Quantum geometrodynamics: whence, whither?

Understand

Quantum geometrodynamics is canonical quantum gravity with the three-metric as the configuration variable.

• Its central equation is the Wheeler--DeWitt equation.
• Here I give an overview of the status of this approach.
• The issues discussed include the problem of time, the relation to the covariant theory, the semiclassical approximation as well as applications to black holes and cosmology.