The advancement of mankind to cross the limitless boundaries, to explore and unravel the mysteries is possible by its scientific and technical superiority. The researches, inventions, and discoveries that occur day by day take us a step forward in this pursuit of reality. One such discovery was to obtain the first original picture of a black hole. But the question which arises in our mind is how to get an image of something from which even light can't escape. After all, an image of an object is the light reflected by the object and here light can not even escape from the black hole.
Scientists unveiled the first image of one of the largest supermassive black hole M87 of the galaxy Messier 87 on 10th April 2019. M87 is 53 million light-years away from earth and contains 6.5 billion solar masses. The scientists created a network of telescopes knows as the Event Horizon Telescope which is a planet-scale array of eight ground-based radio telescopes stationed at different locations. The EHT observations use a technique called Very Long Baseline Interferometry (VLBI) which synchronizes telescope facilities around the world and exploits the rotation of the earth to form one huge, Earth-sized telescope observing at a wavelength of 1.3mm and to achieve an angular resolution of 20 microarcseconds. The image shows plasma rotating around the supermassive black hole. The bright region shows the plasma coming towards us and since it is traveling near the speed of light it appears brighter when coming towards us and dimmer when going away. This is called relativistic beaming.
This imaging project answered many questions like it provided a more direct method of calculating the mass of a black hole. It provides insight into physics and allows us to test observation methods and theories, such as Einstein's theory of general relativity. General relativity predicts that this silhouette would be roughly circular but other theories of gravity predict different shapes. This image shows a circular silhouette, thus lending credibility to Einstein's theory of general relativity. The data also offer some insight into the formation and behavior of black hole structures such as the accretion disc that feeds matter into the black hole and plasma jets that emanate from its center.
Thus many such unanswered questions can be answered and such answers will lead to new sectors of research. And our pursuit of reality will go on and on.