Search Results for: contextuality

2 Time symmetric quantum mechanics

Why is the fun­da­mental the­o­ret­ical frame­work of con­tem­po­rary physics a prob­a­bility cal­culus, and why are the events to which this assigns prob­a­bil­i­ties mea­sure­ment out­comes? It seems to me that all pre­vious attempts to arrive at sat­is­fac­tory answers have foundered on two assump­tions that are at odds with the theory’s onto­log­ical impli­ca­tions. The first is the […]

9 Beyond “either-​​or”

Sup­pose that the sub­spaces A and B rep­re­sent two pos­sible out­comes of the same mea­sure­ment. What mea­sure­ment out­come is rep­re­sented by the span AUB of A and B? (You will remember that the span of A and B is the smallest sub­space con­taining both A and B.) The fol­lowing obser­va­tions are rel­e­vant here. Let p(A) […]

7 The GHZ experiment

As Green­berger, Horne, and Zeilinger have shown,[1] quantum mechanics allows us to pre­pare three par­ti­cles A, B, C and to sub­ject each to either of two mea­sure­ments X, Y in such a way that the out­come of each mea­sure­ment is either +1 or −1, the product of the three out­comes is −1 if each par­ticle is subjected […]