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membrane_theory [2011-02-14 17:04] – FdiywlvrLMtZXEnRU 174.132.220.135membrane_theory [2011-10-27 19:46] (current) – [Subject: we have a theory of everything now - we can all relax] 86.147.222.50
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-lFsgau  <a href="http://ybtliuyixyxi.com/">ybtliuyixyxi</a>, [url=http://nfrydgmgutxz.com/]nfrydgmgutxz[/url], [link=http://bnlnyxebwtwg.com/]bnlnyxebwtwg[/link], http://mygwnjadawis.com/+ 
 +==== Subject: we have a theory of everything now - we can all relax ==== 
 + 
 + 
 + 
 +by Honor Harger (with small edits and transclusions by [[nik gaffney]]) 
 + 
 + 
 +basically, it appears that thanks to the popularisation of the eleventh dimension, a rock climbing physicist's fascination with parallel universes, and some crazy talk by three physicists stuck in a train on their way to london, we now understand everything... 
 +==== The [Latest] Theory of Everything. ==== 
 + 
 +Yep, its sorted now.  We apparently understand more or less everything 
 +about where the universe began, what started it, and what's in it.  It 
 +turns out we live in a lumpy multiversal sea where bubble-like 
 +universes are thrown into each other like tidal waves. 
 + 
 +Here is the deal ..... 
 + 
 + 
 +In the effort to establish a unified theory of everything, a theory of 
 +matter was developed in the 1980s and 90s called String Theory. 
 + 
 + 
 +For years it had been an article of faith that all the matter in the 
 +Universe was made of tiny, invisible particles. In the 1980s the 
 +particle physicists discovered they'd been studying the wrong thing. 
 +The particles were really tiny, invisible strings. The theory was 
 +called String Theory and it maintained that matter emanated from these 
 +tiny strings like music. 
 + 
 + 
 +As physicist, Burt Ovrut comments: "you can think of it as a violin 
 +string or a guitar string. If you pluck it in a certain way you get a 
 +certain frequency, but if you pluck it a different way you can get more 
 +frequencies on this string and in fact you have different notes. Nature 
 +is made of all the little notes, the musical notes, that are played on 
 +these super-strings." 
 + 
 + 
 +Another physicist, Michio Kaku reiterates, "All of a sudden we realised 
 +the Universe is a symphony and the laws of physics are harmonies of a 
 +super-string" 
 + 
 + 
 +String Theory proved provocative.  It was widely considered to be the 
 +closest theory to explaining everything which existed in the Universe. 
 +It seemed to neatly summarise the material aspects of the universe. 
 + 
 + 
 +String Theory utilised additional dimensions in its framework.  The 
 +extra dimensions were spaces in the Universe which we could not 
 +perceive.  String Theory was characterised by considering the universe 
 +as a ten dimensional, but other theories used different numbers of 
 +dimensions. For instance, super gravity, argued by Michael Duff of the 
 +University of Michigan, was a comparatively obscure theory which had 
 +long existed in the shadow of String Theory, as a single unifying 
 +universal theory.  Super gravitists posited that the Universe was 
 +composed of 11 dimensions.  The Eleventh Dimension had always been 
 +ridiculed by String Theorists. 
 + 
 + 
 +If String Theory was to become Einstein's missing Theory of Everything 
 +it would have to pass one test. It would have to explain the birth of 
 +the Universe.  The origins of the Universe had always been the subject 
 +of the cosmologists who believed things had started with a giant 
 +explosion - the Big Bang.  While initially String Theory and the Big 
 +Bang seemed to work perfectly in tandem as dual explanations for the 
 +Universe (one explained its origins, the other everything which existed 
 +in the Universe), problems soon started to emerge. 
 + 
 + 
 +In the early 1990s a major problem with String Theory developed.  As 
 +more people worked in it, competing theories began to be developed, 
 +variants on the original premises of the theory.  In the end, five 
 +separate theories existed, each a subtle variant on the original String 
 +Theory.  For a theory proposing to address the universe's questions, 
 +this was a major problem.  String Theory's credibility rested on its 
 +claim to be a single answer to the universe's mysteries. 
 + 
 + 
 +At the same moment, String Theory began to break down, cosmologists 
 +began to have major problems with the Big Bang as a theory of 
 +explaining the origin of the universe.  As Alan Guth, a cosmologist 
 +explains: "In spite of the fact that we call it the Big Bang Theory it 
 +really says absolutely nothing about the Big Bang. It doesn't tell us 
 +what banged, why it banged, what caused it to bang. It doesn't even 
 +describe, doesn't really allow us to predict what the conditions are 
 +immediately after this bang." 
 + 
 + 
 +In the early 1990s, with String Theory in tatters, a group of 
 +physicists tried one last variant in their calculations.  In a final 
 +desperate move the string theorists tried adding the very thing they 
 +had spent a decade rubbishing: the eleventh dimension. Something almost 
 +magical happened.  When the calculations were re-done, with the 
 +addition of the new dimension, all five variants on String Theory 
 +turned out to be the same theory.  The five String Theories turned out 
 +to be simply different manifestations of a more fundamental theory. 
 +The additional dimension, had not only solved String Theory's problems, 
 +but also had rehabilitated the work of the super gravitists who had 
 +long been operating in the Eleventh Dimension. 
 + 
 + 
 +It looked as if a single unifying theory explaining the universe was, 
 +after all, plausible. 
 + 
 + 
 +The new dimension - the Eleventh - was a strange place.  It was 
 +calculated to be infinitely long, yet extremely narrow in width - an 
 +estimated trillionth of a millimetre wide (and thus imperceptible). The 
 +laws of physics as we know them would likely not operate in this 
 +dimension. 
 + 
 + 
 +When scientist began to experiment using the Eleventh Dimension, 
 +something very odd began to happen.  When physicists began to recreate 
 +their experiments using the additional dimension, they began to 
 +discover that the 'strings' of previous theoretical assumptions, were 
 +turning out to be distinctly 'unstringy'.  The stuff which all matter 
 +was composed, in this new theory seemed much more lumpy, more elastic 
 +than a string.  Now, with the addition of the eleventh dimension, the 
 +tiny invisible strings were changing. They stretched and they combined. 
 +The astonishing conclusion was that all the matter in the Universe was 
 +connected to one vast structure: a membrane. In effect, our entire 
 +Universe is a membrane. The quest to explain everything in the Universe 
 +could begin again and at its heart would be this new theory. Membrane 
 +Theory, or M-Theory for short. 
 + 
 + 
 +( 
 +While all of this took place a rock-climbing physicist from Harvard 
 +University - Lisa Randall - had been greatly troubled by one of our 
 +physical forces: gravity.  Why was it that gravitational force was so 
 +comparatively weak, when compared with other physical forces? Though 
 +intuitively gravity seems rather strong - it fixes us to the planet, 
 +for instance - it is in fact surprisingly weak.  Despite the force of 
 +the sum of the Earth's gravitation pull on us, we are still able to 
 +move, for instance.  Gravity's force can be overcome extremely simply, 
 +by using a weak magnet.  A metallic object such as a pin can be lifted 
 +out of gravity's pull very simply using such a magnet.  Why is this? 
 +Could it be that its force is being dissipated in some way?  Could 
 +gravity be somehow 'leaking' into, for instance, the Eleventh 
 +Dimension?  When Lisa Randall carried out experiments to check the 
 +validity of this hypothesis, her calculations wouldn't compute.  Then, 
 +she started to consider a bizarre proposition.  Instead of gravity 
 +leaking from our universe into one of our more unusual dimensions, 
 +could gravity be instead **originate** from a different membrane, 
 +elsewhere, and be leaking into our universe?  In effect, could gravity 
 +come from a parallel universe?  When Lisa Randall redid her 
 +calculations using an alternative membrane as a point of origin for 
 +gravity, she resolved her equations. The weakness of gravity could at 
 +last be explained, but only by introducing the idea of a parallel 
 +universe 
 + 
 + 
 +The concept of a parallel universe seemed to be hypothetically 
 +plausible, under M-Theory.  Now suddenly physicists all over the world 
 +piled into the eleventh dimension trying to solve age-old problems and 
 +every time it seemed the perfect explanation was another parallel 
 +universe. Everywhere they looked it seemed they began to find more and 
 +more of them. From every corner of the eleventh dimension parallel 
 +universes came crawling out of the woodwork. Some took the form of 
 +three-dimensional membranes, like our own Universe. Others were merely 
 +sheets of energy. Then there were cylindrical and even looped 
 +membranes. Within no time at all the eleventh dimension seemed to be 
 +jam-packed full of membranes.  Physicist Burt Ovrut also proposed that 
 +occasionally membranes would collide.  Universes in the Eleventh 
 +dimension would behave in much the same way as massive turbulent waves, 
 +occasionally banging into each other, creating vast disturbances. 
 + 
 + 
 +M Theory was getting stranger and stranger, but could it really be a 
 +theory which explained everything in our Universe? To have any chance 
 +of that it would have to do something no other rival theory had ever 
 +been able to do. It would have to make sense of the baffling 
 +singularity at the beginning of the Big Bang. 
 + 
 + 
 +In 2002, Neil Turok, Paul Steinhardt and Burt Ovrut had a crazy 
 +conversation in a train on the way to London.  They wondered if the Big 
 +Bang might be the aftermath of some encounter between two parallel 
 +worlds.  Membranes which behaved as waves do, membranes which ripple, 
 +would, in a collision create clumps of energy, some of which could form 
 +into matter. 
 + 
 + 
 +The singularity had disappeared and it had taken them just under an 
 +hour.  If it computed it later experiments, M Theory may really be 
 +able to explain everything in the Universe. 
 + 
 + 
 +Later experiments and calculations seem to have borne out the train 
 +chat.  It seems indeed that our universe could be just one bubble 
 +floating in an ocean of other bubbles. 
 + 
 + 
 +**References:**  
 + 
 + 
 +  * M-theory, the theory formerly known as Strings: The Standard Model Cambridge http://www.damtp.cam.ac.uk/user/gr/public/qg_ss.html 
 +  * Burt Ovrut Dept Physics, University of Pennsylvania http://dept.physics.upenn.edu/facultyinfo/ovrut1.htm 
 +  * The Endless Universe: A Brief Introduction to the Cyclic Universe by Paul J. Steinhardt 
 +  * Joseph Henry Laboratories, Princeton University, Princeton, NJ 08544, USA http://feynman.princeton.edu/~steinh/cyclintro/ 
 +  * Brane-Storm' Challenges Part of Big Bang Theory By Robert Roy Britt http://www.space.com/scienceastronomy/astronomy/bigbang_alternative_010413-1.html 
 +  * Connecting Fundamental Physics and Cosmology http://www.newton.cam.ac.uk/programs/SFU/sfuw03.html 
 +  * Big Bang's New Rival Debuts With a Splash by Charles Seife http://www.phy.pku.edu.cn/~xuegong/ccp1/html/news/sciencenews/sn%204.14%20New%20Rival%20Debuts.htm 
 +  * transcript of BBC interview with Ovrut, Turok and co. http://www.bbc.co.uk/science/horizon/2001/parallelunitrans.shtml 
 + 
 + 
 +more (or less related) notes 
 +  * http://xxx.soton.ac.uk/abs/hep-th/0209158 
 + 
 + 
 +[[Category Physics]]

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