Georg Simon Ohm's work in the field of electricity led to what is now considered to be the most fundamental law of electrical circuits, Ohm's Law. Much less known is that only months earlier, Ohm had published another law—one that differed significantly from the now accepted one. The latter entailed a logarithmic relation between the length of the conductor and a parameter that Ohm called “loss of force.” This paper discusses how Ohm came up with an initial law that he (...) felt compelled to correct a few months later. We analyze Ohm's publication as well as his laboratory notes, relating them to our own laboratory experiences while using the replication method to study his work. We also discuss the conceptual background of Ohm's work. We conclude that he was significantly influenced by French studies in the field of electricity, most notably the ones by Charles Augustin Coulomb. (shrink)

What does quilting have to do with electric circuit theory? The answer is just one of the fascinating ways that best-selling popular math writer Paul Nahin illustrates the deep interplay of math and physics in the world around us in his latest book of challenging mathematical puzzles, Mrs. Perkins's Electric Quilt. With his trademark combination of intriguing mathematical problems and the historical anecdotes surrounding them, Nahin invites readers on an exciting and informative exploration of some of the (...) many ways math and physics combine to create something vastly more powerful, useful, and interesting than either is by itself. In a series of brief and largely self-contained chapters, Nahin discusses a wide range of topics in which math and physics are mutually dependent and mutually illuminating, from Newtonian gravity and Newton's laws of mechanics to ballistics, air drag, and electricity. The mathematical subjects range from algebra, trigonometry, geometry, and calculus to differential equations, Fourier series, and theoretical and Monte Carlo probability. Each chapter includes problems--some three dozen in all--that challenge readers to try their hand at applying what they have learned. Just as in his other books of mathematical puzzles, Nahin discusses the historical background of each problem, gives many examples, includes MATLAB codes, and provides complete and detailed solutions at the end. Mrs. Perkins's Electric Quilt will appeal to students interested in new math and physics applications, teachers looking for unusual examples to use in class--and anyone who enjoys popular math books. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Journal of the History of Ideas 63.1 (2002) 105-128 [Access article in PDF] The Metaphoric Circuit: Organic and Technological Communication in the Nineteenth Century Laura Otis [Figures]In a public lecture in 1851, Emil DuBois-Reymond proposed that the wonder of our time, electrical telegraphy, was long ago modeled in the animal machine. But the similarity between the two apparatus, the nervous system and the electric telegraph, has a (...) much deeper foundation. It is more than similarity; it is a kinship between the two, an agreement not merely of the effects, but also perhaps of the causes. 1In 1851 the telegraph and the nervous system appeared to be doing the same things and for the same reasons. Their common purpose was the transmission of information, and they both conveyed this information as alterations in electrical signals. By calling the nervous system a "model" for the telegraph, DuBois-Reymond suggested that organic communications systems offered solutions to problems encountered by technological ones.In the same decade, however, Claude Bernard remained skeptical about the epistemological value of metaphor. From the classical notion of nervous fluid to the more recent ones of animal spirits and animal electricity, he pointed out, people's "knowledge" of the nervous system had consisted largely of a series of comparisons, "the expression of a way of seeing meant to explain the facts." 2 Priding himself on his empiricism, Bernard mistrusted analogy as a means of constructing knowledge. Does one know more or less about something, if one asserts that it is like something else? What exactly is the relationship between metaphor and knowledge? [End Page 105]Many scientific investigators have shared Bernard's concern that claims of likeness will change their perceptions of physiological systems, but for the same reason some scholars of language are more optimistic about the epistemological possibilities of metaphor. George Lakoff and Mark Johnson assert that the role of metaphor in scientific thinking provides one of the best illustrations of how metaphors reflect and influence what we see and do. "Formal scientific theories are attempts to consistently extend a set of ontological and structural metaphors," they argue. 3 This "extension," though, is just what worried Bernard. Metaphors provoke and give birth to new images. By establishing and reinforcing connections, they encourage us to see in new ways. While Bernard is correct that assertions of likeness alter the way we see, Lakoff and Johnson are equally correct in claiming that "much of cultural change arises from the introduction of new metaphorical concepts and the loss of old ones." 4 Alterations in the way we see can be extremely productive.One of the most intriguing cases through which to study the epistemological role of metaphor is that of comparisons between physiological and technological communications systems. Throughout the nineteenth century scientists' electrophysiological understanding of the nervous system closely paralleled technological knowledge that allowed for the construction of telegraph networks. Timothy Lenoir has demonstrated that Hermann Helmholtz and Emil DuBois-Reymond, the nineteenth-century scientists who made some of the greatest contributions to neurophysiology, worked closely with communications engineers like Werner Siemens. By developing models that reflected the apparatus they had adapted from physics and media technology, Helmholtz, and DuBois-Reymond changed people's understanding of the way nerves transmitted impulses. I agree with Lenoir that these comparisons between organic and technological systems were not mere devices for popularization but became incorporated into the scientists' own vision and understanding of the nervous system. 5 When one reads the proposals of nineteenth-century engineers, one begins to suspect that communication in the body and in society can only be understood in terms of each other. But can one claim that comparisons of communication mediated by bodies and machines actually contributed to knowledge of the nervous system and of early telecommunications networks?From the late eighteenth century onward, scientists studying organic and technological communications systems continually inspired one another. As Friedrich Kittler argues in Discourse Networks, nineteenth-century media for writing and communication—the telegraph, typewriter, and telephone—affected not just the way people wrote and... (shrink)

Between 1886 and 1889, the British scientific and engineering communities witnessed several controversies regarding the principles underlying certain components of electrical circuits. The purpose of this paper is to show that these controversies should be regarded as reflecting a stage in the emergence of basic industrial research as a mediating agency between practical engineering and pure science. It will be suggested that the resolution of these controversies required careful formulation of approximations guided by a practical familiarity with the details of (...) the relevant systems. This underscored an approach to basic engineering problems within which practical experience and scientific theory were regarded as equally fundamental. (shrink)

This study describes the results of experiments motivated by an attempt to understand spectral processing in the cerebral cortex (DeValois and DeValois, 1988; Pribram, 1971, 1991). This level of inquiry concerns processing within a restricted cortical area rather than that by which spatially separate circuits become synchronized during certain behavioral and experiential processes. We recorded neural responses for 55 locations in the somatosensory (barrel) cortex of the rat to various combinations of spatial frequency (texture) and temporal frequency stimulation of their (...) vibrissae. The recordings obtained from single and multi-unit bursts of spikes were mapped as surface distributions of local dendritic potentials. The distributions showed a variety of patterns that are asymmetric with respect to the spatial and temporal parameters of stimulation, and were, therefore, not simply reflecting whisker flick rate. Next, a simulation of our results showed that these surface distributions of local dendritic potentials can be described by Gabor-like functions much as in the visual system. The results provide support for a model of distributed cortical processing that imposes a physiologically derived frame (the limited extent of a dendritic patch) and an anatomically derived (axonal) sampling of the distributed process. This combination provides a complex Gabor wavelet that encodes phase, which is necessary to processing such details as edges and texture in a scene. The synchronization across cortical areas that make the Gabor wavelet processes within restricted cortical areas available to one another (the binding problem) proceed at a ''higher order'' level of integration. Both levels of distributed processing accomplish computation in the conjoint spacetime and spectral domain. (shrink)

Evolutionary computation has been applied to numerous design tasks, including design of electric circuits, neural networks, and genetic circuits. Though it is a very effective solution for optimizing network structures, genetic algorithm faces many difficulties, often referred to as the permutation problems, when both topologies and the weights of the network are the target of optimization. We propose a new crossover method used in conjunction with a genotype with information tags. The information tags allow GA to recognize and preserve (...) the common structure of parent chromosomes during genetic crossover. The method is implemented along with subpopulating strategies to make the parallel evolution of network topology and weights feasible and efficient. The proposed method is evaluated on a few typical and practical problems, and shows improvement from conventional methodologies and genotypes. (shrink)

Wansing’s extended intuitionistic linear logic with strong negation, called WILL, is regarded as a resource-conscious refinment of Nelson’s constructive logics with strong negation. In this paper, (1) the completeness theorem with respect to phase semantics is proved for WILL using a method that simultaneously derives the cut-elimination theorem, (2) a simple correspondence between the class of Petri nets with inhibitor arcs and a fragment of WILL is obtained using a Kripke semantics, (3) a cut-free sequent calculus for WILL, called twist (...) calculus, is presented, (4) a strongly normalizable typed λ-calculus is obtained for a fragment of WILL, and (5) new applications of WILL in medical diagnosis and electric circuit theory are proposed. Strong negation in WILL is found to be expressible as a resource-conscious refutability, and is shown to correspond to inhibitor arcs in Petri net theory. (shrink)

A classic source for understanding the connections between information theory and physics, this text was written by one of the giants of 20th-century physics and is appropriate for upper-level undergraduates and graduate students. Topics include the principles of coding, coding problems and solutions, the analysis of signals, a summary of thermodynamics, thermal agitation and Brownian motion, and thermal noise in an electric circuit. A discussion of the negentropy principle of information introduces the author's renowned examination of Maxwell's demon. (...) Concluding chapters explore the associations between information theory, the uncertainty principle, and physical limits of observation, in addition to problems related to computing, organizing information, and inevitable errors. 1962 ed. 81 figures. 14 tables. (shrink)

Error-based Simulation is a framework for assisting a learner to become aware of his error. It makes simulation based on his erroneous hypothesis to show what unreasonable phenomena would occur if the hypothesis were correct, which has been proved effective in causing cognitive conflict. In making EBS, it is necessary to make simulation by dealing with a set of inconsistent constraints because erroneous hypotheses often contradict the correct knowledge, and to estimate the 'unreasonableness' of phenomena in simulation because it must (...) be recognized to be 'unreasonable' by a learner. Since the method used in previous EBS-systems was much domain-dependent, this paper describes a method for making EBS based on any inconsistent simultaneous equations/inequalities by using TMS '). It also describes a set of general heuristics to estimate the 'unreasonableness' of physical phenomena. By using PCA and the heuristics, a prototype of EBS-system for elementary mechanics and electric circuit problems was implemented in which a learner is asked to set up equations of the systems. A preliminary test proved our method useful in which most of the subjects agreed that the EBSs and explanations made by the prototype were effective in making a learner be aware of his error. (shrink)

In this paper, we examine the period that immediately followed the invention of the Leiden jar. Historians of science have developed narrations that emphasize the role of grounding during the process of charging the jar. In this respect, this episode shows significant aspects that can be used to characterize science, scientific knowledge production, and the nature of science. From our own experimentation, we learned that grounding was not necessary in order to produce the effect. These experiences inspired us to go (...) back to primary sources. In doing so, we came to a new understanding of the early period after Kleist’s and Musschenbroek’s initial creation of the effect. From our analysis, we conclude that it is not the grounding which was perceived as a major innovation during this early period of the discussion but the concept of an electrical circuit. This understanding was fundamental in characterizing the Leiden jar as a new device challenging the then current knowledge of experimental practices in the field of electricity. (shrink)

In this paper a Knowledge-Based System (KBS) for determining the appropriate students major according to his/her preferences for sophomore student enrolled in the Faculty of Engineering and Information Technology in Al-Azhar University of Gaza was developed and tested. A set of predefined criterions that is taken into consideration before a sophomore student can select a major is outlined. Such criterion as high school score, score of subject such as Math I, Math II, Electrical Circuit I, and Electronics I taken (...) during the student freshman year, number of credits passed, student cumulative grade point average of freshman year, among others, were then used as input data to KBS. KBS was designed and developed using Simpler Level Five (SL5) Object expert system language. KBS was tested on three generation of sophomore students from the Faculty of Engineering and Information Technology of the Al-Azhar University, Gaza. The results of the evaluation show that the KBS is able to correctly determine the appropriate students major without errors. (shrink)

Just as non-well-founded sets extend the usual sets of ZF, so do root reflexive propositional formulas extends the usual class of Boolean expressions. Though infinitary, these formulas are generated by finite patterns. They possess transition functions instead of truth values and have applications in electric circuit theory.

The paper introduces the concept of relativistic ontological realism, and the corresponding notion of relativistic realization of objects. The conditions that allow for the relativistic realization of objects are determined. In particular, the paper indicates the way the imposition of organizational structures on already existent objects supports the relativistic realization of new, more complex ones. A type-theoretic presentation of the principles of relativistic ontological realism is given in the language of predicate calculus, making use of the notion of typed world (...) and the condition of effectiveness in the determination of the existence of objects. Two case studies illustrating the way the notion of relativistic ontological realism supports ontological analysis are presented, both concerning the ontology of computations, more specifically, the relativistic realization of computational levels in computational systems. The first case study deals with the realization of logical circuits through structural arrangements of electrical circuits. The second, with the realization of software systems through computer programming. A conception of the mechanics of the relativistic realization of objects, taking the imposition of organizational structures on previously extant objects as its basis, is proposed and briefly analyzed. (shrink)

In this paper we will show that Hempel's covering law model can't deal very well with explanations that are based on incomplete knowledge. In particular the symmetry thesis, which is an important aspect of the covering law model, turns out to be problematic for these explanations. We will discuss an example of an electric circuit, which clearly indicates that the symmetry of explanation and prediction does not always hold. It will be argued that an alternative logic for causal (...) explanation is needed. And we will investigate to what extent non-monotonic epistemic logic can provide such an alternative logical framework. Finally we will show that our non-monotonic logical analysis of explanation is not only suitable for simple cases such as the electric circuit, but that it also sheds new light on more controversial causal explanations such as Milton Friedman's explanation of the business cycle. (shrink)

The scope of the thermodynamic theory of nonlinear irreversible processes is widened to include the nonlinear stability analysis of system motion. The emphasis is shifted from the analysis of instantaneous energy flows to that of the average work performed by periodic nonlinear processes. The principle of virtual work separates dissipative and conservative forces. The vanishing of the work of conservative forces determines the natural period of oscillation. Stability is then determined by the variations of the dissipative forces with amplitude of (...) oscillation. If the work is a minimum, under certain conditions, the motion is stable. Reduction to linear analysis shows the coincidence with the impedance analysis of electrical circuit theory. The theory is applied to the analysis of temporal interactions of nonlinear irreversible processes in the particular cases of synchronization and hysteresis. Characteristic nonequilibrium phenomena of directional energy transfers, self-excitation, system passivity, wave modulation, and “beat” phenomena are observed. Possible relationships with biological processes are discussed. (shrink)

The Oxford English Dictionary explains that the word “consent” originally derives from the “Latin consentīre to feel together, agree, accord harmonize”, further broken down into “con- together + sentīre to feel, think, judge, etc.” Thus, consent is originally a matter of mutual activity and receptivity, specifically a co-creating co-creation based on shared, ongoing feeling. What this seems to imply – and this is certainly always been true in my experiences with social Latin dance – is that consent is not a (...) static thing, not an object or product that has been definitively produced and recorded. Instead, consent is an ongoing process, a reciprocating experiencing that is crucially both beyond one individual dancer, and also simultaneously active and receptive. Altogether, then, consent in social Latin dance emerges as a process of doing and undergoing together. Thus, if the connection of dancing consent is broken, for example if one partner shifts from the acting/receiving balance to a state of exclusive acting (with no receiving), then consent is no longer transpiring, which greatly increases the risk of unwanted touch beginning and continuing. Put simply, wanted touch is consensual touch, and consensual touch is touch that is supported by an ongoing activity and receptivity of consent. Wanted touch in dance is thus analogous to a “closed” electrical circuit. (In fact, at the cellular level of a dancer’s body this truth is literal rather than merely analogous, given the neurochemical dimension of the body’s activities). A closed circuit, in this technical sense, refers to a circuit in which there is no break in the path (for example between a device and an outlet), an unbrokenness that sustains a live current in the circuit. By contrast, unwanted touch in social Latin dance is like an open circuit, involving a break in the path between the partners, which entails the absence of the necessary current of consent. (shrink)

Aberrations -- Absorption -- Accuracy and precision -- Alpha radiation -- Amplitude -- Angular forces -- Angular momentum -- Antenna -- Arago dot -- Aperture -- Archimedes's principle -- Band theory of solids -- Bernoulli's principle -- Beta radiation -- Blackbody radiation -- Bohr atom -- Bose condensation -- Bra-ket notation -- British thermal unit (BTU) -- Calculating system efficiency -- Circular motion -- Closed systems and isolated systems -- Concave and convex -- Conservation of charge -- Conservation of energy (...) -- Convection and conduction -- Cosmic radiation -- Crest and trough -- Density and specific gravity -- Diode -- Distance and area -- Distortion -- Doppler effect -- Dynamic systems theory -- Edison effect -- Eigenvectors -- Elastic and inelastic collisions -- Electric circuits: Parallel vs series, diagrams and components -- Electric potential -- Energy and power -- Enthalpy -- Entropy -- Euler's laws of motion -- Falling bodies and physics -- Faraday's law -- Feynman diagrams -- Flywheel -- Focal point -- Free body diagram -- Frequency -- Gamma radiation -- Gauss's law -- Gluon -- Gravitational potential energy -- Harmonic oscillator -- Harmonics -- Heisenberg uncertainty principle -- Higgs boson -- Horsepower -- Ideal gas law -- Joule --. (shrink)

Multimedia learning theories suggest presenting associated pieces of information in spatial and temporal contiguity. New technologies like Augmented Reality allow for realizing these principles in science laboratory courses by presenting virtual real-time information during hands-on experimentation. Spatial integration can be achieved by pinning virtual representations of measurement data to corresponding real components. In the present study, an Augmented Reality-based presentation format was realized via a head-mounted display and contrasted to a separate display, which provided a well-arranged data matrix in spatial (...) distance to the real components and was therefore expected to result in a spatial split-attention effect. Two groups of engineering students performed six experiments exploring fundamental laws of electric circuits. Cognitive load and conceptual knowledge acquisition were assessed as main outcome variables. In contrast to our hypotheses and previous findings, the Augmented Reality group did not report lower extraneous load and the separate display group showed higher learning gains. The pre- and posttest assessing conceptual knowledge were monitored by eye tracking. Results indicate that the condition affected the visual relevancy of circuit diagrams to final problem completion. The unexpected reverse effects could be traced back to emphasizing coherence formation processes regarding multiple measurements. (shrink)

In 1918–1919 Walter G. Cady was the first to recognize the significant electrical consequences of the fact that piezoelectric crystals resonate at very sharp, precise and stable frequencies. Cady was also the first to suggest the employment of these properties, first as frequency standards and then to control frequencies of electric circuits—an essential component in electronic technology. Cady’s discovery originated in the course of research on piezoelectric ultrasonic devices for submarine detection (sonar) during World War I. However, for the (...) discovery Cady had to change his research programme to crystal resonance. This change followed Cady’s experimental findings and the scientific curiosity that they raised, and was helped by the termination of the war. Cady’s transition was also a move from “applied” research, aimed at improving a specific technology, to “pure” research lacking a clear practical aim. This article examines how Cady reached the discovery and his early ideas for its use. It shows that the discovery was not an instantaneous but a gradual achievement. It further suggests that disinterested “scientific” research (rather than “engineering” research) was needed in this process, while research aimed at design was required for the subsequent development of technological devices. (shrink)