Lorentzian geometrical structures with global time, Gravity and Electrodynamics

We investigate Lorentzian structures in the four-dimensionalspace-time, supplemented either by a covector field of thetime-direction or by a scalar field of the global time. Furthermore,we propose a new metrizable model of the gravity. In contrast to theusual Theory of General Relativity where all ten components of thesymmetric pseudo-metrics are independent variables, the presentedhere model of the gravity essentially depend only on singlefour-covector field, restricted to have only three-independentcomponents. However, we prove that the Gravitational field, ruled bythe proposed model and generated by some massive body, resting andspherically symmetric in some coordinate system, is given by apseudo-metrics, which coincides with thewell known Schwarzschild metric from the General Relativity. TheMaxwell equations and Electrodynamics are also investigated in theframes of the proposed model. In particular, we derive the covariantformulation of Electrodynamics of moving dielectrics andpara/diamagnetic mediums.

Analogue gravitational field from nonlinear fluid dynamics

The dynamics of sound in a fluid is intrinsically nonlinear. We derive the consequences of this fact for the analogue gravitational field experienced by sound waves, by first describing generally how the nonlinearity of the equation for phase fluctuations back-reacts on the definition of the background providing the effective space-time metric. Subsequently, we use the analytical tool of Riemann invariants in one-dimensional motion to derive source terms of the effective gravitational field stemming from nonlinearity. Finally, we show that the consequences of nonlinearity we derive can be observed with Bose-Einstein condensates in the ultracold gas laboratory.

Gravitational Fields and Gravitational Waves

The relative velocity between objects with finite velocity affects the reaction between them. This effect is known as general Doppler effect. The Laser Interferometer Gravitational-Wave Observatory (LIGO) discovered gravitational waves and found their speed to be equal to the speed of light c. Gravitational waves are generated following a disturbance in the gravitational field; they affect the gravitational force on an object. Just as light waves are subject to the Doppler effect, so are gravitational waves. This article explores the following research questions concerning gravitational waves: What is the spatial distribution of gravitational waves? Can the speed of a gravitational wave represent the speed of the gravitational field (the speed of the action of the gravitational field upon the object)? What is the speed of the gravitational field? Do gravitational waves caused by the revolution of the Sun affect planetary precession? Can we modify Newton’s gravitational equation through the influence of gravitational waves?

Dynamics of machines with ideal inertial motion

The term "inertioid" and its first design in 1936 was invented by engineer V. N. Tolchin. Despite the demonstration of unsupported motion using a physical model, the mystery of the inertioid has existed for almost a century. There are several theories explaining the motion of the inertioid (or mechanisms with inertial motion). These theories include the theory of friction, which proves that the movement of the device occurs due to the difference between the coefficients of friction and the coefficients of rolling resistance in contact between the bottom of the machine and the road. In some works, to explain the physical nature of this phenomenon, it is often legitimate to use A. Einstein's theory of relativity from a scientific point of view. In our opinion, the approach to the study of the process of motion of the inertioid should be based on the theory of the gravitational field. In the theory of relativity, A. Einstein notes that rapidly moving frames of reference create their own gravitational fields. Rotating weights create their own potential fields, since they are affected by centripetal accelerations. When the field of rotating loads is imposed on the gravitational field of the earth, accelerations appear that cause the movement of an inertioid (machines with an inertial mover). In fact, we constantly encounter this kind of overlap of potential fields in our daily life. For example, the effect of latitude on the value of the free fall acceleration of a body above the earth's surface is explained by the imposition of the earth's gravitational field of the potential field of its rotation around its axis. In the paper an inertioid with an idealized engine, which creates a constant driving (traction) force directed towards the movement has been investigated. As a result of the study, the equations of the translational motion of a machine with an ideal inertial engine were obtained, an expression for calculating its maximum speed was determined, and the maximum required engine power for the movement of a machine with an ideal inertial engine was determined.

Gravitational Fields and Gravitational Waves

The relative velocity between objects with finite velocity affects the reaction between them. This effect is known as general Doppler effect. The Laser Interferometer Gravitational-Wave Observatory (LIGO) discovered gravitational waves and found their speed to be equal to the speed of light c. Gravitational waves are generated following a disturbance in the gravitational field; they affect the gravitational force on an object. Just as light waves are subject to the Doppler effect, so are gravitational waves. This article explores the following research questions concerning gravitational waves: What is the spatial distribution of gravitational waves? Can the speed of a gravitational wave represent the speed of the gravitational field (the speed of the action of the gravitational field upon the object)? What is the speed of the gravitational field? Do gravitational waves caused by the revolution of the Sun affect planetary precession? Can we modify Newton’s gravitational equation through the influence of gravitational waves?