Blackhole radiation v Second Law

In summary, the conversation discusses the concept of Hawking-Bernstein radiation causing a black hole to evaporate and the second law of black hole dynamics stating that the area of the event horizon cannot decrease. The question arises if this is a contradiction and if the size of the event horizon differs depending on the observer's state. There is also a mention of using PI to calculate the area of a black hole in heavily warped space and a request for help with Killing Vectors. The Wikipedia article on black hole thermodynamics is referenced for further information.
  • #1
ash99
1
0
Can someone help me on this: Hawking Bernstein radiation can cause a BH to evaporate. The second law of BH dynamics says that the area of the event horizon cannot decrease. Isn't this a contradiction? Also when considering the size of the event horizon, is it different depending on wheather one is in free fall or static. Finally is it ok to use PI to calculate spherical area in heavily warped space?
If the answers involve Killing Vectors, I'll need help with those as well.
 
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  • #2
The Second Law

The horizon area is, assuming the weak energy condition, a non-decreasing function of time,

This "law" was superseded by Hawking's discovery that black holes radiate, which causes both the black hole's mass and the area of its horizon to decrease over time.

Above from:

http://en.wikipedia.org/wiki/Black_hole_thermodynamics
 
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FAQ: Blackhole radiation v Second Law

1. What is blackhole radiation?

Blackhole radiation refers to the emission of energy and particles by a black hole. This phenomenon is predicted by the theory of quantum mechanics and is also known as Hawking radiation, named after the physicist who first proposed it.

2. How is blackhole radiation related to the Second Law of Thermodynamics?

The Second Law of Thermodynamics states that the total entropy of a closed system will always increase over time. Blackhole radiation is significant because it suggests that black holes are not entirely "black" and can emit radiation, which decreases their entropy and violates the Second Law.

3. How does blackhole radiation impact our understanding of black holes?

Blackhole radiation challenges our previous understanding of black holes as purely consuming entities with no means of emitting energy. It also raises questions about the ultimate fate of black holes and the possibility of their eventual evaporation.

4. Can blackhole radiation be observed?

Currently, we do not have the technology to directly observe blackhole radiation. However, there have been theoretical proposals to detect the radiation indirectly through its effects on the surrounding matter and energy.

5. What are the implications of blackhole radiation for the universe?

If blackhole radiation is confirmed, it would have significant implications for our understanding of the universe and its laws. It could also provide insights into the connection between quantum mechanics and gravity, which are currently two separate and incompatible theories.

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