{"id":4583,"date":"2012-04-17T14:17:06","date_gmt":"2012-04-17T18:17:06","guid":{"rendered":"http:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=4583"},"modified":"2012-04-17T17:04:35","modified_gmt":"2012-04-17T21:04:35","slug":"quantum-gravity-at-scientific-american","status":"publish","type":"post","link":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=4583","title":{"rendered":"Quantum Gravity at Scientific American"},"content":{"rendered":"<p>Scientific American is doing a good job this month of putting out stories related to quantum gravity that actually make sense, steering clear of the multiverse and other pseudo-science.  This month&#8217;s magazine has a <a href=\"http:\/\/www.nature.com\/scientificamerican\/journal\/v306\/n4\/full\/scientificamerican0412-40.html\">very nice article <\/a>by Steven Carlip about quantum gravity in 2+1 dimensions.  For a more technical introduction to the subject, Carlip&#8217;s <a href=\"http:\/\/www.amazon.com\/Quantum-Dimensions-Cambridge-Monographs-Mathematical\/dp\/0521545889\">book<\/a> and <a href=\"http:\/\/arxiv.org\/abs\/gr-qc\/0409039\">review article<\/a> are good places to start.<\/p>\n<p>I haven&#8217;t seen the new May issue yet, but from <a href=\"http:\/\/www.scientificamerican.com\/sciammag\/?contents=2012-05\">their web-site<\/a>, it seems that their cover story on new ideas about &#8220;A Unified Physics&#8221; is what looks to be an interesting article from Zvi Bern, Lance Dixon and David Kosower: <a href=\"http:\/\/www.scientificamerican.com\/article.cfm?id=search-for-new-physics\">Quantum &#8220;Graviton&#8221; Particles May Resemble Ordinary Particles of Force<\/a>, summarized as<\/p>\n<blockquote><p>Maybe unifying the forces of nature isn&#8217;t quite as hard as physicists thought it would be.<\/p><\/blockquote>\n<p>I&#8217;m curious to see the full article, but I assume it&#8217;s about the intriguing work on amplitudes of recent years that has shown that supergravity theories have fewer divergences than people thought, for reasons that are still unclear.  There&#8217;s presumably some new symmetry structure here, and understanding it may offer a way around the old argument that &#8220;you can&#8217;t put quantum mechanics and general relativity together, the quantum fluctuations at short distances are just too violent.&#8221;  Maybe you don&#8217;t need strings, M-theory, the multiverse, and all the other baggage theorists have been weighed down by for the last quarter-century.  There has been quite a bit of discussion about this topic here, the earliest posting is <a href=\"http:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=268\">this one from 2005<\/a>.  For another take on how these ideas might lead to a new way to handle quantum gravity, the latest visionary talk by Nima Arkani-Hamed from last week at the Simons Center is available <a href=\"http:\/\/media.scgp.stonybrook.edu\/video\/video.php?f=20120411_2_Arkani-Hamed_qtp.mp4\">here<\/a>.<\/p>\n<p>Also at Scientific American, George Musser has been producing some interesting blog entries on these topics.  There&#8217;s a <a href=\"http:\/\/www.scientificamerican.com\/article.cfm?id=quantum-gravity-eliminating-dimension-space\">video here<\/a> about the Carlip piece, a <a href=\"http:\/\/blogs.scientificamerican.com\/observations\/2012\/03\/30\/the-emperor-darth-vader-and-the-ultimate-ultimate-theory-of-physics-2\/\">story about Darth Vader and the Emperor Palpatine<\/a> that was discussed <a href=\"http:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=4527\">here<\/a>, and a recent nice explanation of work on higher spin theories <a href=\"http:\/\/blogs.scientificamerican.com\/observations\/2012\/04\/12\/where-do-space-and-time-come-from-new-theory-offers-answers-if-only-physicists-can-figure-it-out\/\">here<\/a>.<\/p>\n<p><strong>Update<\/strong>:  Also in the May issue, from Davide Castelvecchi, there is a shorter article, <em>Is Supersymmetry Dead?<\/em> with summary<\/p>\n<blockquote><p>The grand scheme, a stepping-stone to string theory, is still high on physicists\u2019 wish lists. But if no solid evidence surfaces soon, it could begin to have a serious PR problem.<\/p><\/blockquote>\n<p>Peskin is still a believer though:<\/p>\n<blockquote><p>\u201cIt is the next step up toward the ultimate view of the world, where we make everything symmetric and beautiful,\u201d says Michael Peskin, a theorist at SLAC National Accelerator Laboratory&#8230;<\/p>\n<p>Many are still hopeful. \u201cThere are still very viable ways of building supersymmetry models,\u201d Peskin says. Expecting to see new physics after just a year of data taking was unrealistic, says Joseph Lykken, a theorist on the CMS team.<\/p><\/blockquote>\n","protected":false},"excerpt":{"rendered":"<p>Scientific American is doing a good job this month of putting out stories related to quantum gravity that actually make sense, steering clear of the multiverse and other pseudo-science. This month&#8217;s magazine has a very nice article by Steven Carlip &hellip; <a href=\"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/?p=4583\">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_post_was_ever_published":false,"_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":""},"categories":[1],"tags":[],"class_list":["post-4583","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\/4583","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=4583"}],"version-history":[{"count":11,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/4583\/revisions"}],"predecessor-version":[{"id":4594,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/4583\/revisions\/4594"}],"wp:attachment":[{"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=4583"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=4583"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.math.columbia.edu\/~woit\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=4583"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}