We usually talk about R₀, the average number of people one sick person infects as if it belongs to the disease. Measles is "an R₀ of 15," COVID was "around 3," and so on.
But R₀ can't be a property of the pathogen alone. It's a property of the pathogen meeting a population. Change who's standing next to whom, and the same virus gets a different number.
Network epidemiology and spatial lattice models have been theoretically mature since the early 2000s.
Tools or custom agent-based models exist, but they are either
(a) expert-only
(b) mean-field approximations that hide the network, or (c) too computationally heavy for real-time play.
MemeLab runs a high-performance, deterministic cellular automata SEIRSD on a toroidal grid in the browser, crucially an analytical R₀ tied directly to the current topology.
Low to high urbanization produces an R₀ of 5-8.3, with an identical pathogen.
Switch to Voronoi → Settlements
slide Urbanization, and the model wires up realistic clustered cities on the fly.
The contact graph changes; R₀ updates instantly. No PhD, no supercomputer, no code. This is the first time the full power of contact networks has been made this accessible.
thememeticist.github.io/Meme…