- "They were first proposed by Oliver Heaviside in 1893 and then later by Henri Poincaré in 1905..."
Ripples in spacetime caused by the acceleration of massive objects.
General Relativity: The theory of gravitation developed by Albert Einstein that explains the behavior of objects under the influence of gravity.
Spacetime: The concept of space and time being unified into a four-dimensional continuum in which all events occur.
Curvature: The degree to which spacetime is curved in the presence of mass or energy.
Tensor Calculus: The mathematical language used to describe the behavior of spacetime and the curvature of spacetime in the presence of mass or energy.
Astrophysics: The study of the behavior and properties of celestial objects, including stars, galaxies, and black holes.
Cosmology: The study of the structure, origin, and evolution of the universe as a whole.
Wave Motion: The propagation of disturbances or vibrations through a medium.
Gravitational Waves: Ripples in the fabric of spacetime caused by the acceleration of massive objects, predicted by Einstein's theory of general relativity.
Detection Methods: Techniques used to observe gravitational waves, such as interferometers, laser interferometry, and pulsar timing arrays.
Black Holes: Extremely dense regions of space where the gravitational force is so strong that nothing, including light, can escape.
Neutron Stars: Highly compact stars that are created by the collapse of a massive star and are composed of densely packed neutrons.
Binary Systems: Pairs of massive objects, such as black holes, neutron stars, or white dwarfs, that orbit around each other and emit gravitational waves.
Event Horizon: The boundary in which the gravitational pull of a black hole becomes so strong that not even light can escape.
Gravitational Lensing: The bending of light by the curvature of spacetime in the presence of massive objects, such as galaxies or black holes.
LIGO: The Laser Interferometer Gravitational-Wave Observatory, a collaborative project between the United States and Europe, designed to detect gravitational waves.
Virgo: A gravitational wave detector located in Italy that works in conjunction with LIGO to search for gravitational waves.
KAGRA: A gravitational wave detector located in Japan that is currently under construction.
Data Analysis: The process of extracting gravitational wave signals from noisy data and interpreting their properties, such as direction, polarization, and frequency.
Sources of Gravitational Waves: Objects and events that are believed to generate gravitational waves, such as merging binary black holes, supernovae, and cosmic strings.
Continuous waves: These are generated when two massive objects orbit each other, such as two black holes or neutron stars. They generate a continuous stream of waves that could be detected for years.
Burst waves: These are short-lived signals generated by a sudden event, such as a supernova or a merger of two black holes. These waves are stronger than continuous ones but last for a shorter time.
Stochastic waves: These waves arise from the background of numerous smaller sources, such as black hole mergers throughout the Universe.
Primordial waves: These are generated during the very early stages of the Universe's formation, resulting from tiny fluctuations in the fabric of spacetime.
Inspiral waves: These occur when two massive objects, such as black holes or neutron stars, spiral closer and closer together before finally merging into a larger object.
Ringdown waves: These waves are emitted after the merger of two massive objects, once the newly-formed object "rings down" and settles into a stable state.
Polarization waves: These are a type of wave that travels in two perpendicular directions, instead of just one direction. They can be caused by sources that exhibit strong asymmetry, such as supernovae or spinning neutron stars.
Electromagnetic waves: These are waves that are generated by charged particles, and are distinct from gravitational waves, which are generated by mass. However, some astrophysical events, such as a neutron star merger, can generate both electromagnetic and gravitational waves simultaneously.
- "Gravitational waves were later predicted in 1916 by Albert Einstein..."
- "Gravitational waves...propagate as waves outward from their source at the speed of light."
- "Gravitational waves transport energy as gravitational radiation, a form of radiant energy similar to electromagnetic radiation."
- "...Newton's law of universal gravitation...does not provide for their existence, since that law is predicated on the assumption that physical interactions propagate instantaneously (at infinite speed)..."
- "The first indirect evidence for the existence of gravitational waves came in 1974 from the observed orbital decay of the Hulse–Taylor binary pulsar..."
- "...the observed orbital decay of the Hulse–Taylor binary pulsar, which matched the decay predicted by general relativity as energy is lost to gravitational radiation."
- "In 1993, Russell A. Hulse and Joseph Hooton Taylor Jr. received the Nobel Prize in Physics for this discovery."
- "The first direct observation of gravitational waves was made in 2015..."
- "...when a signal generated by the merger of two black holes was received by the LIGO gravitational wave detectors in Livingston, Louisiana, and in Hanford, Washington."
- "The 2017 Nobel Prize in Physics was subsequently awarded to Rainer Weiss, Kip Thorne and Barry Barish for their role in the direct detection of gravitational waves."
- "In gravitational-wave astronomy, observations of gravitational waves are used to infer data about the sources of gravitational waves."
- "Sources that can be studied this way include binary star systems composed of white dwarfs, neutron stars, and black holes..."
- "...events such as supernovae..."
- "...and the formation of the early universe shortly after the Big Bang."
- Gravitational waves...propagate as waves outward from their source at the speed of light."
- "...waves similar to electromagnetic waves but the gravitational equivalent."
- "Later he refused to accept gravitational waves."
- "The first direct observation of gravitational waves was made in 2015... The 2017 Nobel Prize in Physics was subsequently awarded... for their role in the direct detection of gravitational waves."
- "...showing one of the ways the methods of Newtonian physics are unable to explain phenomena associated with relativity."