[codethief]

I sympathize with your view a lot and it is, in some way, also the way I (degree in mathematical & theoretical physics) think about it.

Do note, however, that the wavefunction and its collapse are at odds with special relativity and thus cannot be an object of reality. (Provided you're interested in realism to begin with.) Take two entangled electrons, for instance, which get sent out from the origin 0 in opposite directions towards detectors A and B, respectively, which are placed at equal distance from 0.

Now take two observers, one moving in the direction from 0 to B and one moving in the opposite direction. Then, depending on which observer's POV you take, it is either detector A might makes the wavefunction of the two electrons collapse (because the electron 1 reaches detector A and interacts with it before electron 2 reaches detector B) in which case interaction of electron 2 and detector B doesn't do anything. Or, vice versa, it is detector B which makes the wavefunction collapse but then detector A doesn't do anything special.

Either way, if the collapse were actually something physical, both observers would have to agree on the causality chain of events. But they can't. In fact, varying the above setup a bit, they won't even in general agree on whether the wave function of a given system has or has not yet collapsed.

[archibaldJ]

What I particularly find interesting is that there is a nice correspondence of this in programming language theory where depending on the evaluation strategy the same values are derived differently from a set of expressions i.e. values are computed in different orders and different causality relationships arise (causality in the sense of which expressions cause another expressions to get evaluated e.g. call by value vs call by name) but ultimately you arrive at the same result (or varying the initial “setup” may result in some expression not being evaluated)

[rkagerer]

Thanks for weighing in, I really appreciate the comments people are leaving. One thing I've struggled for clarity on: in examples like that one, is "agree" meant to apply at the instant either observes their event (ie. some omnipresent referee not subject to relatavistic limitations) or later on when they get together to compare notes?