See: Brian Greene
How many goodly creatures are there here!
How beauteous mankind is! O brave new world,
That has such people in't.
|Brave New World Revisited|
In the Kaluza-Klein picture, the extra dimensions are envisioned as being rolled up in compact space with a very small volume, with massive excited states called Kaluza-Klein modes whose mass makes them too heavy to be observed in current or future accelerators.
The braneworld scenario for having extra dimensions while hiding them from easy detection relies on allowing the extra dimensions to be noncompact, but with a warped metric that depends on the extra dimensions and so is not a direct product space. A simple model in five spacetime dimensions is the Randall-Sundrum model, with metric See: Kaluza-Klein in String Theory
The general theory of relativity is as yet incomplete insofar as it has been able to apply the general principle of relativity satisfactorily only to gravitational fields, but not to the total field. We do not yet know with certainty by what mathematical mechanism the total field in space is to be described and what the general invariant laws are to which this total field is subject. One thing, however, seems certain: namely, that the general principal of relativity will prove a necessary and effective tool for the solution of the problem for the total field. -Out of My Later Years, Pg 48, Albert Einstein (bold and underlined added for emphasis)
We argue that the following three statements cannot all be true: (i) Hawking radiation is in a pure state, (ii) the information carried by the radiation is emitted from the region near the horizon, with low energy effective field theory valid beyond some microscopic distance from the horizon, and (iii) the infalling observer encounters nothing unusual at the horizon. Perhaps the most conservative resolution is that the infalling observer burns up at the horizon. Alternatives would seem to require novel dynamics that nevertheless cause notable violations of semiclassical physics at macroscopic distances from the horizon. Black Hole: Complementarity vs Firewall
|See:The elephant and the event horizon 26 October 2006 by Amanda Gefter at New Scientist.|
Various neutron interferometry experiments demonstrate the subtlety of the notions of duality and complementarity. By passing through the interferometer, the neutron appears to act as a wave. Yet upon passage, the neutron is subject to gravitation. As the neutron interferometer is rotated through Earth's gravitational field a phase change between the two arms of the interferometer can be observed, accompanied by a change in the constructive and destructive interference of the neutron waves on exit from the interferometer. Some interpretations claim that understanding the interference effect requires one to concede that a single neutron takes both paths through the interferometer at the same time; a single neutron would "be in two places at once", as it were. Since the two paths through a neutron interferometer can be as far as 5 cm to 15 cm apart, the effect is hardly microscopic. This is similar to traditional double-slit and mirror interferometer experiments where the slits (or mirrors) can be arbitrarily far apart. So, in interference and diffraction experiments, neutrons behave the same way as photons (or electrons) of corresponding wavelength. See: Complementarity (physics)
At the heart of modern cosmology is a mystery: Why does our universe appear so exquisitely tuned to create the conditions necessary for life? In this tour de force tour of some of science's biggest new discoveries, Brian Greene shows how the mind-boggling idea of a multiverse may hold the answer to the riddle.Brian Greene is perhaps the best-known proponent of superstring theory, the idea that minuscule strands of energy vibrating in a higher dimensional space-time create every particle and force in the universe.
|Fig.3 Revisionist History and String Theory and the Real World|
|The newly-installed Alpha Magnetic Spectrometer-2 (AMS)|
Excerpt from "Alpha Magnetic Spectrometer - A Physics Experiment on the International Space Station" by Dr. Sam Ting: The Alpha Magnetic Spectrometer (AMS-02) is a state-of-the-art particle physics detector constructed, tested and operated by an international team composed of 60 institutes from 16 countries and organized under United States Department of Energy (DOE) sponsorship. The AMS-02 will use the unique environment of space to advance knowledge of the universe and lead to the understanding of the universe's origin by searching for antimatter, dark matter and measuring cosmic rays.
Experimental evidence indicates that our Galaxy is made of matter; however, there are more than 100 hundred million galaxies in the universe and the Big Bang theory of the origin of the universe requires equal amounts of matter and antimatter. Theories that explain this apparent asymmetry violate other measurements. Whether or not there is significant antimatter is one of the fundamental questions of the origin and nature of the universe. Any observations of an antihelium nucleus would provide evidence for the existence of antimatter. In 1999, AMS-01 established a new upper limit of 10-6 for the antihelium/helium flux ratio in the universe. AMS-02 will search with a sensitivity of 10-9, an improvement of three orders of magnitude, sufficient to reach the edge of the expanding universe and resolve the issue definitively.
The visible matter in the universe (stars) adds up to less than 5 percent of the total mass that is known to exist from many other observations. The other 95 percent is dark, either dark matter (which is estimated at 20 percent of the universe by weight or dark energy, which makes up the balance). The exact nature of both still is unknown. One of the leading candidates for dark matter is the neutralino. If neutralinos exist, they should be colliding with each other and giving off an excess of charged particles that can be detected by AMS-02. Any peaks in the background positron, anti-proton, or gamma flux could signal the presence of neutralinos or other dark matter candidates.
Six types of quark (u, d, s, c, b and t) have been found experimentally, however all matter on Earth is made up of only two types of quarks (u and d). It is a fundamental question whether there is matter made up of three quarks (u, d and s). This matter is known as Strangelets. Strangelets can have extremely large mass and very small charge-to-mass ratios. It would be a totally new form of matter. AMS will provide a definitive answer on the existence of this extraordinary matter. The above three examples indicates that AMS will probe the foundations of modern physics.
Cosmic radiation is a significant obstacle to a manned space flight to Mars. Accurate measurements of the cosmic ray environment are needed to plan appropriate countermeasures. Most cosmic ray studies are done by balloon-borne satellites with flight times that are measured in days; these studies have shown significant variations. AMS-02 will be operative on the ISS for a nominal mission of 3 years, gathering an immense amount of accurate data and allowing measurements of the long term variation of the cosmic ray flux over a wide energy range, for nuclei from protons to iron. After the nominal mission, AMS-02 can continue to provide cosmic ray measurements. In addition to the understanding the radiation protection required for manned interplanetary flight, this data will allow the interstellar propagation and origins of cosmic rays to be pinned down. See: The newly-installed Alpha Magnetic Spectrometer-2 (AMS)
|Click on Image to go to appropriate site for image dedication|
|Albrecht Dürer(self portrait at 28) See also: Albrecht Durer and His Magic Square|
Physicists Andrew Strominger and Cumrin Vafa, showed that this exact entropy formula can be derived microscopically (including the factor of 1/4) by counting the degeneracy of quantum states of configurations of strings and D-branes which correspond to black holes in string theory. This is compelling evidence that D-branes can provide a short distance weak coupling description of certain black holes! For example, the class of black holes studied by Strominger and Vafa are described by 5-branes, 1-branes and open strings traveling down the 1-brane all wrapped on a 5-dimensional torus, which gives an effective one dimensional object -- a black hole.
The crystalline state is the simplest known example of a quantum , a stable state of matter whose generic low-energy properties are determined by a higher organizing principle and nothing else. Prof. Robert B. Laughlin
Using the anti–de Sitter/conformal field theory correspondence to relate fermionic quantum critical fields to a gravitational problem, we computed the spectral functions of fermions in the field theory. By increasing the fermion density away from the relativistic quantum critical point, a state emerges with all the features of the Fermi liquid. See:String Theory, Quantum Phase Transitions, and the Emergent Fermi LiquidWhat can we say then is emergent? So you are learning to count in geometrical expressions as a placement of the Genus figures? So what correlations can be drawn toward the beginning of such counting?
Where would these other universes be in relation to ours? Is there a way to envision it?Well, we live in three spatial dimensions: We move back and forth, up and down, left to right. And then there's time, so that's our four-dimensional universe. Another universe might be essentially right next to ours by going in another direction that's not one of those four. We might call it "another kind of sideways." See: Riddles of the Multiverse
SOCRATES: But if he always possessed this knowledge he would always have known; or if he has acquired the knowledge he could not have acquired it in this life, unless he has been taught geometry; for he may be made to do the same with all geometry and every other branch of knowledge. Now, has any one ever taught him all this? You must know about him, if, as you say, he was born and bred in your house.SEE:Meno by Plato
LEE SMOLIN- Physicist, Perimeter Institute; Author, The Trouble With Physics
Thinking In Time Versus Thinking Outside Of Time
One very old and pervasive habit of thought is to imagine that the true answer to whatever question we are wondering about lies out there in some eternal domain of "timeless truths." The aim of re-search is then to "discover" the answer or solution in that already existing timeless domain. For example, physicists often speak as if the final theory of everything already exists in a vast timeless Platonic space of mathematical objects. This is thinking outside of time. See:A "scientific concept" may come from philosophy, logic, economics, jurisprudence, or other analytic enterprises, as long as it is a rigorous conceptual tool that may be summed up succinctly (or "in a phrase") but has broad application to understanding the world.
It is believed that in the first few microseconds after the Big Bang, our universe was dominated by a strongly interacting phase of nuclear matter at extreme temperatures. An impressive experimental program at the Brookhaven National Laboratory on Long Island has been studying the properties of this nuclear plasma with some rather surprising results. We outline how there may be a deep connection between extra-dimensional gravity of String Theory and the fundamental theories of subatomic particles can solve the mystery of the near-ideal fluid properties of the strongly coupled nuclear plasma.
PHENIX, the Pioneering High Energy Nuclear Interaction eXperiment, is an exploratory experiment for the investigation of high energy collisions of heavy ions and protons. PHENIX is designed specifically to measure direct probes of the collisions such as electrons, muons, and photons. The primary goal of PHENIX is to discover and study a new state of matter called the Quark-Gluon Plasma.
In summary, experiments at RHIC have shown that a very dense QCD medium is formed in high-energy heavy-ion collisions. Other measurements, namely elliptic flow and baryon-to-meson ratios, indicate that this medium is characterized by partonic degrees offreedom and that its expansion and cooling is well described by hydrodynamical models with high viscosity. Thus, this medium is more similar to a liquid than to a gas of gluons and quarks.Review on Heavy-Ion Physics
To be sure, the majority of research into string theory is not focused on how the theory connects to the real world; rather, most physicists are exploring questions at a more theoretical level. Such formal work is necessary, because as noted above, we need a deeper understanding to fully formulate the theory. Even the many theorists who are interested in how string theory connects to the real world don’t typically think much about what it means to test the theory. Fortunately, an increasingly active group of “string phenomenologists” are focusing on formulating a string-based description of the world and testing that understanding. They are already making testable predictions, and will increasingly do so.String Theory and the Real World by Gordon Kane
|Pythagoras, the man in the center with the book, teaching music, in The School of Athens by Raphael|
The Greek Pythagoras, for instance, was able to use abstract but simple mathematics to describe a natural phenomenon very precisely. He discovered the fractions that govern the harmonious musical notes. For example, a stretched string on a violin that produces a C note when you strike it, will give a C an octave higher when you divide its length by two. (Similarly, when we cut of a quarter of the length of the original string, the new string will sound like an E note) This is a famous early example of the use of mathematics to describe a physical phenomenon accurately. Pythagoras used the mathematics of fractions to describe the frequency of musical notes. In the ages that followed, of Galilei, Kepler, Newton and Einstein, mathematics became the prime language to depict nature. The mathematics of numbers, sets, functions, surfaces et cetera turned out to be the most useful tool for those people that felt the urge to understand the laws governing nature. See: Beyond String Theory-Introduction-Natural Language
music theory, the major scale or Ionian scale is one of the diatonic scales. It is made up of seven distinct notes, plus an eighth which duplicates the first an octavesolfege these notes correspond to the syllables "Do, Re, Mi, Fa, Sol, La, Ti/Si, (Do)", the "Do" in the parenthesis at the end being the octave of the root. The simplest major scale to write or play on the piano is C major, the only major scale not to require sharps or flats, using only the white keys on the piano keyboard:
Monochord is a one-stringed instrument with movable bridges, used for measuring intervals. The first monochord is attributed to Pythagoras.
The story is told that Pythagoras wished to invent an instrument to help the ear measure sounds the same way as a ruler or compass helps the eye to measure space or a scale to measure weights. As he was thinking these thoughts, he passed by a blacksmith's shop. By a happy chance, he heard the iron hammers striking the anvil. The sounds he heard were all consonant to each other, in all combinations but one. He heard three concords, the diaspason (octave), the diapente (fifth), and the diatessaron (fourth). But between the diatessaron (fourth) and the diapente (fifth), he found a discord (second). This interval he found useful to make up the diapason (octave). Believing this happy discovery came to him from God, he hastened into the shop and, by experimenting a bit, found that the difference in sounds were determined by the weight of the hammers and not the force of the blows. He then took the weight of the hammers and went straight home. When he arrived home, he tied strings from the beams of his room. After that, he proceeded to hang weights from the strings equal to the weights he found in the smithy's shop. Setting the strings into vibration, he discovered the intervals of the octave, fifth and fourth. He then transferred that idea into an instrument with pegs, a string and bridges. The monochord was the very instrument he had dreamed of inventing. See: String Instruments including Oud, Folk Fiddle, and Monochord, dan bau, from Carousel Publications Ltd
Pythagoras could be called the first known string theorist. Pythagoras, an excellent lyre player, figured out the first known string physics -- the harmonic relationship. Pythagoras realized that vibrating Lyre strings of equal tensions but different lengths would produce harmonious notesratio of the lengths of the two strings were a whole number. (i.e. middle C and high C) if the
Pythagoras discovered this by looking and listening. Today that information is more precisely encoded into mathematics, namely the wave equation for a string with a tension T and a mass per unit length m. If the string is described in coordinates as in the drawing below, where x is the distance along the string and y is the height of the string, as the string oscillates in time t,
See: Official String Theory Web Site
All our dreams can come true, if we have the courage to pursue them.
Witten once called string theory "a bit of 21st century physics that somehow dropped into the 20th century." If so, Witten clearly has the 21st century mind to handle it.
fancier way of saying that is that in general, it's okay to model the space around us using the Euclidean metric. But the Euclidean model stops working when gravity becomes strong, as we'll see later. The Euclidean model for space
We are told that "mathematics is that study which knows nothing of observation..." I think no statement could have been more opposite to the undoubted facts of the case; that mathematical analysis is constantly invoking the aid of new principles, new ideas and new methods, not capable of being defined by any form of words, but springing direct from the inherent powers and activity of the human mind, and from continually renewed introspection of that inner world of thought of which the phenomena are as varied and require as close attention to discern as those of the outer physical world, ...that it is unceasingly calling forth the faculties of observation and comparison, that one of its principal weapons is induction, that it has frequent recourse to experimental trial and verification, and that it affords a boundless scope for the exercise of the highest efforts of imagination and invention. ...Were it not unbecoming to dilate on one's personal experience, I could tell a story of almost romantic interest about my own latest researches in a field where Geometry, Algebra, and the Theory of Numbers melt in a surprising manner into one another.
It was the beginning of what might be called (and in fact is called) Stringy Geometry. The point is that strings are not points, and specifically, their extended nature means that in addition to being able to see the usual geometrical properties of a space that the theory like General Relativity can see, the strings can see other, intrinsically stringy, data. There is a quantity in the theory that is called the Kalb-Ramond field (or just the “B-field”) that can be used to measure how much the string can winds on or wraps a piece of the geometry, in essence. The parameter a that measures the size of a piece of the space that collapses when the geometry becomes singular, is essentially joined by another parameter, b, that sort of measures how much the strings have wound or smeared themselves on that piece of the space. The upshot is that a and b naturally combine themselves into a complex parameter that naturally describes the resolution process, solving the puzzle that the Mathematicians faced.Beyond Einstein: Fixing Singularities in Spacetime
"I have never deviated from the name I use, so you get the sense of who I am.
I do not see how "pushing back the physics and energies involved" would have made these issues abut cosmology inept or classed as fantasy in the making.
Tim May, some things helped toward our understanding whether they are in the kitchen "to help gain in conceptual understanding, what others are less then able to explain in their opinion biased.Gabe:I really don’t have any knowledge of this, but: What exactly are they trying to say about liquid helium phases and extra dimensions?
Has anyone has sufficiently answered Coin or Gabe in their questions to have offered a conclusion?
Thanks Bee for challenging what would have otherwise been a chorus of the same ole, same ole."
DOI: 10.1038/nphys815-Richard Haley, George Pickett and co-workers have taken a lateral step to address this barrier. They cool helium-3 isotope to a superfluid state — that is, a quantum fluid with non-classical properties such as completely frictionless flow. Adding a magnetic field creates a second superfluid phase, and the interface between these two phases behaves like a two-dimensional brane. Indeed, the collision of a brane–antibrane pair leaves traces of a stringy residue of defects: a tangle of vortices.
Yes, according to one group of physicists. A team at Lancaster University in the United Kingdom has used liquid helium and a magnetic field to build a finger-sized representation of the early cosmos. Their findings, published today in Nature Physics 1, could help string theorists to refine their models.
The subject of string cosmology is a hot one these days, with theoretical advances in understanding string dynamics riffing with recent precise observations of the cosmic microwave background
The quality of the details of the comparison between 3He and cosmology is not really the point. Like a tap-dancing snake, what is amazing is not that it is done well, but that it is done at all.
The test tube, the size of a little finger, has been cooled to a fraction of a degree above the lowest possible temperature, absolute zero, which is just over 273 degrees below the freezing point of water.
Inside the tube an isotope of helium (called helium three) forms a "superfluid", an ordered liquid where all the atoms are in the same state according to the theory that rules the subatomic domain, called quantum theory.
What is remarkable is that atoms in the liquid, at temperatures within a thousandth of a degree of absolute zero, form structures that, according to the team at Lancaster University, are similar those seen in the cosmos.
"In effect, we have made a universe in a test tube," says Richard Haley, who did the work with Prof George Pickett and other members of the "Ultra-low Temperature Group."