{"id":4004,"date":"2011-10-03T12:06:25","date_gmt":"2011-10-03T16:06:25","guid":{"rendered":"http:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=4004"},"modified":"2011-10-03T12:06:25","modified_gmt":"2011-10-03T16:06:25","slug":"new-pursuit-of-schrodingers-cat","status":"publish","type":"post","link":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=4004","title":{"rendered":"New Pursuit of Schrodinger&#8217;s Cat"},"content":{"rendered":"<p>Prospect magazine has an excellent <a href=\"http:\/\/www.prospectmagazine.co.uk\/2011\/09\/quantum-theory-paradox-philip-ball-new-pursuit-of-schrodinger%E2%80%99s-cat\/\">new article by Philip Ball<\/a> on recent developments in the fundamental problem of the interpretation of quantum mechanics: why don&#8217;t we see superpositions?  Most popular discussions of this seem to me to be stuck back in debates from the 1930s, and ignore the main question.  QM is a simple, beautiful mathematical structure that works perfectly experimentally, the confusing question is that of how classical behavior emerges during a measurement process (typically involving huge numbers of degrees of freedom, making analysis difficult). <\/p>\n<p>At the end of the article, Ball mentions one particularly intriguing set of ideas, due to Wojciech Zurek, about &#8220;quantum Darwinism&#8221;.  For more about this, see Zurek&#8217;s survey <a href=\"http:\/\/arxiv.org\/abs\/0903.5082\">here<\/a>.<\/p>\n<p>There&#8217;s a new preprint out by Steven Weinberg on <a href=\"http:\/\/arxiv.org\/abs\/1109.6462\">Collapse of the State Vector<\/a>.  Weinberg claims that &#8220;There is now no entirely satisfactory interpretation of quantum mechanics&#8221;, and refers for more detail about this claim to Section 3.7 of his <em>Lectures on Quantum Mechanics<\/em>, a manuscript that is &#8220;to be published&#8221;.  I&#8217;m definitely looking forward to this book when it comes out.   The sort of thing that Weinberg examines in the preprint though, modifying QM to take into account wave-function collapse, is the kind of idea I&#8217;ve never found promising.  Why modify QM, it works perfectly and is mathematically extremely aesthetically compelling?  Better to keep QM as is, and closely examine one&#8217;s understanding of what the problem really is. <\/p>\n","protected":false},"excerpt":{"rendered":"<p>Prospect magazine has an excellent new article by Philip Ball on recent developments in the fundamental problem of the interpretation of quantum mechanics: why don&#8217;t we see superpositions? Most popular discussions of this seem to me to be stuck back &hellip; <a href=\"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=4004\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[1],"tags":[],"class_list":["post-4004","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/4004","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=4004"}],"version-history":[{"count":2,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/4004\/revisions"}],"predecessor-version":[{"id":4006,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/4004\/revisions\/4006"}],"wp:attachment":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4004"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4004"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4004"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}