{"id":31553,"date":"2016-10-31T12:47:46","date_gmt":"2016-10-31T19:47:46","guid":{"rendered":"http:\/\/lifeboat.com\/blog\/2016\/10\/why-the-many-worlds-formulation-of-quantum-mechanics-is-probably-correct"},"modified":"2017-06-04T14:06:19","modified_gmt":"2017-06-04T21:06:19","slug":"why-the-many-worlds-formulation-of-quantum-mechanics-is-probably-correct","status":"publish","type":"post","link":"https:\/\/lifeboat.com\/blog\/2016\/10\/why-the-many-worlds-formulation-of-quantum-mechanics-is-probably-correct","title":{"rendered":"Why the Many-Worlds Formulation of Quantum Mechanics Is Probably Correct"},"content":{"rendered":"

<\/a><\/p>\n

\"universe-splitter\"<\/a> I have often talked about the Many-Worlds<\/a> or Everett<\/a> approach to quantum mechanics \u2014 here\u2019s an explanatory video<\/a>, an excerpt<\/a> from From Eternity to Here<\/em><\/a>, and slides<\/a> from a talk. But I don\u2019t think I\u2019ve ever explained as persuasively as possible why I think it\u2019s the right approach. So that\u2019s what I\u2019m going to try to do here. Although to be honest right off the bat, I\u2019m actually going to tackle a slightly easier problem: explaining why the many-worlds approach is not completely insane<\/em>, and indeed quite natural. The harder part is explaining why it actually works<\/em>, which I\u2019ll get to in another post.<\/p>\n

Any discussion of Everettian quantum mechanics (\u201cEQM\u201d) comes with the baggage of pre-conceived notions. People have heard of it before, and have instinctive reactions to it, in a way that they don\u2019t have to (for example) effective field theory<\/a>. Hell, there is even an app, universe splitter<\/a>, that lets you create new universes from your iPhone. (Seriously.) So we need to start by separating the silly objections to EQM from the serious worries.<\/p>\n

The basic silly objection is that EQM postulates too many universes<\/a>. In quantum mechanics, we can\u2019t deterministically predict the outcomes of measurements. In EQM, that is dealt with by saying that every measurement outcome \u201chappens,\u201d<\/em> but each in a different \u201cuniverse\u201d or \u201cworld.\u201d Say we think of Schr\u00f6dinger\u2019s Cat: a sealed box inside of which we have a cat in a quantum superposition of \u201cawake\u201d and \u201casleep.\u201d (No reason to kill the cat<\/a> unnecessarily.) Textbook quantum mechanics says that opening the box and observing the cat \u201ccollapses the wave function\u201d into one of two possible measurement outcomes, awake or asleep. Everett, by contrast, says that the universe splits in two: in one the cat is awake, and in the other the cat is asleep. Once split, the universes go their own ways, never to interact with each other again.<\/p>\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

I have often talked about the Many-Worlds or Everett approach to quantum mechanics \u2014 here\u2019s an explanatory video, an excerpt from From Eternity to Here, and slides from a talk. But I don\u2019t think I\u2019ve ever explained as persuasively as possible why I think it\u2019s the right approach. So that\u2019s what I\u2019m going to try [\u2026]<\/p>\n","protected":false},"author":387,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1512,1617],"tags":[],"class_list":["post-31553","post","type-post","status-publish","format-standard","hentry","category-mobile-phones","category-quantum-physics"],"_links":{"self":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/31553","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/users\/387"}],"replies":[{"embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/comments?post=31553"}],"version-history":[{"count":3,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/31553\/revisions"}],"predecessor-version":[{"id":65883,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/posts\/31553\/revisions\/65883"}],"wp:attachment":[{"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/media?parent=31553"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/categories?post=31553"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lifeboat.com\/blog\/wp-json\/wp\/v2\/tags?post=31553"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}