Technically any object whose radius is smaller than its Schwarzschild Radius is called a "Black Hole" and Every galaxy has a super massive black hole at the center of it, The closest super massive black hole to Earth is about 27000 light year away in the center of our galaxy. It's name is " Sagittarius A* " (Coordinates: RA 1h 11m 3s | Dec -29° 0′ 28″) ..... when a star runs out of fuel and it can no longer keep itself hot enough, it collapse to a single ,smallest point, which known as a "Singularity" . And it's outer surface generally called the "Event horizon", this is a place between Singularity & Space . According to Professor Kip Thorne (California Institute of Technology)-"Event Horizon is not made of matter, it's just a unique location, where gravity is become so strong and just inside them that nothing can escape".Because a black hole is an object which escape velocity is more then the speed of light if we wanna make a black hole we must have the any mass equal or above to Planck Mass, because smallest mass of a black hole is approximately the Planck Mass. simply we can say that when a star dies, it become a Gravitational Ghost, called "The Black Hole". A Black hole not actually a hole and it doesn't suck anything, because suction is caused by pulling something into a vacuum. According to the NASA scientists a black hole is a place where Gravity pulls so much that even light can't get out, So we can't able to see a black hole. According to the Einstein's theory of General Relativity, Space-time fabric is like a rubber sheet not a solid surface and Gravitational Field bends the space-time fabric.But, In my opinion, Our sensory existence is limited to the three dimensions that's why space-time is almost impossible to inspect or observe and a black hole is actually an absence of space-time because according to the Einstein theory, gravity causes displacement of space-time..! so absence of space time must be pure gravity.This enormous gravity of black hole is due to the density of it. because matter has been squeezed into a tiny space. In this sense when light comes behind a black hole then it's outstandingly distorted this effect called "Gravitational Lensing"
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"Gravitational Lensing" |
Mainly there are three type of black holes on the basis of there size :-
- The first type is a tiny one it may be as small as just one atom, called "Primordial Black Hole" or "PBH" for short. They have extremely small Schwarzschild Radius and its density at the size would be so high. Therefore scientists say that they born in the beginning of our universe(During BIG BANG) when the density was extremely high.
- The second one is called "Stellar Black Hole" or "SBH", Which have about 20 times of solar mass. They have about 1018 kg/m3 of density and they are much bigger then a PBH. That's why they have bigger Schwarzschild Radius and less density then a PBH. They born when a star die or two neutron star collides.
- The third one is called "The Super Massive Black Hole " or "SMBH" these type of black holes are the largest black holes. It have mass about one million times of solar mass but comparatively they have lower density and high Schwarzschild Radius then SBH. They lurk in the heart of galaxies. For example :- "Galaxy NGC4889" have a SMBH in the center of it..... which have up to 21 billion of solar mass.
and some other types of black hole are; Charged Black Holes, Virtual Black Holes, Kugelblits Black Hole, Naked Singularity, Spinning Black Holes & Non-spinning Black Holes.
- Charged Black Holes:- As the name gives information about it. A charged black hole have enormous amount of electric charge. They have two Horizon (1). Event Horizon. (2). Couchy Horizon.
- Virtual Black Hole :- These black holes are temporary. And they born as a fluctuation of quantum space time.
- Kugelblits Black Hole :- A Kugelblits Black Hole created by the collapsing of photons and this is the hottest thing in the universe.
- Naked Singularity :-This is a Gravitational singularity without an Event Horizon and technically it is observable.
- Spinning or Rotating Black Hole:-They also known as "Kerr black hole". We know that singularity is a infinite small point of a black hole, with no surface area.
A Spinning Black Hole Spinning Black Hole's Diagram
According to the Ricci Scalar (Scalar curvature) The curvature of the inner horizon is always negative throughout poles. But the curvature of Outer Horizon at the poles is negative but curvature of the equator is positive. It is assumed Spinning black hole transfers it's own kinetic energy in the form of rotation. So when we give some mass energy, it gives us some rotational energy. . To understand this concept let's take a example, When an object enters in a whirlpool, so the whirlpool pulls it inside it....... but not directly, it is sucked through spinning water current ,in this rotating area water current pulls that thing towards the water's direction. On the basis of this fact "Roger Penrose" theorized a creepy mechanism to extract this Rotational energy from a Spinning Black Hole, called "Penrose Mechanism". And another important theory is "Blandford-Znajek Process" , Theorized by "Roger Blandford" and "Roman Znajek" in 1977, in this process the concept of Horizon surface is replaced with the concept of Electromagnetic Active medium. - Non-Spinning or Non-Rotating Black Hole :-They also known as a Stationary Black Hole or Schwarzschild Black Hole. They would have to be created with material, having no angular momentum. But Non Rotating Black Hole are not likely to actually happen. In my opinion may be these are also rotate with a negligible speed of momentum or almost zero angular momentum.
Recently, two neutron star collided 130 million years ago and this greatest event was detected by LIGO-VIRGO. this observation done on August 17 , 2017 at 08:11 AM even this is a solid proof of a kilonova, A precious metal which can make Earth's of gold silver platinum ...etc. LIGO data revealed that the object created by the neutron-star merger is about 2.7 times the mass of the sun. It is therefore either the lowest-mass black hole ever identified. This video is first LIGO/Virgo detection of a binary neutron star merger (GW170817).
WHAT HAPPENS WHEN SOMETHING FALL IN A BLACK HOLE:-
Imagine when a person or for example my friend "Junaid Ahmed" wanna go to the another galaxy but he accidentally get closer to the black hole's gravitational area he get sucked into it with the speed of light instead, he experience his further journey become...slower, slower and slower until he reach the event horizon. During this he would look as if the black hole diminishingly away from him, Because his field of view would highly increased, in this sense..... Junaid would able to see almost everything behind him and suddenly he would see the black hole just front of his eyes. After that he become increasingly red shifted. After it the closer he get to the singularity the more power of gravity he experience ,this effect called "Tidal Force" and which body part are closer to the black hole, would be pulled more strongly to the singularity in this consequence the entire body of my friend would be stretched towards the singularity this process known as "Spatighittification". During Spatighittification effect which caused by tidal force every molecule of the body would be stretched until they torn apart. During this my friend who is almost 6 feet guy, become 600 feet or may be more taller for a moment.
WHEN TWO BLACK HOLES COLLIDE :-
The Galaxy NGC 6240 has two super massive black holes at the center of it. Scientists believe that one day these black holes may very well collide with each other.
the collision of two black holes is such a rare and the disastrous event. there's basically two possible results.which possibility depends on the speed at which the two black holes are traveling. If the two black holes are spinning at extremely high speed and come together at just the right angle, the smaller black hole will be catapulted away from the bigger black hole. But the second one is more likely outcome is that they will slowly come closer and closer together, until they become collapsed. this scenario would be incredible. After that the resulting black hole is known as a "Binary Black Hole". as the two black hole start to merge they would appear to be distorted mass of matter. But as they come closer together the resulting black holes through a process known as "Ring-Down".this is when any distortion in the shape is slowly deformed and the new binary black holes becomes more circular. until any asymmetry is lost and the black hole, become larger then ever before. The energy emitted from the collision would be incredible..... it would spread ripples through the space-time fabric of the universe. these ripples are are known as "Gravitational Waves".
Check this out; GW170814
Two Black Holes Colliding Signals detected by LIGO
THE WORMHOLE:-
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In 2006
Iranian Physicist "Mohd. Mansouryar" was claimed to that he creates a nano sized wormhole and his theoretical wormhole would exist on Planck scale and he believe, He could build a ring of several of them with the space in between collapsing and forming a larger wormhole. But for the creation of this we required The "Exotic Matter" which have the negative mass. Because positive mass is attractive because of gravity but negative mass would be repulsive, and it's make a kind of anti-gravity . Because experts thinks that The Exotic Matter must deploy extreme pressure to neutralize the gravitational force and push space-time open, in another words this kind of matter use to stabilize the wormhole.
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Mohd. Mansouryar |
THE WHITE HOLE:-
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A White Hole |
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