Umwelt

Every organism, and every apparatus, builds its world from what its own sensors register. The tick's world is three cues; a proximity sensor's is one number, and nothing else exists for it. Two systems in the same physical space can inhabit almost non-overlapping worlds. This names a limit on sorting prior to any question of the sorter wearing out: a system cannot fail to register what it has no organ for — which is the structural answer to where is noise located.