For specific combinations of orientations, perfect ( rather than statistical ) correlations between the three polarizations are predicted by both local hidden variable theory ( aka " local realism " ) and by quantum mechanical theory, and the predictions may be contradictory.
22.
The magnetic domain theory of how ferromagnetic cores work was first proposed in 1906 by French physicist Pierre-Ernest Weiss, and the detailed modern quantum mechanical theory of ferromagnetism was worked out in the 1920s by Werner Heisenberg, Lev Landau, Felix Bloch and others.
23.
In fact, this equivalence of Hamiltonians descends to an equivalence of two quantum mechanical theories : One of these theories describes strings propagating on a circle of radius R, while the other describes string propagating in a circle of radius 1 / R with momentum and winding numbers interchanged.
24.
The London theory has much similarity to the quantum mechanical theory of light dispersion, which is why London coined the phrase " dispersion effect . " In physics, the term " dispersion " describes the variation of a quantity with frequency, which is the fluctuation of the electrons in the case of the London dispersion.
25.
With the measurements oriented at intermediate angles between these basic cases, the existence of local hidden variables could agree with a linear dependence of the correlation in the angle but, according to Bell's inequality ( see below ), could not agree with the dependence predicted by quantum mechanical theory, namely, that the correlation is the negative cosine of the angle.
