BY FRANK A. WILCZEK
School of Natural Science
Institute for Advanced Study
" The construction of a theory that simultaneously incorporates both Einstein's gravitational dynamics of space-time and quantum mechanics has been for some time a major goal of theoretical physics. Severe conceptual and practical problems must be faced, in any such construction. Recently, new insights have emerged from studying the problem in a smaller number of dimensions. Two significant papers report results from studies of this kind.
S. Carlip, "Exact quantum scattering in 2+1 dimensional gravity," Nuclear Physics B, 324, 106-22, 18 September 1989. (Institute for Advanced Study, Princeton, NJ.)
J. Polchinski, "A two-dimensional model for quantum gravity," Nuclear Physics B, 324, 123-40, 18 September 1989. (University of Texas, Austin)
" The most ambitious and compelling attempt to address the problems of quantum gravity is superstring theory. A simple nontechnical account of the...