While it’s true geocentrism is a valid frame of reference a la Einstein, the whole point of relativity is that ANY frame of reference is just as valid as any other. The claim of the geocentrists is that Earth is THE frame of reference; that still doesn’t jive with relativity. And @Korinthian: you can model the solar system with Earth at the center, it’s just way WAY simpler to do it with the Sun at the center (including the fact that a geocentric solar system is a non-inertial frame of reference, i.e. physics becomes weird if you do it that way).