Editing John Stewart Bell (section)

===Bell's theorem===
{{Main|Bell's theorem}}
[[File:John Bell commenting the famous Bell's inequalities (8206241).jpg|left|thumb|Bell discussing Bell's inequality at CERN in 1982]]
In 1964, after a year's leave from [[CERN]] that he spent at [[Stanford University]], the [[University of Wisconsin–Madison]] and [[Brandeis University]], Bell wrote a paper entitled "On the [[Einstein–Podolsky–Rosen paradox]]".<ref name="Bell1964">{{cite journal
 | first = John Stewart
 | last = Bell
 | title = On the Einstein Podolsky Rosen paradox
 | journal = [[Physics Physique Физика]]
 | volume = 1
 | issue = 3
 | pages = 195–200
 | year = 1964
 | doi = 10.1103/PhysicsPhysiqueFizika.1.195
 | url = https://cds.cern.ch/record/111654
| doi-access = free
 }}</ref> In this work, he showed that carrying forward EPR's analysis<ref name="EPR1935">{{cite journal
 | last1 = Einstein
 | first1 = Albert
 | last2 = Podolsky
 | first2 = Boris
 | last3 = Rosen
 | first3 = Nathan
 | title = Can quantum-mechanical description of physical reality be considered complete?
 | journal = Physical Review
 | volume = 47
 | issue = 10
 | pages = 777–780
 | year = 1935
 | doi = 10.1103/PhysRev.47.777
 | bibcode = 1935PhRv...47..777E
 | url = https://cds.cern.ch/record/405662
| doi-access = free
 }}</ref> permits one to derive the famous [[Bell's theorem]].<ref name="CERN2014">{{cite web
 |url= https://home.cern/news/news/physics/fifty-years-bells-theorem
 |title= Fifty years of Bell's theorem 
 |last = Sutton
 |first = Christine
 |date = 4 November 2014
 |website = CERN official website
 |publisher = [[CERN]]
 |access-date = 8 October 2019
 |quote = A paper by John Bell published on 4 November 1964 laid the foundations for the modern field of quantum-information science}}</ref> The resultant inequality, derived from basic assumptions that apply to all classical situations, is violated by quantum theory.