# Hawking Radiation Explained

Electromagnetic radiation which, according to theory, should be emitted by a black hole. The radiation is due to the black hole capturing one of a particle-antiparticle pair created spontaneously near to the event horizon.

Back in 1974, Stephen Hawking proposed
and predicted that there is a radiation emitted by black holes. In
honour of the physicist Mr.Stephen hawking, this was known as The
Hawking Radiation.

It started in 1973, when Hawking visited
Moscow where he met soviet scientist Yakov Zeldovich and Alexei
Starobinsky who showed him that according to theory of quantum
mechanics, Black holes should emit particles and radiation. In 1974, he
then predicted the radiation.

This phenomenon happens incredibly slowly at first and gets faster as the black hole becomes smaller and then in the last moments it radiates away with the energy f billions of nuclear bombs in a huge explosion. It also seems like black hole getting evaporated.

This is not yet confirmed because the
black holes we know suck in huge amount of gases and mass, such that its
radiation swamp this little effect. Hawking said that if the black hole
has mass say M, then it will glow like a blackbody of temperature 6 x
10^-8/M kelvins . This tells us that it is significant for small black
holes.

This process is incredibly slow, the total age of the black hole of M solar masses is 10^71 M^3 . This means that when the last black hole will get evaporated, no one would be around to witness it. The universe would have become uninhabitable long before then.

### Black hole information paradox

Soon after the prediction of this theory, it was realised that this created an information loss problem.

In 1973, John wheeler proposed the idea
of “bald blackholes or no hair blackholes”. He said that black holes
could only be distinguished by the externally visible parameters i.e by
its mass, electric charge and angular momentum. And does not depend upon
the type of information absorbed or lost in the black hole. For example
if two black holes have identical visible parameters they are
indistinguishable irrespective of the matter it is made of, it may
happen that one is made up of matter and another is made up of
antimatter. Hawking always remained against this ‘no hair theorem’ .

### Possible Solution Proposed by Hawking

In January, this year Hawking published a paper
online which is alleged to give a possible solution to the information
loss paradox of hawking radiation. In this paper, Hawking said that when
the particles are absorbed inside the black hole they leave behind the
information associated to the particle in form of two-dimensional
holographic imprint on the event horizon. So when the particles which
escapes the black hole during hawking radiation pick up the imprint from
the event horizon and bring it back to the universe. But this solution
is highly controversial and is already the centre of many discussions
all over the world. Till scientists find the perfect solution to this ,
you sitback and keep reading at Scienceaholic.com .

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