Topics of discussion will include: 

1. The conceptual difference between a discrete approximation to a continuum and a continuum approximation to a discrete entity. 

2. A dual conjecture that a combinatorial simplicial complex cannot be approximated by a  Lorentzian manifold,  whereas a combinatorial simplicial complex can be approximated by a Riemannian manifold. 

3. A review of the Kronheimer-Penrose-Hawking-Malament Theorem  that the causal order of a 4-d distinguishing Lorentzian manifold contains 9/10 of the geometry. Its implications for discrete Lorentzian Geometry and the Causal Set (aka Discrete Order) Hypothesis.  

4. A random discrete Ricci scalar curvature estimator for Lorentzian manifolds: evidence that it works well in the low curvature regime and reasons to doubt that it works well outside that regime due to the essential nonlocality of Lorentzian geometry. 

5. A Lorentzian version of the Erdos-Renyi random graph as a toy model of dynamics for a discrete Lorentzian geometry.