>[!abstract] >In special and general relativity, a light cone (or "null cone") is the path that a flash of light, emanating from a single event (localized to a single point in space and a single moment in time) and traveling in all directions, would take through spacetime (Wikipedia, 2025). >[!related] >- **North** (upstream): — >- **West** (similar): [[Adjacent possible]] >- **East** (different): — >- **South** (downstream): [[Causality]]