Quantum entanglement and the uncertainty relations

Entangled EPR two-particle system is characterized by Δ(p1+p2)=0 and Δ(x1-x2)=0, simultaneous. Even the momentum and position of each individual particle are completely undefined: Δpj∝∞, Δxj∝∞. This remarkable feature does not violate the uncertainty principle of quantum theory. It is the result of the surprising two-particle quantum coherent superposition. Although questions regarding fundamental issues of quantum theory still exist, quantum entanglement has brought about a novel concept in nonlocal timing and positioning measurements with ultra-high accuracy, even beyond the classical limit. (Abstract Copyright [2004], Wiley Periodicals, Inc.)