Is the statement "Claims demand evidence" always true?

[bennyboy]

Yes, and I've read that even sets of macro objects, like say a few quadrillion office chairs, if treated properly, will also do so, though of that I'm pretty dubious.

I'd love an attribution on that.  That other elementary particles, atoms and molecules present themselves as-such has been experimentally demonstrated...but I'm not aware of any experiment to that effect involving office chairs.  Would be interesting to see how they draw the conclusion, at least.  

I wish I could remember. I think it was in an introductory video on QM, specifically the ones where you check your detector AFTER the photon has already passed the slit, with the result that detecting spookily affects the resultant interference pattern anyway. Super spooky, amirite?

I can't find the thing about chairs (it might have been another mundane object tbh), but here's an interesting article where they used molecules with 5000 each of neutrons, protons and electrons:

https://medium.com/the-physics-arxiv-blo....xwikveurq

and in that source I found (though not explained):

According to quantum mechanics, wave-particle duality and quantum superpositions must also occur for macroscopic objects such as viruses, cells and even baseballs larger objects.

I don't have a problem with it, because I view truth values in this case context-dependent.

You just said it didn't make sense to you.  I'd call that a problem.  I'm suggesting that you've invented a dubious solution for a non-existent problem.   

I think the way I wrote the dual-nature with the '<->' appeared confusing. I didn't mean that ambiguities in QM don't make sense to me, but that defining QM particles outsude of some observational context (i.e. an all-inclusive objective "truth") didn't make sense to me. But I can see now that that wasn't expressed very clearly.

I've often argued against science, at least as described by materlialists like you.  But in this case, I'd say that many of the new contexts through which we view our experiences, could only come about through scientific theorization and experimentation.  While duality/ambiguity have been around for thousands of years, science has really given us tools to play with them.

Indeed it has, some of those tools may speak to the things that don't make sense to you.  Bohmian mechanics, for example, doesn't require a "truth-in-context" workaround to the issue that vexes you.  It has the benefits of predicting everything that the models which -do- see paradox predict, but also of handling things which completely baffle other interpretations.  This isn't to say it's without objections (or even remotely true).  One common objection is that it's merely the same model, supplied with an ontology....but..given your previous statements, ontology is -precisely- what you seem to be wondering about.

There's no conceivable real-world framework that is conceivable at least to me in which you could say, "The buck stops here. For sure there's no other framework, no greater context of which all this is a subset, and which must be accounted for in determining that some truths are actually global."