### 17 Bell and von Neumann

Sunday, August 22nd, 2010In 1932, the distinguished mathematician John von Neumann wrote ‘The Mathematical Foundations of Quantum Mechanics’[i], which is famous for the elegant mathematical formalism it introduced and for its proof of the non-existence of hidden variables. In 1964, John S. Bell is credited with discovering a ‘flaw’ in this proof, and with correcting it.

The phrase ‘hidden variables’ is another of those in modern theoretical physics that is imprecisely used and inconsistently defined. One approach to it is as follows. We might infer that light is a wave from its remarkably wave-like properties, but we have historically only been able to observe its effect on absorption by a molecule on photographic paper or in our eye. Its wave nature, if it exists, is supposedly hidden from us and so would be a hidden variable in any theory. (more…)