Quantum mechanics predicts many effects that may seem impossible from our ordinary view of the world. One of these is the existence of entangled states of two distant particles. These states have the property that a measurement made on one particle will instantly change the properties of the other, distant particle. Any classical interpretation of these effects would require that information must travel faster than the speed of light. That is not the correct quantum-mechanical interpretation, however, and no messages can be sent faster than the speed of light.
Nevertheless, Einstein did not believe in the existence of effects of this kind or in the randomness that occurs in quantum mechanics, referring to entanglement as “spooky action at a distance”. Recent experiments using pairs of photons (particles of light) separated by large distances have demonstrated the existence of these effects as predicted by quantum mechanics. Somewhat surprisingly, the effects of entanglement also have practical applications for secure communications and quantum computing. The fundamental implications of entanglement will be discussed along with some of its implications.
Dr. James Franson received his bachelor’s degree in physics from Purdue University and his Ph.D. from the California Institute of Technology. He is currently a professor at the University of Maryland at Baltimore County (UMBC). Dr. Franson was previously a member of the Principal Staff at the Johns Hopkins Applied Physics Laboratory and research professor in the Johns Hopkins school of electrical and computer engineering. His group was the first to demonstrate quantum cryptography in optical fibers as well as the first quantum logic operations using photons as the bits or qubits. In addition to his work on entanglement and quantum information, Dr. Franson is investigating the properties of quantum mechanics in the curved spacetime of general relativity. He is a Fellow of the American Physical Society and the Optical Society of America.