scholarly journals What are Gravitational waves?

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Bhanu Pratap Singh

The purpose of this article is not to present a popular history of mathematical physics nor even to display for the general reader some of the result of research in the history of science, Rather the intention is to explore one important aspect of the great scientific revaluation of recent times which proves the existence of Gravitational wave, predicted by Dr. Albert Einstein about a hundred years ago in his general theory of relativity. Gravitational waves are ripples in the fabric of space time caused by some of the most violent and energetic processes in the universe. They are produced by catastrophic events such as colliding Black hole as well as the collapse of stellar super nova.

2021 ◽  
Vol 52 (1) ◽  
pp. 12-14
Author(s):  
Roger Blandford

Black holes, a seemingly inevitable consequence of Einstein’s general theory of relativity and stellar and galactic evolution are being observed in many new ways with masses ranging from roughly three to ten billion solar masses. Their masses and spins determine how they power the most luminous objects in the universe and impact their environments.


2021 ◽  
Vol 58 (4) ◽  
pp. 175-195
Author(s):  
Vladimir P. Vizgin ◽  

The article is based on the concepts of epistemic virtues and epistemic vices and explores A. Einstein’s contribution to the creation of fundamental physical theories, namely the special theory of relativity and general theory of relativity, as well as to the development of a unified field theory on the basis of the geometric field program, which never led to success. Among the main epistemic virtues that led Einstein to success in the construction of the special theory of relativity are the following: a unique physical intuition based on the method of thought experiment and the need for an experimental justification of space-time concepts; striving for simplicity and elegance of theory; scientific courage, rebelliousness, signifying the readiness to engage in confrontation with scientific conventional dogmas and authorities. In the creation of general theory of relativity, another intellectual virtue was added to these virtues: the belief in the heuristic power of the mathematical aspect of physics. At the same time, he had to overcome his initial underestimation of the H. Minkowski’s four-dimensional concept of space and time, which has manifested in a distinctive flexibility of thinking typical for Einstein in his early years. The creative role of Einstein’s mistakes on the way to general relativity was emphasized. These mistakes were mostly related to the difficulties of harmonizing the mathematical and physical aspects of theory, less so to epistemic vices. The ambivalence of the concept of epistemic virtues, which can be transformed into epistemic vices, is noted. This transformation happened in the second half of Einstein’s life, when he for more than thirty years unsuccessfully tried to build a unified geometric field theory and to find an alternative to quantum mechanics with their probabilistic and Copenhagen interpretation In this case, we can talk about the following epistemic vices: the revaluation of mathematical aspect and underestimation of experimentally – empirical aspect of the theory; adopting the concepts general relativity is based on (continualism, classical causality, geometric nature of fundamental interactions) as fundamental; unprecedented persistence in defending the GFP (geometrical field program), despite its failures, and a certain loss of the flexibility of thinking. A cosmological history that is associated both with the application of GTR (general theory of relativity) to the structure of the Universe, and with the missed possibility of discovering the theory of the expanding Universe is intermediate in relation to Einstein’s epistemic virtues and vices. This opportunity was realized by A.A. Friedmann, who defeated Einstein in the dispute about if the Universe was stationary or nonstationary. In this dispute some of Einstein’s vices were revealed, which Friedman did not have. The connection between epistemic virtues and the methodological principles of physics and also with the “fallibilist” concept of scientific knowledge development has been noted.


Science ◽  
2019 ◽  
Vol 365 (6454) ◽  
pp. 664-668 ◽  
Author(s):  
Tuan Do ◽  
Aurelien Hees ◽  
Andrea Ghez ◽  
Gregory D. Martinez ◽  
Devin S. Chu ◽  
...  

The general theory of relativity predicts that a star passing close to a supermassive black hole should exhibit a relativistic redshift. In this study, we used observations of the Galactic Center star S0-2 to test this prediction. We combined existing spectroscopic and astrometric measurements from 1995–2017, which cover S0-2’s 16-year orbit, with measurements from March to September 2018, which cover three events during S0-2’s closest approach to the black hole. We detected a combination of special relativistic and gravitational redshift, quantified using the redshift parameter ϒ. Our result, ϒ = 0.88 ± 0.17, is consistent with general relativity (ϒ = 1) and excludes a Newtonian model (ϒ = 0) with a statistical significance of 5σ.


Author(s):  
David D. Nolte

This chapter describes how gravity provided the backdrop for one of the most important paradigm shifts in the history of physics. Prior to Albert Einstein’s general theory of relativity, trajectories were paths described by geometry. After the theory of general relativity, trajectories are paths caused by geometry. This chapter explains how Einstein arrived at his theory of gravity, relying on the space-time geometry of Hermann Minkowski, whose work he had originally harshly criticized. The confirmation of Einstein’s theory was one of the dramatic high points in twentieth-century history of physics when Arthur Eddington journeyed to an island off the coast of Africa to observe stellar deflections during a solar eclipse. If Galileo was the first rock star of physics, then Einstein was the first worldwide rock star of science.


2015 ◽  
Vol 4 ◽  
pp. 49-52
Author(s):  
Ranjit Prasad Yadav

General relativity was developed by Albert Einstein near about 100 Years ago. This article attempt to give an outline about the brief history of general theory of relativity and to understand the background to the theory we have to look at how theories of gravitation developed. Before the advent of GR, Newton's law of gravitation had been accepted for more than two hundred years as a valid description of the gravitational force between masses i.e. gravity was the result of an attractive force between massive objects. General relativity has developed in to an essential tool in modern astrophysics. It provides the foundation for the understanding of black holes, regions of space where gravitational attraction is strong that not even light can escape and also a part of the big bang model of cosmology.DOI: http://dx.doi.org/10.3126/av.v4i0.12358Academic Voices Vol.4 2014: 49-52


2017 ◽  
Vol 9 (2) ◽  
pp. 87
Author(s):  
Mehmet Bora Cilek

General Theory of Relativity constitutes the framework for our understanding of the universe, with an emphasis on gravity. Many of Einstein’s predictions have been verified experimentally but General and Special Theories of Relativity contain several anomalies and paradoxes, yet to be answered. Also, there are serious conflicts with Quantum Mechanics; gravity being the weakest and least understood force, is a major problem.Supported by clear experimental evidence, it is theorised that gravity is not a field or spacetime curvature effect, but rather has a flow mechanism. This is not an alternative theory of gravity with an alternative metric. Established laws and equations from Newton and Einstein are essentially left unchanged. However, spacetime curvature is replaced with flow, producing a refined and compatible theory.


Author(s):  
Serge L. Parnovsky ◽  

The Nobel Prize in Physics in 2020 was awarded to the famous British physicist, mathematician, philosopher of science Roger Penrose “for the discovery that black hole formation is a robust prediction of the general theory of relativity” as well as German astrophysicist Reinhard Genzel and American astronomer Andrea Ghez “for the discovery of a supermassive compact object at the center of our galaxy.”


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