Blackhole radiation v Second Law

AI Thread Summary
Hawking radiation leads to black hole evaporation, raising questions about its compatibility with the second law of black hole dynamics, which states that the event horizon area cannot decrease. The discussion highlights that while the second law suggests a non-decreasing horizon area under the weak energy condition, Hawking's findings indicate that black holes can lose mass and area over time. Additionally, the size of the event horizon may vary depending on whether an observer is in free fall or static. The use of π for calculating spherical area in warped space is also questioned. Understanding these concepts may require knowledge of Killing Vectors and their implications in black hole thermodynamics.
ash99
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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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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This "law" was superseded by Hawking's discovery that black holes radiate, which causes both the black hole's mass and the area of its horizon to decrease over time.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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