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How the Bell tests changed quantum physics

Nature Reviews Physics volume 3, pages 674–676 (2021)Cite this article

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More than 40 years ago the first Bell tests translated a purely philosophical conundrum to a physical experiment. In doing so, they changed our understanding of quantum mechanics and contributed to the development of quantum technologies.

Despite its indisputable success, quantum mechanics remains uncomfortable. Whether one subscribes to any of its philosophical interpretations or the pragmatic ‘shut up and calculate’ approach, challenging the very notion of reality is not something with which human beings feel at ease. Intuitively, the physical properties of an object ought to be well defined and independent of the measurements performed on them or nonlocal influences. Yet, such a reasonable worldview, known as local realism, seems to be at odds with the predictions of quantum mechanics, an issue pointed out in 1935 by Albert Einstein, Boris Podolsky and Nathan Rosen, which became known as the EPR paradox.

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Fig. 1: John Bell at CERN around 1982.

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    Iulia Georgescu

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  1. Iulia Georgescu
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Correspondence to Iulia Georgescu.

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Georgescu, I. How the Bell tests changed quantum physics. Nat Rev Phys 3, 674–676 (2021). https://doi.org/10.1038/s42254-021-00365-8

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