The author thanks Abilio De Freitas, Aaron Grant, David Dunbar,
David Kosower, Maxim Perelstein, Joel Rozowsky, Henry Wong, and
especially Lance Dixon for collaboration on work described here
and for sharing their insight into quantum gravity. The author
also thanks Eduardo Guendelman for a number of interesting
discussions on the Einstein-Hilbert action and its relation to
gauge theory. This work was supported by the US Department of
Energy under grant DE-FG03-91ER40662.
