Quantum gravity is the field of theoretical physics attempting to unify the subjects of
Quantum mechanics and
General relativity, which in their current formulations are mutually incompatible. Such a theory is required in order to understand those problems involving the combination of very large mass or energy and very small dimensions of space, such as the behaviour of
black holes, and the
origin of the universe.
There are a number of proposed quantum gravity theories and proto-theories, including (for example) string theory and the [loop quantum gravity]? of Smolin and Rovelli - see http://www.livingreviews.org/Articles/Volume1/1998-1rovelli/
The famous spoof of postmodernism by Alan Sokal (see Sokal Affair) was entitled "Transgressing the Boundaries: Toward a Transformative Hermeneutics of Quantum Gravity".