Gravitational wave is a concept that Albert Einstein predicted in 1916. Albert Einstein proposed an idea that gravity comes from the warps and curves in the fabric of space. Gravitational wave is actually like a ripple in the fabric of space. According to Einstein if rapidly orbiting neutron stars or black holes occur on the fabric of space, it creates ripples and these ripples are called as the gravitational waves.
As the gravitational waves passes by anything, it stretches and compresses it. If we take the case of earth, the ripples will stretch and compress the earth by less than an atomic diameter. Scientists at Laser Interferometer Gravitational-Wave Observatory discovered the first gravitational wave on 14 September 2015 and was announced by the LIGO and Virgo collaborations on 11 February 2016.
Since the stretching and compression is of very small size, it is not practical to measure it directly. But scientists have came up with an idea where they use interference pattern of a laser beam to detect the gravitational wave. In order to do this, a laser is sent to a considerable long distance of about 2.5 miles through a vacuum pipe and it is reflected back from a mirror kept in the other end. Both these beams interact with each other and creates an interference pattern.
But this interference pattern is highly dependent on the distance that the beam travels. So when a gravitation wave compresses or stretches one distance in relative to the other, the interference pattern will change. For example, change in the above given interference pattern under the influence of a normal audible sound wave is given below.
You can see that the pattern has changed. But since it is a sound wave, the change in pattern is clearly visible. But in case of gravitational wave we use sophisticated technologies to detect the change in the pattern.
The discovery of gravitational wave is so important because gravitational waves are immune to natural disturbances and it can travel through anything in the universe. So this discovery could help studying black holes, big bang theory and the universe itself.
The most recent gravitational wave detection was on 17th August 2017 when LIGO interferometer detected a gravitational wave signal which lasted about 100 seconds. This gravitational wave was a result of two merging neutron stars. After 11 hours of initial detection, astronomers observed a bright spot in the NGC4993 galaxy where the neutron star merge was happened 130 million years ago and the waves traveled from that galaxy to ours.
As the gravitational waves passes by anything, it stretches and compresses it. If we take the case of earth, the ripples will stretch and compress the earth by less than an atomic diameter. Scientists at Laser Interferometer Gravitational-Wave Observatory discovered the first gravitational wave on 14 September 2015 and was announced by the LIGO and Virgo collaborations on 11 February 2016.
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| Virgo Interferometer, Italy |
Since the stretching and compression is of very small size, it is not practical to measure it directly. But scientists have came up with an idea where they use interference pattern of a laser beam to detect the gravitational wave. In order to do this, a laser is sent to a considerable long distance of about 2.5 miles through a vacuum pipe and it is reflected back from a mirror kept in the other end. Both these beams interact with each other and creates an interference pattern.
But this interference pattern is highly dependent on the distance that the beam travels. So when a gravitation wave compresses or stretches one distance in relative to the other, the interference pattern will change. For example, change in the above given interference pattern under the influence of a normal audible sound wave is given below.
You can see that the pattern has changed. But since it is a sound wave, the change in pattern is clearly visible. But in case of gravitational wave we use sophisticated technologies to detect the change in the pattern.
The discovery of gravitational wave is so important because gravitational waves are immune to natural disturbances and it can travel through anything in the universe. So this discovery could help studying black holes, big bang theory and the universe itself.
The most recent gravitational wave detection was on 17th August 2017 when LIGO interferometer detected a gravitational wave signal which lasted about 100 seconds. This gravitational wave was a result of two merging neutron stars. After 11 hours of initial detection, astronomers observed a bright spot in the NGC4993 galaxy where the neutron star merge was happened 130 million years ago and the waves traveled from that galaxy to ours.
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