{"id":1057,"date":"2006-12-19T05:33:16","date_gmt":"2006-12-19T10:33:16","guid":{"rendered":"http:\/\/blogs.discovermagazine.com\/cosmicvariance\/2006\/12\/19\/what-we-know-and-dont-and-why\/"},"modified":"2006-12-19T05:33:16","modified_gmt":"2006-12-19T10:33:16","slug":"what-we-know-and-dont-and-why-2","status":"publish","type":"post","link":"https:\/\/preposterousuniverse.com\/blog\/2006\/12\/19\/what-we-know-and-dont-and-why-2\/","title":{"rendered":"What We Know, and Don&#8217;t, and Why"},"content":{"rendered":"<p>Yeah, I already <a href=\"http:\/\/preposterousuniverse.blogspot.com\/2004\/12\/what-we-know-and-dont-and-why.html\">used this title<\/a> once before.  It&#8217;s a good title, okay?  Cut me a little holiday slack here.<\/p>\n<p>By way of slightly-warmed-over blogging, I present to you the <a href=\"http:\/\/preposterousuniverse.com\/talks\/whatweknow\/\">slides from a talk<\/a> I gave a few weeks ago at Villanova, my undergrad alma mater.   The original mandate was to talk about scientific literacy to a collection of undergrads, but I didn&#8217;t know how to make that fascinating.  So I took it to the next level and went a bit meta, talking about the way science works.  It was at a fairly abstract level &#8212; I didn&#8217;t go into building detectors, and error bars, or anything like that &#8212; but not too highbrow philosophy-of-sciencey &#8212; I didn&#8217;t get into Kuhn vs. Popper, much less Feyerabend or the <a href=\"http:\/\/en.wikipedia.org\/wiki\/Strong_programme\">Strong Programme<\/a>, although you&#8217;ll find touches here and there.<\/p>\n<p><a href=\"http:\/\/preposterousuniverse.com\/talks\/whatweknow\/\"><img class='center' src='http:\/\/blogs.discovermagazine.com\/cosmicvariance\/files\/uploads\/whatweknow.gif' alt='' \/><\/a><\/p>\n<p>To bring things down to earth (relatively speaking), most of the talk consisted of an extended look at the battle between &#8220;dark matter&#8221; and &#8220;modified gravity.&#8221;  It goes all the way back to <a href=\"http:\/\/en.wikipedia.org\/wiki\/Leverrier\">Leverrier<\/a> and the discovery of Neptune, whose existence was inferred via its gravitational tug on the orbit of Uranus.  Neptune was the first successful prediction of dark matter &#8212; some unseen substance whose existence is revealed by its gravitational influence.  Leverrier tried again with the similarly-discrepant orbit of Mercury, positing a planet called Vulcan; but this time it turned out that gravity itself was the culprit, after Einstein showed that general relativity correctly accounted for the precession of Mercury&#8217;s orbit.  So the lesson from history is &#8212; different ideas work in different circumstances.  Keep an open mind until the data come down on one side or another.  (And once they do, admit it.)<\/p>\n<p>Today, of course, we&#8217;re dealing with an analogous problem, given that 25% of the universe is apparently some kind of dark matter that doesn&#8217;t fit into the Standard Model of particle physics, and 70% is some kind of dark energy that is even more mysterious.  Modified gravity might be at work here as well, and I talked about the prospects.<\/p>\n<p>Along the way, I drew out some of the lessons about how science works that these various investigations have taught us.  I intentionally did not try to wrap it all up with a neat bow into a catch-all philosophy of science, as I think the reality is kind of messy, and it&#8217;s worth admitting that.  The closest I came was the famous quote from <a href=\"http:\/\/blogs.discovermagazine.com\/cosmicvariance\/2006\/11\/10\/toward-a-unified-epistemology-of-the-natural-sciences\/\">Professor Rumsfeld<\/a>, previously shared.  This led to a series of cautionary homilies warning against misuse of the hypothesis-testing nature of scientific inquiry.  The truth is, scientific knowledge is inevitably tentative, not metaphysically certain.  But that doesn&#8217;t mean that anything goes &#8212; some things we really do understand!  So I cautioned against various mistakes, using perpetual-motion machines, Intelligent Design, and <em>What the Bleep Do We Know<\/em> as good examples of what not to do.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Yeah, I already used this title once before. It&#8217;s a good title, okay? Cut me a little holiday slack here. By way of slightly-warmed-over blogging, I present to you the slides from a talk I gave a few weeks ago at Villanova, my undergrad alma mater. The original mandate was to talk about scientific literacy [&hellip;]<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[28],"tags":[],"class_list":["post-1057","post","type-post","status-publish","format-standard","hentry","category-science"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/posts\/1057","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=1057"}],"version-history":[{"count":0,"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/posts\/1057\/revisions"}],"wp:attachment":[{"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/media?parent=1057"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/categories?post=1057"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/preposterousuniverse.com\/blog\/wp-json\/wp\/v2\/tags?post=1057"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}