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Title: Cosmic Bell Test: Measurement Settings from Milky Way Stars

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 in this paper 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 p values of ≲1.8 × 10 -13 and ≲4.0 × 10 -33, respectively,more » thereby pushing back by ~600 years the most recent time by which any local-realist influences could have engineered the observed Bell violation.« less
Authors:
 [1] ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
  1. Austrian Academy of Sciences, Vienna, Austria
Publication Date:
Grant/Contract Number:
SC0012567
Type:
Published Article
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 118; Journal Issue: 6; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS
OSTI Identifier:
1342816
Alternate Identifier(s):
OSTI ID: 1425643