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This article introduces a new field theory formulation. The new field theory formulation recognizes vector continuity as a general principle and begins with a field that satisfies vector continuity equations. Next, independent of the new formulation, this article introduces a new space-time adjustment. Then, we solve the one-body gravitational problem by applying the space-time adjustment to the new field theory formulation. With the space-time adjustment, the new formulation predicts precisely the same precession of Mercury and the same bending of light as general relativity. The reader will find the validating calculations to be simple. The equations of motion that govern the orbital equations are in terms of Cartesian coordinates and time. An undergraduate college student, with direction, can perform the validations. [ABSTRACT FROM AUTHOR]

Since changes in all 4 dimensions of spacetime are components of displacement for gravitational waves, a theoretical result is presented that their speed is undefined, and that the Theory of Relativity is not reliable to predict their speed. Astrophysical experiments are proposed with objectives to directly measure gravitational wave speed, and to verify these theoretical results. From the circumference of two merging black hole's final orbit, it is proposed to make an estimate of a total duration of the last ten orbits, before gravitational collapse, for comparison with durations of reported gravitational wave signals. It is proposed to open a new field of engineering of spacetime wave modulation with an objective of faster and better data transmission and communication through the Earth, the Sun, and deep space. If experiments verify that gravitational waves have infinite speed, it is concluded that a catastrophic gravitational collapse, such as a merger of quasars, today, would re-define the geometry and curvature of spacetime on Earth, instantly, without optical observations of this merger visible, until billions of years in the future. [ABSTRACT FROM AUTHOR]

Fanny-Leicht Gymnasium Stuttgart, Fanny-Leicht Str. 13, 70563 Stuttgart-Vaihingen, Germany In an advanced course on general relativity, some exotic spacetimes like wormholes with a more complex topology than the standard Schwarzschild spacetime can be studied in detail. In this regard, it has been pointed out by Morris and Thorne that wormholes could be a valuable tool for teaching general relativity. In this paper, we claim rotating wormholes might also have a pedagogical role in general relativity, and present an empirical approach to explore periodic orbits of such, that could be applied also to other spacetimes. [ABSTRACT FROM AUTHOR]

In general relativity, gravitational collapse of matter fields ends with the formation of a spacetime singularity, where the matter density becomes infinite and standard physics breaks down. According to the weak cosmic censorship conjecture, singularities produced in the gravitational collapse cannot be seen by distant observers and must be hidden within black holes. The validity of this conjecture is still controversial and at present we cannot exclude that naked singularities can be created in our Universe from regular initial data. In this paper, we study the radiation emitted by a collapsing cloud of dust and check whether it is possible to distinguish the birth of a black hole from the one of a naked singularity. In our simple dust model, we find that the properties of the radiation emitted in the two scenarios is qualitatively similar. That suggests that observational tests of the cosmic censorship conjecture may be very difficult, even in principle. [ABSTRACT FROM AUTHOR]

ABSTRACT Cosmological redshift z grows as the Universe expands and is conventionally viewed as a third form of redshift, beyond the more traditional Doppler and gravitational effects seen in other applications of general relativity. In this paper, we examine the origin of redshift in the Friedmann-Robertson-Walker (FRW) metrics with constant space-time curvature, and show that - at least for the static space-times - the interpretation of z as due to the 'stretching' of space is coordinate dependent. Namely, we prove that redshift may also be calculated solely from the effects of kinematics and gravitational acceleration. This suggests that its dependence on the expansion factor is simply a manifestation of the high degree of symmetry in FRW, and ought not be viewed as evidence in support of the idea that space itself is expanding. [ABSTRACT FROM AUTHOR]

It is asserted that we live in a world in which space itself, a real quantum-fluid-like background medium named quantum space (QS), inherently moves in the ordinary three dimensions about each astronomical body according to a circular differential velocity field, consistent with the local main astronomical motions. Light and all the elementary particles are conceived as persistent excitations (resonances) of this real space itself and therefore this moving QS is their medium of propagation and the ultimate reference for their motions. Within this viewpoint, motions of the laboratory with respect to the resting QS or of the QS through the resting laboratory are perfectly equivalent and generate identical effects. These velocity fields of the QS about each astronomical body rightly produce the inertial dynamics observed within the gravitational fields. Interestingly enough, in this velocity field the orbiting natural planets, stars, and the galactic centers throughout the universe do all very nearly rest with respect to the local moving QS while carrying with them their own velocity fields. This, while naturally leading to the observed (null) results of the Michelson light anisotropy experiments, also increases the go-return round trip time of light and of matter waves in general within our laboratories and thereby correctly engenders all the effectively observed effects, caused by the gravitational fields. It rightly slows down all the time standards (clocks) and the physical processes in general, which is the gravitational time dilation. It also causes the gravitational redshifts of atomic and nuclear spectra and properly simulates the apparently deformed metric of space underlying Einstein's spacetime curvature. This same spacedynamics moreover crucially predicts the very small genuine anisotropy of the velocity of light of nearly 8 km/s, fixed with respect to the earth-based laboratories and caused by the earth velocity field alone. This small anisotropy was detected systematically by sensitive Michelson interferometers rotating in the earth-based laboratories but was inexplicably discarded as spurious by enthusiasts of the theory of relativity. Spacedynamics also rightly points out the genuine physical origin of the excess time delays in the roundtrips of radar signals within the solar system and the observed anomalous (non-Doppler) red-/blueshifts of radiation coming to us by passing near heavy bodies. It also forthrightly explains the absence of effects of the solar gravitational potential on the GPS clock rates and the origin of the apparent bias of earth-based clocks synchronized along very long baselines when confronted with the highly stable clock ticks of distant pulsars. [ABSTRACT FROM AUTHOR]

This essay deals with the conception of space time and equivalence principle giving a rejustification for the new meaning of relativity as proposed by Einstein. Experiments and examples which can feed hack with a scrutiny and ably detect even a slightest flaw in Einstein's theory of relativity and gravitation are given in order to reach to a scientific conclusion in a more logical manner in light of present known scientific events. Hawking [The Theory of Everything (Jaico, Delhi, 2008)] argued that the psychological arrow is determined by the thermodynamic arrow of time and both always point in the same direction. Few examples of stochastic processes are discussed which may not allow one to reach to the same conclusions as Hawking argued regarding the arrow of time. I have discussed varying speed of light theories and their Lorentz symmetry breaking which seem to exist in some comer events of nature and are supposed to be a part of early Universe evolution. First relativity principle also known as relativity principle is usually considered as a complete symmetry among infinitely large class of observers moving with constant relative velocity with respect to each other. Such symmetry also exists in general relativity between an observer in an accelerated frame and another one in a weak gravitational field. A rationale approach has been developed to give the coherent idea of space time and the principle of equivalence when introducing to relativity. Einstein gave his theory of relativity nearly a century back. Many new scientific events have been discovered since then. But the concepts of relativity remain unparallel though many experiments at very microscopic and large scales have raised many intriguing questions. [ABSTRACT FROM AUTHOR]

In the present article, we derive the space-time action of the bosonic string in terms of geometrical quantities. First, we study the space-time geometry felt by a probe bosonic string moving in antisymmetric and dilaton background fields. We show that the presence of the antisymmetric field leads to space-time torsion, and the presence of the dilaton field leads to space-time non-metricity. Using these results we obtain the integration measure for space-time with stringy non-metricity, requiring its preservation under parallel transport. We derive the Lagrangian depending on stringy curvature, torsion and non-metricity. [ABSTRACT FROM AUTHOR]

It is shown in this article how it is possible to calculate so-called special relativistic phenomena maintaining classical conceptions of relativity, using the substantiated conception that the velocity of electromagnetic radiation is determined by the minimum energy principle. In this context the characteristics of time and space get a different interpretation than that of relativistic physics. [ABSTRACT FROM AUTHOR]