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Engines of Change: Machines Drive American Industry

Susan Branson

in Scientific Americans: Invention, Technology, and National Identity

This chapter explains why machines captured the public's attention in so profound a way by surveying the early nineteenth-century venues in which Americans encountered mechanical technologies. ... More

This chapter explains why machines captured the public's attention in so profound a way by surveying the early nineteenth-century venues in which Americans encountered mechanical technologies. Demonstrations of new machines acquainted men and women with inventions that enhanced daily life. One continually pursued idea was resurrected in an American context when Charles Redheffer's perpetual motion device caught the public's imagination. It sparked a national discussion of how the invention would propel the United States to global preeminence. Redheffer's failure to deliver on his promise dampened, but did not diminish, American hopes that technology was the answer to national development. The steam engine, on the other hand, quickly became useful and ubiquitous. The engines that propelled boats and railcars and powered looms and spindles literally drove the changes that helped the United States strive for economic independence. Americans expressed their enthusiasm for the steam engine's importance to national prosperity in poetry, fiction, and the purchase of steam-themed consumer items.Less

Theaters of Visuality

Wendy Bellion

in Citizen Spectator: Art, Illusion, and Visual Perception in Early National America

This chapter describes Charles Redheffer's unveiling of his invention—a perpetual motion machine. Such a discovery promised a technological marvel. The prospect of a self-renewing energy source was ... More

This chapter describes Charles Redheffer's unveiling of his invention—a perpetual motion machine. Such a discovery promised a technological marvel. The prospect of a self-renewing energy source was as much a hopeful desire of earlier centuries as it is today, and hence it was little surprise that Philadelphia's scientific and mechanic communities greeted the machine with wonder and excitement when it was exhibited at a house in Germantown, some ten miles outside the city. Eager to learn whether Redheffer's discovery could be replicated, a local group hired Lukens to construct a duplicate. Lukens was a clockmaker, a man practiced in the making of delicate things, and, turning an experienced eye on Redheffer's instrument, he quickly realized that his fellow mechanics had been fooled.Less

The Necessity of Classical Mechanics

Olivier Darrigol

in Physics and Necessity: Rationalist Pursuits from the Cartesian Past to the Quantum Present

This chapter combines some assumptions of the rationalist founders of mechanics (the impossibility of perpetual motion, the causal relation between force and motion, the relativity principle, and ... More

This chapter combines some assumptions of the rationalist founders of mechanics (the impossibility of perpetual motion, the causal relation between force and motion, the relativity principle, and what I call the secularity principle) with the definitions of four classes of ideal mechanical systems (connected systems, particles acting at a distance, continuous media, colliding particles) in order to derive the laws of equilibrium and motion of these systems. The usual laws of mechanics are retrieved in each case. The conclusion is that classical mechanics is the only theory of motion complying with a few natural requirements on the comprehensibility of motion at the macroscopic scale.Less

The G-minor Presto

Joel Lester

in Bach's Works for Solo Violin: Style, Structure, Performance

The continuous sixteenth notes of the Presto may seem akin to later composers' perpetual-motion movements. But whereas later instances (such as Paganini's) have a swift and supple surface overlying a ... More

The continuous sixteenth notes of the Presto may seem akin to later composers' perpetual-motion movements. But whereas later instances (such as Paganini's) have a swift and supple surface overlying a bel canto texture, the rhythms and metric hierarchy of Bach's Presto create a vibrant rhythm that articulates many cross rhythms. This recurrent feature of Bach's style versus later styles affects all sorts of textures—exemplified by the differences between the C-major Prelude in the Well-Tempered Clavier and Gounod's Ave Maria (that adds a melody to that prelude), and the differences between Bach's orchestration of his E-major Preludio and Robert Schumann's accompaniment to the same movement. Parallel-section construction with heightening activity offers deeper insights into Bach's two-part movements than later notions of “binary form”.Less

From Mechanical Reduction To General Principles

Olivier Darrigol

in Physics and Necessity: Rationalist Pursuits from the Cartesian Past to the Quantum Present

This chapter is devoted to a few general principles that have received mechanical or dynamical justifications: the principle of energy conservation, the principle of least action, and the two laws of ... More

This chapter is devoted to a few general principles that have received mechanical or dynamical justifications: the principle of energy conservation, the principle of least action, and the two laws of thermodynamics. Historically, the evolution of mechanical reductionism and a new emphasis on conversion processes led to the energy principle. There were reductionist arguments for the necessity of this principle, and more satisfactory arguments by Mach and Planck based on the impossibility of perpetual motion. The principle of least action, conceived as a general principle of physics, resulted from the blackboxing of mechanism in the optical and electromagnetic theories of the nineteenth century. There is no good argument for its necessity, despite its extreme power. The two laws of thermodynamics have an impurely rational but still persuasive kind of necessity as they express the impossibility of processes or devices never seen in nature. Statistical mechanics further justifies them if we accept the possibility of a dynamical reduction compatible with the existence and uniqueness of thermodynamic equilibrium.Less

The Quest for Perpetually Acting Machines

Jennifer Coopersmith

in Energy, the Subtle Concept: The discovery of Feynman's blocks from Leibniz to Einstein

Perpetual motion—a perpetually acting machine— had been attempted for so many years, and in so many ways, but was never successful (the French Royal Academy of Sciences said ‘Non’, no more ... More

Perpetual motion—a perpetually acting machine— had been attempted for so many years, and in so many ways, but was never successful (the French Royal Academy of Sciences said ‘Non’, no more submissions). But did this mean that something was being conserved? This was a question that could barely be put—let alone answered—and was not finally resolved until the riddle of energy was solved in the middle of the nineteenth century. However, the sheer variety of ways in which perpetual motion was sought, and was failing, was in itself illuminating (overbalancing wheels, perpetually cycling water or air, chemical, magnetic, and adhesive attractions, gravity shields, and so on). Stevin famously used the impossibility of perpetual motion in a reductio ad absurdum proof (using his ‘wreath of spheres’).Less

Energy and its Ultimate Fate

E. C. Pielou

in The Energy of Nature

This chapter begins with a brief description of friction and drag. Friction and drag have one property in common — both are nonconservative forces; that is, they cannot be stored as potential energy ... More

This chapter begins with a brief description of friction and drag. Friction and drag have one property in common — both are nonconservative forces; that is, they cannot be stored as potential energy of one kind or another for later retrieval. Rather, they “go to waste” and produce “useless” heat. The discussions then turn to heat and work, heat and temperature; heat and internal energy; entropy; the impossibility of perpetual motion; and mythical perpetual motion machines.Less

The lever

Robert T. Hanlon

in Block by Block: The Historical and Theoretical Foundations of Thermodynamics

Analysis of the lever led to the creation of potential energy.

Modeling Without a Specific Target

Michael Weisberg

in Simulation and Similarity: Using Models to Understand the World

Target-directed modeling, the practice of constructing a single model to study a specific target, is not representative of the entire practice of modeling. Indeed, theoretical research typically ... More

Target-directed modeling, the practice of constructing a single model to study a specific target, is not representative of the entire practice of modeling. Indeed, theoretical research typically involves the exploration of classes of models aimed at understanding classes of phenomena, not the study of individual observations or individual phenomena. Such investigations can take several forms. One type of investigation involves the construction of models in order to study general phenomena such as parasitism or sexual reproduction. A second is when theorists construct models to study nonexisting phenomena. A third type of investigation involves studying a model with no target at all, stopping at the analysis stage of modeling. This chapter is about these three kinds of modeling, called generalized modeling, hypothetical modeling, and targetless modeling.Less

Default Status: Making Sense of the World

Garrett Hardin

in Living within Limits: Ecology, Economics, and Population Taboos

"There are three kinds of lies," said Benjamin Disraeli, Queen Victoria's favorite prime minister: "lies, damned lies and statistics." Scientists are inclined to argue with this, holding that ... More

"There are three kinds of lies," said Benjamin Disraeli, Queen Victoria's favorite prime minister: "lies, damned lies and statistics." Scientists are inclined to argue with this, holding that statistics (properly used) are one of the glories of the scientific method. But since statistics are often not properly used it must be admitted that Disraeli had a point. As used, statistics are often a sort of black magic, accompanied by a disparagement of common sense. That won't do. As the logician Willard Van Orman Quine has said: "Science itself is a continuation of common sense. The scientist is indistinguishable from the common man in his sense of evidence, except that the scientist is more careful.” The physicist John Platt agrees in minimizing the distance between science and common sense: "It may surprise many people to know that the chain of new scientific reasoning in a whole research study is frequently less complex than an everyday business decision or a crossword puzzle or a game of chess. It would have a salutary effect on our attitudes if for twenty-four hours we could cross out the words 'science' and 'scientist' wherever they appear and put in their place the words 'man reasoning.'" Stereotypes of scientists often imply that being scientific means having a perpetually open mind. Not so. A claim that lies too far outside the accepted view of things is often completely ignored by the scientific community. For instance, half a century ago the writer of a letter to the British journal Nature claimed that the average gestation period of different animals, from rabbits to cows, was an integral multiple of the number pi (3.14159 . . .). The evidence was ample, the statistical agreement was good. But, to this day, the scientific community has ignored this claim. No understandable reason was proposed for the association of the two phenomena, and no one has been able to imagine any. It is just too ridiculous. Evidently the scientific mind is not completely open. To what extent is it closed, and how is this partial closure justified? Since population inquiries are beset by statistics, we need to understand the accepted limits of scientific inquiry. Less

Making Room for Human Will

Garrett Hardin

in Living within Limits: Ecology, Economics, and Population Taboos

Anything to be done about human populations necessarily depends on the will to do it. But what does the word will mean? Much has been written about it, but most of the rhetoric is nonsense. Rather ... More

Anything to be done about human populations necessarily depends on the will to do it. But what does the word will mean? Much has been written about it, but most of the rhetoric is nonsense. Rather than add one more explicit (and probably faulty) definition to the roster I will treat "will" ostensively, that is by pointing to passages that throw some light on its meaning (Box 18-1). The contributions of academics are commonly belittled by "practical" people, who trust more in the guidance of intuition. In a classic statement John Maynard Keynes argued that such guidance often came through unconscious memory. Because of the heavy demands on their time, politicians seldom read any work of substance after the age of thirty. Their responses are, Keynes said, distilled "from some academic scribbler a few years back." Looking at the situation with a different orientation in time, we argue that it is worthwhile for the inventor or scholar to try to get his views accepted by those who are young and powerless now because some of them may have political power two decades from now, when their days of leisurely reading are long past. In the unending development of human civilization what men think will happen can influence what does happen. The connection between the original ideas and their conversion into action is not rigid, determinative, or well understood: but there is a connection, and this appeals to the ambitions of social inventors. Consequently, as Dennis Gabor says, "The future cannot be predicted, but futures can be invented." As concerns the size of future populations, humanity's problem is to invent the answer. What size do we want human populations to be? On what assumptions do our answers rest? Precisely how can human consent be engineered? There is no pure population problem: the problem is one of population and resources. The well-being of a population depends on the ratio of the size of the population to the magnitude of available resources. What the future holds for population considered by itself is simple enough, as Malthus knew: the perpetual threat posed by population's ability to increase exponentially. But resources? Malthus stubbed his toe on this one, and people are still arguing. The arguments center around the concept of scarcity and the relevance of statistics to predicting the future. Less

James Joule

Robert T. Hanlon

in Block by Block: The Historical and Theoretical Foundations of Thermodynamics

Joule’s journey to his energy conservation law began with his unsuccessful evaluation of the electric motor as a means to achieve perpetual motion. A series of subsequent experiments eventually led ... More

Joule’s journey to his energy conservation law began with his unsuccessful evaluation of the electric motor as a means to achieve perpetual motion. A series of subsequent experiments eventually led him to a definitive experiment in which he demonstrated the transformation of work (a falling weight) into heat (a spinning paddle that heated water) occurs at a precise ratio called the mechanical equivalent of heat (MEH). This and other of his experiments proved that heat is not a conserved quantity and that heat and work are simply two forms of a conserved quantity later to be called energy. He shared his findings with William Thomson (Lord Kelvin) who then went on to establish the field of thermodynamics.Less