The facts that led to establishment of the special theory of relativity are reanalyzed. The analysis leads to the well-known formalism, involving, however, somewhat unusual notations. The object of the analysis is to start more closely from the directly observed experimental facts than is usually done; at the same time, great stress is laid on giving formulations independent of the representation in particular reference systems. A detailed analysis is given as to the actual physical methods involved when introducing three- or (...) four-dimensional reference systems. The orthogonal transformations and also the Lorentz transformations are introduced not so much as coordinate transformations but as operators reflecting physical properties of material systems. The principle of relativity is replaced by a mathematically equivalent principle denoted as theLorentz principle which reflects certain symmetries of the known physical laws. (shrink)

The considerations of Part I are extended and the experimental data and hypotheses that led to the establishment of the general theory of relativity are analyzed. It is found that one of the fundamental assumptions is that light is propagated homogeneously; i.e., by using arbitrary systems of coordinates, propagation of light can be represented by a homogeneous quadratic form. This is shown to be an assumption that can be verified by experiment, at least in principle. As a result of adding (...) a number of further assumptions to this, the usual formalism of the general theory of relativity can be established. In the above point of view, the general theory of relativity—like any other theory—cannot be built upad hoc, but is built on distinct physical hypotheses, each of which can be subjected to test by experiment. (shrink)

The considerations of the two former articles concerning the special and general theories of relativity are extended. The question of the physical reality of the ether and the interpretation of some cosmological problems are discussed. A view is expanded according to which the metric tensor g is taken as the energy momentum tensor of the ether. The gravitational equation of Einstein is considered to represent the equations of motion of the ether. The cosmological red shift is also interpreted in such (...) terms. (shrink)

Summarizing and extending the ideas of many authors and also of our own work, we try to show that the wave equation of the one-body problem can be transformed into a system of equations describing the motion of a deformable medium carrying charge and having permanent magnetic polarization. The wave equation and the system of transformed equations are connected by a strict one-to-one correspondence. The transformation which is not uniquely determined from a mathematical point of view can be chosen so (...) that the new variables have directphysical significance. The latter requirement permits consequently a unique choice of the mathematical possibilities. (shrink)

Continuing the considerations given in the first part of this series (I), we use the analysis of the Aharonov-Bohm effect to show that the hydrodynamical variables by which the quantum mechanical one-body problem can be represented are of direct physical significance. It is shown in a particular case that the final state of a system can be obtained from its initial state in a unique manner if both states are characterized by hydrodynamical variables.

It is shown that the wave equation of anN-body problem can be transformed into a system of “hydrodynamical equations” in a3N-dimensional space. The projections of the hydrodynamical variables in three-dimensional space do not obey strict equations of motion. This is shown to be connected with the fact that the mathematically possible solutions of the wave equations are much more numerous than the states of the system that are usually realized in nature. It is pointed out that the many-body wave equation (...) has to be supplemented with thermodynamic principles, so as to obtain a satisfactory description of real phenomena. (shrink)

It is shown that the nonconservation of energy to the extent given by the uncertainty relation can be interpreted also as the storing of inner energyQ by a wave mechanical system. The latter formalism is, apart from its terminology, identical with the accepted one.