The Observer - Harvard physicist gives talk on string ... - Lisa Randall

<strong>The</strong> <strong>Observer</strong> - <strong>Harvard</strong> <strong>physicist</strong> <strong>gives</strong> <strong>talk</strong> on string theory●●Middle East conflictSex & Dating: SpringBreak QuizOne Foot Out the Door:Symptoms of senioritiskicking inLast Issue● Epic visually lush 300first worthwhile film of2007●●Erb, Hrinda, andHannen bring homevictoriesSagartz sisters to sharesoftball diamond onelast time next week<strong>The</strong> current particle physics view is that the universeis made up of fundamental particles which are unableto be broken down into smaller parts."It's funny that the name for atoms comes from thefact that they are supposed to be indivisible andunchanging," said Randall. "But we detected thembecause they change and divide."<strong>The</strong> current candidate for the most fundamentalparticle is the quark, which makes up protons andneutrons. However, Randall asserts that the standardmodel is incomplete, and that string theory canaccount for the discrepancies.One problem that Randall noted is the difficulty inreconciling general relativity, used in large-scaleproblems, and quantum theory, used on muchsmaller scales. One method of reconciliation is stringtheory, which states that fundamental particles aresimply one-dimensional strings. <strong>The</strong>se strings vibratein different ways that mark them as the neutrons,protons, and other particles that we see.Randall also promoted the idea of multipledimensions as a way to address problems that havebaffled <strong>physicist</strong>s for years and to deduceconnections that might otherwise be missed. Shenoted that string theory only makes sense if thereare extra dimensions to work with. She remainedpragmatic, however."Even if there are no extra dimensions, thinkingoutside of our framework raises other questions,"said Randall.She then discussed how extra dimensions wouldwork in geometry, starting with a zero-dimensionalpoint and working up to a four-dimensionalhypercube. She also mentioned the difficulty inrendering a hypercube in three or even twodimensions."Just because extra dimensions are hard to picturedoesn't mean they don't exist," said Randall.As an example, she brought up the book Flatland byEdwin A. Abbott, wherein a two-dimensional squareencounters a three-dimensional sphere. <strong>The</strong> onlyway for the square to experience the sphere is as aseries of expanding and shrinking circles. Similarly, ahypercube could only be experienced by threedimensionalhumans as a series of expanding andshrinking cubes.Randall contended that the best way to describe suchobjects is with words. "With this, a word is worth1000 pictures."If all these extra dimensions exist, why can't they beseen? Several theories abound, including the ideathat the extra dimensions are rolled up to a tiny size."People think, if something's that tiny, it might aswell not be there," said Randall.Randall's theory is that there are "membranes" thathttp://observer.case.edu/Archives/Volume_39/Issue_21/Story_1553/ (2 of 3)5/19/2008 4:16:01 PM