scholarly journals Comment on “Does the Equivalence between Gravitational Mass and Energy Survive for a Composite Quantum Body?”

2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
B. Crowell
Keyword(s):  
Hydrogen Atom ◽  
Gravitational Potential ◽  
Radiation Detectors ◽  
Gravitational Mass ◽  
Astronomical Observations ◽  
Nuclear Excitations

Lebed has given an argument that when a hydrogen atom is transported slowly to a different gravitational potential, it has a certain probability of emitting a photon. He proposes a space-based experiment to detect this effect. I show here that his arguments also imply the existence of nuclear excitations, as well as an effect due to the earth’s motion in the sun’s potential. This is not consistent with previous results from underground radiation detectors. It is also in conflict with astronomical observations.

scholarly journals Atomic stability and the quantum mass equivalence

2019 ◽  
Vol 34 (35) ◽  
pp. 1950293
Author(s):  
Pedro Sancho
Keyword(s):  
Gravitational Field ◽  
Hydrogen Atom ◽  
Equivalence Principle ◽  
Quantum Systems ◽  
Gravitational Mass ◽  
Internal Variables ◽  
Gravitational Fields

We consider an unexplored aspect of the mass equivalence principle in the quantum realm, its connection with atomic stability. We show that if the gravitational mass were different from the inertial one, a Hydrogen atom placed in a constant gravitational field would become unstable in the long term. In contrast, independently of the relation between the two masses, the atom does not become ionized in a uniformly accelerated frame. This work, in the line of previous analyses studying the properties of quantum systems in gravitational fields, contributes to the extension of that program to internal variables.

scholarly journals Does the Equivalence between Gravitational Mass and Energy Survive for a Composite Quantum Body?

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
A. G. Lebed
Keyword(s):  
Hydrogen Atom ◽  
Mass Operator ◽  
Energy Operator ◽  
Quantum States ◽  
Gravitational Mass ◽  
Hydrogen Atoms ◽  
Expectation Values ◽  
Direct Experiment ◽  
Stationary Quantum ◽  
Passive Gravitational Mass

We define passive and active gravitational mass operators of the simplest composite quantum body—a hydrogen atom. Although they do not commute with its energy operator, the equivalence between the expectation values of passive and active gravitational masses and energy is shown to survive for stationary quantum states. In our calculations of passive gravitational mass operator, we take into account not only kinetic and Coulomb potential energies but also the so-called relativistic corrections to electron motion in a hydrogen atom. Inequivalence between passive and active gravitational masses and energy at a macroscopic level is demonstrated to reveal itself as time-dependent oscillations of the expectation values of the gravitational masses for superpositions of stationary quantum states. Breakdown of the equivalence between passive gravitational mass and energy at a microscopic level reveals itself as unusual electromagnetic radiation, emitted by macroscopic ensemble of hydrogen atoms, moved by small spacecraft with constant velocity in the Earth’s gravitational field. We suggest the corresponding experiment on the Earth’s orbit to detect this radiation, which would be the first direct experiment where quantum effects in general relativity are observed.

scholarly journals The Quantum Black Hole as a Gravitational Hydrogen Atom

2019 ◽  
Author(s):  
Christian Corda ◽  
Fabiano Feleppa
Keyword(s):  
Black Holes ◽  
Black Hole ◽  
Energy Spectrum ◽  
Hydrogen Atom ◽  
Gravitational Potential ◽  
Particle System ◽  
Energy Levels ◽  
Planck Scale ◽  
Dinger Equation ◽  
The One

In this paper only one basic assumption has been made: if we try to describe black holes, their behavior should be understood in the same language as the one we use for particles; black holes should be treated just like atoms. They must be quantum forms of matter, moving in accordance with Schrödinger equations just like everything else. In particular, Rosen’s quantization approach to the gravitational collapse is applied in the simple case of a pressureless “star of dust” by finding the gravitational potential, the Schrödinger equation and the solution for the collapse’s energy levels. By applying the constraints for a Schwarzschild black hole (BH) and by using the concept of BH effective state, previously introduced by one of the authors (CC), the BH quantum gravitational potential, Schrödinger equation and the BH energy spectrum are found. Remarkably, such an energy spectrum is in agreement (in its absolute value) with the one which was conjectured by Bekenstein in 1974 and consistent with other ones in the literature. This approach also permits to find an interesting quantum representation of the Schwarzschild BH ground state at the Planck scale. Moreover, two fundamental issues about black hole quantum physics are addressed by this model: the area quantization and the singularity resolution. As regards the former, a result similar to the one obtained by Bekenstein, but with a different coefficient, has been found. About the latter, it is shown that the traditional classical singularity in the core of the Schwarzschild BH is replaced, in a full quantum treatment, by a two-particle system where the two components strongly interact with each other via a quantum gravitational potential. The two-particle system seems to be non-singular from the quantum point of view and is analogous to the hydrogen atom because it consists of a “nucleus” and an “electron”.

scholarly journals Black Hole as Gravitational Hydrogen Atom by Rosen’s Quantization Approach

2018 ◽  
Author(s):  
Christian Corda ◽  
Fabiano Feleppa
Keyword(s):  
Black Hole ◽  
Mass Spectrum ◽  
Hydrogen Atom ◽  
Gravitational Collapse ◽  
Gravitational Potential ◽  
Ground State ◽  
Energy Levels ◽  
Planck Scale ◽  
Schroedinger Equation ◽  
Exact Quantum

We apply Rosen’s approach to the quantization of the gravitational collapse in the simple case of a pressureless “star of dust” and we find the gravitational potential, the Schroedinger equation and the solution for the collapse’s energy levels without any approximation. By applying the constrains for a black hole (BH), we found the analogous quantum quantities and the BH mass spectrum, again without any approximation. Remarkably, such a mass spectrum is the same which was found by Beken- stein in 1974. Finally, our approach permits to find the exact quantum representation of the Schwarzschild BH ground state at the Planck scale.

scholarly journals Variation of fundamental constants and white dwarfs

2019 ◽  
Vol 15 (S357) ◽  
pp. 45-59
Author(s):  
Susana J. Landau
Keyword(s):  
Spatial Variation ◽  
Gravitational Potential ◽  
White Dwarfs ◽  
Alternative Theories Of Gravity ◽  
Fundamental Constants ◽  
Astronomical Observations ◽  
Fundamental Interactions ◽  
Theories Of Gravity ◽  
Alternative Theories ◽  
Constants Of Nature

AbstractTheories that attempt to unify the four fundamental interactions and alternative theories of gravity predict time and/or spatial variation of the fundamental constants of nature. Different versions of these theories predict different behaviours for these variations. As a consequence, experimental and observational bounds are an important tool to check the validity of such proposals. In this paper, we review constraints on the possible variation of the fundamental constants from astronomical observations and geophysical experiments designed to test the constancy of the fundamental constants of nature over different timescales. We also focus on the limits that can be obtained from white dwarfs, which can constrain the variation of the constants with the gravitational potential.

scholarly journals Inequivalence between gravitational mass and energy due to quantum effects at microscopic and macroscopic levels

2017 ◽  
Vol 26 (13) ◽  
pp. 1730022 ◽  
Author(s):  
Andrei G. Lebed
Keyword(s):  
Hydrogen Atom ◽  
Quantum Effects ◽  
Gravitational Mass ◽  
Expectation Values ◽  
Gedanken Experiment ◽  
Einstein's Equation ◽  
Experimental Possibility ◽  
Stationary Quantum ◽  
The Masses ◽  
Passive Gravitational Mass

In this paper, we review recent theoretical results, demonstrating breakdown of the equivalence between active and passive gravitational masses and energy due to quantum effects in general relativity. In particular, we discuss the simplest composite quantum body — a hydrogen atom — and define its gravitational masses operators. Using Gedanken experiment, we show that the famous Einstein’s equation, [Formula: see text], is broken with small probability for passive gravitational mass of the atom. It is important that the expectation values of both active and passive gravitational masses satisfy the above-mentioned equation for stationary quantum states. Nevertheless, we stress that, for quantum superpositions of stationary states in a hydrogen atom, where the expectation values of energy are constant, the expectation values of the masses oscillate in time and, thus, break the Einstein’s equation. We briefly discuss experimental possibility to observe the above-mentioned time-dependent oscillations. In this review, we also improve several drawbacks of the original pioneering works.

scholarly journals Black Hole as Gravitational Hydrogen Atom by Rosen’s Quantization Approach

2018 ◽  
Author(s):  
Christian Corda ◽  
Fabiano Feleppa
Keyword(s):  
Black Hole ◽  
Mass Spectrum ◽  
Hydrogen Atom ◽  
Gravitational Collapse ◽  
Gravitational Potential ◽  
Ground State ◽  
Energy Levels ◽  
Planck Scale ◽  
Schroedinger Equation ◽  
Exact Quantum

We apply Rosen’s approach to the quantization of the gravitational collapse in the simple case of a pressureless “star of dust” and we find the gravitational potential, the Schroedinger equation and the solution for the collapse’s energy levels without any approximation. By applying the constrains for a black hole (BH), we found the analogous quantum quantities and the BH mass spectrum, again without any approximation. Remarkably, such a mass spectrum is the same which was found by Beken- stein in 1974. Finally, our approach permits to find the exact quantum representation of the Schwarzschild BH ground state at the Planck scale.

scholarly journals Gravitational potential and X-ray luminosities of early-type galaxies observed with XMM-Newton and Chandra

2009 ◽  
Vol 5 (H15) ◽  
pp. 93-95
Author(s):  
Ryo Nagino ◽  
Kyoko Matsushita
Keyword(s):  
Dark Matter ◽  
Gravitational Potential ◽  
Stellar Mass ◽  
Gravitational Mass ◽  
Temperature Profiles ◽  
Early Type ◽  
Central Mass ◽  
Radial Temperature ◽  
X Ray ◽  
Luminous Galaxies

We study the dark matter content in early-type galaxies and investigate whether X-ray luminosities of early-type galaxies are determined by the surrounding gravitational potential. We derived gravitational mass profiles of 22 early-type galaxies observed with XMM-Newton and Chandra. Sixteen galaxies show constant or decreasing radial temperature profiles, and their X-ray luminosities are consistent with kinematical energy input from stellar mass loss. The temperature profiles of the other 6 galaxies increase with radius, and their X-ray luminosities are significantly higher. The integrated mass-to-light ratio of each galaxy is constant at that of stars within 0.5–1re, and increases with radius. The scatter of the central mass-to-light ratio of galaxies was less in K-band light. At 3re, the integrated mass-to-light ratios of galaxies with flat or decreasing temperature profiles are twice the value at 0.5re, where the stellar mass dominates, and at 6re, these increase to three times the value at 0.5re. This feature should reflect common dark and stellar mass distributions in early-type galaxies: Within 3re, the mass of dark matter is similar to the stellar mass, while within 6re, the former is larger than the latter by two-fold. In contrast, X-ray luminous galaxies have higher gravitational mass in the outer regions than X-ray faint galaxies. We describe these X-ray luminous galaxies as the central objects of large potential structures; the presence or absence of this potential is the main source of the large scatter in the X-ray luminosity.

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

The Role of VLBI in the Establishment of Coordinate Systems

1975 ◽  
Vol 26 ◽  
pp. 293-295 ◽  
Author(s):  
I. Zhongolovitch
Keyword(s):  
General Solution ◽  
Future Development ◽  
Rational Approach ◽  
Radio Telescopes ◽  
Coordinate Systems ◽  
Tectonic Plates ◽  
Astronomical Observations ◽  
Optical Instruments ◽  
Fundamental Polyhedron

Considering the future development and general solution of the problem under consideration and also the high precision attainable by astronomical observations, the following procedure may be the most rational approach:1. On the main tectonic plates of the Earth’s crust, powerful movable radio telescopes should be mounted at the same points where standard optical instruments are installed. There should be two stations separated by a distance of about 6 to 8000 kilometers on each plate. Thus, we obtain a fundamental polyhedron embracing the whole Earth with about 10 to 12 apexes, and with its sides represented by VLBI.

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