Lecture 4

In lecture 4, we complete our discussion of the Penrose process and frame the laws of Black Hole Thermodynamics. The rest of the lecture is an overview of what happens when we add quantum mechanics. We will review the old information paradox, which is a simple question of reversibility, and can be resolved rather easily. Then, we sketch more modern versions of the information paradox which are more subtle and may require us to accept that degrees of freedom in quantum gravity are (1) not exactly local and (2) state-dependent.

We will cover these topics in greater detail in the next 5 lectures.