{"id":3792,"date":"2017-02-21T00:00:00","date_gmt":"2017-02-21T00:00:00","guid":{"rendered":"https:\/\/wpdev.hmc.edu\/physics\/2017\/02\/21\/cosmic-bell-test-measurement-settings-from-milky-way-stars\/"},"modified":"2017-02-21T00:00:00","modified_gmt":"2017-02-21T00:00:00","slug":"cosmic-bell-test-measurement-settings-from-milky-way-stars","status":"publish","type":"physics_colloquium","link":"https:\/\/www.hmc.edu\/physics\/research\/colloquium\/cosmic-bell-test-measurement-settings-from-milky-way-stars\/","title":{"rendered":"Cosmic Bell Test: Measurement Settings from Milky Way Stars"},"content":{"rendered":"<figure id=\"page-featured-image\" class=\"wp-block-image is-style-alignleft\" data-pic=\"\"><img decoding=\"async\" src=\"https:\/\/www.hmc.edu\/physics\/wp-content\/uploads\/sites\/22\/2023\/01\/\" alt=\"Promotional image for talk: Elements of a successful scientific talk\" data-pic=\"\" \/><\/figure>\n<p><strong>Speaker(s):<\/strong> Jason Gallicchio<\/p>\n<p>Bell\u2019s theorem states that some predictions of quantum mechanics cannot be reproduced by a local-realist theory. That conflict is expressed by Bell\u2019s 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 \u201cfreedom of choice\u201d was addressed by ensuring that selection of measurement settings via conventional \u201cquantum random number generators\u201d was space-like 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. I\u2019ll talk about a new experimental test of Bell\u2019s inequality that, for the first time, uses distant astronomical sources as \u201ccosmic setting generators.\u201d In our tests with polarization-entangled photons, measurement settings were chosen using real-time observations of Milky Way stars while simultaneously ensuring locality. This pushes back by ~600 years the most recent time by which any local-realist influences could have engineered the observed Bell violation.<\/p>\n","protected":false},"author":1,"featured_media":0,"template":"","class_list":["post-3792","physics_colloquium","type-physics_colloquium","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.hmc.edu\/physics\/wp-json\/wp\/v2\/physics_colloquium\/3792","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.hmc.edu\/physics\/wp-json\/wp\/v2\/physics_colloquium"}],"about":[{"href":"https:\/\/www.hmc.edu\/physics\/wp-json\/wp\/v2\/types\/physics_colloquium"}],"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=3792"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}