Observer-Equivariance: Objectivity as Invariance Under Perspective Change
Observer-Equivariance: Objectivity as Invariance Under Perspective Change By Gustaf Ullman Modern physics is saturated with perspective-laden structure: reference frames, gauges, coordinate charts, foliations, clock choices, operational access, and observer-dependent decompositions. Yet the usual philosophical picture of “objectivity” is often described as if objectivity were achieved by removing perspective. This is not how physics actually works. The guiding idea of Observer-Equivariance (OE) is simple to state: physical objectivity is not the absence of perspective but invariance (or descent) under permitted changes of perspective . OE makes explicit what is tacit in ordinary practice: the formalism of physics already binds a perspective variable. Contents 1. The core idea 2. The span: Phenomenology, perspectives, structure 3. The Quinean diagnosis: the silent bound variable 4. Monad and time:...