2 I. INTRODUCTION The AdS/CFT correspondence has revolutionized how we think about strongly quantum field theories and quantum gravity [1]. Because of these discoveries, classical gravitational techniques can be used to produce non-trivial statements about strongly coupled field theo- ries. On the other hand, the manifest unitarity of the field theory seems to resolve (at least in principle), the information paradox related to the formation and evaporation of black holes [2]. Obviously, if the two sides are truly equivalent, we should ask that the quantum gravi- tational theory encode individual quanta and other phenomena that we associate to weakly coupled field theories. By the same token, we should be able to answer geometric questions posed in the gravity theory by studying the degrees of freedom of the quantum field theory directly. The usual AdS/CFT dictionary [3, 4] usually works as a black box: it permits us to compare calculations between the AdS and CFT setups, but it does not explain how the degrees of freedom of the field theory reorganize themselves as geometry. Nor does it tell us how geometry breaks down. What is needed is a theory of emergent geometry: a reason why higher dimensional geometry is the right answer for certain classes of questions. Solving the AdS/CFT correspondence requires doing this. The full answer to this question is still beyond what is currently known. However, a model that seem to capture some of these fea- tures is available [5] and can be used to explore the passage from a microscopic description of the degrees of freedom to collective degrees of freedom that represent geometry. Given a model of emergent geometry, one can then ask for the simplest geometric ques- tions, like what is the size of an object or geometric feature. This will be the main purpose of the present paper: to understand and explore how one can measure geometric properties of the dual spacetime directly in the quantum field theory. We will do this by Monte-Carlo simulations of a collection of minisuperspace wave functions in field theory, following the ideas presented in [6, 7]. Numerical methods to study gravity problems with a dual quan- tum mechanics have been advocated also in [8–14]. In particular these other studies try to match the black hole specific heat and perhaps even the radius of the horizon for a black hole made of D0 branes in ten dimensions. Those simulations use the full N × N matrix degrees of freedom in a Euclidean time formulation, so taking N large is problematic. Other approaches to study N = 4 SYM for large N numerically use clever truncations to matrix