Showing papers on "Special relativity (alternative formulations) published in 1991"

Einstein and the History of General Relativity

Abstract: This book is a collection of essays by the authors and other people that deal with scientific opinions that led Einstein and his contemporaries to their views of general relativity. Some of the essays explore Einstein's passage from the special theory through a sequence of gravitational theories to the discovery of the field equations of the grand theory in November 1915. Two other essays discuss Einstein's public and private exchanges with Max Abraham and Tullio Levi-Civita in 1913 and 1914. A sympathetic picture of H.A. Lorentz's reaction to the general theory of relativity is included, and a careful and insightful essay on the early understanding of the Schwarzschild-Droste solution to the field equations of general relativity is presented. One paper presents a discussion on the state of the enterprise of general relativity between 1925 and 1928, and a short essay details the history of steps toward quantum gravitational through canonical quantization. A discussion of the history of derivations of the geodesic equation of motion from the field equation and conservation laws of the general theory is presented. The early history of geometrical unified field theories is included.

Some remarks on classical electromagnetism and the principle of relativity

Abstract: In connection with a note by Rindler on relativity and electromagnetism, it is shown that classically interpreted electromagnetism and special relativity already diverge in their predictions on the behavior of a very simple electrodynamical system, even for ‘‘low’’ velocities.

Synchronization and relativity

Abstract: The author gives an introduction to the concepts of both special and general relativity-particularly as they apply to time coordination. The use of concepts and formulas of the special and of the general theory of relativity has become a necessity in electronic systems that use high precision timing, especially space systems. The principles involved are reviewed with emphasis on practical applications and operational standards used in timekeeping and remote synchronization. >

"Waves," "Objects" and Special Relativity

Abstract: Field theories such as Maxwell's equations for electrodynamics describe a continuum and predict the existence of waves. A contact to mechanics and its classical kinematical concepts of localized objects, or particles, moving at certain group velocities along well-defined trajectories, is achieved by defining wave packets and developing the Hamilton ray equations governing their motion. The wave packets contain many oscillations which are modulated by a slowly tapering envelope defining the extent of this packet in space and time. It is shown here that the solitary waves, i.e., waves which are characterized by very sharp localized pulses consisting of a small number of oscillations, are described differently. The two entities are analogous when we compare the behavior of one in configuration space-time with the other in representation space. This analogy is remarkable and leads to new concepts that might prove useful for many applications. Thus it is shown that the solitary wave can be described in terms of analog rays in representation space, on which a group slowness function is defined. In space-time the solitary wave is characterized by a wave surface evolving according to the relevant slowness function at each point. For objects and therefore for wave packets, there exists a relativistic formalism in terms of four-vectors. Thus the Hamilton ray equations can be represented in terms of the four-velocity, involving a differentiation of the position four-vector with respect to the proper time. The analog treatment leads to a differentiation of the representation four-vector with respect to the new concept: the proper frequency. Finally, the analogy provides an explanation for the stability of solitary waves in the presence of nonlinear media, without the need for discussing specific differential equations: It is argued that self defocusing of the analog rays in representation space provides the \"glue\" which counteracts dispersive effects in configuration space, and thus obviates the fissioning of the solitary wave.

Velocity-dependent mass of proper time?

Abstract: Physics teachers and high-energy physicists express different opinions concerning the velocity-dependent mass. To understand this issue better a resume of velocity-dependent mass as well as of proper time is given in a historical setting. The role of both concepts in physics teaching is considered. From a four-dimensional point of view in elementary special relativity the introduction of proper time and of constant mass with velocity-dependent mass are discussed.

Test of special relativity or of the isotropy of space by use of infrared masers

Abstract: Test of isotropy of space for light propagation and effect of earth orbital velocity on velocity of light, using he-ne infrared masers

A remark on the twin ``paradox''

Abstract: The twin “paradox” is investigated using a method that emphasises the symmetry between the twins. All the calculations are performed using the Schwarzschild metric, making the result valid in general relativity as well in the special case of Minkowski space.

Taming the Curvature

Abstract: We have seen that if space is curved, we may someday be able to travel rapidly and easily through it to distant points in the universe. So far, though, we have said nothing about how space becomes curved, or if, indeed, it happens at all. What would cause space to curve?

Pourquoi il faut lire Hestenes

Abstract: Cet article explique pourquoi les travaux d'Hestenes sur l'algebre de Clifford d'espace-temps meritent un examen attentif et approfondi de la part de ceux qui ont des doutes sur la valeur des principes generaux de la mecanique quantique

A Charged Kerr Metric Solution in New General Relativity : Astrophysics and Relativity

Abstract: We give an exact solution of the gravitational and electromagnetic field equations with a charged rotating source in new general relativity. The solution has three parameters Q, h and a, and it gives a charged Kerr metric space-time. The parallel vector fields and the electromagnetic vector poten- \" tial are axially symmetric. In this space-time, we cannot discriminate new general relativity \"from general relativity, so far as scalar, the Dirac and the Yang-Mills fields and macroscopic bodies are used as probes. The space-time does not have singularities at all, although it has an \"effective singularity\". Two kinds of Reissner-Nordstrom metric solutions, one is our solution with h=O and the other is a solution given by Hayashi and Shirafuji, are physically equivalent with each other. Nevertheless, these are markedly different from each other with regard to the asymptotic behavior of the torsion tensor for r -+ 00 and the space-time singularities.

ZUR THEORIE DER LORENTZTRANSFORMATIONEN Eine Erwiderung

Abstract: On the Theory of the Lorentz transformations. A Reply The author defends the notion of absolute time and classical kinematics in special relativity against various objections raised against his theory of the Lorentz transformations.