In another thread it was said: (my bold) In Rindler coordinates a "Rindler horizon" forms at a fixed distance below the Rindler observer (accelerating uniformly "vertically upwards" and Born-rigidly in flat spacetime, in the absence of gravity). This horizon has many of the properties of a Schwarzchild horizon around a black hole: a free-falling object takes infinite coordinate time to drop to it, nothing (not even light) passes vertically upward through the horizon, the coordinate speed of light at the horizon is zero, and so on. Yet, it can't be claimed (can it?) that the Rindler horizon "is an objective physical truth that all coordinate systems agree on" because in Minkowski coordinates nothing unusual happens at all. Now I guess this may depend on precisely how you define what an "event horizon" actually is. Maybe the Rindler horizon doesn't count as an event horizon under some definitions. So, is an event horizon an artefact of a coordinate chart?