Consequence Of General Relativity Research Articles

Charged dust solutions for the warp drive spacetime

The Alcubierre warp drive metric is a spacetime construction where a massive particle located inside a spacetime distortion, called warp bubble, travels at velocities arbitrarily higher than the velocity of light. This theoretically constructed spacetime geometry is a consequence of general relativity where global superluminal velocities, also known as warp speeds, are possible, whereas local speeds are limited to subluminal ones as required by special relativity. In this work we analyze the solutions of the Einstein equations having charged dust energy-momentum tensor as source for warp velocities. The Einstein equations with the cosmological constant are written and all solutions having energy-momentum tensor components for electromagnetic fields generated by charged dust are presented, as well as the respective energy conditions. The results show an interplay between the energy conditions and the electromagnetic field such that in some cases the former can be satisfied by both positive and negative matter density. In other cases the dominant and null energy conditions are violated. A result connecting the electric energy density with the cosmological constant is also presented, as well as the effects of the electromagnetic field on the bubble dynamics.

Dust content solutions for the Alcubierre warp drive spacetime

The Alcubierre metric is a spacetime geometry where a massive particle inside a spacetime distortion, called warp bubble, is able to travel at velocities arbitrarily higher than the velocity of light, a feature known as the warp drive. This is a consequence of general relativity, which allows for global superluminal velocities but restricts local speeds to subluminal ones as required by special relativity. In this work we solved the Einstein equations for the Alcubierre warp drive spacetime geometry considering the dust matter distribution as source, since the Alcubierre metric was not originally advanced as a solution of the Einstein equations, but as a spacetime geometry proposed without a source gravity field. We found that all Einstein equations solutions of this geometry containing pressureless dust lead to vacuum solutions. We also concluded that these solutions connect the Alcubierre metric to the Burgers equation, which describes shock waves moving through an inviscid fluid. Our results also indicated that these shock waves behave as plane waves.

The Development of Relativity and Einstein

There are errors in general relativity that must be rectified. As Zhou pointed out, Einstein’s covariance principle is proven to be invalid by explicit examples. Linearization is conditionally valid. Pauli's version of the equivalence principle is impossible in mathematics. Einstein's adaptation of the distance in Riemannian geometry is invalid in physics as pointed out by Whitehead. Moreover, it is inconsistent with the calculation on the bending of light, for which a Euclidean-like framework is necessary. Thus, the interpretation of the Hubble redshifts as due to receding velocities of stars is invalid. The Einstein equation has no dynamic solutions just as Gullstrand suspected. All claims on the existence of dynamic solutions for the Einstein equation are due to mistakes in non-linear mathematics. For the existence of a dynamic solution, the Einstein equation must be modified to the Lorentz-Levy-Einstein equation that have additionally a gravitational energy-stress tensor with an anti-gravity coupling. The existence of photons is a consequence of general relativity. Thus, the space-time singularity theorems of Hawking and Penrose are actually irrelevant to physics because their energy conditions cannot be satisfied. The positive mass theorem of Schoen and Yau is misleading because invalid implicit assumptions are used as Hawking and Penrose did. There are three experiments that show formula E = mc2 is invalid, and a piece of heated-up metal has reduced weight just as a charged capacitor. Thus, the weight is temperature dependent. It is found, due to the repulsive charge-mass interaction, gravity is not always attractive to mass. Since the assumption that gravity is always attractive to mass is not valid, the existence of black holes are questionable. Because of the repulsive charge-mass interaction, the theoretical framework of general relativity must be extended to a five-dimensional relativity of Lo, Goldstein & Napier. Thus Einstein's conjecture of unification is valid. Moreover, the repulsive gravitational force from a charged capacitor is incompatible with the notion of a four-dimensional space. In Quantum theory, currently the charge-mass interaction is neglected. Thus, quantum theory is not a final theory as Einstein claims.

Gravitational lensing in quasar samples

The first cosmic mirage was discovered approximately 20 years ago as the double optical counterpart of a radio source. This phenomenon had been predicted some 70 years earlier as a consequence of General Relativity. We present here a summary of what we have learnt since. The applications are so numerous that we had to concentrate on a few selected aspects of this new field of research.This review is focused on strong gravitational lensing, i.e. the formation of multiple images, in QSO samples. It is intended to give the reader an up-to-date status of the observations and to present an overview of its most interesting potential applications in cosmology and astrophysics, as well as numerous important results achieved so far.The first section follows an intuitive approach to the basics of gravitational lensing and is developed in view of our interest in multiply imaged quasars. The astrophysical and cosmological applications of gravitational lensing are outlined in Sect. 2 and the most important results are presented in Sect. 5. Sections 3 and 4 are devoted to the observations. Finally, conclusions are summarized in the last section.We have tried to avoid duplication with existing (and excellent) introductions to the field of gravitational lensing. For this reason, we did not concentrate on the individual properties of specific lens models, as these are already well presented in Narayan and Bartelmann (1996) and on a more intuitive ground in Refsdal and Surdej (1994). Wambsganss (1998) proposes a broad view on gravitational lensing in astronomy; the reviews by Fort and Mellier (1994) and Hattori et al. (1999) deal with lensing by galaxy clusters; microlensing in the Galaxy and the local group is reviewed by Paczyński (1996) and a general panorama on weak lensing is given by Bartelmann and Schneider (1999) and Mellier (1999). The monograph on the theory of gravitational lensing by Schneider, Ehlers and Falco (1992) also remains a reference in the field.

Theory of local times

A model of a stationary universe is proposed. In this framework, time is defined as a local and quantum-mechanical notion in the sense that it is defined for each local and quantum-mechanical system consisting of finite number of particles. The total universe consisting of infinite number of particles has no time associated. It is a stationary bound state of the total Hamiltonian of infinite degrees of freedom. The quantum mechanics and the theory of general relativity are consistently united in this context if one uses this notion of local and quantum-mechanical time. As one of the consequences, the Einstein-Podolsky-Rosen paradox is resolved. The Hubble red-shift is explained as a consequence of general relativity which is consistent with quantum mechanics. This does not require us to argue on the beginning nor the end of the universe. The universe just exists without time. (published in Il Nuovo Cimento, Vol. 109 B, N. 3, 1994, pp. 281-302)

Some philosophical aspects of black holes

In this paper I would like to take a philosophical look at black holes. However, the issues I want to discuss do not concern just black holes themselves. I am not going to be concerned with such questions as whether black holes can or cannot exist, or what the proper way of characterizing them are. These questions, while fascinating, I take to be philosophically unproblematic. Since the pioneering work of Pen rose and Hawking it has been generally agreed that it is an unavoid able consequence of general relativity that black holes exist, and in a few cases there is observational (or astronomical) evidence for the existence of a black hole-the most prominent one being the X-ray source Cygnus X-l in the constellation Cygnus. Rather, I will be concerned with how black holes are connected with, and can shed light on, some familiar philosophical issues. Among these are whether the past and future are finite, the conceivability and possibility of time travel, and the intelligibility of the program of geometrodynamics.

Pulsation of tectonic phenomena and tectonophysical mechanisms

At present, it is believed that the main tectonic phenomena result from progressive displacements of a small number of rigid plates which form the crust of the Earth. If the plates separate, a rift (of oceanic type) will open; and, if they approach, compression will shorten the crust and form eventually a mountain chain. Both rifting and compression produce earthquakes at the plate borders, and the seismic activity must depict the rate of movement of the plates. There is some indication that this seismic activity occurs in pulses with a period of about 11 years, rifting probably alternating with compression. For long lasting monotonic plate movements, thermal convection and radioactive undations could be adequate causes; but, for these short-period alternating phenomena, gravitational pulsations are considered the best available mechanism. Gravitational pulsations seem to be a necessary consequence of General Relativity, when applied to a convenient cosmological model.

On electric phenomena in gravitational fields

It is a consequence of general relativity that all electromagnetic and optical phenomena are influenced by a gravitational field. Indeed, the first prediction of relativity-theory, namely, the bending of light-rays when they pass near a massive body such as the sun, was a p articular application of this principle. Evidently, therefore, the classical electromagnetic theory must be rewritten in order to take account of the interaction between electromagnetism and gravitation; but beyond laying down general principles, comparatively little progress has been made hitherto in this task, the mathematical difficulties of solving definite electrical problems in a gravitational field being somewhat formidable. The subject is, however, of some interest to atomic physics; for if we assume that the atom has a massive nucleus with electrons in its immediate neighbourhood, the behaviour of such electrons (especially with regard to radiation) will be affected by the gravitational field of the nucleus. In the present paper two kinds of gravitational field are considered, namely, the field due to a single attracting centre ( i, e ., the field whose metric was discovered by Schwarzschild) and a limiting form of it. Within these gravita­tional fields we suppose electromagnetic fields to exist. Strictly speaking, the electromagnetic field has itself a gravitational effect, i.e. , it changes the metric everywhere; but this effect is in general; small, and we shall treat the ideal case in which it is ignored, so we shall suppose the metric to be simply that of the gravitational field originally postulated. The general equations of the electro­magnetic field are obtained, and particular solutions are found, which are the analogues of well-known particular solutions in the classical electromagnetic theory; notably the fields due to electrons at rest, electrostatic fields in general, and spherical electromagnetic waves. The results of the investigation are for the most part expressible only in terms of Bessel functions and certain new functions which are introduced; but in some interesting cases the electro­magnetic phenomena can be represented in term s of elementary functions, as, for instance, the electric field due to an electron in a quasi-uniform gravitational field (equations (15) and (19) below) and the spherical electromagnetic waves of short wave-length about a gravitating centre (equation (43) below).