Spooky Action at a Distance and Quantum Technology

Quantum Mechanics Overview

http://edu-observatory.org/olli/Quantum/Week1.html

Reality In physics, reality is based on the empirical results of observation and experiment. Visualization of Quantum Physics (Quantum Mechanics) (14+ min) https://www.youtube.com/watch?v=p7bzE1E5PMY This video visually demonstrates some basic quantum physics concepts using the simple case of a free particle. Quantum Mechanics: Animation explaining quantum physics (26 min) https://www.youtube.com/watch?v=iVpXrbZ4bnU Covers all topics, including wave particle duality, Schrodinger's cat, EPR / Bell inequality, and the relationship between measurement and entanglement. Quantum Mechanics and Quantum Physics. Einstein's "Spooky Action at a Distance" (historical) https://www.technologyreview.com/s/427174/einsteins-spooky-action-at-a-distance-paradox-older-than-thought/ Einstein's phrase "spooky action at a distance" has become synonymous with one of the most famous episodes in the history of physics-his battle with Bohr in the 1930s over the completeness of quantum mechanics. Einstein's weapons in this battle were thought experiments that he designed to highlight what he believed were the inadequacies of the new theory. Quoting John Wheeler from Stephen Hawking's "A Brief History Of Time, A Reader's Companion", "I had worked with the other great man in the quantum debate, Niels Bohr, in Copenhagen. And I know no greater debate in the last hundreds of years than the debate between Bohr and Einstein, no greater debate between two greater men, or one that extended over a longer period of time--twenty-eight years--at a higher level of colleagueship. To put it in brief: Does the world exist out there independent of us, as Einstein thought; or, as Bohr thought, is there some sense in which we, through our choice of observing equipment, have something to do with what comes about..." Einstein refused to believe in a reality that precluded cause and effect. "God does not play dice with the universe." he declared. He especially objected to the theory's insistence that particles, forces, and events seemed to come into existence only when a measurement or observation was made." For more than half a century physicists and philosophers debated whether the quantum theory really was a complete and accurate description of reality. Then in 1964, physicist John Bell proposed a brilliant method to resolve the issue. "Bell's Theorem", says the eminent physicist Henry Stapps, "is the most profound discovery of science." By the early 1980s a number of elegant experiments applying Bell's Theorem have proved that quantum theory, which speaks in terms of probabilities rather than actualities, is indeed a complete explanation of reality... God DOES play dice with the universe! Is the Moon There When Nobody Looks? Reality and the Quantum Theory https://physicstoday.scitation.org/doi/10.1063/1.880968 Wikipedia -- Bell's theorem https://en.wikipedia.org/wiki/Bell's_theorem Wikipedia -- Introduction to quantum mechanics https://en.wikipedia.org/wiki/Introduction_to_quantum_mechanics Summary of Important Ideas in Quantum Physics http://faculty.wcas.northwestern.edu/~infocom/Ideas/qn_summary.pdf Wikipedia -- Quantum entanglement https://en.wikipedia.org/wiki/Quantum_entanglement Quantum entanglement is a physical phenomenon which occurs when pairs or groups of particles are generated, interact, or share spatial proximity in ways such that the quantum state of each particle cannot be described independently of the state of the other(s), even when the particles are separated by a large distance-instead, a quantum state must be described for the system as a whole. Measurements of physical properties such as position, momentum, spin, and polarization, performed on entangled particles are found to be correlated. For example, if a pair of particles is generated in such a way that their total spin is known to be zero, and one particle is found to have clockwise spin on a certain axis, the spin of the other particle, measured on the same axis, will be found to be counterclockwise, as is to be expected due to their entanglement. However, this behavior gives rise to seemingly paradoxical effects: any measurement of a property of a particle performs an irreversible collapse on that particle and will change the original quantum state. In the case of entangled particles, such a measurement will be on the entangled system as a whole. Given that the statistics of these measurements cannot be replicated by models in which each particle has its own state independent of the other, it appears that one particle of an entangled pair "knows" what measurement has been performed on the other, and with what outcome, even though there is no known means for such information to be communicated between the particles, which at the time of measurement may be separated by arbitrarily large distances. Quantum Entanglement & Spooky Action at a Distance https://www.youtube.com/watch?time_continue=36&v=ZuvK-od647c Bell's theorem (Review) https://en.wikipedia.org/wiki/Bell's_theorem Book Recommendation "Entanglement: The Greatest Mystery in Physics" Amir D Aczel 2002 John Wiley & Sons/Four Walls Eight Windows https://www.amazon.com/Entanglement-Greatest-Amir-D-Aczel/dp/1568582323 "There are two kinds of books about quantum mechanics. There are those in which we learn about abstract concepts such as Hilbert spaces, state vectors and density matrices, but where the author never addresses - or only pays lip-service to - the question of what quantum mechanics actually means. This is the approach often taken in textbooks. The other, quite opposite, approach focuses on the interpretative question - drawing all kinds of conclusions and analogies, talking about telepathy and other mysteries, and perhaps even claiming that quantum mechanics transcends Western philosophy. "Neither approach is very helpful when one wants to understand what quantum mechanics really means in a deep philosophical sense. Amir Aczel's new book on entanglement - falling as it does into neither category - avoids such pitfalls." ~Anton Zeilinger from the Institute of Experimental Physics at the University of Vienna reviews the book in the May issue of Physics World Quantum entanglement of identical particles by standard information-theoretic notions http://arxiv.org/abs/1511.03445 sam.wormley@gmail.com