Why is everyone talking about Black Hole?
Recently, there has been a lot of buzz about the Black Hole and how scientists made a revolution after years of study and research of the Black Hole. Physics were taken to a level that famous scientists from the past and present centuries, had wished to take it to. It was indeed a revolution in the field of Physics and a huge win for science.
So, what exactly is a black hole?
A black hole is a huge astrophysical region with exuding strong gravitational forces. The gravitational force is so strong that not even light or any other particle can escape from it. As the name suggests, black hole acts like a black body as it does not reflect any light.
Let us find out more about the black hole, its concept and the evolution of its theories.
Evolution of the Concept of Black Holes
As aforementioned, a black hole is an escape, a region with a force of gravity so intense and strong that once you enter, you can’t return. Albert Einstein invested years in creating equations and papers, trying to solve the theory of Black Holes. He himself wrongly thought that a black hole cannot actually be formed. But this theory was dismissed and by 1960, the majority of scientists and researchers believed that there was no obstacle to an event horizon formation.
Roger Penrose theorized and demonstrated that on formation of an event horizon, general relativity requires a singularity to form within, without quantum mechanics. Not much later, Stephen Hawking demonstrated a number of cosmological solutions. These solutions of Hawking showed and described that the Big Bang has singularities without scalar fields and any other form of exotic matter.
Then Kerr Geometry, also known as Kerr Metric came into the picture. The Kerr Metric describes the geometry or metric of an empty space-time around a rotating uncharged axially-symmetric black hole. This basically showed that physical properties of black holes are simple and easily comprehensible. Similar to Kerr Solution, another theorem called the no-hair theorem also showed the comprehensibility of researching black holes.
No-Hair Theorem theorized and postulated that all Einstein-Maxwell equations of electromagnetism as well as gravity in general relativity, the solutions to the aforementioned equations could be entirely characterized by just three classic parameters. These parameters are actually externally observable. These parameters include the classic; electric charge, mass, as well as angular momentum. This observation is quite consistent with Hawking’s theories on black holes.
Hawking and Malcolm Perry also came up with a ‘Soft Hair’ theory. It was a study that postulated that black holes may contain ‘soft hair’ as well. This gave black holes more freedom of degree than ever thought of before.
Though it is popularly known that black holes are formed due to the gravitational collapse of stars; however they can also be formed due to other processes. If a star has much lesser ‘fuel’ left in it to maintain the temperature of itself by stellar nucleosynthesis, its internal pressure would be insufficient for resisting the gravity of its own self. This will cause the gravitational collapse to occur. This gravitational collapse of big or massive stars is believed to be the cause responsible behind the formation of a stellar-mass black hole.
Present Scenario
Astronomers and researchers from Japan, Taiwan, and the acclaimed Princeton University, have succeeded to have discovered about 83 quasars, which are reportedly powered by massive black holes in the distant universe. This finding increases the number of black holes which are known at epoch and also reveals, for the first ever time that how common black holes are early in the history of the universe.
The team of researchers had used the data that was taken with this amazing, cutting-edge instrument called, ‘Hyper Suprime Cam’ (HSC). It was then affixed and mounted on Subaru Telescope of National Astronomical Observatory belonging to Japan, located on the peak of Mauna Kea in Hawaii.
The present-day study of black holes was only made possible by the surveyability of the Subaru and the HSC. Till the present day, from Einstein’s theory of relativity to theories formed by scientists since centuries, there have been a number of descriptions formed by mathematical equations on how a black hole may look like or appear to be. Until now, there has never ever been visual evidence or observational evidence on whether black holes even exist.
On 10th of April, 2019, astronomers and researchers shared a live image, glorified by millions of people in the world, and leaving people around the world amazed by the mere possibility of its existence. This live image was of the black hole from the Messier 87, also known as M87. The image of gravitational region was a bit out-of-focus. Orangish-yellow flames could be seen surrounding the black hole’s center. This was not much different than the estimations by scientists regarding the appearance of a black hole. The black hole was reportedly measured to be 40 billion kilometers across the earth. This is about 55 million light years away from earth. This black hole is even bigger than the whole of our solar system.
Future Programs
Even though more than 200 scientist and researches contributed to the world-ogling discovery of the observational and visual evidence on the existence of black holes, the project’s work, as ascertained by the scientists, researchers, astronomers, and mathematicians themselves are far from being completed or ‘done’. The team is now set to get a perfect and clear picture of the black hole Sagittarius A*, the object or region at the heart of our own Milky Way, which is about 26,000 light-years away and holds about 4.3 million solar mass.
The team will soon affix another dish atop the Kitt Peak which is located in Southern Arizona. This will help in increasing the fidelity of the imaging. There is also NASA’s project of the Nuclear Spectroscopic Telescope Array. The spacecraft is searching and helping in characterizing the massive black holes all around the universe.
Another project called the Laser Interferometer Space Antenna Mission, started by the European Space Agency is scheduled by the agency to launch in the year 2030. Its main aim is to spot the gravitational waves exuded by the mergers of massive or supermassive black holes.
Needless to say, a lot of upcoming discoveries and research on the study of black holes will soon be witnessed in the 21st century, all credit goes to the contribution of former, newer and upcoming scientists, researchers, astronomers, mathematicians and various other people involved behind astronomical discoveries.
