Black Hole: At a Glance - Daily Current Affair Article

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A supermassive black hole whose mass, estimated to be up to 100 billion times the mass of the Sun, is surprisingly missing. This phenomenon has surprised astronomers.

Introduction

Nearly all large galaxies in the universe have a supermassive black hole at the center, whose mass is millions or millions of times that of the Sun. The black hole named Sagittarius A * is found in our Milky Way. "Abel 2261"galaxy, about 2. 7 billion light-years away from Earth, the black hole in the galaxy has surprisingly disappeared. Scientists have discovered a black hole using NASA's Lunar X-ray Observatory and the Hubble Space Telescope, but so far it has not been successful in its discovery.

What is black hole?

  • A black hole is such an astronomical object with such a powerful gravitational field, that nothing but light can escape from the gravitational effect. No other things, including light, can be returned after a point called Event Horizon around the Black hole.
  • It is called "black" because it also absorbs all the light that falls on it and does not reflect anything. It is exactly like a perfect black body in thermodynamics.

Formation of Black hole

  • A black hole is a dead star. Stars originate from Nebula made of dust and gas present in the galaxy of the universe where an excess of hydrogen is found. When the density of these clouds i.e. nebula made of dust and gas increases, at that time it starts to get compressed due to its gravity and the temperature inside it increases so much that the hydrogen atoms collide and they forms Helium. Here the process of nuclear fusion starts which released energy. Due to motion and contraction, they unite to form a round or almost circular shape. And thus a star is formed. In this situation, the forces of nuclear fusion energy and gravitational force are employed in the stars.
  • When the energy (fuel or hydrogen) of these stars is exhausted, then they slowly cool down. Now the stars which have exhausted their fuel, which cannot handle themselves against their gravity, there is an explosion inside such a star which is called a supernova explosion.
  • These are the invisible bodies that we call black holes. The entire mass of a black hole is concentrated in a small point called a central singularity point. The spherical boundary or horizon around this point is called an event horizon. Light or any object cannot go outside this event horizon.

Einstein's Theory of Special Relativity

  • The light which has a speed of 2.99792458 x 10 8 m / s i.e. nearly 3 lakh kilometers per second, also distorts both space and time due to its inclusion in it.
  • According to Einstein's Theory of Special Relativity an observer standing at a certain range away from the horizon of this black hole will be slowed down very slowly and its time will be very slow. This phenomenon is called time dilation.
  • According to Einstein's Theory of Special Relativity, the length of an observer standing at a certain range away from the horizon of this black hole will also be seen and it will be very short. This phenomenon is called length contraction.

How is the location of a black hole detected?

In deep space, a black hole is such a place where nothing is visible. Therefore, the position of a black hole is detected by the reflected light from any other celestial body that is around the black hole.

Types of black holes: -

Stellar Black hole: -

A star whose mass is slightly higher than our Sun and eventually becomes a black hole due to gravity contraction is called a Stellar black hole.

Supermassive Black hole: -

Black holes of immense density and mass size that form in the center of the galaxy are called supermassive black holes. The mass of such a black hole is millions of times greater than our Sun.

Small Black hole: -

Those whose mass is less than Sun and which are not formed due to gravitational contraction but due to the richness of their center matter, are called small black holes.

Is there a relationship between the black hole and time travel?

  • Newton described time as absolute or absolute, but according to Einstein's theory of relativity, change in time is also possible.
  • Theoretically if there is a planet having a life near Black hole, then in comparison of other places or our earth, there time will move slowly, that is, if we go from Earth to that imaginary planet and then come back to Earth, we will be in the future. This mode can only be accessed in the future.
  • Practically it has many other problems. First of all, the closest black hole of our Earth is V616 Monocerotis which is 3000 light-years away from us, so it is not possible to reach even around it. Thereafter, there will be many difficulties in living near the Black hole. So, at present, it seems impossible.

The conclusion

Although 2.7 billion light-years away from Earth, the Earth should not have any impact in its near future but space still has many secrets to hide and man does not know much about space at this time, it is necessary to monitor it by scientists.

General Studies Paper 1
  • Geography

Mains Question:-

  • What do you understand by black hole? While describing the process of its construction, describe Einstein's theories related to the black hole?