EPRparadoksi

The EPR paradox, named after its originators Albert Einstein, Boris Podolsky, and Nathan Rosen, is a thought experiment that highlights seemingly counter-intuitive aspects of quantum mechanics. First proposed in 1935, the paradox challenges the completeness of quantum theory by suggesting that if quantum mechanics is correct, then certain phenomena must be non-local, meaning that measuring a property of one particle instantaneously influences the property of another entangled particle, regardless of the distance separating them.

The core of the paradox lies in the concept of quantum entanglement. When two particles are entangled, their quantum states are linked in such a way that they cannot be described independently. Measuring a specific property of one entangled particle, such as its spin, immediately determines the corresponding property of the other particle. Einstein, Podolsky, and Rosen argued that this "spooky action at a distance," as Einstein famously put it, implied that either quantum mechanics was incomplete and there were "hidden variables" determining these properties all along, or that nature allowed for faster-than-light communication, which contradicted their understanding of relativity.

Subsequent developments in quantum mechanics and experimental verification, particularly Bell's theorem and its experimental tests, have largely supported the predictions of quantum mechanics over local hidden variable theories. While the EPR paradox remains a powerful illustration of quantum entanglement's peculiar nature, it is now widely accepted that the correlations observed in entangled systems do not violate causality or allow for superluminal information transfer. Instead, they represent a fundamental feature of quantum reality that defies classical intuition.