Editing Hidden-variable theory (section)

== Motivation ==
Macroscopic physics requires classical mechanics which allows accurate predictions of mechanical motion with reproducible, high precision. Quantum phenomena require quantum mechanics, which allows accurate predictions of statistical averages only. If quantum states had hidden-variables awaiting ingenious new measurement technologies, then the latter (statistical results) might be convertible to a form of the former (classical-mechanical motion).<ref>{{Cite journal |last=Bell |first=John S. |date=1966-07-01 |title=On the Problem of Hidden Variables in Quantum Mechanics |url=https://link.aps.org/doi/10.1103/RevModPhys.38.447 |journal=Reviews of Modern Physics |language=en |volume=38 |issue=3 |pages=447–452 |doi=10.1103/RevModPhys.38.447 |bibcode=1966RvMP...38..447B |osti=1444158 |issn=0034-6861}}</ref>

This classical mechanics description would eliminate unsettling characteristics of quantum theory like the [[uncertainty principle]]. More fundamentally however, a successful model of quantum phenomena with hidden variables implies quantum entities with intrinsic values independent of measurements. Existing quantum mechanics asserts that state properties can only be known after a measurement. As [[N. David Mermin]] puts it:{{blockquote|It is a fundamental quantum doctrine that a measurement does not, in general, reveal a pre-existing value of the measured property.  On the contrary, the outcome of a measurement is brought into being by the act of measurement itself...<ref>{{Cite journal |last=Mermin |first=N. David |date=1993-07-01 |title=Hidden variables and the two theorems of John Bell |url=https://link.aps.org/doi/10.1103/RevModPhys.65.803 |journal=Reviews of Modern Physics |language=en |volume=65 |issue=3 |pages=803–815 |doi=10.1103/RevModPhys.65.803 |issn=0034-6861|arxiv=1802.10119 |bibcode=1993RvMP...65..803M |s2cid=119546199 }}</ref>}}
In other words, whereas a hidden-variable theory would imply intrinsic particle properties, in quantum mechanics an electron has no definite position and velocity to even ''be'' revealed.