gravitational radiation

Celestial mechanics is a division of astronomy dealing with the motions and gravitational effects of celestial objects. The field applies principles of physics, historically Newtonian mechanics, to astronomical objects such as stars and planets. It is distinguished from astrodynamics, which is the study of the creation of artificial satellite orbits. Celestial mechanics - History of celestial mechanics. Although modern analytic celestial mechanics starts 400 years ago with Isaac Newton, prior studies addres ...

Including:

• Celestial mechanics - History of celestial mechanics
• Celestial mechanics - Ancient Civilizations
• Celestial mechanics - Claudius Ptolemy
• Celestial mechanics - Johannes Kepler
• Celestial mechanics - Isaac Newton
• Celestial mechanics - Albert Einstein
• Celestial mechanics - Open problems
• Celestial mechanics - Examples of problems
• Celestial mechanics - Perturbation theory
• Celestial mechanics - External link

Read more here: » Celestial mechanics: Encyclopedia - Celestial mechanics

A cosmic string is a hypothetical 1-dimensional topological defect in the fabric of spacetime. Cosmic strings are hypothesized to form when different regions of spacetime undergo phase changes, resulting in domain boundaries between the two regions when they meet. This is somewhat analogous to the boundaries that form between crystal grains in solidifying liquids, or the cracks that form when water freezes into ice. Cosmic strings, if they exist, would be extremely thin with diameters on the same order as a proton. They would h ...

Including:

• Cosmic string - Observational evidence
• Cosmic string - External link

Read more here: » Cosmic string: Encyclopedia - Cosmic string

To help compare orders of magnitude of different times, this page lists times longer than 1019 seconds (320,000 million years) See also times of other orders of magnitude. See the article about the ultimate fate of the Universe for more discussion of these issues. Shorter times 3.3 × 1012 years – According to the traditional Vedic time of Hinduism, this is the lifetime of Brahma. 7.7 × 1015 years – half-life of cadmium-113 1.4 × 1017 year ...

Read more here: » 1 E19 s and more: Encyclopedia - 1 E19 s and more

A wave is a disturbance that propagates in a periodically repeating fashion, often transferring energy. A mechanical wave exists in a medium (which on deformation is capable of producing elastic restoring forces) through which they travel and can transfer energy from one place to another without any of the particles of the medium being displaced permanently; there is no associated mass transport. Instead, any particular point oscillates around a fixed position. However, electromagnetic radiation, and probably gravitational radiation are not mechanical waves, and can ...

Including:

• Wave - The medium which carries a wave
• Wave - Examples of waves
• Wave - Characteristic properties
• Wave - Transverse and longitudinal waves
• Wave - Polarization
• Wave - Physical description of a wave
• Wave - Travelling waves
• Wave - Propagation through strings
• Wave - The wave equation

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General relativity (GR) is the geometrical theory of gravitation published by Albert Einstein in 1915. It unifies special relativity and Isaac Newton's law of universal gravitation with the insight that gravitation is not viewed as being due to a force (in the traditional sense) but rather a manifestation of curved space and time, this curvature being produced by the mass-energy content of the spacetime. Overview of GR History Mathematics Resources Tests Including:

• General relativity - Overview
• General relativity - Justification
• General relativity - Fundamental principles
• General relativity - Spacetime as a curved Lorentzian manifold
• General relativity - The mathematics of general relativity
• General relativity - The Einstein field equations
• General relativity - Coordinate vs. physical acceleration
• General relativity - Predictions of General Relativity
• General relativity - Gravitational effects
• General relativity - Cosmological effects
• General relativity - Other predictions
• General relativity - Relationship to other physical theories
• General relativity - Classical mechanics and special relativity
• General relativity - Quantum mechanics
• General relativity - Alternative theories
• General relativity - History
• General relativity - Status
• General relativity - Quotes
• General relativity - Notes

Read more here: » General relativity: Encyclopedia - General relativity

Some of the major paradigm shifts which occurred during the Golden Age were: wider appreciation of role of curvature in general relativity wider appreciation of importance of the black hole concept wider appreciation of legitimacy of cosmology wider appreciation of geometrical machinery and levels of mathematical structure (especially local versus global) This period also saw the introduction of the first worthy competing theory (the Brans-Dicke scalar tensor theory), the first true pr ...

See also:

Golden Age of General Relativity, Golden Age of General Relativity - Paradigm Shifts, Golden Age of General Relativity - Timeline, Golden Age of General Relativity - End of an era

Read more here: » Golden Age of General Relativity: Encyclopedia II - Golden Age of General Relativity - Paradigm Shifts

Taylor immediately went to the National Radio Astronomy Observatory's telescopes in Green Bank, West Virginia, and participated in the discovery of the first pulsars discovered outside Cambridge. Since then, he has worked on all aspects of pulsar astrophysics. In 1974, Hulse and Taylor discovered the first pulsar in a binary system, named PSR B1913+16 after its position in the sky, during a survey for pulsars at the Arecibo Observatory in Puerto Rico. Although it was not understood at the time, this was also the first of what are now called ...

See also:

Joseph Hooton Taylor Jr., Joseph Hooton Taylor Jr. - Early years, Joseph Hooton Taylor Jr. - Middle years, Joseph Hooton Taylor Jr. - Later years, Joseph Hooton Taylor Jr. - Nobel, Joseph Hooton Taylor Jr. - Other awards

Read more here: » Joseph Hooton Taylor Jr.: Encyclopedia II - Joseph Hooton Taylor Jr. - Middle years

Professor Kip S. Thorne's principal fields of research are relativistic astrophysics and gravitation physics. Thorne's scientific contributions, which focus on the general nature of space, time, and gravity, span the full range of topics in general relativity including means to test general relativity against rival theories of gravity, applications of relativity to stellar structure and evolution (e.g., his studies of the structures and evolution of massive stars that have a black hole or neutron star in their cores), black holes, wormholes, ...

See also:

Kip Thorne, Kip Thorne - Biography, Kip Thorne - Research, Kip Thorne - Publications, Kip Thorne - Honors and awards

Read more here: » Kip Thorne: Encyclopedia II - Kip Thorne - Research

Starting with the metric for a spacetime in the form gab = ηab + hab where is the Minkowski metric and — sometimes written as — is the deviation of from flat spacetime. The metric h is clearly symmetric, hab = hba and the consistency condition gabgbc = δa< ...

See also:

Linearised Einstein field equations, Linearised Einstein field equations - Formulation, Linearised Einstein field equations - Applications

Read more here: » Linearised Einstein field equations: Encyclopedia II - Linearised Einstein field equations - Formulation

In this theory, spacetime is treated as a 4-dimensional Lorentzian manifold which is curved by the presence of mass, energy, and momentum (or stress-energy) within it. The relationship between stress-energy and the curvature of spacetime is governed by the Einstein field equations. The motion of objects being influenced solely by the geometry of spacetime (inertial motion) occurs along special paths called timelike and null geodesics of spacetime. See also:

General relativity, General relativity - Overview, General relativity - Justification, General relativity - Fundamental principles, General relativity - Spacetime as a curved Lorentzian manifold, General relativity - The mathematics of general relativity, General relativity - The Einstein field equations, General relativity - Coordinate vs. physical acceleration, General relativity - Predictions of General Relativity, General relativity - Gravitational effects, General relativity - Cosmological effects, General relativity - Other predictions, General relativity - Relationship to other physical theories, General relativity - Classical mechanics and special relativity, General relativity - Quantum mechanics, General relativity - Alternative theories, General relativity - History, General relativity - Status, General relativity - Quotes, General relativity - Notes

Read more here: » General relativity: Encyclopedia II - General relativity - Overview

Waves can be described using a number of standard variables including: frequency, wavelength, amplitude and period. The amplitude of a wave is the measure of the magnitude of the maximum disturbance in the medium during one wave cycle, and is measured in units depending on the type of wave. For examples, waves on a string have an amplitude expressed as a distance (meters), sound waves as pressure (pascals) and electromagnetic waves as the amplitude of the electric field (volts/meter). The amplitude may be constant (in which case the ...

See also:

Wave, Wave - The medium which carries a wave, Wave - Examples of waves, Wave - Characteristic properties, Wave - Transverse and longitudinal waves, Wave - Polarization, Wave - Physical description of a wave, Wave - Travelling waves, Wave - Propagation through strings, Wave - The wave equation

Read more here: » Wave: Encyclopedia II - Wave - Physical description of a wave

Professor Kip S. Thorne's principal fields of research are relativistic astrophysics and gravitation physics. Thorne's scientific contributions, which focus on the general nature of space, time, and gravity, span the full range of topics in general relativity including means to test general relativity against rival theories of gravity, applications of relativity to stellar structure and evolution (e.g., his studies of the structures and evolution of massive stars that have a black hole or neutron star in their cores), black holes, wormholes, ...

See also:

Kip Thorne, Kip Thorne - Biography, Kip Thorne - Areas of research, Kip Thorne - Publications, Kip Thorne - Honors and awards

Read more here: » Kip Thorne: Encyclopedia II - Kip Thorne - Areas of research

Cosmic strings were once thought to be an explanation of the large scale structure of the universe, but all what is known today through galaxy surveys and precision measurements of the cosmic microwave background fits an evolution out of random, gaussian fluctuations. These precison observations therefore tend to rule out a significant role of cosmic strings. A recent discovery of a "double galaxy" Capodimonte-Sternberg lens candidate 1 (CSL-1) has some interesting implications for cosmic string theory. In an article entitled "CSL-1: ...

See also:

Cosmic string, Cosmic string - Observational evidence, Cosmic string - External link

Read more here: » Cosmic string: Encyclopedia II - Cosmic string - Observational evidence

Although modern analytic celestial mechanics starts 400 years ago with Isaac Newton, prior studies addressing the problem of planetary positions are known going back perhaps 3,000 years. Celestial mechanics - Ancient Civilizations. The Ancient Babylonians had no mechanistic theories regarding celestial motions, but recognized repeating patterns in the motion of the sun, moon, and planets. They used tabulated positions during similar pas ...

See also:

Celestial mechanics, Celestial mechanics - History of celestial mechanics, Celestial mechanics - Ancient Civilizations, Celestial mechanics - Claudius Ptolemy, Celestial mechanics - Johannes Kepler, Celestial mechanics - Isaac Newton, Celestial mechanics - Albert Einstein, Celestial mechanics - Open problems, Celestial mechanics - Examples of problems, Celestial mechanics - Perturbation theory, Celestial mechanics - External link

Read more here: » Celestial mechanics: Encyclopedia II - Celestial mechanics - History of celestial mechanics

Like general relativity and the Brans-Dicke theory of gravitation, Nordström's theory is an example of a class of theories of gravitation called metric theories, because like those theories, in the formulation of Einstein and Fokker it employs a Lorentzian manifold, which is interpreted physically as a mathematical model of spacetime, it uses a stress-energy tensor field to describe the amount and motion of matter, and its field equations can be regarded as enforcing compatibility conditions between the metric tensor and the stress-e ...

See also:

Nordström's theory of gravitation, Nordström's theory of gravitation - Comparison with general relativity, Nordström's theory of gravitation - The field equations

Read more here: » Nordström's theory of gravitation: Encyclopedia II - Nordström's theory of gravitation - Comparison with general relativity

The Einstein tensor of a null dust must have the form where is a null vector field. This definition makes sense in the absence of any physical interpretation, but if we place a stress-energy tensor on our spacetime which happens to have the form then Einstein's field equation is trivially satisfied, and in addition, such a stress-energy tensor has a clear physical interpretation in terms of massless radiation. The vector field specifies the direction in which the radia ...

See also:

Null dust solution, Null dust solution - Mathematical definition, Null dust solution - Physical interpretation, Null dust solution - Einstein tensor, Null dust solution - Examples

Read more here: » Null dust solution: Encyclopedia II - Null dust solution - Mathematical definition

There he worked with Taylor on a large-scale survey for pulsars using the Arecibo Observatory in Puerto Rico. It was this work that led to the discovery of the first binary pulsar. In 1974, Hulse and Taylor discovered binary pulsar PSR B1913+16, which is made up of a pulsar and black companion star. Neutron star rotation emits impulses that are extremely regular and stable in the radio wave region and is nearby condensed material body gravitation (non-detectable in the visible field). Hulse, Taylor, and other colleagues have used this ...

See also:

Russell Alan Hulse, Russell Alan Hulse - Early years, Russell Alan Hulse - Middle years, Russell Alan Hulse - Later years, Russell Alan Hulse - External link

Read more here: » Russell Alan Hulse: Encyclopedia II - Russell Alan Hulse - Middle years

There he worked with Taylor on a large-scale survey for pulsars using the Arecibo Observatory in Puerto Rico. It was this work that led to the discovery of the first binary pulsar. In 1974, Hulse and Taylor discover binary pulsar PSR B1913+16 which is made up of a pulsar and black companion star. Neutron star rotation emits impulses extremely regular and stable in the radio wave region and is nearby condensed material body gravitation (non-detectable in the visible field). Hulse, Taylor, and other colleagues have used this first binar ...

See also:

Russell Alan Hulse, Russell Alan Hulse - Early years, Russell Alan Hulse - Middle years, Russell Alan Hulse - Later years, Russell Alan Hulse - External link

Read more here: » Russell Alan Hulse: Encyclopedia II - Russell Alan Hulse - Middle years

The creator of general relativity, Albert Einstein, argued in 1916 that gravitational radiation should be produced, according to his theory, by any mass-energy configuration which has a time-varying quadrupole moment (or higher multipole moment). Using a linearized field equation (appropriate for the study of weak gravitational fields), he derived the famous quadrupole radiation formula quantifying the rate at which such radiation should carry away energy. Examples of systems with time varying quadrupole moments include vibrating strings, bars rotating about an axis orthogonal to the symmetr ...

See also:

Sticky bead argument, Sticky bead argument - Einstein's double reversal, Sticky bead argument - The Bern and Chapel Hill conferences, Sticky bead argument - Feynman's argument, Sticky bead argument - Rosen's final views

Read more here: » Sticky bead argument: Encyclopedia II - Sticky bead argument - Einstein's double reversal

The scalar part is built using the Ricci scalar , where Rab is the Ricci tensor, and a tensor constructed algebraically from the metric tensor gab, The semi-traceless part is constructed algebraically using the metric tensor and the traceless part of the Ricci tensor where See also:

Ricci decomposition, Ricci decomposition - Mathematical definition, Ricci decomposition - The pieces appearing in the decomposition, Ricci decomposition - Physical interpretation, Ricci decomposition - Reference

Read more here: » Ricci decomposition: Encyclopedia II - Ricci decomposition - The pieces appearing in the decomposition