Suppose there is some piece of information that you want to erase from the entire universe compeletely.For example, let's say it's your answer sheet where you've scored a D grade.You don't want to hear a big lecture from parents, you don't want to feel embarassed or let's just say you don't want it to exist.You could burn,shred ,scribble and crush it.Or, for that matter, you could even send it to some other galaxy! ....But, will it still be compeletely erased?No...This is something just like virtual data stored in a computer,the data won't simply dissapear if you deleted it from the recycle bin.Well,what do you do now?....After a lot of thinking and reseach you decide to send it into a black hole.From where,it will never return and be destroyed compeletely..Well,Really?
The pull of gravity inside a black hole is really strong.Noone can fetch that test paper from the inside of a black hole.Not even your teacher.Because for that,it has to be faster than the speed of light as even light can not escape from the gravitational pull.But, as per Einstein, nothing can travel faster than the speed of light.Now, you might be glad.But...Quantum mechanics holds a law of conservation of information which says that in this universe,information can neither be destroyed,nor created.
One might say that the information inside a blackhole isn't destroyed, but lost.This was what all scientists believed until 1975, when stephen Hawking said that, black holes dematerialize with respect to time.This process is also called the 'Hawking Radiation'.Now, the radiations a black hole will emitt during dematerialization will be felt as a normal radiation will.But what if this evapration isn't compelete and leaves behind small embers?Even the smallest of the embers would have a remarkably huge amount of information stored which has been concentrated.What if we could encode this information at the lip of the event horizon?Does that mean all of our information exists inside the black hole in the form of radiations?Just like a hologram?
For now,what I'll suggest is,it looks much easier to show your parents that answer paper and simply work hard for the next time!
The Black hole information paradox gives rise to many hidden puzzles.You may read more about it.
The nature of Reality , Nova, Hawking evaporation, pbs.org