‘How the most mysterious object of our universe which absorbs even light was pictured’
In a recent scientific breakthrough, a team of Astronomers released the first ever image of a black hole. The astronomers combined eight radio Telescopes set at different places across the globe as a single unit to produce the image of a super massive black hole with mass about 6.5 billion times that of our Sun. This black hole is in the heart of a distant galaxy Messier 87 which is an elliptical galaxy 53 million light-years away from earth (One light being the distance travelled by light in one year in vacuum).
Black Holes are the regions with highly intense gravitational fields which do not let anything escape it-not even light. The term “Black Hole” was first introduced by an American Physicist John Wheeler in 1967. Even before him the idea of the existence of such a body was put forward by an English clergyman John Michell in 1784 who termed such an object as “dark star”.
A black hole is considered to be a ‘dead star’ as it forms from the gravitational collapse of heavy stars. The defining feature of a Black Hole is its ‘Event horizon’- referred to as the perimeter of the black hole. It is a boundary surrounding a black hole which allows unidirectional flow of anything (matter and radiation). The most startling fact about the event horizon is that once you cross it, you can’t come outside it again. It is thus referred to as such because any event occurring inside it can’t be described by a person outside it. The centre of a black hole is referred to as singularity-a point of infinite density. Black holes thus are the most mysterious objects in our Universe.
What makes the image of a black hole so important is that scientists have been able to see what was thought to be invisible. The picture released by the astronomers shows an orange ring surrounding a black region-referred to as dark abyss. This orange ring consist the gas clouds which are swirling the black hole and are heated to a great level to be visible. This ring is a characteristic of a black hole and it is due to this that the existence of black holes has been visually confirmed. But why was such a distant black hole selected to be pictured? There are a huge number of other black holes nearer to earth which could have been chosen.
The reason behind this is that the telescopes available to us at present have a limited resolution (ability of a telescope to produce distinct images). The black holes other than the one in M87 galaxy are small in size to be resolved. Thus, astronomers were in search of a huge black hole. Despite this the telescopes still were not independently able to produce such an image. To solve the problem of resolution, astronomers combined 8 radio telescopes which were set at different places to form what they called an earth-sized telescope. These were synchronized and data was simultaneously collected from them. This data was then fed to supercomputers which converted it to an image.
The big deal about the image of a black hole is the success of human endeavour in revealing the mysteries of the universe, this being another milestone in that process. Until now the black holes were computer simulated and these simulations were used by many film makers in sci-fi movies, Christopher Nolan’s Interstellar being the most vivid example. The present success of obtaining an image of a black hole has once again confirmed Einstein’s General relativity theory which predicted the interaction of light with gravity. In addition to this, it has started a new era of Astronomy and Astrophysics which would go even deeper in the structure of our universe to explain the way it originated and how it is going to evolve in the far future.
Our universe consists of lot many objects with uncanny behaviours ranging from microscopic scale-nuclear dimensions of atoms to macroscopic scale. While Black holes form a part of the later, there are a more than hundred particles-called elementary particles which make up the fundamental constituents of the matter around us. Physics, in its key objectives at present, tries to explain different phenomena at both these scales and has been successful to a greater extent. What Physicists want is a single theory that describes all the phenomena happening at both the micro and the macro level. This is possible only when we can unify all the particle interactions (which are four in number). Although for the past many decades, Physicists have been able to combine few of these and explain many things in a unified way but the fundamental aim still remains unanswered- The theory of everything.