{"id":3143,"date":"2008-11-11T09:33:28","date_gmt":"2008-11-11T09:33:28","guid":{"rendered":"http:\/\/scienceblogs.com\/principles\/2008\/11\/11\/manyworld-vs-multiverse\/"},"modified":"2008-11-11T09:33:28","modified_gmt":"2008-11-11T09:33:28","slug":"manyworld-vs-multiverse","status":"publish","type":"post","link":"http:\/\/chadorzel.com\/principles\/2008\/11\/11\/manyworld-vs-multiverse\/","title":{"rendered":"Many-World vs. Multiverse"},"content":{"rendered":"<p>In the recent <a href=\"http:\/\/scienceblogs.com\/principles\/2008\/11\/whats_the_matter_with_making_u.php\">discussion of Many-Worlds and making universes<\/a>, Jonathan Vos Post asked what science fiction treatments of the idea I like. The answer is pretty much &#8220;none,&#8221; because most SF treatments are distractingly bad.<\/p>\n<p>For example, last night I finished Neal Stephenson&#8217;s <cite>Anathem<\/cite>, a whopping huge brick of a book setting up an incredibly imaginative alternate Earth, with a detailed intellectual history paralleling our own. It&#8217;s got all sorts of great stuff, but it lost me when it started talking about parallel worlds, because it munges together the Many-Worlds Interpretation of quantum physics, and Multiverse Cosmology in a way that I found distracting.<\/p>\n<p>These are very different theories, dealing with very different things:<\/p>\n<p><!--more--><\/p>\n<p>The Many-Worlds Interpretation talks (in its popular formulation) about &#8220;alternate worlds&#8221; in which particular measurements had different outcomes. It&#8217;s not quite right to talk about these as separate universes in their own right (really, they&#8217;re just different parts of the same universal wavefunction), but that&#8217;s the basic idea&#8211; there is a branch of the wavefunction corresponding to each of the possible outcomes of any particular measurement, and those branches are inaccessible to one another.<\/p>\n<p>Multiverse Cosmology, on the other hand, posits the existence of other &#8220;universes&#8221; in which the constants of nature have slightly different values. Depending on which flavor of it you&#8217;re dealing with, these may be completely separate parallel worlds (other Big Bangs leading to other universes) or &#8220;bubbles&#8221; within a single cosmos, stemming from the same Big Bang.<\/p>\n<p>Stephenson blurs the distinction between the two in a way I found annoying. He talks about universes with different physical laws (Multiverse Cosmology) as if they were the same as the different wavefunction branches of Many-Worlds. It&#8217;s not critical to the resolution of the plot, but it was annoying to me in a way that hurt my enjoyment of the end of the book. (Which wouldn&#8217;t&#8217;ve been that great even if he had gotten the details right, but that&#8217;s a topic for another post&#8230;)<\/p>\n<p>Of course, Stephenson uses these ideas about as well as anybody else in SF does. Which is why there isn&#8217;t much SF about these ideas that I would recommend.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>In the recent discussion of Many-Worlds and making universes, Jonathan Vos Post asked what science fiction treatments of the idea I like. The answer is pretty much &#8220;none,&#8221; because most SF treatments are distractingly bad. For example, last night I finished Neal Stephenson&#8217;s Anathem, a whopping huge brick of a book setting up an incredibly&hellip; <a class=\"more-link\" href=\"http:\/\/chadorzel.com\/principles\/2008\/11\/11\/manyworld-vs-multiverse\/\">Continue reading <span class=\"screen-reader-text\">Many-World vs. Multiverse<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"1","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[18,7,37,29],"tags":[],"class_list":["post-3143","post","type-post","status-publish","format-standard","hentry","category-books","category-physics","category-pop_culture","category-sf","entry"],"_links":{"self":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/3143","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/comments?post=3143"}],"version-history":[{"count":0,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/posts\/3143\/revisions"}],"wp:attachment":[{"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/media?parent=3143"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/categories?post=3143"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/chadorzel.com\/principles\/wp-json\/wp\/v2\/tags?post=3143"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}