Part 5/9:

Quantum Entanglement: A Challenge to Fundamentals

Quantum entanglement arises when two particles, having briefly interacted, become interconnected such that the state of one influences the state of the other, regardless of the distance between them. In measurement, the collapse of the wave function of one particle immediately determines the state of its entangled partner, which could appear to contravene locality and even causality.

The implications of entanglement bring us back to Bohr and Einstein’s debate: if measurement impacts the properties of entangled particles instantaneously, could this violate the speed of light barrier established by relativity? This question fueled ongoing resistance from Einstein, who deemed such instantaneous influence as "spooky action at a distance."