A Brief History Of Time: Journal Entry 7

Chapter 7 (Pg 103-117) Today, I started a new chapter that starts with Stephan Hawking talking about how he first got into studying and researching black holes. Then he talks about how light rays can never escape the event horizon and that lies right on the edge of it. Then he talks about entropy, the behavior of a physical quantity, and second law of thermodynamics. He mentions how Jacob Bekenstein suggested that the area of the event horizon was a measure of entropy of the black hole. He talks about how Jacob’s suggestion doesn't violate the second law of thermodynamics, but he noticed a fatal flaw in which that if a black hole has entropy, it must have a temperature. Today, I read about if and how rotating black holes can create and emit particles. Then he talks about how one part of a particle/antiparticle pair will have positive energy while the other will have negative energy. Today I learned that once a black hole’s mass gets incredulously small it disappears in a final burst of emission, the production and discharge of something, especially gas or radiation. It’s said that the gamma rays of a black hole is very useful to the earth since it can power more than 5 power stations. Then he says that once the black hole gets small due to a decreasing mass, it becomes white hot, proving that black holes aren't really black!