  The search for a quantum theory of gravity has followed two parallel but
different paths. One aims at arriving at the final theory starting from a
priori assumptions as to its form and building it from the ground up. The other
tries to infer as much as possible about the unknown theory from the existing
ones and use our current knowledge to constrain the possibilities for the
quantum theory of gravity. Probably the biggest success of the second path has
been the results of black hole thermodynamics. The subject of this essay is a
new, highly promising such result, the application of quasinormal modes in
quantum gravity.
