Space-Time in the Quantum World

摘要: Consider pairs of electrons produced in the singlet state and allowed to separate a very great distance. We know from work Bell that no theory can predict violations Bell’s inequality for spin measurements on those if it satisfied two conditions. The first (condition a) is ascribe either single initial or convex sum states ensemble such are statistically independent later carried out electrons. second b) most easily understood expressed differently deterministic stochastic theories. For we require b′) determine results each measurement solely basis details particle. demand b*) assign probabilities based electron, which unchanged when one conditionalizes obtained other particle pair. (Conditions b′ b* really same condition, case appropriately theory, an indeterministic one. A violates also since conditionalizing information about electron render result certain.) Einstein et al. (1935) had already pointed impossibility non-deterministic obeys recover predictions quantum so argued favor theory. showed obeying could all mechanics. Greenberger (1989) reference ensembles otiose: there be individual triples particles type mechanics b*.