Narrow Results

It is well known that black holes are the most extreme objects in nature: they have the maximal energy and entropy capacities allowed by the laws of physics. In this essay we reveal another extreme property of these fascinating objects: black holes have the fastest relaxation dynamics allowed by a quantum theory of gravity. From information theory and thermodynamic considerations a universal bound on the relaxation time τ of a perturbed physical system is inferred, τ ≥ ħ/πT, where T is the system's temperature. We then show that black holes may actually attain this fundamental bound, which makes them the fastest-relaxing objects in the universe.

It is well known that one could determine the kinematics of gravity by using the Principle of Equivalence and local inertial frames. I describe how the dynamics of gravity can be similarly understood by suitable thought experiments in a local Rindler frame. This approach puts in proper context several unexplained features of gravity and describes the dynamics of space–time in a broader setting than in Einstein's theory.