Unfolding the Mysteries of the Universe- Knowing more about Blackholes

The mysteries of the universe have always fascinated me. Even as a toddler, I would look at the night sky and wonder “What is out there”? I was always curious to know more about the Universe. When I grew up, I understood that we are nothing but a speck in the vast Universe. The universe is so large that our mind can’t possibly comprehend it.

Out of the many objects in the universe, the one that intrigued me the most were Blackholes. They are formed when a massive star, at least having ten to fifteen solar masses, collapses on itself. This happens because stars are stable due to the balance between pressure created by the fusion of Hydrogen into Helium and gravity. The core of the star over time turns into denser and denser elements due to fusion until it reaches Iron. Iron is the densest element and cannot be fused into any other element. At this moment, the balance between pressure and gravity shifts drastically and the star collapses on itself. If the star is big enough, it turns into a Blackhole. Otherwise it will turn into a Neutron star.

We have a lot more to learn about Blackholes. The idea of Blackholes was proposed by Albert Einstein . It was a common debate among the scientists whether they were real or not, until the first picture of a Blackhole was recently taken. It was not a picture of the Blackhole itself, but of the superheated gas surrounding the blackhole. This is because even light cannot escape the gravitational pull of a Blackhole. The existence of Blackholes was also proven mathematically by recent Noble prize winner, Roger Penrose, Reinhard Genzel and Andrea Ghez. They developed a mathematical theory on the existence of Blackholes based on the ideas of Einstein’s ‘Theory of
Gravity’.

Blackholes can be of various masses. Some are about ten to fifteen solar masses, while others can be as massive as millions or even billions of solar masses! The largest Blackholes that we know of, has an estimated mass of more than 40 billion solar masses. The Blackhole in the middle of our Milky
Way galaxy is called ‘Sagittarius A’. It has an estimated mass of more than three million solar masses.

Blackholes also result in the formation of Quasars. These are the brightest objects in the Universe. They can outshine entire galaxies. These are essentially super massive Blackholes which are surrounded by superheated gas which causes them to be so bright.

Blackholes do not exist for ever. They eventually evaporate by Hawking radiation, which is a process in which one particle of a Blackhole escapes at infinity while the other particle is trapped inside the Blackholes horizon. Hawking radiation is a very slow process, so slow that by the time the last blackhole will evaporate, there will be no stars left in the universe.

Blackholes are just one of the many marvelous objects of the universe. There is so much more left to discover in this vast Universe. I hope that one day, we will be able to solve some of the other greatest mysteries of the Universe.