Einstein-Podolsky-Rosen Paper (1935)

The Einstein-Podolsky-Rosen (EPR) paper of 1935 challenges the completeness of quantum mechanics by highlighting what they saw as strange, "spooky" connections between particles. They described a scenario where two particles become linked, so measuring one instantly reveals information about the other, no matter how far apart they are. This seemed to conflict with the idea that nothing can travel faster than light. The paper questioned whether quantum mechanics fully describes reality or if there are hidden, underlying factors—called "hidden variables"—that determine outcomes. It sparked ongoing debates about the nature of reality and the fundamentals of physics.