Abstract
Physics rests on a small list of postulates — Newton’s gravitational constant G, the cosmological constant
Λ, the Born rule, the Tsirelson bound, Heisenberg’s uncertainty, the collapse of the wavefunction,
the arrow of time — that have resisted derivation for decades. Event Density (ED) is a substratebased
ontology in which these postulates are not free assumptions but consequences of an underlying
architecture: a network of discrete events that update one at a time, irreversibly, with each commitment
constrained by the commitments before it. This paper introduces ED’s primitives, explains why
the smooth four‑dimensional manifold of standard physics is a coarse‑grained appearance rather than
a foundation, and derives or reframes seven of the deepest postulates of modern physics from the substrate’s
structure. The result is a single architectural claim with multiple consequences: the manifold
is the surface; the substrate is what lies beneath.