142 The Quantum Structure of Space and Time
compactifications are an attempt, but so far they, and other things, have not
really succeeded.
L. Randall I agree very much with the first part of the comments. I am surprised
at the second part. Actually I thought what, was surprising about this, is how
narrowly defined this discussion is, in the sense that we are looking at the kind
of things we know how to deal with mathematically at this point, namely things
based on supersymmetric structures or even compactification. It seems to me
that, before one starts restricting, one would want to make sure that we have
actually covered the entire true landscape of what is possible.
H. Ooguri The second part of the program is about new geometrical structure that
appears. Since string theory contains gravity, geometry has naturally played an
important rde. We expect that we learn more about geometrical structure from
string theory. We first hear from Nekrasov about new applications of geometric
ideas to physics.
