Slide 13 of 13
So clearly our laws of physics are breaking down. I already said this happens at the
center of a black hole, so why is this more of a problem? As long as the "tear in the
fabric of spacetime" was hidden below the event horizon of a black hole, it did not
ruin the predictability of things that went on outside. However, now we have a breakdown of predictibility, a loss of information, that essentially affects the rest of the
universe. Moreover, the problem is not occurring at absurdly high temperatures and
pressures that exist at the center of the black hole. Its source is just outside the horizon,
and has to do with the interplay between macroscopic physics, and the microscopic
processes that cause the evaporation. Thus the laws of physics are breaking down
a lot sooner than we had any right to expect.
To resolve this problem we have to understand this evaporation process, and
ultimately, we need to understand how gravity and quantum mechanics are to
be unified into a single theory. The strange behaviour of black holes is providing us with value clues that will ultimately lead us to the Holy Grail of theoretical physics: a correct and consistent unification of gravity with the other interactions.