I know this, but how can a physicist write a pamphlet against measurements? Even a theoretical physicist gets unemployed if there are no measurements done anymore (except he can switch to pure mathematics or, horribile dictu, philosophy ;-)).
Bell, of course, is not against doing measurements, or against using the results of measurement to formulate the theory. He is against measurement as a part of formulation of the theory. In classical mechanics, measurement is not a part of the formulation of the theory. In standard quantum mechanics, it is.I know this, but how can a physicist write a pamphlet against measurements?
I don't think so, just as I don't think that decomposing a quantum state in a specified basis for the Hilbert space implicitly assumes measurement.In classical mechanics already writing down a position vector in terms of its Cartesian components implicitly assumes measurements.
The difference is that in classical mechanics you an in principle have several measurement devices at once, measuring all things at once without distorting the system. Ie. you can have a "collection of observers" asking all kinds of questions at once, and then simlpy joing the answers.Well, of course, to measure the position of a particle you need a different device than to meausure its momentum. This is not specific to QT but also the case within classical physics. Indeed there's no problem with this, and it's in no way mystical at all.
You can not in Borhs view properly speak of what is quantum without a classical reference. Surely, you can view the apparatous + system as another "new quantum system" BUT, then you need ANOTHER classical backdrop. To think you can repeat this until you end up with a complete wavefunction of the universe is IMO a fallacy that makes no sense. I think this is Bohrs point. But if we get into the details here, atl east i will raise questions that i think is beyond the scope of the original Einstein Bohr dispute. Bohrs point is I think the most acccurate one if you consider quantum theory as it stands. Even field theory needs a backdrop. The detectors must be attached in a classical world.I've also never understood Bohr's "classical measurement device". According to QT everything is quantum, including macroscopic systems making up measurement devices. The classical behavior of the relevant macroscopic observables (which are coarse-grained by averaging many microscopic degrees of freedom over microscopically large, macroscopically small space-time regions) is emergent.