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**Gravitational waves are ripples in the curvature of spacetime that propagate as waves at the speed of light, generated in certain gravitational interactions that propagate outward from their source. **

The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics.

In physics, spacetime is any mathematical model that combines space and time into a single interwoven continuum.

In mathematics, curvature is any of a number of loosely related concepts in different areas of geometry.

Gravitational Waves: A New Era of Astronomy Begins by World Science Festival

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**The possibility of gravitational waves was discussed in 1893 by Oliver Heaviside using the analogy between the inverse-square law in gravitation and electricity. **

Oliver Heaviside FRS was an English self-taught electrical engineer, mathematician, and physicist who adapted complex numbers to the study of electrical circuits, invented mathematical techniques for the solution of differential equations, reformulated Maxwell's field equations in terms of electric and magnetic forces and energy flux, and independently co-formulated vector analysis.

LIGO Detects Gravitational Waves by Massachusetts Institute of Technology (MIT)

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**In 1905 Henri PoincarĂ© first proposed gravitational waves emanating from a body and propagating at the speed of light as being required by the Lorentz transformations. **

Jules Henri PoincarĂ© was a French mathematician, theoretical physicist, engineer, and philosopher of science.

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**Predicted in 1916 by Albert Einstein on the basis of his theory of general relativity, gravitational waves transport energy as gravitational radiation, a form of radiant energy similar to electromagnetic radiation. **

General relativity is the geometric theory of gravitation published by Albert Einstein in 1915 and the current description of gravitation in modern physics.

In physics, energy is a property of objects which can be transferred to other objects or converted into different forms.

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**Gravitational waves cannot exist in the Newton's law of universal gravitation, since it is predicated on the assumption that physical interactions propagate at infinite speed.
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Newton's law of universal gravitation states that a particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

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**Gravitational-wave astronomy is an emerging branch of observational astronomy which aims to use gravitational waves to collect observational data about objects such as neutron stars and black holes, events such as supernovae, and processes including those of the early universe shortly after the Big Bang.
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Observational astronomy is a division of astronomical science that is concerned with recording data, in contrast with theoretical astrophysics, which is mainly concerned with finding out the measurable implications of physical models.

A supernova is an astronomical event that occurs during the last stellar evolutionary stages of a massive star's life, whose dramatic and catastrophic destruction is marked by one final titanic explosion.

A black hole is a region of spacetime exhibiting such strong gravitational effects that nothingâ€”not even particles and electromagnetic radiation such as lightâ€”can escape from inside it.

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**Various gravitational-wave observatories are under construction or in operation, such as Advanced LIGO which began observations in September 2015.
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The Laser Interferometer Gravitational-Wave Observatory is a large-scale physics experiment and observatory to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool.

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**Potential sources of detectable gravitational waves include binary star systems composed of white dwarfs, neutron stars, and black holes. **

A white dwarf, also called a degenerate dwarf, is a stellar core remnant composed mostly of electron-degenerate matter.

A binary star is a star system consisting of two stars orbiting around their common barycenter.

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**On February 11, 2016, the LIGO Scientific Collaboration and Virgo Collaboration teams announced that they had made the first observation of gravitational waves, originating from a pair of merging black holes using the Advanced LIGO detectors. **

The LIGO Scientific Collaboration is a scientific collaboration of international physics institutes and research groups dedicated to the search for gravitational waves.

The first observation of gravitational waves was made on 14 September 2015 and was announced by the LIGO and Virgo collaborations on 11 February 2016.

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**On June 15, 2016, a second detection of gravitational waves from coalescing black holes was announced.**