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--- membrane_theory [2011-02-14 17:04] – FdiywlvrLMtZXEnRU 174.132.220.135
+++ membrane_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]]