{"id":4749,"date":"2018-01-01T00:00:00","date_gmt":"2018-01-01T08:00:00","guid":{"rendered":"https:\/\/wpdev.hmc.edu\/physics\/2018\/01\/01\/cosmic-bell-test-using-random-measurement-settings-from-high-redshift-quasars\/"},"modified":"2025-12-19T09:02:36","modified_gmt":"2025-12-19T17:02:36","slug":"cosmic-bell-test-using-random-measurement-settings-from-high-redshift-quasars","status":"publish","type":"physics_publications","link":"https:\/\/www.hmc.edu\/physics\/research\/publications\/cosmic-bell-test-using-random-measurement-settings-from-high-redshift-quasars\/","title":{"rendered":"Cosmic Bell Test Using Random Measurement Settings from High-Redshift Quasars"},"content":{"rendered":"\n<p id=\"authors\">Dominik Rauch, Johannes Handsteiner, Armin Hochrainer, <span class=\"facauthor\">Jason Gallicchio<\/span>*, Andrew S. Friedman, <span class=\"studauthor\">Calvin Leung<\/span>, Bo Liu, Lukas Bulla, Sebastian Ecker, Fabian Steinlechner, Rupert Ursin, <span class=\"studauthor\">Beili Hu<\/span>, David Leon, Chris Benn, Adriano Ghedina, Massimo Cecconi, Alan H. Guth, David I. Kaiser, Thomas Scheidl, and Anton Zeilinger<\/p>\n\n\n\n<p id=\"doc-link\"><a href=\"https:\/\/www.hmc.edu\/physics\/wp-content\/uploads\/sites\/22\/2023\/02\/pub-107.pdf\">Cosmic Bell Test Using Random Measurement Settings from High-Redshift Quasars (PDF)<\/a><\/p>\n\n\n\n<p id=\"journal\"><span class=\"journal-title\">Physical Review Letters<\/span> <strong data-vol=\"121\">121<\/strong> <span id=\"journal-year\">(2018)<\/span> <span id=\"journal-pages\" data-pages=\"80403\">80403<\/span><\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Abstract<\/h2>\n\n\n\n<p>In this Letter, we present a cosmic Bell experiment with polarization-entangled photons, in which measurement settings were determined based on real-time measurements of the wavelength of photons from high-redshift quasars, whose light was emitted billions of years ago; the experiment simultaneously ensures locality. Assuming fair sampling for all detected photons and that the wavelength of the quasar photons had not been selectively altered or previewed between emission and detection, we observe statistically significant violation of Bell\u2019s inequality by 9.3 standard deviations, corresponding to an estimated (&nbsp;p )&nbsp;value of ( sim 7.4 times 10^{-21} ). This experiment pushes back to at least \u223c7.8 Gyr ago the most recent time by which any local-realist influences could have exploited the \u201cfreedom-of-choice\u201d loophole to engineer the observed Bell violation, excluding any such mechanism from 96% of the space-time volume of the past light cone of our experiment, extending from the big bang to today.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Dominik Rauch, Johannes Handsteiner, Armin Hochrainer, Jason Gallicchio*, Andrew S. Friedman, Calvin Leung, Bo Liu, Lukas Bulla, Sebastian Ecker, Fabian [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"template":"","publication_author":[16],"class_list":["post-4749","physics_publications","type-physics_publications","status-publish","hentry","publication_author-gallicchio"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.hmc.edu\/physics\/wp-json\/wp\/v2\/physics_publications\/4749","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hmc.edu\/physics\/wp-json\/wp\/v2\/physics_publications"}],"about":[{"href":"https:\/\/www.hmc.edu\/physics\/wp-json\/wp\/v2\/types\/physics_publications"}],"author":[{"embeddable":true,"href":"https:\/\/www.hmc.edu\/physics\/wp-json\/wp\/v2\/users\/1"}],"wp:attachment":[{"href":"https:\/\/www.hmc.edu\/physics\/wp-json\/wp\/v2\/media?parent=4749"}],"wp:term":[{"taxonomy":"publication_author","embeddable":true,"href":"https:\/\/www.hmc.edu\/physics\/wp-json\/wp\/v2\/publication_author?post=4749"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}