Black Hole Information Paradox

Black Hole Information Paradox

Before 14 Sept 2015, There was a question mark on the existence of black holes because before that they only exist in our theories and some researchers believed that there is nothing like the black hole in Universe. 

But at 14 Sept 2015, Ligo first detected the gravitational waves and it is proved that the black holes are not imaginary, they exist in the universe. And now we know that black holes exist but we have not fully understood it, because of this we don't know how this universe actually works.

If we want to know how our universe actually works then we have to know that black holes works and that's the biggest reason why Physicists gave importance to it. 

Before 1974, Black holes are not considered to be paradoxical because then we know that black holes are such places in our universe in which gravitational forces are much stronger than any other region in our universe and even light couldn't escape through it.

It means if an object falls into event horizon then it could not be able to return back means the event horizon can easily enter into event horizon but could not be able to return back because of the strong gravitational force of black hole but the existence of the objects which falls into a black hole never ends.

In 1974,.Stephan Hawkings proved that black holes has its own temperature, which is inversely proportional to the mass of Blackhole. It means the if the mass of the black hole is high then its temperature is very low and they emit radiation's which are known as Hawking's Radiation.

Due to the continuous emission of radiations from a black hole, the black holes which have nothing to swallow become shorter and shorter by losing their mass and Finally, a stage came when it destroys or Evaporates which we call Blackhole Evaporation. And after the destruction of black hole nothing left which could tell us about Blackhole, The information within the black hole also lost.

This theory is perfect and proved itself in theoretically and Mathematically but it gives rise to a paradox known as Blackhole Information Paradox.

According to the law of nature, there are 2 laws which applicable everywhere in the Universe.

1. Quantum Determination: Given a present wave function its future changes are uniquely by the evolution operator.

2. Reversibility: The Evolution operator has an inverse, meaning that the past wave function is similarly unique.

 

Means every unique initial state ends up with every unique end, it doesn't happen that two initial state ends up on the same end. 

It means we can easily tell about the final state of any system by just looking at its initial state and vice verse.

It simply means that information never erased but it remains safe in Universe.

For eg. If we have a book in which something important is written and we burn it then it gets converted into ash which means we lost our information but if we assemble every particle of ash in a correct order we get information back which means information never lost but always remains safe in our universe. 

Every object has its own Unique Initial state and also its Unique final state. If we couldn't be able to tell any object final state by looking at its initial state, and its vice versa then there occurs paradox because it violates the law of Nature.

But it seems that black holes violate the law of nature because after evaporation there's nothing left but the Hawking Radiations which could not be able to give us any information about the black hole. And we could not get any information from it and it cannot be possible for us to tell about, "How the black hole is made and of which?" and It is a paradox.

In the Physics community, there was always a question which always rises up.

Do Black holes have Hair or not?

For eg. If two planets which appear to be same like they are copies of each other. And for this, they must have the same properties and composition at each point. But we know that could not be possible because every object in the universe has its unique property which makes it different from others and the property which makes every object different from each other is called Hair. 

But in the case of Blackhole, There are only 3 properties.

1. Mass 

2. Electric charge

3. Spin 

which means if these 3 properties of any black hole resemble with any other black hole then we can say is that they are copies of each other but for now it is only possible theoretically.

And the outcome of this question is that Blackholes have no hair.

We know that the things which are swallowed by black holes are Stars, and other objects and the information present inside these object is Mass, Size, Shape, Temperature, Color, Texture, Density, Spin, Composition, Pressure, Electric charge, Amplitude, Wavelength. 

but the information present inside the black hole is only in the form of Mass, Electric Charge, Spin.

which means other information lost somewhere and we cannot tell about the initial state of the black hole by looking at its final state and for now, this problem remains unsolved..........