Relativity is the most important scientific idea of the twentieth century. Albert Einstein is the unquestioned founder of modern physics. His Special and General theories of Relativity introduced the idea to the world. In this classic short book he explains clearly, using the minimum amount of mathematical terms, the basic ideas and principles of his theory of Relativity. Unsurpassed by any subsequent books on Relativity, this remains the most popular and useful exposition of Einstein's (...) immense contribution to human knowledge. (shrink)

Time magazine's "Man of the Century", Albert Einstein is the founder of modern physics and his theory of relativity is the most important scientific idea of the modern era. In this short book, Einstein explains, using the minimum of mathematical terms, the basic ideas and principles of the theory that has shaped the world we live in today. Unsurpassed by any subsequent books on relativity, this remains the most popular and useful exposition of Einstein's immense contribution to (...) human knowledge. With a new foreword by Derek Raine. (shrink)

_Time_'s 'Man of the Century', Albert Einstein is the unquestioned founder of modern physics. His theory of relativity is the most important scientific idea of the modern era. In this short book Einstein explains, using the minimum of mathematical terms, the basic ideas and principles of the theory which has shaped the world we live in today. Unsurpassed by any subsequent books on relativity, this remains the most popular and useful exposition of Einstein's immense contribution to human (...) knowledge. (shrink)

Relativity is the most important scientific idea of the twentieth century. Albert Einstein is the unquestioned founder of modern physics. His Special and General theories of Relativity introduced the idea to the world. In this classic short book he explains clearly, using the minimum amount of mathematical terms, the basic ideas and principles of his theory of Relativity. Unsurpassed by any subsequent books on Relativity, this remains the most popular and useful exposition of Einstein's (...) immense contribution to human knowledge. (shrink)

Two leaves of typescript and 7 leaves of galley proofs with corrections in Einstein's hand for the article "Relativity" in American Peoples Encyclopedia.

The articles included in this Volume represent a broad and highly qualified view on the present state of general relativity, quantum gravity, and their cosmological and astrophysical implications. As such, it may serve as a valuable source of knowledge and inspiration for experts in these fields, as well as an advanced source of information for young researchers. The occasion to gather together so many leading experts in the field was to celebrate the centenary of Einstein's stay in (...) Prague in 1911-1912. It was in fact during his stay in Prague that Einstein started in earnest to develop his ideas about general relativity that fully developed in his paper in 1915. Approaching soon the centenary of his famous paper, this volume offers a precious overview of the path done by the scientific community in this intriguing and vibrant field in the last century, defining the challenges of the next 100 years. The content is divided into four broad parts: (i) Gravity and Prague, (ii) Classical General Relativity, (iii) Cosmology and Quantum Gravity, and (iv) Numerical Relativity and Relativistic Astrophysics. (shrink)

We discuss the meaning and prove the accordance of general relativity, wave mechanics, and the quantization of Einstein's gravitation equations themselves. Firstly, we have the problem of the influence of gravitational fields on the de Broglie waves, which influence is in accordance with Eeinstein's weak principle of equivalence and the limitation of measurements given by Heisenberg's uncertainty relations. Secondly, the quantization of the gravitational fields is a “quantization of geometry.” However, classical and quantum gravitation have the same (...) physical meaning according to limitations of measurements given by Einstein's strong principle of equivalence and the Heisenberg uncertainties for the mechanics of test bodies. (shrink)

A Finslerian extension of general relativity is examined with particular emphasis on the Finslerian generalization of the equation of motion in a gravitational field. The construction of a gravitational Lagrangian density by substituting the osculating Riemannian metric tensor in the Einstein density is studied. Attention is drawn to an interesting possibility for developing the theory of test bodies against the Finslerian background.

Albert Einstein insists that his epistemology made his discovery of relativity possible. He believed it was his understanding of the relationship of experience and reason that allowed him to reconsider certain “truths” of physics. Specifically, he believed that reality and thought were independent but related, and that conceptual systems are independent of but conditioned by experience. Failure to understand the relation between experience and reason had, Einstein believed, limited progress in science. His understanding of the relation, on the other (...) hand, enabled him to formulate relativity theory and therefore provides one example of the relevance of philosophy to scientific inquiry. When Albert Einstein discussed his discoveries in physics, particularly the theory of relativity, he often began with an explanation of his epistemology and referred to thinkers like Hume and Kant. Einstein may have been a physicist, but he had definite ideas about how we know and regarded epistemological theories as crucial to science, especially to physics. Indeed, he placed such importance on the question of how we know that the discussion of his work in his “Autobiographical Notes” begins with the question, “What, precisely, is ‘thinking?'” (1951, 7). The correct answer to this philosophical question, he believed, makes progress in science possible. The present article focuses on the relationship of the two elements, experience and reason, in Einstein's epistemology. Einstein himself frequently concentrates on what he characterizes as “the eternal antithesis between the two inseparable components of our knowledge, the empirical and the rational” (1934b, 271) in his papers and lectures on physics, for he regards them as independent in origin but related in scientific truth. His insistence that experience and reason do not determine one another yet must be related proved, for him, to be a necessary but not sufficient condition for the formulation of relativity theory and for scientific progress in general. The discussion of the relationship has four parts. First, experience and reason are explained; included in this explanation are Einstein's reasons for maintaining that the two are independent. The second section discusses the connection between the two that produces truth and knowledge. The third section follows with discussion of the way that Einstein believes reason can be both conditioned by and independent of experience. Finally, the significance of this understanding of the relation for relativity theory is examined. (shrink)

The arguments are exhibited in favour of the necessity to modify the history of the genesis and advancement of general relativity (GR). I demonstrate that the dynamic creation of GR had been continually governed by internal tensions between two research traditions, that of special relativity and Newton’s gravity. The encounter of the traditions and their interpenetration entailed construction of the hybrid domain at first with an irregular set of theoretical models. Step by step, on eliminating the contradictions (...) between the models contrived, the hybrid set was put into order. It is contended that the main reason of the GR victory over the rival programmes of Abraham and Nordström was a synthetic character of Einstein’s programme. Einstein had put forward as a basic synthetic principle the principle of equivalence that radically differed from that of rival approaches by its open, flexible and contra-ontological character. (shrink)

The current technoscientific progress has led to a sectorization in the philosophy of science. Today the philosophy of science isn't is informal interested in studying old problems about the general characteristics of scientific practice. The interest of the philosopher of science is the study of concepts, problems and riddles of particular disciplines. Then, within this progress of philosophy of science, neuroscientific research stands out, because it invades issues traditionally addressed by the humanities, such as the nature of consciousness, action, (...) knowledge, normativity, etc. As a result, the new area of interdisciplinary study of neuroscience and philosophy arises: neurophilosophy. This emerging area applies neuroscientific concepts to traditional philosophical questions, limiting their responses to neuroscientific revelations about nervous systems. Neurophilosophy research focuses on problems related to the indirect nature of mind and brain, computational or representative analysis of brain process, relationships between psychological and neuroscientific research, adequate adaptations of physical and philosophical concepts in neuroscience and the place of cognitive functions. Now, the temporal representation of conscious experience and the types of the neural architecture to represent objects in time have aroused scientific interest. Under these interests, we focus on the studies on the temporary triadic structure of phenomenological consciousness in Dan Lloyd and Rick Grush. From Grush’s studies, the importance of Kantian ideas for cognitive neuroscience emerges, due to the active way in which Kant conceived space and time as forms of intuition, within which the mind interprets its experience. Under this perspective, the theoretical arguments of Dennett-Kinsbourne and Eagleman-Sejnowski represent winks in the direction of Kant-Husserl within the neuroscientific goal while considering that the contents provided by the mind included space, objects and perception of causal relationships. Then, theories of cognitive neuroscience are beginning to suggest that these elements are also, as Kant argued, interpretative elaborations provided by mind / brain, and not only content received from outside. In other words, current cognitive neuroscientific theories try to pass from its Humean phase to a Kantian phase. So, the challenge has been to explain that these elements are provided by the mind and the world itself, and how they have the content they have come from. These are lacking in current studies. Filling this gap helps to involve the analysis of the scientist’s experience in his theoretical attitude. In this sense, an investigation under the Kantian-Husserlian approach that involves pure intuitions a priori with the experience of the scientific and neuroscientific concepts represents a ground-breaking. At present, a neurophilosophical study about this does not exist. In this sense, one feasible proposal for research would be based on the application of neuroscientific results of Moser-Britt to philosophical problems of foundational notions in relativistic physics: space, time, space-time, field, etc., under the Kantian-Husserlian approach, which allows to demonstrate the multidisciplinary link between neurophilosophy and physics. This represents a ground-breaking area in current interests in scientific research, with a positive impact in the field of neuroscience, and contributing to the study of abstraction emphasizing the importance of Kant’s Copernican turn and Husserl’s phenomenological ideas in the construction of physical theories. -/- . (shrink)

This excellent, semi-technical account includes a review of classical physics (origin of space and time measurements, Ptolemaic and Copernican astronomy, laws of motion, inertia, and more) and coverage of Einstein’s special and general theories of relativity, discussing the concept of simultaneity, kinematics, Einstein’s mechanics and dynamics, and more.

fasc. 1. Principes généraux; équations d'Einstein. Dynamique et optique. Repérages non einsteiniens. Avec une "Note sur le système Giorgi."--fasc. 2. Le champ statique à symétrie sphérique. Avec la collaboration de J. Moulis.

This book focuses on Albert Einstein and his interactions with, and responses to, various scientists, both famous and lesser-known. It takes as its starting point that the discussions between Einstein and other scientists all represented a contribution to the edifice of general relativity and relativistic cosmology. These scientists with whom Einstein implicitly or explicitly interacted form a complicated web of collaboration, which this study explores, focusing on their implicit and explicit responses to Einstein s work. This analysis uncovers (...) latent undercurrents, indiscernible to other approaches to tracking the intellectual pathway of Einstein to his general theory of relativity. The interconnections and interactions presented here reveal the central figures who influenced Einstein during this intellectual period. Despite current approaches to history presupposing that the efforts of scientists such as Max Abraham and Gunnar Nordström, which differed from Einstein s own views, be relegated to the background, this book shows that they all had an impact on the development of Einstein s theories, stressing the limits of approaches focusing solely on Einstein. As such, General Relativity Conflict and Rivalries proves that the general theory of relativity was not developed as a single, coherent construction by an isolated, brooding individual, but, rather, that it came to fruition through Einstein's conflicts and interactions with other scientists, and was consolidated by his creative processes during these exchanges. (shrink)

In early April 1911 Albert Einstein arrived in Prague to become full professor of theoretical physics at the German part of Charles University. It was there, for the first time, that he concentrated primarily on the problem of gravitation. Before he left Prague in July 1912 he had submitted the paper "Relativität und Gravitation: Erwiderung auf eine Bemerkung von M. Abraham" in which he remarkably anticipated what a future theory of gravity should look like. At the occasion of the Einstein-in-Prague (...) centenary an international meeting was organized under a title inspired by Einstein's last paper from the Prague period: "Relativity and Gravitation, 100 Years after Einstein in Prague". The main topics of the conference included: classical relativity, numerical relativity, relativistic astrophysics and cosmology, quantum gravity, experimental aspects of gravitation, and conceptual and historical issues. The conference attracted over 200 scientists from 31 countries, among them a number of leading experts in the field of general relativity and its applications. This volume includes abstracts of the plenary talks and full texts of contributed talks and articles based on the posters presented at the conference. These describe primarily original results of the authors. Full texts of the plenary talks are included in the volume "General Relativity, Cosmology and Astrophysics--Perspectives 100 Years after Einstein in Prague", editions. J. Bičák and T. Ledvinka, published also by Springer Verlag. (shrink)

Einstein located the foundations of general relativity in simple and vivid physical principles: the principle of equivalence, an extended principle of relativity and Mach's principle. While these ideas played an important heuristic role in Einstein's thinking, they provide a dubious logical foundation for his final theory. Einstein was also guided to his final theory, I argue, by a second tier of more prosaic heuristics. I trace one strand among them. The principle of equivalence guided Einstein well (...) until it led him to a theory that contradicted the conservation of momentum. Einstein converted the requirement of conservation of energy and momentum into a procedure that he used repeatedly for finding gravitational field equations. That procedure survives in present day developments of general relativity. (shrink)

In the same days in which Albert Einstein was completing his formulation of the theory of general relativity, David Hilbert arrived to the same field equations following a different path and different mathematical procedures. In this article, both ways to get to the same formal result will be analyzed, together with the exchange of letters between the two scientists, underlining the two different, but extremely sharp, creativities.

This paper will serve as the editorial note on Einstein's 1916 review article on general relativity in a planned volume with all of Einstein's papers in Annalen der Physik. It summarizes much of my other work on history of general relativity and draws heavily on the annotation of Einstein's writings and correspondence on general relativity for Vols. 4, 7, and 8 of the Einstein edition.

Readers of this volume will notice that it contains only a few papers on general relativity. This is because most papers documenting the genesis and early development of general relativity were not published in Annalen der Physik . After Einstein took up his new prestigious position at the Prussian Academy of Sciences in the spring of 1914, the Sitzungsberichte of the Berlin academy almost by default became the main outlet for his scientific production. Two of the (...) more important papers on general relativity, however, did find their way into the pages of the Annalen [35,41]. Although I shall discuss both papers in this essay, the main focus will be on [35], the first systematic exposition of general relativity, submitted in March 1916 and published in May of that year. (shrink)

ArgumentThe paper is an exploration of the interactions between Einstein and Oppenheimer. It highlights the sharp differences in Einstein's and Oppenheimer's approach to physics, in their presentation of self as iconic figures, and in their relation to the communities they considered themselves part of. To understand their differing approaches to physics it briefly reviews the kinds of unifications that took place in physics during the first two-thirds of the twentieth century and points to the 1961 MIT centennial celebration to (...) demonstrate the potency of Einstein's vision that there might be a fundamental theory from which all known theories could be derived. It also briefly reviews various aspects of the development of theoretical physics and of general relativity in the first two-thirds of the twentieth century, to better understand the context of the sharp, negative remarks that Oppenheimer made about Einstein and about his theory of general relativity in 1965 on the occasion of the tenth anniversary of Einstein's death. To answer the question: “Why the antagonism on Oppenheimer's part?” it looks at Oppenheimer's and Einstein's relation to their Jewish roots, their stance regarding nationalism, and their philosophical commitments. (shrink)

The philosophy of physics literature contains conflicting claims on the heuristic significance of general covariance. Some authors maintain that Einstein's general relativity distinguishes itself from other theories in that it must be generally covariant, for example, while others argue that general covariance is a physically vacuous and trivial requirement applicable to virtually any theory. Moreover, when general covariance is invested with heuristic significance, that significance as a rule is assigned to so-called “active” general (...) covariance, underwritten by the principle of background independence, rather than to general covriance as Einstein understood it. While agreeing with the latter group of commentators that general covariance indeed carries heuristic significance, I argue that a background independent theory need not be generally covariant and that instead the Principle of Equivalence as Einstein understood it provides the key to understanding the heuristic power of general covariance as a “mathematical sieve” for determining the gravitational field law. However, heuristic significance accrues to general covariance only indirectly, by its encompassing the relativity of frames underwritten by Einstein's principle of equivalence. (shrink)

Modern readers turning to Einstein’s famous 1905 paper on special relativity may not find what they expect. Its title, “On the electrodynamics of moving bodies,” gives no inkling that it will develop an account of space and time that will topple Newton’s system. Even its first paragraph just calls to mind an elementary experimental result due to Faraday concerning the interaction of a magnet and conductor. Only then does Einstein get down to the business of space and time and (...) lay out a new theory in which rapidly moving rods shrink and clocks slow and the speed of light becomes an impassable barrier. This special theory of relativity has a central place in modern physics. As the first of the modern theories, it provides the foundation for particle physics and for Einstein’s general theory of relativity; and it is the last point of agreement between them. It has also received considerable attention outside physics. It is the first port of call for philosophers and other thinkers, seeking to understand what Einstein did and why it changed everything. It is often also their last port. The theory is arresting enough to demand serious reflection and, unlike quantum theory and general relativity, its essential content can be grasped fully by someone merely with a command of simple algebra. It contains Einstein’s analysis of simultaneity, probably the most celebrated conceptual analysis of the century. (shrink)

The book you hold in your hands is the outcome of the "ISCS 2013: Interdisciplinary Symposium on Complex Systems" held at the historical capital of Bohemia as a continuation of our series of symposia in the science of complex systems. Prague, one of the most beautiful European cities, has its own beautiful genius loci. Here, a great number of important discoveries were made and many important scientists spent fruitful and creative years to leave unforgettable traces. The perhaps most significant period (...) was the time of Rudolf II who was a great supporter of the art and the science and attracted a great number of prominent minds to Prague. This trend would continue. Tycho Brahe, Niels Henrik Abel, Johannes Kepler, Bernard Bolzano, August Cauchy Christian Doppler, Ernst Mach, Albert Einstein and many others followed developing fundamental mathematical and physical theories or expanding them. Thus in the beginning of the 17th century, Kepler formulated here the first two of his three laws of planetary motion on the basis of Tycho Brahe’s observations. In the 19th century, nowhere differentiable continuous functions (of a fractal character) were constructed here by Bolzano along with a treatise on infinite sets, titled “Paradoxes of Infinity” (1851). Weierstrass would later publish a similar function in 1872. In 1842, Doppler as a professor of mathematics at the Technical University of Prague here first lectured about a physical effect to bear his name later. And the epoch-making physicist Albert Einstein – while being a chaired professor of theoretical physics at the German University of Prague – arrived at the decisive steps of his later finished theory of general relativity during the years 1911–1912. In Prague, also many famous philosophers and writers accomplished their works; for instance, playwright arel ape coined the word "robot" in Prague (“robot” comes from the Czech word “robota” which means “forced labor”). (shrink)

This is the chapter on general relativity for the Cambridge Companion to Einstein which I am co-editing with Christoph Lehner.

This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be (...) preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant. (shrink)

The main objective of this book is to present the theory of general relativity in a direction that will be intelligible, informative, and interesting to the individual reader. Many of the texts about general relativity are either too thin on detail or too narrow in scope; this book was written with the aim of rectifying these shortcomings.

Einstein's gravitational redshift derivation in his famous 1916 paper on general relativity seems to be problematic, being mired in what looks like conceptual difficulties or at least contradictions or gaps in his exposition. Was this derivation a blunder? To answer this question, we will consider Einstein’s redshift derivations from his first one in 1907 to the 1921 derivation made in his Princeton lectures on relativity. This will enable to see the unfolding of an interdependent network of (...) concepts and heuristic derivations in which previous ideas inform and condition later developments. The resulting derivations and views on coordinates and clocks are in fact not without inconsistencies. However, we can see these difficulties as an aspect of an evolving network understood as a “work in progress”. (shrink)

This book pieces together the jigsaw puzzle of Einstein's journey to discovering the special theory of relativity. Between 1902 and 1905, Einstein sat in the Patent Office and may have made calculations on old pieces of paper that were once patent drafts. One can imagine Einstein trying to hide from his boss, writing notes on small sheets of paper, and, according to reports, seeing to it that the small sheets of paper on which he was writing would vanish (...) into his desk-drawer as soon as he heard footsteps approaching his door. He probably discarded many pieces of papers and calculations and flung them in the waste paper basket in the Patent Office. The end result was that Einstein published nothing regarding the special theory of relativity prior to 1905. For many years before 1905, he had been intensely concerned with the topic; in fact, he was busily working on the problem for seven or eight years prior to 1905. Unfortunately, there are no surviving notebooks and manuscripts, no notes and papers or other primary sources from this critical period to provide any information about the crucial steps that led Einstein to his great discovery. In May 1905, Henri Poincare sent three letters to Hendrik Lorentz at the same time that Einstein wrote his famous May 1905 letter to Conrad Habicht, promising him four works, of which the fourth one, Relativity, was a rough draft at that point. In the May 1905 letters to Lorentz, Poincare presented the basic equations of his 1905 "Dynamics of the Electron", meaning that, at this point, Poincare and Einstein both had drafts of papers relating to the principle of relativity. The book discusses Einstein's and Poincare's creativity and the process by which their ideas developed. The book also explores the misunderstandings and paradoxes apparent in the theory of relativity, and unravels the subtleties and creativity of Einstein. (shrink)

The author's transition from physics to the history of science was caused in a large part by his desire "to know more about the relativity paper and its author". Indeed, the entire book could be considered as an exegesis of the Einstein paper "On the Electrodynamics of Moving Bodies" and its broad physical and philosophical background. The special theory of relativity not only opened a new era in physics but it also changed the philosophical perspective from which man (...) looks at the universe. Intellectual struggles around the foundations of physics in the first decade of our century throw a new light on the "drama of science": "The drama of science in the making centered on the interplay between empirical data and physical theory, the clinging to notions that were neither always articulable nor clearly testable, the great investment of effort in empirical data and in already existing physical theories, and the irresistible drive toward the long-sought-after unification of the sciences". (shrink)

We extend to curved space-time the field theory on R×S3 topology in which field equations were obtained for scalar particles, spin one-half particles, the electromagnetic field of magnetic moments, an SU2 gauge theory, and a Schrödinger-type equation, as compared to ordinary field equations that are formulated on a Minkowskian metric. The theory obtained is an angular-momentum representation of gravitation. Gravitational field equations are presented and compared to the Einstein field equations, and the mathematical and physical similarity and differences between them (...) are pointed out. The problem of motion is discussed, and the equations of motion of a rigid body are developed and given explicitly. One result which is worth emphazing is that while general relativity theory yields Newton's law of motion in the lowest approximation, our theory gives Euler's equations of motion for a rigid body in its lowest approximation. (shrink)

On the side of Niels Bohr, not to mention a few other physicists, there is an honest acknowledgment of a difficulty in understanding Einstein's objection to the “completeness” of the Ψ-function description of the quantum phenomenon. Yet the weight which Bohr himself attaches to Einstein's insistence may indicate that if the latter's difficulty could be understood, then, through the cooperation of understanding physicists, another great accomplishment of unification might be obtained which would be as fruitful for the future (...) as either or both the general theory of relativity and Bohr's statistical theory have been to the present. (shrink)

The dynamics of general relativity is encoded in a set of ten differential equations, the so-called Einstein field equations. It is usually believed that Einstein's equations represent a physical law describing the coupling of spacetime with material fields. However, just six of these equations actually describe the coupling mechanism: the remaining four represent a set of differential relations known as Bianchi identities. The paper discusses the physical role that the Bianchi identities play in general relativity, (...) and investigates whether these identities --qua part of a physical law-- highlight some kind of a posteriori necessity in a Kripkean sense. The inquiry shows that general relativistic physics has an interesting bearing on the debate about the metaphysics of the laws of nature. (shrink)

The philosopher who is interested in developments of modern physics may turn with some profit to an argument that has recently evolved between the late George Birkhoff and Hermann Weyl. Birkhoff and his associates have constructed a theory of relativity differing in various ways from Einstein's general theory. Weyl has offered a critical analysis of the Birkhoff theory along with a defense of the Einstein theory; and Birkhoff has presented his rebuttal to Weyl.

Reiser declares that what the modern world needs is a new system of thought, a new world-view that will integrate the "mystical participation of an earlier age" with the "hard core of scientific objectivity." And so he proceeds to build one, drawing on diverse attempts of East and West to decipher the mysteries of the universe. The result is a "Hindu-Pythagoras-Stoic-Bruno-Spinoza-Einstein world-view" that is intriguing if not entirely palatable. His treatments of such topics as space-time, field forces, the double-helix, (...) class='Hi'>relativity, and the Heisenberg principle are clear but sketchy. In fact, many of his entries for discussion, although impeccably up-to-date and relevant, are too brief to give a strong account of themselves, even though they seem to serve adequately to support his over-all project of synthesizing modern scientific breakthroughs with ancient insights. Physics, chemistry, biology, music, cybernetics, mathematics, astrophysics, psychology, and history of religions all find themselves with interrelating contributions to make to Reiser's gestalt of Cosmic Humanism.—S. O. H. (shrink)

It is argued that, under the assumption that the strong principle of equivalence holds, the theoretical realization of the Mach principle (in the version of the Mach-Einstein doctrine) and of the principle of general relativity are alternative programs. That means only the former or the latter can be realized—at least as long as only field equations of second order are considered. To demonstrate this we discuss two sufficiently wide classes of theories (Einstein-Grossmann and Einstein-Mayer theories, respectively) both embracing (...) Einstein's theory of general relativity (GRT). GRT is shown to be just that “degenerate case” of the two classes which satisfies the principle of general relativity but not the Mach-Einstein doctrine; in all the other cases one finds an opposite situation.These considerations lead to an interesting “complementarity” between general relativity and Mach-Einstein doctine. In GRT, via Einstein's equations, the covariant and Lorentz-invariant Riemann-Einstein structure of the space-time defines the dynamics of matter: The symmetric matter tensor Ttk is given by variation of the Lorentz-invariant scalar densityL mat, and the dynamical equations satisfied by Tik result as a consequence of the Bianchi identities valid for the left-hand side of Einstein's equations. Otherwise, in all other cases, i.e., for the “Mach-Einstein theories” here under consideration, the matter determines the coordinate or reference systems via gravity. In Einstein-Grossmann theories using a holonomic representation of the space-time structure, the coordinates are determined up to affine (i.e. linear) transformations, and in Einstein-Mayer theories based on an anholonomic representation the reference systems (the tetrads) are specified up to global Lorentz transformations. The corresponding conditions on the coordinate and reference systems result from the postulate that the gravitational field is compatible with the strong equivalence of inertial and gravitational masses. (shrink)

En las actividades ordinarias de nuestra vida cotidiana encontramos nuestros actos de percepción confrontados por las cosas materiales. A ellos ─actos de percepción─ les atribuimos una existencia "real" asumiéndolos de tal manera que los sumergimos y transfundimos, de forma múltiple e indefinida, dentro del entorno de realidades análogas que se unen para formar un único mundo al que yo, con mi propio cuerpo, pertenezco. Ahora bien sí frente a la cotidianidad descrita anteriormente asumimos una actitud escéptica acerca de lo que (...) es “real” en el mundo,nos descubriremos haciendo una reflexión filosófica. Bajo esta deliberación encontramos que, por ejemplo, la cualidad "verde", tiene existencia por medio de la sensación "verde"asociada a un objeto dado por la percepción, lo que nos lleva a pensar que no tiene sentido vincularla sensación como cosa en sí misma a cosas materiales existentes en sí mismos , esto nos lleva a pensar que las cualidades de los sentidostienen carácter subjetivo.A pesar de esta reflexión es conveniente acotar que esta subjetividad no interesaa las ciencias exactas ya que éstas procuran lo objetivo. -/- Desde este punto de vista,encontramos dentro de los estudios de Galileo Galilei el principio que subyace al método matemáticoconstructivo de nuestra física moderna ; de esta manera, y bajo este principio,los colores ─ por ejemplo “verde”─ son solo vibraciones en un medio repudiando de esta forma el carácter subjetivo a la vez que se mantiene la objetividad. Sin embargo, dentro del campo de la filosofía el idealismo transcendental de Kant marca un cambio de paradigma en relación a lo anterior. Kant sostiene que no solamente las cualidades de los sentidos tienen carácter subjetivo, sino que espacio y tiempo, conceptos fundacionales dentro de la física, no tienen significación absoluta; en otras palabras, espacio y tiempo son formas de nuestra percepción . Para Kant aquello que sustenta nuestra percepción y aquello que sustenta el conocimiento matemático aplicado a la experiencia son lo mismo: intuiciones puras a priori del espacio y el tiempo. De esta manera, y bajo esta perspectiva, sólo la teoría de la relatividad deja muyen claro que las dos esencias: espacio y tiempo, como formas de la intuición en términos kantianos, no tienen lugar en el mundo construido por la física matemática concebida por Galileo . -/- Según esto, los colores no son siquiera vibraciones en un medio sino simplemente una serie de valores de funciones matemáticas en las que se producen cuatro parámetros independientes que corresponden a las tres dimensiones del espacio y la del tiempo, expresado como principio general esto significa que el mundo real y cada uno de sus constituyentes con sus características sólo pueden ser, en términos husserlianos, objetos intencionales de actos de conciencia . En otras palabras: los datos inmediatos que recibo son las experiencias de la conciencia. Esto nos permite afirmar que la sensación de un objeto está presente de una forma físicamente real para mí con quien esa sensación se relaciona. Esto es lo que Brentano llama objeto intencional ;es así como al percibir un objeto, por ejemplo: veo este “libro” mi atención está totalmente dirigida hacia él. Yo "tengo" la percepción, pero sólo cuando hago de esta percepción ─ acto libre de reflexión ─algo que "conozco" con respecto a ella ─y no sólo el “libro”─ llego precisamente a un segundo acto: objetos intencionales de actos de conciencia, que son a los que referíamos antes . -/- El objeto intencional es inmanente y lo que es inmanente es absoluto ; es exactamente lo que es en la forma en que lo tengo, y puedo reducir esto, su esencia, por los actos de reflexión . En otras palabras, es un componente real de mis experiencias; contrario a lo que sucede con el acto primario de percepción, donde el objeto es trascendental , esto es, se da en una experiencia de conciencia pero no es un componente real de la misma. Por otra parte, los objetos trascendentales tienen sólo una existencia fenoménica; son apariencias que se presentan de múltiples maneras. Ninguno de estos modos de aparición puede pretender presentar aquello que percibimos – por ejemplo el libro- tal como es en sí, además en toda percepción está involucrada la tesis de la realidad del objeto que aparece en ella; este último es, de hecho, un elemento fijo y duradero de la tesis general de la realidad del mundo . En resumen, lo que interesa ver claramente es la importancia enel dato de la conciencia como punto de partida en el que debemos situarnos si queremos comprender el significado absoluto . (shrink)

This volume is the first systematic presentation of the work of Albert Einstein, comprising fourteen essays by leading historians and philosophers of science that introduce readers to his work. Following an introduction that places Einstein's work in the context of his life and times, the book opens with essays on the papers of Einstein's 'miracle year', 1905, covering Brownian motion, light quanta, and special relativity, as well as his contributions to early quantum theory and the opposition to (...) his light quantum hypothesis. Further essays relate Einstein's path to the general theory of relativity (1915) and the beginnings of two fields it spawned, relativistic cosmology and gravitational waves. Essays on Einstein's later years examine his unified field theory program and his critique of quantum mechanics. The closing essays explore the relation between Einstein's work and twentieth-century philosophy, as well as his political writings. (shrink)

This paper considers the early reception of Einstein's theory of relativity in the Arab world, with emphasis directed to its popularization. Educated Arabs generally had no contention with Einstein's political, religious or cultural background. On the contrary, they viewed him as the genius of the age and defended him against his critics.

Relativity was Einstein’s main research programme and scientific project. It was an open-ended programme that developed throughout Einstein’s scientific career, giving rise to special relativity (SR), general relativity (GR), and unified field theory. In this article, we want to uncover the methodological logic of the Einsteinian programme, which animated the whole programme and its development, and as it was revealed in SR, GR, and unified field theory. We aver that the same methodological logic animated all these (...) theories as Einstein’s work progressed. Each of these theories contributed towards constructing Einstein’s ambitious programme. This article is not a contribution to the history of relativity, but, rather, it utilises our knowledge of this history to uncover the methodological logic of the relativity programme and its development. This logic is latent in the historical narrative but is not identical to it. We hope to show that the Einsteinian relativity project is still relevant today as a theoretical scheme, despite its failures and despite quantum mechanics. (shrink)

In 1907, Einstein set out to fully relativize all motion, no matter whether uniform or accelerated. After five failed attempts between 1907 and 1918, he finally threw in the towel around 1920, setting himself a new goal. For the rest of his life he searched for a classical field theory unifying gravity and electromagnetism. As he struggled to relativize motion, Einstein had to readjust both his approach and his objectives at almost every step along the way; he got himself hopelessly (...) confused at times; he fooled himself with fallacious arguments and sloppy calculations; and he committed what he later allegedly called the biggest blunder of his career: he introduced the cosmological constant. There is a very uplifting moral to this somber tale. Although Einstein never reached his original destination, the harvest of his thirteen-year odyssey is quite impressive. First of all, what is left of absolute motion in general relativity is far more palatable than absolute motion in special relativity or Newtonian theory. And general relativity does seem to eliminate absolute space. More importantly, from a modern physics point of view, Einstein produced a spectacular new theory of gravity based on what he called the equivalence principle. This principle says that inertial and gravitational effects are due to one and the same structure, the inertio-gravitational field, which in Einstein’s theory is represented by a metric tensor field. In addition to laying the foundations of this theory, Einstein, among other things, launched relativistic cosmology, suggested the possibility of gravitational waves, gave the first sensible definition of a space-time singularity, and caught on to the intimate connection between general covariance and energy-momentum conservation, an example of the general connection between symmetries and conservation laws of Noether’s theorems. These results more than make up for the—at least by the standards of modern philosophy of science—rather opportunistic way in which they were obtained.. (shrink)