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 success of their observation. Initially two detectors were used that were vastly apart in 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 end of this year
LIGO stands for Laser Interferometer Gravitational wave obersvatory. This project is supported by 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 observatory matched and scientists confirmed the theory.
This observation confirms the predictions of General relativity. The observed waves are formed by inward spiral of two merging black holes. After the merger they form a single big black hole. The ripple that was observed was due to collision of black holes 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 great achievement in field of science. For this year, graviational waves is one of the biggest discovery.
What are Gravitational Waves?
The concept of these waves come from the Albert Einstein’s General Theory of Relativity. This explains the spacetime fabric and curvature caused due to the celestial masses of 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 legendary scientist correct after about a century.
To understand spacetime continuum, simply imagine a trampoline and think of a heavy ball at center as the sun which creates a curvature in the tight trampoline then add some marbles at certain distance from the ball or center. You will notice less curvature for objects of less weight and higher for heavier ones.
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 to merging of two massive binary black holes. We can imagine them as disturbance created in water surface due to some object.
LIGO, NSF and Research
The National Science Foundation (NSF) funds the experiement. These observational are possible only due to LIGO. There are two apparatus currently in the USA. One is in Hanford and other is in Livingston. Both have same kind of lab structure to measure and find the existence. 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. It is because, scientists need very high precision and accuracy.
However after many years, the investment paid off. MIT crew played very important roles in the construction, instrumentation and data analysis. The existence was proved by matching data of both centers. Global expansion is in the process for further study. India, Australia and various parts of Europe may soon have new LIGO.
These waves or ripples travel across the universe. In addition, have certain velocity which is euqual to 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 study of the phenomenon how disruption is caused due to gravity and heavy mass. This discovery proves the fact that black holes actually exist and also proves fast of expansion of 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 an 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 mirros reflect the laser beams. When a gravitational wave passes, there is disturbance in the space and there is 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 earthquake can affect this experiment. This is why the intereformeters are in far places and apart. When there are data of two place and they match, we can be sure that they are not due to some geological or environmental factor.
These kind 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 on our universe. Scientists want to know its origin, expansion, constituents, physical forces, phenomenons and extra terrestrial life possibilities. NSF is continuing this study with even better instruments. We might see new detections in future soon.