History #

Following the declaration by Max Born that quantum mechanics is probabilistic in nature in 1926, Albert Einstein famously criticized the theory by saying “God does not play dice”. Niels Bohr, who supported the theory, reportedly told Einstein to “stop telling God what to do”. The debate between Einstein and Bohr continued for about 8 years, before Einstein formulated his best argument against Bohr’s theory: the EPR (Einstein-Podolsky-Rosen) paradox. Quantum entanglement was first discussed in this paradox, though the three scientists did not coin the term quantum entanglement. Shortly after, Erwin Schrödinger recognized the importance of the EPR paradox, and gave it the name “Verschränkung”, which translated by himself as “entanglement”. The EPR paradox sparked interest among the physicists at that time. However, it was until 1964 before the inconsistencies of the EPR paradox was found by John Stewart Bell. He then formulated his famous inequality: Bell’s inequality, which carried the analysis of quantum entanglement much further.