{"id":52,"date":"2017-05-03T18:53:57","date_gmt":"2017-05-03T18:53:57","guid":{"rendered":"https:\/\/magazine.hmc.edu\/spring-2017\/?p=52"},"modified":"2017-08-09T16:33:16","modified_gmt":"2017-08-09T16:33:16","slug":"researchers-seek-astronomical-answers-quantum-questions","status":"publish","type":"post","link":"https:\/\/magazine.hmc.edu\/spring-2017\/researchers-seek-astronomical-answers-quantum-questions\/","title":{"rendered":"Researchers Seek Astronomical Answers to Quantum Questions"},"content":{"rendered":"

Last summer, mathematics and physics double<\/strong>\u00a0major Calvin Leung \u201917 and physics major Amy Brown \u201917 built an inconspicuous-looking instrument that performs a rather remarkable task. The device, a black box that could be confused for a piece of camera equipment, generates random numbers using photons from astronomical sources. Successful tests of the device were an early step in research they are doing with Assistant Professor of Physics Jason Gallicchio, who devised an idea to use starlight to improve tests of quantum mechanics. Gallicchio and Leung are co-authors, along with their colleagues, on the paper \u201cA Cosmic Bell Test with Measurement Settings from Astronomical Sources,\u201d recently published by Physical Review Letters.<\/p>\n

Gallicchio studies experimental cosmology, the study of the origin and evolution of the universe. The paper aims to close a loophole in tests of physicist John Bell\u2019s inequalities\u2014which confirm the \u201cspooky action at a distance\u201d between quantum entangled particles\u2014by using telescopes that look at widely separated stars to generate the random settings in experiments on quantum entanglement. \u201cThis particular project is interesting and different,\u201d Gallicchio explains, \u201cbecause it combines astrophysics and quantum mechanics; things on big, distant scales and things that we tend to think of as being on tiny scales. We\u2019re using light that\u2019s coming from far, far away as a tool to do tests of quantum mechanics.\u201d<\/p>\n

\"JASON<\/a><\/figure>\n
\n

If you hope that there\u2019s some locality-friendly thing happening under quantum mechanics, it\u2019s much less plausible now.<\/p>\n

\u2014JASON GALLICCHIO, ASSISTANT PROFESSOR OF PHYSICS<\/cite><\/p><\/blockquote>\n

Albert Einstein was famously uncomfortable with quantum mechanics because it didn\u2019t fit with his physical realist attitude toward physics. Initially, beginning in the early 1930s, the discussion around the mysterious aspects of quantum mechanics seemed like a philosophical debate. Then, in 1964, Bell looked at it as an experimental question, stating that if straightforward implementations of Einstein\u2019s theory of relativity held, tests would give results different than what quantum mechanics predicts. Since that time, all experiments have confirmed quantum mechanics, but they leave open loopholes that could, in principle, still allow an explanation that would satisfy Einstein’s strong preference for local influences.<\/p>\n

The \u201cfree will\u201d or \u201cfreedom-of-choice\u201d loophole suggests that seemingly randomly selected measurement settings could have been affected by some unknown cause and therefore have influenced the results of tests on quantum entangled particles. It\u2019s also a problem if results could be predicted, even if they couldn’t have been influenced. By using 600-year-old starlight to determine the random measurement settings, Gallicchio and his colleagues are able to show that if there is an underlying influence at work, it has to have been working for at least that long to have affected any influence or prediction.<\/p>\n

Gallicchio\u2019s idea to use light from stars as a tool to generate random measurements came to him when he was an undergrad, taking one class in the philosophy of physics and another in quantum mechanics. He developed his idea further, writing the first draft of the paper during a year spent at the South Pole studying the cosmic microwave background. He returned to the U.S. and later flew to Vienna, Austria, to work on convincing his colleagues there, including leading physicists and cosmologists, to perform the experiments, which generated exciting results. \u201cWith starlight, it\u2019s harder to say there\u2019s something happening that can be explained locally,\u201d Gallicchio says. \u201cIf you hope that there\u2019s some locality-friendly thing happening under quantum mechanics, it\u2019s much less plausible now.\u201d<\/p>\n

Though the experiment was performed in Vienna, Gallicchio is currently working with other students to build an improved version of this experiment at Harvey Mudd, which would be an exciting development on any scale.<\/p>\n","protected":false},"excerpt":{"rendered":"

Last summer, mathematics and physics double\u00a0major Calvin Leung \u201917 and physics major Amy Brown \u201917 built an inconspicuous-looking instrument that […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[3],"tags":[],"class_list":["post-52","post","type-post","status-publish","format-standard","hentry","category-faculty"],"acf":[],"_links":{"self":[{"href":"https:\/\/magazine.hmc.edu\/spring-2017\/wp-json\/wp\/v2\/posts\/52","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/magazine.hmc.edu\/spring-2017\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/magazine.hmc.edu\/spring-2017\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/magazine.hmc.edu\/spring-2017\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/magazine.hmc.edu\/spring-2017\/wp-json\/wp\/v2\/comments?post=52"}],"version-history":[{"count":0,"href":"https:\/\/magazine.hmc.edu\/spring-2017\/wp-json\/wp\/v2\/posts\/52\/revisions"}],"wp:attachment":[{"href":"https:\/\/magazine.hmc.edu\/spring-2017\/wp-json\/wp\/v2\/media?parent=52"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/magazine.hmc.edu\/spring-2017\/wp-json\/wp\/v2\/categories?post=52"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/magazine.hmc.edu\/spring-2017\/wp-json\/wp\/v2\/tags?post=52"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}