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You can't "disfavor" a wave--like electromagnetic waves, they travel right through you, whether you like them or not. And they are as real as neutrinos or Higgs bosons.
:::''Gravitational waves are often incorrectly called "[[Gravity waves]]". See that page for a discussion of this point.''
:::''Gravitational waves are often incorrectly called "[[Gravity waves]]". See that page for a discussion of this point.''
'''Gravitational waves''' are distortions in space that travel at the [[speed of light]] away from a mass that accelerates. Predicted by [[Albert Einstein]]'s [[Theory of Relativity]] in 1916, gravitational waves were first observed and their existence confirmed in early 2016.<ref>http://journals.aps.org/prl/pdf/10.1103/PhysRevLett.116.061102</ref>
'''Gravitational waves''' are distortions in space that travel at the [[speed of light]] away from a mass that accelerates. Predicted by [[Albert Einstein]]'s [[Theory of Relativity]] in 1916, they were first observed, and their existence confirmed, in early 2016. <ref>http://journals.aps.org/prl/pdf/10.1103/PhysRevLett.116.061102</ref>
==Description==
==Description==
Gravitational waves are essentially "ripples", similar to the ripples made in a pond when a pebble is tossed in, but on a cosmological scale. The mass in question are binary systems - pulsars, neutron stars, or black holes - which orbit around each other. According to Einstein's [[General relativity|General Theory of Relativity]], both objects emit gravitational waves while losing energy as they gradually approach, eventually resulting in a collision at one-half the speed of light, forming a single object as well as emitting a final, very strong burst of gravitational waves
Gravitational waves are "ripples", similar to the ripples made in a pond when a pebble is tossed in, but on a cosmological scale. The masses in question are binary systems - pulsars, neutron stars, or black holes - which orbit around each other. According to Einstein's [[General relativity|General Theory of Relativity]], both objects emit gravitational waves and lose energy as they gradually approach, eventually resulting in a collision, and emitting a final, very strong burst of gravitational waves
As part of his relativity theory, Einstein came up with his "quadrupole formula", which describes the rate of wave emissions from a system of astronomical masses based on the change of the mass itself, what he called the "quadrupole moment". His formula as originally postulated was
As part of his relativity theory, Einstein came up with his "quadrupole formula", which describes the rate of wave emissions from a system of astronomical masses based on the change of the mass itself, what he called the "quadrupole moment". His formula as originally postulated was
Unlike most astronomical wave phenomena, the gravitational waves from black hole mergers are approximately in the audible range. With only a small amount of signal processing, the signal was made audible; it's sort of a "chirp".<ref>https://www.ligo.caltech.edu/video/ligo20160211v2</ref> For a while this "chirp" became something of an internet sensation.
Unlike most astronomical wave phenomena, the gravitational waves from black hole mergers are approximately in the audible range. With only a small amount of signal processing, the signal was made audible; it's sort of a "chirp".<ref>https://www.ligo.caltech.edu/video/ligo20160211v2</ref> For a while this "chirp" became something of an internet sensation.
Other articles: [http://www.nbcnews.com/science/science-news/gravitational-waves-ripples-space-time-detected-first-time-n516566], [https://www.youtube.com/watch?v=aEPIwEJmZyE]
Other articles: [https://www.nbcnews.com/science/science-news/gravitational-waves-ripples-space-time-detected-first-time-n516566], [https://www.youtube.com/watch?v=aEPIwEJmZyE]
=== The event of December 26, 2015 ===
=== The event of December 26, 2015 ===
A second black hole merger was detected two months later.<ref>http://www.nbcnews.com/science/science-news/it-wasn-t-fluke-scientists-see-black-holes-collide-again-n593156</ref><ref>https://www.cbsnews.com/news/scientists-detect-second-gravitational-wave-einstein-predicted/</ref><ref>https://www.ligo.caltech.edu/news/ligo20160615</ref>
A second black hole merger was detected two months later.<ref>https://www.nbcnews.com/science/science-news/it-wasn-t-fluke-scientists-see-black-holes-collide-again-n593156</ref><ref>https://www.cbsnews.com/news/scientists-detect-second-gravitational-wave-einstein-predicted/</ref><ref>https://www.ligo.caltech.edu/news/ligo20160615</ref>
Here is a comparison of the "chirps" from the two events. The December event was significantly less powerful that the September one. It was 1.4 billion light years away.<ref>https://www.ligo.caltech.edu/video/ligo20160615v2</ref>
Here is a comparison of the "chirps" from the two events. The December event was significantly less powerful that the September one. It was 1.4 billion light years away.<ref>https://www.ligo.caltech.edu/video/ligo20160615v2</ref>
A third event was detected in early 2017. This one was 3 billion light years away.<ref>https://phys.org/news/2017-06-gravitational-insight-black-holes.html</ref>
A third event was detected in early 2017. This one was 3 billion light years away.<ref>https://phys.org/news/2017-06-gravitational-insight-black-holes.html</ref>
===Further events ===
Since those very early announcements, further observations of gravitational waves have continued to come in.<ref>https://ligo.org</ref> In August 2019 the first detection of the gravitational waves from the merger of a [[black hole]] and a neutron star occurred.<ref>https://ligo.org/news/index.php#O3updateAug19</ref> This was event S190814bv, 870 million light years away, and hence actually occurred 870 million years ago.<ref>https://www.extremetech.com/extreme/296902-scientists-detect-first-ever-collision-between-black-hole-and-neutron-star</ref>
== The LISA project ==
== The LISA project ==
An even more ambitious and sensitive detector, previously called LISA and now called eLISA (Evolved Laser Interferometer Space Antenna), is being designed by an international consortium of agencies. This one involves satellites in heliocentric orbit, using laser interferometers to measure changes in the distance between "test masses" inside the satellites.
An even more ambitious and sensitive detector, previously called LISA and now called eLISA (Evolved Laser Interferometer Space Antenna), is being designed by an international consortium of agencies. This one involves satellites in heliocentric orbit, using laser interferometers to measure changes in the distance between "test masses" inside the satellites.
A test of the underlying test mass technology, called the LISA Pathfinder test, succeeded on June 6, 2016.<ref>http://www.bbc.co.uk/news/science-environment-36472434#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa</ref>
A test of the underlying test mass technology, called the LISA Pathfinder test, succeeded on June 6, 2016.<ref>https://www.bbc.co.uk/news/science-environment-36472434#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa</ref>
== See also ==
== See also ==