In March 2011, Joy Christian claimed to have disproved this theorem by applying it to a system on a hypersphere.
In March 2011, Joy Christian claimed to have disproved this theorem by applying it to a system on a hypersphere. The original paper deriving this theorem uses an epsilon-delta proof to show that 2 forms of the expected value of the product of 2 quantities are not equal. A switch determines which electro-acoustical transducer activates and disturbs a pool of water in an experiment testing this theorem. The CHSH inequality  uses the fact that the quantum correlation of 2 variables must be between 2 and -2 to test this theorem that was originally proposed in terms of two particles being measured using Stern-Gerlach Magnets. Based off of the EPR paradox, this is, for 10 points, what inequality which states that no local hidden variables theory is physically accurate. 
In March 2011, Joy Christian claimed to have disproved this theorem by applying it to a system on a hypersphere.
Bell's Inequality or  theorem