RQM may not end in an I, but it is still an interptetation.
What the I in MWI means is that it is an interpretation, not a theory, and therefore neither offers new mathematical apparatus, nor testable predictions.
and finally we reject the idea that these observer-dependent representations can be combined to one global representation.
Not exactly, RQM objects to observer independent state. You can have global state, providing it is from the perspective of a Test Observer, and you can presumably stitch multiple maps into such a picture.
Or perhaps you mean that if you could write state in a manifestly basis-free way, you would no longer need to insist on an observer? I’m not sure. A lot of people are concerned about the apparent disappearance of the world in RQM.
There seems to be a realistic and a non realistic version of RQM. Rovellis version was not realistic, but some have added an ontology of relations.
In other words, where should we begin searching for maps of a territory containing observers that make accurate maps with QM that cannot be combined to a global map?
its more of a should not than a cannot.
2) What experiment could we do to distinguish between RQM and for example MWI?
Well, we can’t distinguish between MWI and CI, either.
Just because something is called an ‘interpretation’ does not mean it doesn’t have testable predictions. For example, macroscopic superposition discerns between CI and MWI (although CI keeps changing its definition of ‘macroscopic’).
I notice that I am getting confused again. Is RQM trying to say that reality via some unknown process the universe produces results to measurements, and we use wavefunctions as something like an interpolation tool to account for those observations, but different observations lead to different inferences and hence to different wavefunctions?
There is nothing in Copenhagen that forbids macroscopic superposition. The experimental results of macroscopic superposition in SQUIDs are usually calculated in terms of copenhagen (as are almost all experimental results).
That’s mainly because Copenhagen never specified macrsoscopic …but the idea of an unequivocal “cut” was at the back of a lot of copenhagenists minds, and it has been eaten away by various things over the years.
So there are obviously a lot of different things you could mean by “Copenhagen” or “in the back of a lot of copenhagenist minds” but the way it’s usually used by physicists nowadays is to mean “the Von Neumann axioms” because that is what is in 90+% of the textbooks.
Physicists are trained to understand things in terms of mathematical formalisms and experimental results, but that falls over when dealing with interpretation. Interpretations canot be settled empirically, by definition,, and formulae are not self interpreting.
For some values of “wavefunction”, you are going to have different observers writing different wavefunctions just because they are using different bases...that’s a practical issue that’s still true if you believe in, but cannot access, theOne True Basis, like a many worlder.
RQM may not end in an I, but it is still an interptetation.
What the I in MWI means is that it is an interpretation, not a theory, and therefore neither offers new mathematical apparatus, nor testable predictions.
Not exactly, RQM objects to observer independent state. You can have global state, providing it is from the perspective of a Test Observer, and you can presumably stitch multiple maps into such a picture.
Or perhaps you mean that if you could write state in a manifestly basis-free way, you would no longer need to insist on an observer? I’m not sure. A lot of people are concerned about the apparent disappearance of the world in RQM. There seems to be a realistic and a non realistic version of RQM. Rovellis version was not realistic, but some have added an ontology of relations.
its more of a should not than a cannot.
Well, we can’t distinguish between MWI and CI, either.
Just because something is called an ‘interpretation’ does not mean it doesn’t have testable predictions. For example, macroscopic superposition discerns between CI and MWI (although CI keeps changing its definition of ‘macroscopic’).
I notice that I am getting confused again. Is RQM trying to say that reality via some unknown process the universe produces results to measurements, and we use wavefunctions as something like an interpolation tool to account for those observations, but different observations lead to different inferences and hence to different wavefunctions?
There is nothing in Copenhagen that forbids macroscopic superposition. The experimental results of macroscopic superposition in SQUIDs are usually calculated in terms of copenhagen (as are almost all experimental results).
That’s mainly because Copenhagen never specified macrsoscopic …but the idea of an unequivocal “cut” was at the back of a lot of copenhagenists minds, and it has been eaten away by various things over the years.
So there are obviously a lot of different things you could mean by “Copenhagen” or “in the back of a lot of copenhagenist minds” but the way it’s usually used by physicists nowadays is to mean “the Von Neumann axioms” because that is what is in 90+% of the textbooks.
The von Neumann axioms aren’t self interpreting .
Physicists are trained to understand things in terms of mathematical formalisms and experimental results, but that falls over when dealing with interpretation. Interpretations canot be settled empirically, by definition,, and formulae are not self interpreting.
My point was only that nothing in the axioms prevents macroscopic superposition.
For some values of “wavefunction”, you are going to have different observers writing different wavefunctions just because they are using different bases...that’s a practical issue that’s still true if you believe in, but cannot access, theOne True Basis, like a many worlder.