Sometimes physics seems to be strange than fiction. You may probably heard this lines if you are a follower of astrophysics. Then Do Black Hole really exists? Why this small medley is so important for physics? Why this black thing have billions of mass?
If these are your question then you are on right place. Hey Avidian, Let’s Start.
History of Black Hole
Black Hole history is so much complicated than any history of physics because it simple enough to just visualize and imagine Black hole but very difficult to place into in space. From Ismaël Bullialdus to Event Horizon Telescope, every work in this field can’t fully define what exactly Black Hole is.
An American Scientist John Wheeler emphasized that stars could eventually or at last collapse. Debate on this fact is very immense in physics, although very scientist believe in this fact.
The Idea of Space Time singularity was however coined by Physicist Stephen Hawkings. He then demonstrated “Black Hole” in his own way. In 1972 Stephen Hawking proved that the area of a classical black hole’s event horizon cannot decrease. In that same year James Bardeen, Brandon Carter, and Stephen Hawking propose four laws of black hole mechanics in analogy with the laws of thermodynamics and Jacob Bekenstein suggests that black holes have an entropy proportional to their surface area due to information loss effects.
In 2006 Event Horizon started collecting data and then in finally 2019 it gave us the very fist image of Black Hole on 10 April.
What exactly Black Hole is and How it forms?
I will try to explain in it simple but very physical manner.
A star in it’s life oppose to it’s own gravity by thermal pressure. Thermal Pressure is a pressure that tries to expand the stars layer to outward.
But eventually star loses it’s energy, it loses it’s bank of thermal pressure. And then star began to contract. Then some of it contract to white dwarf, however Indian Physicist Chandrashekar showed that the maximum mass of white dwarf is 1.4 Times that of sun. This limit is known as Chandrashekar Limit.
But the question is what if the star breaks Chandrashekar Limit, that question was answered by Robert Oppenheimer in 1939. That he answered that such a star could not be supported by outward pressure and that if you take pressure out of the circulation then a uniform spherically systematic symmetric star would contract to a single point of infinite density. And that point is what we called Singularity, that was later examined by Stephen Hawkings.
If we conclude then , One Black Hole was initially a star that was collapsed by another star or by it’s own gravity and get fit into a space-time singularity where space and times comes to end. Black Hole is so dense that’s why gravitational energy that it have is so great that even a light that get inside that can’t exit from there.
Types of Black Hole
On the basis of mass and size black hole are of three types ;
- The smallest ones are known as primordial black holes. These are smallest black holes and are small in size in compare to other.
- Then medium ones are known as stellar black holes. The mass of a stellar black hole can be up to 20 times greater than the mass of the sun but it may be only about 10 kilometers across in size.
- The massive ones are known as supermassive black hole. It is believed that every galaxy have a supermassive black hole in it’s center. The supermassive black hole at the center of the Milky Way galaxy is called Sagittarius A. It has an estimated mass equal to about 4 million suns but its estimated size is about the size of our Sun only.
You may notice that black hole’s mass is so great but size is small when we compare with it’s mass.
The boundary of Black Hole is called Event Horizon from where gravity escapes.
Falling in black hole is just like falling in Niagara Falls, if you near the point from where water splash to downward then as fast as you can paddle fast from there the chances of survival are high.
Then why we can’t see black hole ?
Answer is Black Holes are not black they are just named like this, because of light get into black hole and that is other matter that it don’t reflect from there because of event horizon that’s why according to optics we can’t see black hole.
Why it does weighs so much
Because it gets denser and denser and contracted during it collapse mass gets bigger and bigger and bigger, and when size becomes small and density becomes immense, the mass scale goes up according to mechanics.
The pure answer of Black Hole is yet packed in that Black Hole, but for physics it is really important to draw those facts to understand universe.