Gravitational Waves Waves Demonstration
Gravitational Waves Waves Demonstration Image Credit: NASA

Today the National Science Foundation confirmed the existence of gravitational waves. These waves were predicted by the Einstein Field Equations. On the day of February 11th, 2016, scientists involved in this experiment publicly announced the success of their observation. Initially, two detectors were used that were vastly apart in the distance. Some physicists claimed that this might be the Nobel prize winner of this year. In order to expand the study, LIGO India is initiating soon at the end of this year. This is a very big discovery in the field of physics.

LIGO stands for Laser Interferometer Gravitational-wave observatory. This is a massive project and it is supported by the National Science Foundation, Caltech, and MIT. Two detectors were used in this current discovery. There are many reasons for keeping them apart. It is to check for errors, local disturbance, and verify data. The data from both observatories matched, and scientists confirmed the theory.

This observation confirms the predictions of general relativity. The observed waves are formed by an inward spiral of two merging black holes. After the merging, they form a single big black hole. The ripple that was observed was due to the collision of black holes that were 1 billion light-years away from earth. We can understand them as waves and ripples in the space-time fabric of our universe. Last year in 2015, scientists discovered Pentaquark, and that was a great achievement in the field of science. For this year, gravitational waves are one of the biggest discoveries.

What are Gravitational Waves?

The concept of these waves comes from Albert Einstein’s General Theory of Relativity. This explains the spacetime fabric and curvature caused due to the celestial masses of the universe. The masses like planets, stars exist in this fabric and interact in a spectacular way. Einstein formulated that the interaction of heavy masses can form ripples or disturbances known as Gravitational waves. It was not confirmed earlier. But this experiment proves the Albert Einstein correct after about a century.

To understand the spacetime continuum, simply imagine a trampoline and think of a heavy ball at the center as the sun. This creates a curvature in the tight trampoline. Then add some marbles at a certain distance from the ball or center. You will notice less curvature for objects of less weight and higher for heavier ones. It should help you get some idea of spacetime curvature.

The new discovery of these ripples in the universe was detected using highly sophisticated equipment with extremely large apparatus and intense calculation. This captured data of these waves was due to the merging of two massive binary black holes. We can imagine them as disturbance created in the water surface due to some object. However, there is much complex physics involved in this process.

Space-time curvature example
Space-time curvature: Wikimedia commons

LIGO, NSF and Research

The National Science Foundation (NSF) funded the experiment. These observations are possible only due to LIGO. There are two apparatus currently in the USA. One is in Hanford, and the other is in Livingston. Both have same kind of lab structure to measure and find the existence. By the way, they are thousand of miles apart. This helps scientists to get two sets of data and confirm them. The construction began in 1994. It was considered a very risky investment for the foundation. However, after many years, the investment paid off.

MIT crew played very important roles in construction, instrumentation, and data analysis. The existence was proved by matching data of both centers. Global expansion is in the process of further study. India, Australia, and various parts of Europe may soon have new LIGO. All scientists are now working together to create a bigger impact and take the research further.

These gravitational waves or ripples travel across the universe. In addition, they have a certain velocity which is equal to the velocity of light. Therefore they carry important information about the history of our universe. The waves can tell about its origin, time of creation, place of the incident, and energy released during the merge event.

The discovery adds another dimension to the study of our space. It helps in the study of the phenomenon of how disruption is caused due to gravity and heavy mass. This discovery proves the fact that black holes actually exist and also confirm the fast expansion of the universe. Scientists of many countries were involved in this experiment. Researcher Sudarshan Karki of Nepal also played a major role in this experiment. Therefore he is getting a lot of attention and respect from his home country.


Hows does LIGO detectors work?

This is a very complex setup. But we want to put some light on this. The basic working uses lasers, reflectors, and sensors. There are long arms at the right angle. Each arm is about 4 KM long. This means they are very long and big. At end of each arm, there are mirrors. One arm end has a powerful laser. The mirrors reflect the laser beams. When a gravitational wave passes, there is a disturbance in the space, there is a very small change in interferometer arm length. Due to this, the lasers beams are not in phase and we observe interference pattern.

The gravitational-wave strain is very small, and it needs highly sensitive sensors. This requires high precision because the strain is very small. Environmental factors and geological activities like earthquakes can affect this experiment. This is why the interferometers are in far places and apart. When there are data from two places, and they match, we can be sure that they are not due to some geological or environmental factors.

These kinds of discoveries are great, and they give new information to everyone. We can understand our universe better. Scientists all over the world are always trying to find more knowledge of our universe. Scientists want to know its origin, expansion, constituents, physical forces, phenomenons, and extraterrestrial life possibilities. NSF is continuing this study with even better instruments. We might see new detections in the future soon.


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