Do Black Holes Emit Radiation - 1

We all know that black holes suck every thing even light inside it but according to quantum mechanics, they emit radiation at finite rates. But how is this possible? Does it mean that the radiated particles are fast enough to get away from the gravity of black hole? Today, we will look at the answers of some of these questions.

   Stephen Hawking was the pioneer in the topics related to black hole and time. He also worked with another well-known scientist, Roger Penrose. Back in 1970's there was no particular definition of black holes. Therefore, Stephen and Roger worked out a definition that stated that, "A set of events from which it was not possible to escape to a large distance". This is now the generally accepted definition. It means that the event horizon is formed by the light rays that just fail to escape from the black hole and are now hovering just on the edge.

     The thing to note is that he path of the light rays on the event horizon could never approach one another because if they did, they must eventually run into one another. therefore, if two light rays coming down from the opposite direction than they would after colliding with one another lay still and therefore their speed would be zero and therefore, they would be sucked inside that black hole. Therefore, it must be absolute necessary that these light rays should always be moving parallel from one another or be moving away from each other.

  
   Another thing to be noted is that the event horizon can increase with time t but it should never decrease in size because that would mean that some of the light rays merged with each other. This nondecreasing property of the event horizon's area placed an important restriction on the possible behaviour of black holes.


Note :- "Do Black Holes Emit Radiation - 2" will be published soon today.