beecee Posted August 27, 2018 Posted August 27, 2018 https://phys.org/news/2018-08-physicists-demystify-einstein-spooky-science.html Physicists race to demystify Einstein's 'spooky' science August 27, 2018 by Cynthia Dillon, University of California - San Diego Schematic of the 2018 “Cosmic Bell” experiment at the Roque de Los Muchachos Observatory in the Canary Islands, where two large telescopes observed the fluctuating color of light from distant quasars (red and blue galaxies). The green beams indicate polarization-entangled photons sent through the open air between stations separated by about one kilometer. Credit: Andrew S. Friedman and Dominik Rauch When it comes to fundamental physics, things can get spooky. At least that's what Albert Einstein said when describing the phenomenon of quantum entanglement—the linkage of particles in such a way that measurements performed on one particle seem to affect the other, even when separated by great distances. "Spooky action at a distance" is how Einstein described what he couldn't explain. While quantum mechanics includes many mysterious phenomena like entanglement, it remains the best fundamental physical theory describing how matter and light behave at the smallest scales. Quantum theory has survived numerous experimental tests in the past century while enabling many advanced technologies: modern computers, digital cameras and the displays of TVs, laptops and smartphones. Quantum entanglement itself is also the key to several next-generation technologies in computing, encryption and telecommunications. Yet, there is no clear consensus on how to interpret what quantum theory says about the true nature of reality at the subatomic level, or to definitively explain how entanglement actually works. Read more at: https://phys.org/news/2018-08-physicists-demystify-einstein-spooky-science.html#jCp <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> the paper: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.060401 Cosmic Bell Test: Measurement Settings from Milky Way Stars: ABSTRACT: Bell’s theorem states that some predictions of quantum mechanics cannot be reproduced by a local-realist theory. That conflict is expressed by Bell’s inequality, which is usually derived under the assumption that there are no statistical correlations between the choices of measurement settings and anything else that can causally affect the measurement outcomes. In previous experiments, this “freedom of choice” was addressed by ensuring that selection of measurement settings via conventional “quantum random number generators” was spacelike separated from the entangled particle creation. This, however, left open the possibility that an unknown cause affected both the setting choices and measurement outcomes as recently as mere microseconds before each experimental trial. Here we report on a new experimental test of Bell’s inequality that, for the first time, uses distant astronomical sources as “cosmic setting generators.” In our tests with polarization-entangled photons, measurement settings were chosen using real-time observations of Milky Way stars while simultaneously ensuring locality. Assuming fair sampling for all detected photons, and that each stellar photon’s color was set at emission, we observe statistically significant ≳7.31σ and ≳11.93σ violations of Bell’s inequality with estimated pvalues of ≲1.8×10−13 and ≲4.0×10−33, respectively, thereby pushing back by ∼600 years the most recent time by which any local-realist influences could have engineered the observed Bell violation.
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