Specker's parable of the overprotective seer: Implications for Contextuality, Nonlocality and Complementarity Speaker(s): Robert Spekkens
Abstract: I revisit an example of strongerthanquantum correlations that was discovered by Ernst Specker in 1960. The example was introduced as a parable wherein an overprotective seer sets a simple prediction task to his daughter's suitors. The challenge cannot be met because the seer asks the suitors for a noncontextual assignment of values but measures a system for which the statistics are inconsistent with such an assignment. I will show how by generalizing these sorts of correlations, one is led naturally to some wellknown proofs of nonlocality and contextuality, and to some new ones. Specker's parable involves a kind of complementarity that does not arise in quantum theory  three measurements that can be implemented jointly pairwise but not triplewise  and therefore prompts the question of what sorts of foundational principles might rule out this kind of complementarity. This is joint work with Howard Wiseman and YeongCherng Liang.
Date: 12/10/2010  4:00 pm
Series: Quantum Foundations
