IS THERE A MINIMUM LENGTH IN D = 4 LATTICE QUANTUM-GRAVITY

It is argued that, as in string theory, a minimum length exists in D = 4 quantum gravity. The argument is based on a (naive) lattice regularization of tetrad gravity, where it appears that any formal reduction of the lattice spacing epsilon = x(n+1) - x(n) is countered by an increase in metric fluctuations. In D = 4 dimensions, these fluctuations prevent the average physical separation between neighboring lattice points from falling below a certain minimum, which is on the order of the Planck length.