Showing papers on "Special relativity (alternative formulations) published in 1973"
01 Jan 1973
TL;DR: The purpose of these lectures was to give a survey of Einstein’s theory of gravitation and the connection between physical and mathematical concepts and ideas.
Abstract: The purpose of these lectures was to give a survey of Einstein’s theory of gravitation. Since special astrophysical topics have been covered by other lecturers and the principal mathematical tools of general relativity were also considered separately, I tried to concentrate on the general structure of the theory and the connection between physical and mathematical concepts and ideas; examples and applications have been mentioned briefly only.
212 citations
TL;DR: In this article, the Einstein-Maxwell field equations in the presence of one Killing vector are shown to possess covariance under an eight-parameter group of linear substitutions in the field variables.
Abstract: The Einstein‐Maxwell field equations in the presence of one Killing vector are shown to possess covariance under an eight‐parameter group of linear substitutions in the field variables. This internal symmetry group is isomorphic to SU(2,1). Three of the degrees of freedom correspond to gage transformations, but the remaining ones allow us to generate a five‐parameter family of solutions given a single solution.
159 citations
TL;DR: In this paper, it was shown that changes of topology in the spacetime of classical general relativity are consistent with stable causality, future causal geodesic completeness, and finite, positive energy density.
Abstract: It is shown that ‘changes of topology’ (of spacelike sections) in the spacetime of classical general relativity are consistent with the following requirements: (i) stable causality, (ii) future causal geodesic completeness, and (iii) finite, positive energy density This amounts to showing that the framework of classical general relativity encompasses ‘changes of topology’
37 citations
01 Jan 1973
TL;DR: The nature and role of the various relativity principles has been correspondingly unclear as discussed by the authors, and exactly how they are associated with given physical theories, has been far from clear, as well as the nature of the role of these principles.
Abstract: Traditionally, certain physical theories have been thought to have relativity principles associated with them. Associated with Newtonian mechanics is the principle of Galilean relativity, associated with special relativity is the special or restricted principle of relativity, associated with general relativity is the general principle of relativity, etc. Such relativity principles are often expressed in terms of groups of transformations. The principle of Galilean relativity is expressed by the ‘invariance’ of Newtonian mechanics under the Galilean group, that of special relativity by the ‘invariance’ of special relativity under the Lorentz group, and that of general relativity by the ‘invariance’ (or ‘covariance’) of general relativity under the group of all 1–1 transformations with non-vanishing Jacobian. Unfortunately, just what these various groups are groups of, and exactly how they are associated with given physical theories, has been far from clear. Similarly, the nature and role of the various relativity principles has been correspondingly unclear.
25 citations
TL;DR: In this article, it was pointed out that if one did not know the Einstein-HamiltonJacobi equation one might hope to derive it straight off from plausible first principles, without ever going through the formulation of the Einstein field equations themselves.
Abstract: It is pointed out that if one did not know the Einstein--HamiltonJacobi equation one might hope to derive it straight off from plausible first principles, without ever going through the formulation of the Einstein field equations themselves. (auth)
25 citations
18 citations
10 citations
TL;DR: In this article, the Lorentz-covariant two-body problem was shown to be solvable for straight-line motiom and admits solutions in which the charges move in circles about a commom center.
Abstract: S>We treat a Lorentz-covariant two-body problem due to Fokker: One electric charge experiences the retarded field of a second, while the he first; this is pure action at a distance, with no self-action; conservation principles exist. We show that this (apparently generally soluble) time-asymmetric problem is exactly soluble for straight-line motiom and admits solutions in which the charges move in circles about a commom center. We briefly consider nonelectrodynamic time-asymmetric interactions and aspects of quantizing thc motions. (auth)
9 citations
TL;DR: In this paper, an argument is presented that negative energy tachyons do not exist, based on an apparent inconsistency with special relativity, and a misunderstanding of the Dirac-Stueckelburg-Feynman-Sudarshan reinterpretation principle.
Abstract: An argument is presented that negative-energy tachyons do not exist. The argument is based on an apparent inconsistency with special relativity, and a misunderstanding of the Dirac-Stueckelburg- Feynman-Sudarshan reinterpretation principle''. (LBS)
8 citations
Journal Article•
TL;DR: In this paper, the relationship between the Petrov classification of Riemannian space times and the Debever-Penrose principal null directions is developed in explicit algebraic terms, and the relation between Petrov's classification and the principal null direction is analyzed in terms of algebraic relations.
Abstract: The relationship between the Petrov classification of Riemannian space‐times and the Debever‐Penrose principal null directions is developed in explicit algebraic terms.
TL;DR: The advantages of introducing special relativity as a unifying concept, providing at the same time better physical insight into electricity and magnetism and their mutual relationship are discussed.
Abstract: When students are introduced for the first time to electromagnetic theory, it is either presented as a set of separate aspects like electrostatics, magnetostatics, slow and fast varying fields etc., or in the unified form of Maxwell's equations. In the first case, students are likely to consider the different aspects as physically different phenomena, whilst in the last case, the mathematical formalism makes the physical understanding of electromagnetism difficult. This paper discusses the advantages of introducing special relativity as a unifying concept, providing at the same time better physical insight into electricity and magnetism and their mutual relationship. A description of an introductory course in relativity, given by the author to second year undergraduates, is presented. A list of educational objectives stated in behavioral terms is also given. This list of objectives has been found particularly helpful in designing instruction and establishing evaluation criteria.
TL;DR: In this article, a purely geometrical proof of the conformity of the mapping of the celestial sphere onto itself induced by spinors is given, where no knowledge in representation theory is presupposed.
Abstract: Spinors are introduced using geometrical concepts only, such that no knowledge in representation theory is presupposed. The essential part is the purely geometrical proof of the conformity of the mapping of the celestial sphere onto itself induced by spinors.
TL;DR: In this paper, the dynamical problem for a continuous body constrained to undergo only plane BORN motions is solved in special relativity, where the body is assumed to be a continuous point cloud.
Abstract: The dynamical problem for a continuous body constrained to undergo only plane BORN motions is solved in special relativity.
TL;DR: In this paper, the e-generalized Lorentz equations derived by Winnie are the equations governing accelerated systems and the e -generalized equation for time is used in analyzing two cases of the clock paradox.
Abstract: Within Special Relativity accelerated systems can be described as those systems in which standard clock synchronism does not hold. Therefore, the e -generalized Lorentz equations derived by Winnie are the equations governing accelerated systems. The e -generalized equation for time is used in analyzing two cases of the clock paradox: (1) the case in which a clock travels in a straight line, stops, and returns, and (2) the case in which a clock travels with uniform velocity in a circular path. The treatment of case (1) of the paradox within this generalization of the Special Theory is compared with Moller's treatment of it within the General Theory.
01 Oct 1973
TL;DR: A simple explanation of the clock paradox of special relativity is obtained by considering the aberration of light as mentioned in this paper, which is a simple way to explain the anomalous behavior of light.
Abstract: A simple explanation of the clock paradox of special relativity is obtained by considering the aberration of light.
TL;DR: In this paper, the problem of observing a collision between two spaceships is utilized to illustrate the misuse of time dilation and length contraction, and the incorrect description of space-time coordinates in special relativity.
Abstract: The problem of observing a collision between two spaceships is utilized to illustrate the misuse of time dilation and length contraction, and the incorrect description of space-time coordinates in special relativity. By emphasizing the equivalence of all inertial frames, students can be guided to correct descriptions of space-time coordinates and to proper applications of time dilation and length contraction.
TL;DR: In this article, a metric form allowing the simultaneous solution of the Einstein and Maxwell solutions for an isotropic electromagnetic field is derived in explicit form, and a metric space allowing a normal, shear-free, expanding congruence of geodesics is considered.
Abstract: Spaces allowing a normal, shear-free, expanding congruence of isotropic geodesics are considered. A metric form allowing the simultaneous solution of the Einstein and Maxwell solutions for an isotropic electromagnetic field is derived in explicit form.
TL;DR: In this article, a general method of obtaining solutions is proposed in which the passage from one frame of reference to the other satisfies the correspondence principle, and the solution is shown to be Newtonian.