Observer (special Relativity) - "Observer" As A Form of Relative Coordinates

"Observer" As A Form of Relative Coordinates

Egocentric direction or relative direction is a concept found in many human languages. In English, a description of the spatial location of an object may use terms such as "left" and "right" which are relative to the speaker or relative to a particular object or perspective (e.g. "to your left, as you are facing the front door.")

The degree to which such a description is subjective is rather subtle. See the Ozma Problem for an illustration of this.

Some impersonal examples of relative direction in language are the nautical terms bow, aft, port, and starboard. These are relative, egocentric-type spatial terms but they do not involve an ego: there is a bow, an aft, a port, and a starboard to a ship even when no one is aboard.

Special relativity statements involving an "observer" are in some measure articulating a similar kind of impersonal relative direction. An "observer" is a perspective in that it is a context from which events in other inertial reference frames are evaluated but it is not the sort of perspective that a single particular person would have: it is not localized and it is not associated with a particular point in space, but rather with an entire inertial reference frame that may exist anywhere in the universe (given certain lengthy mathematical specifications and caveats.)