What if a simulated universe advanced only when something actually happened? This episode explores Cortex, a deterministic world engine that replaces the global simulation tick with explicit cause. We trace its clockless local time, transactional state changes, compact geometric memory, exact replay, and version-gated bridge to real-world hardware. From planetary open worlds and multiscale physics to robotics, operating systems, and connectome-based neural networks, Cortex proposes one foundation where physics, persistence, and learning become different expressions of retained causal history.