On the Role of Hidden Variables in Quantum Mechanics

Hidden variables intend to bridge the gap of indeterminism in quantum mechanics theories. Some scientists, such as Einstein, believe that local hidden variables need to exist, because theories should completely explain a phenomenon without the use of probability. Others, such as Bohm, prefer to support non-local hidden variable theories, wherein correlations can travel faster than the speed of light, violating special relativity. Despite the dissent of famous scientists, the generally accepted view is that hidden variables are not necessary for a complete theory of quantum mechanics; John Bell first disproved the need for local hidden variables in 1964.

Rise of local hidden variable theory

With the rise of the Copenhagen interpretation and Heisenberg’s uncertainty principle, scientists felt quantum mechanics was incomplete with its lack of determinism. The most prominent among these scientists was Einstein, who is often quoted as saying, “God does not place dice,” in response to Max Born’s paper on probability in wavefunctions. Einstein searched for a local hidden variable theory, first finding it alongside Podolsky and Rosen in the Einstein, Podolsky, and Rosen (EPR) paradox.

The Copenhagen interpretation of quantum mechanics holds that physical systems have no predefined properties before measurement, and that quantum mechanics only produces the probabilities that measurement will have specific results. Heisenberg’s uncertainty principle…