The October 2014
Astronomy article, “Can the cosmos test quantum entanglement?” introduced an experiment my colleagues and I have proposed: using distant active galaxies called quasars to choose detectors’ settings in a real-world test of the limits of Bell’s theorem, itself one of the most important quantum mechanical results of the past century. We need pairs of quasars on opposite sides of the sky that emitted their light at least 12.1 billion years ago to ensure that there would not have been enough time for either of them to be influenced by each other or anything else since the universe’s beginning.
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