Trying to understand what members of the forum feel about the correctness and completeness of existing relativity theory. Are there sufficient grounds to consider that existing relativity theory, as formulated by Einstein, is the best possible description of the real Universe we live in (making allowances for minor uncertainty)? Or is there significant doubt about that? Two guiding thoughts on this which I have seen in this forum and outside: - Quantum theory and GR are yet to be reconclied. Both are great theories well accepted by scientists and able to make good predictions, but there still isn't a generally accepted 'quantum theory of gravity' - There are many opinions but little concensus among experts, esp. in SR, about the resolution of paradoxes and explanations of experimental observations A relevant quote by Einstein [The Meaning of Relativity, 6th Ed, 1955]: "In my opinion the theory presented here is the logically simplest relativistic field theory which is at all possible. But this does not mean that nature might not obey a more complex field theory. More complex field theories have frequently been proposed... In my view, such more complicated systems and their combinations should be considered only if there exist physical-empirical reasons to do so." My question is, with 50+ years of experiments and observations since the above statement, are there enough reasons to do so?