When were the gravitational waves detected?
September 14, 2015
The gravitational waves were detected on September 14, 2015 at 5:51 a.m. Eastern Daylight Time (09:51 UTC) by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, USA.
- They were first proposed by Henri Poincaré in 1905 and subsequently predicted in 1916 by Albert Einstein on the basis of his general theory of relativity. Gravitational waves transport energy as gravitational radiation, a form of radiant energy similar to electromagnetic radiation.
- Gravitational waves are 'ripples' in the fabric of space-time caused by some of the most violent and energetic processes in the Universe. Albert Einstein predicted the existence of gravitational waves in 1916 in his general theory of relativity.
- LIGO's multi-kilometer-scale gravitational wave detectors use laser interferometry to measure the minute ripples in space-time caused by passing gravitational waves from cataclysmic cosmic sources such as the mergers of pairs of neutron stars or black holes, or by supernovae.
United States of America
- By mid-September 2015 "the world's largest gravitational-wave facility" completed a 5-year US $200-million overhaul at a total cost of $620 million. On 18 September 2015, Advanced LIGO began its first formal science observations at about four times the sensitivity of the initial LIGO interferometers.
- We all know light obeys a speed limit — roughly 186,000 miles per second. Nothing travels faster. But why should gravity travel at the same speed? That question requires a quick dive into Albert Einstein's general relativity, or theory of gravity — the same theory that predicted gravitational waves a century ago.
- Eastern Daylight Time (09:51 UTC), the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, USA both measured ripples in the fabric of spacetime – gravitational waves – arriving at the Earth from a cataclysmic event in the distant universe
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. Previously gravitational waves had only been inferred indirectly, via their effect on the timing of pulsars in binary star systems.
- Black holes are the blackest things in the universe. Because of their enormous, space-bending gravity, everything that falls into them is instantly ripped apart and lost. Scientists have never seen a black hole, because nothing, not even light, can escape them.
- The most massive black holes in the Universe, the supermassive black holes with millions of times the math of the Sun will have a temperature of 1.4 x 10^-14 Kelvin. That's low. Almost absolute zero, but not quite. A solar mass black hole might have a temperature of only .0.00000006 Kelvin.
- Within this nebula, the hot core of the star remains—crushed to high density by gravity—as a white dwarf with temperatures over 180,000 degrees Fahrenheit (100,000 degrees Celsius). Eventually—over tens or even hundreds of billions of years—a white dwarf cools until it becomes a black dwarf, which emits no energy.
Updated: 3rd December 2019