Quantum weirdness

Quantum weirdness encompasses the aspects of quantum mechanics that challenge and defy human physical intuition.¹

Human physical intuition is based on macroscopic physical phenomena as are experienced in everyday life, which can mostly be adequately described by the Newtonian mechanics of classical physics.² Early 20th-century models of atomic physics, such as the Rutherford–Bohr model, represented subatomic particles as little balls occupying well-defined spatial positions, but it was soon found that the physics needed at a subatomic scale, which became known as "quantum mechanics", implies many aspects for which the models of classical physics are inadequate.³ These aspects include:

• quantum entanglement;⁴⁵
• quantum nonlocality, referred to by Einstein as "spooky action at a distance";⁴ see also EPR paradox;
• quantum superposition, presented in dramatic form in the thought experiment known as Schrödinger's cat;⁵⁶
• the uncertainty principle;⁴
• wave–particle duality;⁷
• the probabilistic nature of wave function collapse, decried by Einstein, saying, "God does not play dice".⁵