  This article provides a cartoon of the quantization of General Relativity
using the ideas of effective field theory. These ideas underpin the use of
General Relativity as a theory from which precise predictions are possible,
since they show why quantum corrections to standard classical calculations are
small. Quantum corrections can be computed controllably provided they are made
for the weakly-curved geometries associated with precision tests of General
Relativity, such as within the solar system or for binary pulsars. They also
bring gravity back into the mainstream of physics, by showing that its
quantization (at low energies) exactly parallels the quantization of other,
better understood, non-renormalizable field theories which arise elsewhere in
physics. Of course effective field theory techniques do not solve the
fundamental problems of quantum gravity discussed elsewhere in these pages, but
they do helpfully show that these problems are specific to applications on very
small distance scales. They also show why we may safely reject any proposals to
modify gravity at long distances if these involve low-energy problems (like
ghosts or instabilities), since such problems are unlikely to be removed by the
details of the ultimate understanding of gravity at microscopic scales.
