"Look for hard cut-offs to detect system limits Tyson argues that if you are inside a simulation or a programmed universe, you would eventually bump into artificial ceilings — places where physical constants stop smoothly tapering and instead abruptly cut off. He uses cosmic ray energy distributions as a real example: "Suppose you get to a point where there's a cutoff and it doesn't sort of blend into nothingness — that could be the upper energy limit of the programmer." Applying this thinking more broadly, whenever a system shows a suspiciously sharp boundary instead of a gradual fade, it is worth asking whether you have hit a structural constraint rather than a natural one. Source: Neil deGrasse Tyson, StarTalk, Cosmic Queries Episode"