General Principle of Relativity (GPoR)
The General Principle of Relativity ("GPoR") is that the principle of relativity does not just apply to simple inertial motion, but applies generally, to all situations, including those involving physical acceleration or rotation.
The GPoR is the central principle of a general theory of relativity.
... under GR1916
- Einstein's 1916 theory was designed to be an implementation of the GPoR. However, as an implementational detail, Einstein also had the theory incorporate and reduce to special relativity. T
- In 1950, Einstein expressed misgivings as to whether the explicit incorporation of SR had been justifiable, and in 1960 it was realised by the community that SR and the GPoR were actually incompatible, making GR1916 logically invalid.
... under GR1960
- The community's response to the 1960 crisis was to reason that that if the GPoR was wrong we lost the basis of GR1916, but if SR was wrong, we lost the 1916 theory and the 1905 theory, wiping out almost all popular mainstream research into relativity theory that had been done during the previous fifty years and leaving us with a theoretical void, and no obvious schedule for how long it would take to write a replacement. Faced with this choice, the community decided that special relativity couldl not be allowed to be wrong, and made SR-compliance a prerequisite for any gravitational model that wanted to be considered viable.
... under "advanced GR"
- Under advanced general relativity, the central principle of the GPoR is restored, and inertial physics is redesigned to be GPoR-compatible. This involves replacing the special theory with a more geometrically advanced system that embraces curved spacetime principles – a relativistic acoustic metric. Since GR1960's SR component seems to be the core reason why GR1960 conflicts with QM, a bonus of restoring the GPoR is that using an "acoustic" general theory then appears also to be compatible with quantum mechanics.