧽ such that x1,...,xn exemplify α at the possible world w. States of affairs and properties can be constructed out of one another using logical operators like conjunction, negation, quantification, and so on.
Acceptance Rules
Authors: Pollock John L.
Published: November 2020

I have urged that nomic probability be analyzed in terms of its conceptual role. The conceptual role analysis of nomic probability has four parts: (1) an account of statistical induction; (2) an account of the computational principles that allow some nomic probabilities to be derived from others; (3) an account of acceptance rules; and (4) an account of direct inference. The purpose of the present chapter is to develop and defend the acceptance rules that will play a central role in the theory of nomic probability. The theories of direct inference and statistical induction will then be derived from the acceptance rules and the computational principles defended in the last chapter. Although some of the computational principles are novel, they still amount to little more than an embellishment of the classical probability calculus. The main philosophical weight of the theory of nomic probability will be borne by the acceptance rules. A simple acceptance rule will be described and defended in section 2. The epistemological framework presupposed by the rule will be discussed and refined in section 3. Sections 4 and 5 will demonstrate that more powerful rules can be derived from the simple acceptance rule described in section 2. The philosophical literature contains numerous proposals for probabilistic acceptance rules. For instance, the following “Simple Rule” has had a number of proponents: . . . Belief in P is justified iff P is probable. . . . Note, however, that this rule is formulated in terms of definite probabilities. This is true of most candidate acceptance rules. However, nomic probability is an indefinite probability. It would make no sense to propose a rule like the Simple Rule for nomic probability. Nevertheless, there is an obvious candidate for an acceptance rule formulated in terms of nomic probability. This is the Statistical Syllogism, whose traditional formulation is something like the following: . . . Most A’s are B’s. This is an A./ Therefore, this is a E. . . . It seems clear that we often reason in roughly this way. For instance, on what basis do I believe what I read in the newspaper?
Recapitulation
Authors: Pollock John L.
Published: November 2020

The purpose of this book is to clarify probability concepts and analyze the structure of probabilistic reasoning. The intent is to give an account that is precise enough to actually be useful in philosophy, decision theory, and statistics. An ultimate objective will be to implement the theory of probabilistic reasoning in a computer program that models human probabilistic reasoning. The result will be an AI system that is capable of doing sophisticated scientific reasoning. However, that takes us beyond the scope of the present book. The purpose of this chapter is to give a brief restatement of the main points of the theory of nomic probability and provide an assessment of its accomplishments. The theory of nomic probability has a parsimonious basis. This consists of two sets of principles. First, there are the epistemic principles (A3) and (D3):(A3) If F is projectible with respect to G and r > .5, then ┌prob(F/G) > r┐ is a prima facie reason for the conditional ┌Gc ⊃ Fc┐, the strength of the reason depending upon the value of r. (D3) If F is projectible with respect to H then ┌Hc & prob(F/G&H) < prob(F/G) ┐ is an undercutting defeater for rprob(F/G) > r┐ as a prima facie reason for ┌Gc ⊃ Fc┐. Second, there are some computational principles that generate a calculus of nomic probabilities. These principles jointly constitute the conceptual role of the concept of nomic probability and are the basic principles from which the entire theory of nomic probability follows. The epistemic principles presuppose a prior epistemological framework governing the interaction of prima facie reasons and defeaters. Certain aspects of that framework play an important role in the theory of nomic probability. For example, the principle of collective defeat is used recurrently throughout the book. The details of the epistemological framework are complicated, but they are not specific to the theory of probability. They are part of general epistemology. The computational principles are formulated in terms of what some will regard as an extravagant ontology of sets of possible objects and possible worlds. It is important to realize that this ontology need not be taken seriously.
Advanced Topics: Defeasible Reasoning
Authors: Pollock John L.
Published: November 2020

The principal novelty this book brings to probability theory is a sophisticated epistemology accommodating defeasible reasoning. It is this that makes the theory of nomic probability possible. Earlier theories lacked the conceptual framework of prima facie reasons and defeaters, and hence were unable to adequately formulate principles of probabilistic reasoning. Thus far, the book has relied upon a loosely formulated account of the structure of defeasible reasoning, but that must be tightened up before the theory can be implemented. This chapter gives a more rigorous account of defeasible reasoning and compares the present theory with some related work in AI. Reasoning begins from various kinds of inputs, which for convenience I will suppose to be encoded in beliefs. Crudely put, reasoning proceeds in terms of reasons. Reasons are strung together into arguments and in this way the conclusions of the arguments become justified. The general notion of a reason can be defined as follows: (2.1) A set of propositions {P1,...,Pn} is a reason for S to believe Q if and only if it is logically possible for S to be justified in believing Q on the basis of believing P1, ...,Pn. There are two kinds of reasons-defeasible and nondefeasible. Nondefeasible reasons are those reasons that logically entail their conclusions. For instance, (P&Q) is a nondefeasible reason for P. Such reasons are conclusive reasons. P is a defeasible reason for Q just in case P is a reason for Q, but it is possible to add additional information that undermines the justificatory connection. Such reasons are called ‘prima facie reasons’. This notion can be defined more precisely as follows: (2.2) P is a prima facie reason for S to believe Q if and only if P is a reason for S to believe Q and there is an R such that R is logically consistent with P but (P&R) is not a reason for S to believe Q.
Advanced Topics: Induction
Authors: Pollock John L.
Published: November 2020

It is well known, since Goodman [1955], that principles of induction require a projectibility constraint. On the present account, such a constraint is inherited from the projectibility constraint on (A1)–(A3). It remains to be shown, however, that this derived constraint is the intuitively correct constraint. Let us define: (1.1) A concept B (or the corresponding property) is inductively projectible with respect to a concept A (or the corresponding property) iff ┌X is a set of A’s, and all the members of X are also B’s┐ is a prima facie reason for ┌A ⇒ B┐, and this prima facie reason would not be defeated by learning that there are non-B’s. A nomic generalization is projectible iff its consequent is inductively projectible with respect to its antecedent. What is needed is an argument to show that inductive projectibility is the same thing as projectibility. To make this plausible, I will argue that inductive projectibility has the same closure properties as those defended for projectibility in Chapter 3. Goodman introduced inductive projectibility with examples of nonprojectible concepts like grue and bleen, and the impression has remained that only a few peculiar concepts fail to be inductively projectible. That, however, is a mistake. It is not difficult to show that most concepts fail to be inductively projectible, inductive projectibility being the exception rather than the rule. This results from the fact that, just like projectibility, the set of inductively projectible concepts is not closed under most logical operations. In particular, I will argue below that although inductive projectibility is closed under conjunction, it is not closed under either disjunction or negation. That is, negations or disjunctions of inductively projectible concepts are not automatically inductively projectible. Just as for projectibility, we can argue fairly conclusively that inductive projectibility is closed under conjunction. More precisely, the following two principles hold: (1.2) If A and B are inductively projectible with respect to C, then (A&B) is inductively projectible with respect to C. (1.3) If A is inductively projectible with respect to both B and C, then A is inductively projectible with respect to (B&C).
When the Old Left Was Young
Authors: Cohen Robert
Published: November 2020

The Depression era saw the first mass student movement in American history. The crusade, led in large part by young Communists, was both an anti-war campaign and a movement championing a broader and more egalitarian vision of the welfare state than that of the New Dealers. The movement arose from a massive political awakening on campus, caused by the economic crisis of the 1930s, the escalating international tensions, and threat of world war wrought by fascism. At its peak, in the late 1930s, the movement mobilized at least a half million collegians in annual strikes against war. Never before, and not again until the 1960s, were so many undergraduates mobilized for political protest in the United States. The movement lost nearly all its momentum in 1939, when the signing of the Hitler-Stalin pact served to discredit the student Communist leaders. Adding to the emerging portrait of political life in the 1930s, this book is the result of an extraordinary amount of research, has fascinating individual stories to tell, and offers the first comprehensive history of this student insurgency.
Spies, Suppression, and Free Speech on Campus
Authors: Cohen Robert
Published: November 2020

As the student movement spread across America from 1933 to 1935, it encountered strong opposition from college and university administrators. The anti-war demonstrations and strikes, the mass endorsement of the Oxford Pledge, and the rising influence of leftist-led student organizations outraged many of these administrators. This activism seemed so radical and sudden a departure from the political quiescnce of the collegiate past that campus officials often found it intolerable. The initial impulse of many college deans and presidents was to try suppressing this student activism, in a manner quite similar to that previously seen on New York’s campuses during the early days of the NSL. But just as repression had failed to kill New York’s student movement in 1931 — 1932, it would also fail to stop the rapid growth of the movement nationally in the mid-1930s. This was due in large part to the determined free speech fights waged by student activists, who made campus political rights a top priority for their movement. Free speech became a “cause célèbre” on campus because, as former NSL leader Celeste Strack recalled, students found administration acts of suppression politically offensive and personally insulting: . . . While the war and peace issue was becoming big, academic freedom was already a hot issue because no matter what you wanted to talk about you were up against the effort . . . [of] the administration not to give you the right to talk like grown up people about issues. . . . They . . . [would] treat us like children, and that was very deeply resented, [and] . . . this was a very important question. . . . The disrespect of college administrators for student political rights ran deeper, however, than even most movement activists could have guessed; it led these campus officials to infringe upon student civil liberties not only publicly but also covertly. College and university administrators opposed to the student movement became involved in secretly feeding information on student protesters to the Federal Bureau of Investigation (FBI), enabling the Bureau to open dossiers on many of these Depression era campus activists.
Activist Impulses
Authors: Cohen Robert
Published: November 2020

No sooner had the student movement emerged than speculation began about the sources of campus activism. Since such large scale student protest was unprecedented in the nation’s history, it was natural that a variety of theories would evolve as Depression America sought to explain this new phenomenon. An assortment of conservatives—which included superpatriots, redbaiting editors, and politicians— wrote the most and screamed the loudest about the causes of student radicalism during the 1930s; they did so because of their outrage at the growth of Left-led organizations and student anti-war demonstrations on campus. Their most frequent explanation for this unwelcome upsurge of student activism centered on the faculty, whom they blamed for corrupting and radicalizing youth. The conservative press depicted college faculty as dangerously subversive. Professors emerged in these pages as a sort of academic branch of the Red Army. “There are few colleges or universities where parents may send their sons and daughters without their being contaminated with some phase of the vilest of Communistic and allied teaching,” warned Roscoe J.C. Dorsey, in the The National Republic, a superpatriot magazine which crusaded against faculty and student radicalism. In this same journal E.D. Clark, president of the Indiana State Medical Association, diagnosed “Red Microbes in Our Colleges,” evoking fears of political and sexual radicalism. The Hoosier doctor claimed that “under the guise of ‘academic freedom’ many professors . . . are not only teaching communism, socialism, anarchy . . . but are also endorsing ‘free love’ and unrestricted sex relations between unmarried people.” This rightwing indictment of the faculty was not confined, however, to the college level. Conservatives hurled similar charges against teachers in secondary and even elementary schools. The Hearst press, which did so much to give such charges national circulation, claimed in 1935 that thanks to the work of subversives in the nation’s school systems “two hundred thousand Soviet schoolbooks have been imported into America.” According to these rightwing critics, youths’ support for radicalism in college derived from exposure to subversion by teachers at all levels of the American educational system.
Consonant Omissions
Authors: Treiman Rebecca
Published: November 2020

In this chapter, I turn from vowel omission errors to consonant omission errors. Consider the child who spelled blow as BOW. This child did not include any letter for /l/. Similarly, the child who spelled tumble as TUBOL failed to represent /m/. In this chapter, I ask when children omit consonant phonemes from their spelling and why they do so. As in Chapter 7, omission errors are defined phonologically rather than orthographically. Thus, the child who spelled thin as TIN symbolized each phoneme in the word’s spoken form, although he did not spell /θ/ in the conventional manner. From a phonological point of view, this child did not make an omission error. The study of consonant omissions is particularly important in light of the claim that beginning spellers often omit the final consonants of monosyllabic words (Morris & Perney, 1984). For example, children may misspell back as B or BA. Why do they do this? Is it because /k/ is the last consonant in the word, because /k/ is the last consonant in the syllable, or for both reasons? To address these questions, it is necessary to look beyond the simple consonant-vowel-consonant monosyllables that have been analyzed in much of the previous research. An examination of more complex words can also shed light on children’s omissions of consonants in clusters, as in BOW for blow. In the present study, consonant omission errors were not as common as consonant substitution errors. Of the children’s spellings of consonants, 7.4% or 800 out of 10,831 were omission errors. In contrast, 13.3% of all consonant spellings were substitution errors. Although the percentage of consonant omission errors was relatively low overall, omissions were quite common for certain consonants. For example, omissions were relatively common for the /l/ of blow and the /m/ of tumble; they were rare for the /l/ of love and the /m/ of milk. When interpreting the omission rates reported in this chapter, remember that the percentages are out of all the children’s spellings—correctly spelled words as well as incorrectly spelled words.
Environmental Cognition through Direct and Representational Experiences: A Life-Span Perspective
Authors: Liben Lynn S.
Published: November 2020

The purpose of this chapter is to provide a review of past research and theory in environmental cognition from the perspective of life-span developmental psychology, to suggest future directions for work in this area, and to lay the groundwork for questions of application that are discussed elsewhere in this volume. Before it is possible to address these goals, however, it is essential to establish what is meant by “a life-span developmental approach to environmental cognition.” The first section of the chapter is thus devoted to a discussion of these definitional issues. The second section provides a selective review of past research. The research has been chosen to illustrate how changes in individual development in a variety of domains (e.g., development of logical classification skills in the cognitive domain, or development of interpersonal attachment in the socioemotional domain) may have consequences for environmental cognition. The review of past work leads to the observation that most research has focused on how environmental cognition is derived from direct experience in environments. It is argued that another extremely influential source of environmental cognition is through exposure to representations of environments. Thus, the final section of the chapter contains discussions of the roles of environmental representations for environmental cognition, and descriptions of some recent research in this area. In the original conceptualization of the conference on which this volume is based, Evans and Gärling (1987) defined environmental cognition as . . . the processes involved in the perception and cognition of spatial information in the real world. Most of this research has not examined preference or evaluation. Instead the focus has been primarily on understanding the cognitive processes themselves and how they are influenced by person variables (e.g. age, gender, familiarity) and by environmental variables such as landmarks, path structures, or overall organizational factors, (p. 2) . . . This definition works well for the purpose intended, that is, for distinguishing environmental cognition from environmental assessment, on the one hand, and from decision making and action, on the other. In part, these distinctions are congruent with a taxonomy developed earlier (Liben, 198la), which similarly placed environmental cognition in a broader context.
Life-Span Developmental Issues in Environmental Assessment, Cognition, and Action: Applications to Environmental Policy, Planning, and Design
Authors: Moore Gary T.
Published: November 2020

This chapter addresses the question of how research on environmental assessment, cognition, and action can be utilized in the professional arenas of public policy, urban planning, and architectural design. Initially a discussion on three papers (Chapters 12, 13, and 14), the chapter attempts to extrapolate policy and design implications for the built environment from current knowledge on life-span developmental issues as represented by these three chapters. Suggestions of other research questions, issues, and strategies that might better inform policy and design are then discussed. In conclusion, the chapter briefly explores six general issues about the interaction of environmental cognition and research utilization. The contributions to this volume by Giovanna Axia, Erminielda Mainardi Peron, and Maria Rosa Baroni, by Lynn Liben, and by Roger Hart and Michael Conn have dealt heavily with child development and very little with aging or life-span development. Little evidence is presented from the gerontological and geriatric literatures, and less from the life-span literature. Liben presents a clear conceptualization of lifespan developmental approaches to environmental cognition, but to date there have been few studies and thus no data specifically on life-span developmental changes in environmental cognition. My chapter, therefore, will be weighted most heavily on the earlier phases of human development though, where feasible, it will comment on implications for the environment of elderly adults and on the environmental context of life-span developmental changes. Despite their titles and intentions, the three chapters focus most heavily on environmental cognition and much less on assessment and action. For example, after discussing the wide variety of possible definitions of assessment, including appraisal, evaluation, preferences, and attachment. Axia et al. focus most heavily on the cognitive aspects of schemata, representation, and organization of knowledge. Similarly, Hart and Conn valiantly take on the challenge of reporting on children's decision making and environmental behavior, but their empirical examples are also limited to cognitive and metacognitive issues. My chapter will thus also focus on environmental knowing. There are many interesting points of a theoretical and conceptual nature to raise about environmental assessment, cognition, and action from these three chapters, but this task is left to the other commentary chapter by Christopher Spencer.
Spectra and Cospectra Over Flat Uniform Terrain
Authors: Kaimal J. C. , Finnigan J. J.
Published: November 2020

Turbulent flows like those in the atmospheric boundary layer can be thought of as a superposition of eddies—coherent patterns of velocity, vorticity, and pressure— spread over a wide range of sizes. These eddies interact continuously with the mean flow, from which they derive their energy, and also with each other. The large “energy-containing” eddies, which contain most of the kinetic energy and are responsible for most of the transport in the turbulence, arise through instabilities in the background flow. The random forcing that provokes these instabilities is provided by the existing turbulence. This is the process represented in the production terms of the turbulent kinetic energy equation (1.59) in Chapter 1. The energy-containing eddies themselves are also subject to instabilities, which in their case are provoked by other eddies. This imposes upon them a finite lifetime before they too break up into yet smaller eddies. This process is repeated at all scales until the eddies become sufficiently small that viscosity can affect them directly and convert their kinetic energy to internal energy (heat). The action of viscosity is captured in the dissipation term of the turbulent kinetic energy equation. The second-moment budget equations presented in Chapter 1, of which (1.59) is one example, describe the summed behavior of all the eddies in the turbulent flow. To understand the conversion of mean kinetic energy into turbulent kinetic energy in the large eddies, the handing down of this energy to eddies of smaller and smaller scale in an “eddy cascade” process, and its ultimate conversion to heat by viscosity, we must isolate the different scales of turbulent motion and separately observe their behavior. Taking Fourier spectra and cospectra of the turbulence offers a convenient way of doing this. The spectral representation associates with each scale of motion the amount of kinetic energy, variance, or eddy flux it contributes to the whole and provides a new and invaluable perspective on boundary layer structure. The spectrum of boundary layer fluctuations covers a range of more than five decades: millimeters to kilometers in spatial scales and fractions of a second to hours in temporal scales.
Changing Patterns of Medical Study Before 1800
Authors: Bonner Thomas Neville
Published: November 2020

For the traditional physician of the eighteenth century, medicine was above all a humane study, mastered largely through books and the careful examination of medicine’s past and leavened now by a growing concern to know something firsthand of the feel of the human body in sickness and in health. To be a French or German or British physician in these years was to be a member of a cultural elite who, like other university graduates, found the truth in the rich treasures of ancient Greek and Latin writings. A degree in medicine was a testament of higher learning, not merely a professional qualification, and Latin was the visible symbol of that learning. Medicine was valued not so much for its efficacy in curing patients as for the knowledge it implied about the universe and humankind. Such notable figures as Quesnay, who had a medical degree, and Diderot, Voltaire, and Rousseau studied medicine as an integral part of a broad, humanistic culture. The character of a physician, wrote an English practitioner in 1794, “ought to be that of a gentleman, which cannot be maintained . . . but by a man of literature. He is much in the world, and mixes in society with men of every description.” Students were easily converted to the idea of the centrality of classical study in their lives. A young man in Edinburgh, for example, ridiculed his medical professors in 1797 for their ignorance and that of their students, who “could not translate the easiest passage in Latin.” On the Continent, a Munich professor offered at about the same time to instruct a whole class of medical students in liberal studies, since “their knowledge of the Latin language, philosophy, logic, and other general branches of education” brought “shame” to the faculty. Such complaints were frequent by 1800, revealing the growing tension between the ideal and the real in the classical training of students and professors. What kind of education, then, was suitable for a late-eighteenth-century physician? The mastery of ancient literature and medical texts was still essential to one’s status as a gentleman but was no longer regarded as the sole qualification for success as a physician.
Locating the Body in Electrical Space and Time Competing Authorities
Authors: Marvin Carolyn
Published: November 2020

In any culture codes for bodily communication are conventionally elaborated and, like other codes, require skillful manipulation. The body is the most familiar of all communicative modes, as well as the sensible center of human experience, which lives or dies with it. Upon it, all other codes are inscribed to a greater or lesser extent. There is no form of communication that does not require the body's engagement, though printed and written messages may involve a smaller direct range of its perceptual and motor capacities than oral-gestural messages do. In addition, strange experiences are often translated and made familiar by comparisons with the body, and by categories of classification derived from the body's experience. The body is a convenient touchstone by which to gauge, explore, and interpret the unfamiliar, an essential information-gathering probe we never quite give up, no matter how sophisticated the supplemental modes available to us. The body is also squarely at the critical juncture between nature and culture. It is nature, or in any case man's most direct link to nature, capable of opposing and resisting it at least for a while, either its own or that external to it. The inscription of cultural codes upon the body is perhaps the principal means of detaching it from nature and transforming it into culture. The body and its actions, therefore, have a richly ambiguous social meaning. They can be made to emphasize perceived distinctions between nature or culture as the need arises, or to reconcile them. Because men use what is known to them to make sense of what is not, a deep inquisitiveness about the relationship between electricity and the human body was part of the process of becoming socially acquainted with that novel and mysterious force in the late nineteenth century. And though electricity might be discussed either as an extension of nature or of the body, or as something opposed to and outside them, it was defined in any case inescapably with reference to them.
Thermodynamic Terms
Authors: Anderson Greg M. , Crerar David A.
Published: November 2020

Thermodynamics is the science that deals with energy differences and transfers between systems, and with systematizing and predicting what transfers will take place. Such fundamental topics naturally find application in all branches of science, and have been of interest since the earliest beginnings of science. In general, since we are dealing with energy transfers between systems, most of what follows has to do with what the entities (equilibrium states) are from which and to which energy is being transferred, and the boundaries or walls through which or by which the transfer is effected. It is in these considerations that we first see the differences between natural systems (reality) and our models of these systems. System refers to any part of the universe we care to choose, whether the contents of a crucible, a cubic centimeter in the middle of a cooling magma, or the solar system. Depending on the nature of the discussion, it must be more or less clearly defined and separated (in fact or in thought) from the rest of the universe, which then becomes known as the system's surroundings. At the outset, we will effect an enormous simplification by considering only systems that are unaffected by electrical, magnetic, or gravitational fields, and in which particles are sufficiently large that surface effects can be neglected. Each of these topics can be incorporated into the basic thermodynamic network to be developed, but it is a nuisance to carry them all along from the beginning, and a great deal can be done without considering them at all. More exactly, a great deal can be done if we choose to consider systems where these fields and surfaces play a minor role. Clearly we would not get very far if we tried to understand the solar system without considering gravitational fields. Chemical and geochemical problems however commonly do not need to have these factors included in order to be understood. In science, when a problem or a phenomenon such as the solar system or the boiling of water is said to be understood, what is usually meant is that we have a model of the phenomenon which is satisfactory at some level, and about which virtually all scientists agree.
Partial and Apparent Molar Properties
Authors: Anderson Greg M. , Crerar David A.
Published: November 2020

To this point we have developed a method of dealing with processes involving for the most part material (phases) of fixed composition. To progress further, we need to develop ways of dealing with the properties of dissolved substances, and with phases of variable composition. In other words, we need to deal with solutions. We have seen that the properties of homogeneous substances (usually, but not necessarily pure) are either total or molar properties (neglecting, as usual, specific properties). But obviously substances change drastically when they dissolve. How can we obtain properties for the dissolved substance alone, as opposed to the solution of which it is a part? Properties of dissolved substances are called apparent molar and partial molar properties, and these are the tools we need to discuss the thermodynamics of solutions in the following chapters. Partial molar properties are defined by partial derivatives (equations 2.22,9.7), which does not provide a very easy route to understanding them. There is however a highly intuitive way of thinking about partial molar properties. We will use volume as an example because it is readily visualized, but all relations derived can be used equally well for any other state variable. It will be useful to begin by realizing that we can also use derivatives to define molar properties of pure phases; this mathematical treatment is discussed in Chapter 2. Consider first the volume of a crystalline phase such as NaCl. The volume occupied by the salt, V, varies directly with the quantity of salt, so that a plot of volume versus number of moles of salt is a straight line (Figure 9.1).
Redox Systems
Authors: Anderson Greg M. , Crerar David A.
Published: November 2020

Up until this point we have dealt with familiar intensive variables such as temperature, pressure, density, and molar thermodynamic properties (molar entropies, free energies, and so on). There exists another, equally important intensive variable that we have used implicitly, but have not yet discussed in sufficient detail—the oxidation state of a system. This involves concepts and applications so useful to Earth scientists that we devote a complete chapter to this single variable. Except for nuclear processes, most chemical behavior is determined by electron distributions and interactions. From this point of view, the oxidation state of an atom is among the most fundamental of all its properties. Most elements can exist in multiple valences with each state usually displaying quite different behavior from the others. As an example, consider the element sulfur.
Atmospherically Forced Perturbations in the Oceans
Authors: Kraus Eric B. , Businger Joost A.
Published: November 2020

Kinetic energy flows almost exclusively downward, from the atmosphere into the ocean. The upward flux of energy is thermal, and that will be the topic of our concluding chapter. In the present chapter, we shall deal with the effects of kinetic energy inputs into the ocean. Although this requires some discussion of the different types of oceanic perturbations, our treatment of these topics is necessarily brief and incomplete. We are not concerned with details of the motion pattern in the deeper ocean or with processes involving friction and non-adiabatic mixing in the interior. These processes are essential for an understanding of ocean circulations. They are treated in general oceanographic textbooks and in many monographs that deal specifically with these subjects. Surface stress and air pressure variations produce surface wind waves along with a variety of other wave forms. Most of these waves are relatively slow, with periods that can be measured in hours, days, or even years. The amplitude of internal gravity waves in the oceans is often much larger than that of surface waves and their wavelengths tend to be in the kilometer range. The square of the amplitude-wavenumber product is usually a very small quantity. This makes first order approximations appropriate for many purposes. It justifies use of the hydrostatic approximation and of the linear equations as a basis for the following discussion. To do so, it is necessary to represent the unspecified forcing terms on the right-hand side of those equations in a linearized form. An algorithm for the inclusion of the various atmospheric inputs as a linearized boundary condition in the equations of motion for the ocean is discussed in Section 7.1. Section 7.2 describes a two-layer ocean model. Systems of this type are convenient for the conceptual consideration of atmosphere-ocean interactions, because the wind affects the ocean primarily through action upon the surface mixed-layer. Internal waves, the topic of Section 7.3, are ubiquitous both in the ocean and in the atmosphere. Essentially, sea surface gravity waves can be viewed as internal waves at the interface between two fluids of very unequal density.
Compounds of the Type (A, B)X
Authors: Bayly Brian
Published: November 2020

Compounds such as gallium aluminum arsenide are of interest for two reasons. First, they have practical use, so that benefit comes from understanding their properties and behavior; but second, they can be regarded as mixtures of just two components, GaAs and AlAs, and so serve as a fresh set of examples of the ideas in Chapter 14. A difficulty in that chapter arises from the fact that at some points we need to imagine a mechanical continuum, while at other points we need to imagine particles traveling independently. In this chapter we need to do the same two things but the conflict in our concepts is not as acute; we can use eqn. (14.9) with more confidence and escape from the sense of an internal contradiction. The basis for the discussion is the idea of perfect stoichiometry; in a compound of type (A, B)X it is assumed that although the abundance-ratio of A to B is variable, the ratio of (A + B) to X is always exactly 1. Departures from stoichiometry are, of course, of great importance but constitute a later topic.
Summary
Authors: Bayly Brian
Published: November 2020

The purpose of this chapter is to consolidate. No new ideas are introduced; instead we try to sort the main thread from the side issues, and the parts that are reasonably clear and firm from the parts that are still fuzzy. The core of the chapter is a set of seventeen statements, seventeen vertebrae that form the backbone of the book, but there are also a preface and a postscript. The preface provides the setting for the seventeen-part core and the postscript takes up the question of where to go next. The purpose of the book was given at the start of Chapter 1. Even at that early point, a stressed cylinder was used as an example. The purpose is to make headway with the question: if a state of chemical equilibrium exists under hydrostatic stress and is disturbed by making the stress nonhydrostatic, what processes begin to run, and what quantitative relations should we expect to be followed? Before the seventeen-part "answer" it is to be noted that there are two alternative ways of dividing the subject matter into two parts. The division scheme is displayed in Figure 17.1a and separates eight types of change. (A somewhat similar diagram on page 111, distinguished eight circumstances in which change might be observed—a different system of divisions that is of no use here.) Of the eight boxes set up, four have been discussed, as shown in Figure 17.1b. The two ways of dividing this four-box group are by a horizontal cut or by a vertical cut that separates stars from superscript a’s. (A vertical cut separating the N-box from the rest is of no help; it would be contrary to our theme.) The horizontal cut separates stress-driven effects below from composition-driven effects above. It is in fact the traditional division between mechanics and chemistry; enormous amounts of science fall clearly above the cut or clearly below it and cause no confusion at all. This cut was used as a guide in the early chapters, especially in the flow diagram or organization chart, Figure 8.1. By contrast, the second cut appeared as late as Chapter 15, but deserves emphasis; it is at least as instructive and helpful as the first, and perhaps more helpful.
Mirror Worlds
Authors: Gelernter David
Published: November 2020

Technology doesn't flow smoothly; it's the big surprises that matter, and Yale computer expert David Gelernter sees one such giant leap right on the horizon. Today's small scale software programs are about to be joined by vast public software works that will revolutionize computing and transform society as a whole. One such vast program is the "Mirror world." Imagine looking at your computer screen and seeing reality--an image of your city, for instance, complete with moving traffic patterns, or a picture that sketches the state of an entire far-flung corporation at this second. These representations are called Mirror worlds, and according to Gelernter they will soon be available to everyone. Mirror worlds are high-tech voodoo dolls: by interacting with the images, you interact with reality. Indeed, Mirror worlds will revolutionize the use of computers, transforming them from (mere) handy tools to crystal balls which will allow us to see the world more vividly and see into it more deeply. Reality will be replaced gradually, piece-by-piece, by a software imitation; we will live inside the imitation; and the surprising thing is--this will be a great humanistic advance. we gain control over our world, plus a huge new measure of insight and vision. In this fascinating book--part speculation, part explanation--Gelernter takes us on a tour of the computer technology of the near future. Mirror worlds, he contends, will allow us to explore the world in unprecedented depth and detail without ever changing out of our pajamas. A hospital administrator might wander through an entire medical complex via a desktop computer. Any citizen might explore the performance of the local schools, chat electronically with teachers and other Mirror world visitors, plant software agents to report back on interesting topics; decide to run for the local school board, hire a campaign manager, and conduct the better part of the campaign itself--all by interacting with the Mirror world. Gelernter doesn't just speculate about how this amazing new software will be used--he shows us how it will be made, explaining carefully and in detail how to build a Mirror world using technology already available. we learn about "disembodied machines," "trellises," "ensembles," and other computer components which sound obscure, but which Gelernter explains using familiar metaphors and terms. (He tells us that a Mirror world is a microcosm just like a Japanese garden or a Gothic cathedral, and that a computer program is translated by the computer in the same way a symphony is translated by a violinist into music.) Mirror worlds offers a lucid and humanistic account of the coming software revolution, told by a computer scientist at the cutting edge of his field.
Disembodied Machines
Authors: Gelernter David
Published: November 2020

we begin with the central question. The answer forms the most important part of the Mirror world’s intellectual foundation. It also forms, for that matter, the most important part of computer science’s intellectual foundation; which makes it one of the central questions in modern engineering, and arguably the most important question in the history of technology. Despite which, it is a question that is rarely asked; and on rare occasions when it is, the answers you hear tend to be blatantly wrong. what is a program? what does “software” mean? Any technoglitz book that proposes to slobber on for hundreds of pages about software (there are plenty of them nowadays) should make you acutely uncomfortable unless it starts out by telling you what software is. And not many do. Because (or at least partially because) the answer isn’t simple. Or to put it another way, the answer is simple but it’s also subtle, because it requires that we give a name to something that (like adolescent female pigeons or the sky just as a cold front is arriving) we are accustomed to seeing but not to identifying. I’ve said that a computer program is a kind of machine, which is true. But it’s a funny kind of machine that must be defined with care, or we miss the whole point. I’ll define a program as an example of something I’ll call an “embodied machine”; this will place it roughly at the midpoint between a lathe and a symphony. I need to say, first, what a “machine” is in general. (Arguing about this definition used to be a fairly popular diversion. Machines are not the sexy proposition they once were...) Let us say, for present purposes, that a machine is a man-made structure that converts energy into value. This definition is vague on purpose, but it makes several points. A machine is man-made (a cloud doesn’t qualify), and it is a structure—an object that occupies space and time. (An idea doesn’t qualify). A machine is the meeting place between physics and society: It converts energy, which has a precise physical definition, into value, which doesn’t. Value is whatever you say it is.
Modeling and Simulating Radiative Transfer in the Ocean
Authors: Gordon Howard R.
Published: November 2020

The propagation of light in the sea is of interest in many areas of oceanography: light provides the energy that powers primary productivity in the ocean; light diffusely reflected by the ocean provides the signal for the remote sensing of subsurface constituent concentrations (particularly phytoplankton pigments); light absorbed by the water heats the surface layer of the ocean; light absorbed by chemical species (particularly dissolved organics) provides energy for their dissociation; and the attenuation of light with depth in the water provides an estimate of the planktonic activity. Engineering applications include the design of underwater viewing systems. The propagation of light in the ocean-atmosphere system is governed by the integral-differential equation of radiative transfer, which contains absorption and scattering parameters that are characteristic of the particular water body under study. Unfortunately, it is yet to be shown that these parameters are measured with sufficient accuracy to enable an investigator to derive the in-water light field with the radiative transfer equation (RTE). Furthermore, the RTE has, thus far, defied analytical solution, forcing one to resort to numerical methods. These numerical solutions are referred to here as “simulations.” In this chapter, simulations of radiative transfer in the ocean-atmosphere system are used (1) to test the applicability of approximate solutions of the RTE, (2) to look for additional simplifications that are not evident in approximate models, and (3) to obtain approximate inverse solutions to the transfer equation, e.g., to derive the ocean’s scattering and absorption properties from observations of the light field. The chapter is based on a lecture presented at the Friday Harbor Laboratories of the University of Washington directed to both students and experts. For the students, I have tried to make the material as self-contained as possible by including the basics, i.e., by providing the basic definitions of the optical properties and radiometry for absorbing-scattering media, developing the approximate solutions to the RTE for testing the simulations, detailing the model used for scattering and absorbing properties of ocean constituents in the simulations, and briefly explaining the simulation method employed. For the experts, I hope I have provided some ideas worthy of experimental exploration.