Most common axiomatic geometry is Desarguian. Its projective. https://www.encyclopediaofmath.org/index.php/Desargues_assumption https://www.encyclopediaofmath.

Most common axiomatic geometry is Desarguian. Its projective. https://www.encyclopediaofmath.org/index.php/Desargues_assumption https://www.encyclopediaofmath.org/index.php/Desargues_assum... When light is bent while passing by a huge mass, this axiom fails so does the geometry.