{"id":481,"date":"2004-05-13T13:31:00","date_gmt":"2004-05-13T20:31:00","guid":{"rendered":"http:\/\/www.preposterousuniverse.com\/blog\/misunderconceptionated\/"},"modified":"2004-05-13T13:31:00","modified_gmt":"2004-05-13T20:31:00","slug":"misunderconceptionated","status":"publish","type":"post","link":"https:\/\/preposterousuniverse.com\/blog\/2004\/05\/13\/misunderconceptionated\/","title":{"rendered":"Misunderconceptionated"},"content":{"rendered":"<p>Some reactions to my list of <a href=\"http:\/\/preposterousuniverse.blogspot.com\/2004\/05\/misconceptions.html\">misconceptions about cosmology<\/a>.  Chad Orzel at Uncertain Principles has <a href=\"http:\/\/www.steelypips.org\/principles\/2004_05_09_principlearchive.php#108436820738828315\">misconceptions about quantum mechanics and thermodynamics<\/a>.  It&#8217;s a very good list, even if he does say that vacuum energy is useless.  It&#8217;s useless in the sense that it cannot be made to do thermodynamic work (because the vacuum energy is spread absolutely uniformly), but in another sense it&#8217;s quite useful:  it makes the universe accelerate, thereby giving cosmologists something deep to think about.  (And occasionally get them a <a href=\"http:\/\/preposterousuniverse.blogspot.com\/2004\/04\/full-disclosure.html\">job<\/a>.)<\/p>\n<p><a href=\"http:\/\/www.chriscmooney.com\/blog.asp#789\">Chris C Mooney<\/a> notes that a <a href=\"http:\/\/www.si.edu\/planetarium\" \/>planetarium show at the Smithsonian<\/a> doesn&#8217;t even mention the Big Bang, although it&#8217;s supposed to be a tour of the universe.  So perhaps one of the sources of misconceptions is that we aren&#8217;t clear enough about what we actually do think people need to know?  Right off the top of my head, here are some facts about cosmology I think every educated person should know:<\/p>\n<ul>\n<li> The universe is big.  The Sun is a star, located in a galaxy with about a trillion other stars.  There are a lot of other galaxies in the observable universe (about 100 billion), distributed evenly on large scales.<br \/>\n<\/p>\n<li> It&#8217;s getting bigger.  Very distant galaxies are moving away from each other.<br \/>\n<\/p>\n<li> It&#8217;s old.  If we trace the expansion backwards in time, everything crunches together about 14 billion years ago, at what we call the &#8220;Big Bang.&#8221;<br \/>\n<\/p>\n<li> We don&#8217;t know how it started.  The Big Bang itself lies outside our current understanding, although we do understand things very well at a time only about 1 second after the Bang.  During or before that first second, we have good ideas but no direct empirical constraints.<br \/>\n<\/p>\n<li> It&#8217;s dark and mysterious.  Only five percent of our universe is &#8220;ordinary&#8221; matter; about 25% is some dark matter particle we haven&#8217;t yet discovered in the lab, and about 70% is a smoothly-distributed and nearly-unchanging dark energy.<br \/>\n<\/p>\n<li> We don&#8217;t know how it will end.  To predict the future would require a better understanding of what the dark energy is and how it will behave in the future.  This is one of the things we&#8217;re trying to understand.<\/ul>\n<p>  That&#8217;s not so many, for such a big universe.  How do we get these into high school curricula?<br \/><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Some reactions to my list of misconceptions about cosmology. Chad Orzel at Uncertain Principles has misconceptions about quantum mechanics and thermodynamics. It&#8217;s a very good list, even if he does say that vacuum energy is useless. It&#8217;s useless in the sense that it cannot be made to do thermodynamic work (because the vacuum energy is [&hellip;]<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-481","post","type-post","status-publish","format-standard","hentry","category-miscellany"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/posts\/481","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/comments?post=481"}],"version-history":[{"count":0,"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/posts\/481\/revisions"}],"wp:attachment":[{"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/media?parent=481"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/categories?post=481"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/tags?post=481"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}