# Ciencia

### Publicado el 5 de Junio, 2013, 6:50

Anterior Post

Hacía un tiempo que no escribía sobre el tema. Esta es una serie de notas personales, más que un estudio ordenado del tema. Son notas para servir de base. Las paso por escrito para no perderlas.

Nota 2

Ver Feynman Diagrams for the Masses (part 1) del bueno de Carl Brennan. Leo ahí:

In the usual way of doing physics, one obtains Feynman diagrams after making a guess at the Lagrangian density. Joseph Louis Lagrange was an 18th century mathematician. The Lagrangian is roughly the kinetic energy minus the potential energy. If we choose a particular form for the kinetic and potential energies we can write down the Lagrangian. From the Lagrangian we can compute the equations of motion. We do this by varying the Lagrangian, that is, by computing the Lagrangian for a set of possible paths and picking a path for which small changes to the path do not change the Lagrangian. Such a path is a possible sequence of values for the positions of our particles (and their momenta). The equations of motion will show up as a set of coupled differential equations.

For a wave theory, like quantum mechanics, the kinetic and potential energies are defined at each point in space-time as a functional of the fields. With $psi$ the wave function, T the kinetic energy, and V the potential energy, one could write the Lagrangian as:

También describe lo que es un propagador, funciones de Green, relación con Fourier, etc... Leo:

In the usual way of doing physics, one obtains Feynman diagrams after making a guess at the Lagrangian density. Joseph Louis Lagrange was an 18th century mathematician. The Lagrangian is roughly the kinetic energy minus the potential energy. If we choose a particular form for the kinetic and potential energies we can write down the Lagrangian. From the Lagrangian we can compute the equations of motion. We do this by varying the Lagrangian, that is, by computing the Lagrangian for a set of possible paths and picking a path for which small changes to the path do not change the Lagrangian. Such a path is a possible sequence of values for the positions of our particles (and their momenta). The equations of motion will show up as a set of coupled differential equations.

For a wave theory, like quantum mechanics, the kinetic and potential energies are defined at each point in space-time as a functional of the fields. With $psi$ the wave function, T the kinetic energy, and V the potential energy, one could write the Lagrangian as:

$L(t) = int_{z=-infty}^{+infty}int_{y=-infty}^{+infty}int_{x=-infty}^{+infty}( T(psi(x,y,z,t)) - V(psi(x,y,z,t))dx;dy;dz$

. Instead of getting an equation of motion for the particles, we get a set of coupled partial differential equations. The partial derivatives show up because of the dependency on position.

If we turned off the interaction, the equations of motion we would get from the Lagrangian in the usual QFT technique would be something like Schrödinger"s equation or Dirac"s equation. The propagators (Green"s functions) for these equations of motion are well known. What is not known are the propagators for the more complicated equations of motion that would give the full Lagrangian. Such a propagator is called "exact". We will direct our effort at this sort of problem, that is, finding the exact propagators (or an approximation to them) for complicated Lagrangians.

Y sigue con la discusión ahí.

Sobre Carl Brennan:

Carl Brannen is well known to the regulars of this blog. He is an independent researcher and my favourite non-professional theorist, because he gives me the hope that brilliant minds, who were diverted from the natural path of doing basic research, may return to it for good. And Carl provides us with another important proof: that institutionalized science does sometimes listen to the voice of those who have something to say regardless of who signs their monthly paycheck. It may give them a hard time getting their papers published, though.

Lo encuentro citado en Guest Post: Carl Brannen, "Position, Spin, And The Particle Generations"

Nota 2

Encuentro lagrangianos en el artículo de Gauge Theory de la Wikipedia. Por ejemplo:

### An example: Scalar O(n) gauge theory

The remainder of this section requires some familiarity with classical or quantum field theory, and the use of Lagrangians.
Definitions in this section: gauge group, gauge field, interaction Lagrangian, gauge boson.

The following illustrates how local gauge invariance can be "motivated" heuristically starting from global symmetry properties, and how it leads to an interaction between fields which were originally non-interacting.

Trata el tema de lagrangiano con simetría global, y luego pasa a local:

Now, demanding that this Lagrangian should have local O(n)-invariance requires that the G matrices (which were earlier constant) should be allowed to become functions of the space-time coordinates x.

Unfortunately, the G matrices do not "pass through" the derivatives,....

The difference between this Lagrangian and the original globally gauge-invariant Lagrangian is seen to be the interaction Lagrangian

$mathcal{L}_mathrm{int} = rac{g}{2} Phi^T A_{mu}^T partial^mu Phi + rac{g}{2} (partial_mu Phi)^T A^{mu} Phi + rac{g^2}{2} (A_mu Phi)^T A^mu Phi$

This term introduces interactions between the n scalar fields just as a consequence of the demand for local gauge invariance.

Ver Interaction Lagrangian. Y por supuesto, tenía que llegar a estas nodas: Lagrangian.

The Lagrangian, L, of a dynamical system is a function that summarizes the dynamics of the system. It is named after Joseph Louis Lagrange. The concept of a Lagrangian was introduced in a reformulation of classical mechanics introduced by Joseph Louis Lagrangein 1788, known as Lagrangian mechanics.

Y ver Hamiltonian mechanics:

Hamiltonian mechanics is a theory developed as a reformulation of classical mechanics and predicts the same outcomes as non-Hamiltonian classical mechanics. It uses a different mathematical formalism, providing a more abstract understanding of the theory. Historically, it was an important reformulation of classical mechanics, which later contributed to the formulation of thequantum mechanics.

Hamiltonian mechanics was first formulated by William Rowan Hamilton in 1833, starting fromLagrangian mechanics, a previous reformulation of classical mechanics introduced by Joseph Louis Lagrange in 1788.

Como ven, son temas que nos van llevando por todos lados. De ahí, que tenga que escribir estas notas ;-).

Nos leemos!

Angel "Java" Lopez
http://www.ajlopez.com

Por ajlopez, en: Ciencia

### Publicado el 4 de Junio, 2013, 7:04

 Les debía estos enlaces, algo más actualizados. Hay más, pero por hoy vienen éstos: La física oculta en el infinito, la transmutación dimensional en teorías de Yang-Mills y un millón de dólares « Francis (th)E mule Science's Newshttp://francisthemulenews.wordpress.com/2009/11/17/la-fisica-oculta-en-el-infinito-la-transmutacion-dimensional-en-teorias-de-yang-mills-y-un-millon-de-dolares/ [0911.1013] Mass in Quantum Yang-Mills Theoryhttp://arxiv.org/abs/0911.1013 El bosón de Higgs y el problema del salto de masa para las ecuaciones de Yang-Mills « Francis (th)E mule Science's Newshttp://francisthemulenews.wordpress.com/2011/06/04/el-boson-de-higgs-y-el-problema-del-salto-de-masa-para-las-ecuaciones-de-yang-mills/ Me ha defraudado Óscar García Prada en su charla sobre la "Existencia de Yang-Mills y del salto de masa" « Francis (th)E mule Science's Newshttp://francisthemulenews.wordpress.com/2011/06/02/me-ha-defraudado-oscar-garcia-prada-en-su-charla-sobre-la-existencia-de-yang-mills-y-del-salto-de-masa/ What is the Higgs boson? - video | Science | guardian.co.ukhttp://www.guardian.co.uk/science/video/2012/jul/03/what-is-a-higgs-boson-video Los conceptos de campo, partícula, partícula virtual y vacío « Francis (th)E mule Science's Newshttp://francisthemulenews.wordpress.com/2012/08/15/los-conceptos-de-campo-particula-particula-virtual-y-vacio/ At a Workshop; and Higgs Papers Are Out | Of Particular Significancehttp://profmattstrassler.com/2012/08/02/at-a-workshop-and-higgs-papers-are-out/ Implications of LHC Results | Not Even Wronghttp://www.math.columbia.edu/~woit/wordpress/?p=4873 Two New Experimental Results | Not Even Wronghttp://www.math.columbia.edu/~woit/wordpress/?p=4885 The Post-Higgs Hangover: where"s the new physics?http://www.quantumdiaries.org/2012/07/19/the-post-higgs-hangover-wheres-the-new-physics/ It"s a Boson! The Higgs as the Latest Offspring of Math & Physics | The Crux | Discover Magazinehttp://blogs.discovermagazine.com/crux/2012/07/30/the-mathematical-magic-behind-the-mysterious-higgs-boson/ How the Higgs can lead us to the dark universe | Not Even Wronghttp://www.math.columbia.edu/~woit/wordpress/?p=4897 Pequeño LdN: 27 kilómetros para entender la masahttp://pequenoldn.librodenotas.com/matiaventuras/1499/27-kilometros-para-entender-la-masa Happy Higgs Day | Not Even Wronghttp://www.math.columbia.edu/~woit/wordpress/?p=4829 CERN: We Have Observed a New Particle | Not Even Wronghttp://www.math.columbia.edu/~woit/wordpress/?p=4823 Proof Evidence of "God Particle" Found | Not Even Wronghttp://www.math.columbia.edu/~woit/wordpress/?p=4809 Higgs, Higgs, Higgs | Not Even Wronghttp://www.math.columbia.edu/~woit/wordpress/?p=4837 That Goddamn Particle « Eye on the ICR http://eyeonicr.wordpress.com/2012/07/06/that-goddamn-particle/ Did the 'God Particle' Create Matter?http://www.icr.org/article/did-god-particle-create-matter/ Quantum Diaries http://www.quantumdiaries.org/2012/07/05/the-celebrated-god-particle-by-mark-twain/ Everything must fit nicely togetherhttp://www.quantumdiaries.org/2012/07/10/everything-must-fit-nicely-together/ "Higgs Boson Will Unlock Great Mysteries of the Universe" --Era of New Physics Looming (Weekend Feature) http://www.dailygalaxy.com/my_weblog/2012/07/higgs-boson-will-unlock-great-mysteries-of-the-universe-era-of-new-physics-looming-weekend-feature.html symmetry breaking » Blog Archive » Higgs in perspective; looking back to 1964http://www.symmetrymagazine.org/breaking/2012/07/06/higgs-in-perspective-looking-back-to-1964/ Mis enlaceshttps://delicious.com/ajlopez/higgs Nos leemos! Angel "Java" Lopezhttp://www.ajlopez.comhttp://twitter.com/ajlopez
Por ajlopez, en: Ciencia

### Publicado el 22 de Mayo, 2013, 17:05

Por ajlopez, en: Ciencia

### Publicado el 14 de Abril, 2013, 17:41

 Anterior Post Más enlaces de este tema, algunos modernos (como lo que pasó con un experimento de neutrinos el año pasado, y algunas noticias de Higgs), otros clásicos. Fock spacehttp://en.wikipedia.org/wiki/Fock_space Nobel Prize, Born Lecturehttp://www.nobelprize.org/nobel_prizes/physics/laureates/1954/born-lecture.pdf The Birth of Quantum Mechanicshttp://www.quantumsciencephilippines.com/75/the-birth-of-quantum-mechanics/ Quantum Theory: Max Bornhttp://www.spaceandmotion.com/quantum-theory-max-born-quotes.htmThe Wave Structure of Matter shows that Max Born's Probability Waves Interpretation of Quantum Theory is due to the incorrect 'particle' conception of Matter. Quantum Physics / Mechanics: Max Bornhttp://www.spaceandmotion.com/physics-quantum-mechanics-max-born.htmThe Wave Structure of Matter (WSM) replaces Max Born's 'Probability Waves' Interpretation of Quantum Wave Mechanics with Real Matter Waves in Physical Space. Max Born Biography, Pictures & Quotes. History and Foundations of Quantum Physicshttp://quantum-history.mpiwg-berlin.mpg.de/main Implications of LHC Resultshttp://www.math.columbia.edu/~woit/wordpress/?p=4873 It’s a Boson! The Higgs as the Latest Offspring of Math & Physicshttp://blogs.discovermagazine.com/crux/2012/07/30/the-mathematical-magic-behind-the-mysterious-higgs-boson/ How the Higgs can lead us to the dark universehttp://www.math.columbia.edu/~woit/wordpress/?p=4897 Spinning out of control!http://www.quantumdiaries.org/2012/07/16/spinning-out-of-control/ Matter wavehttp://en.wikipedia.org/wiki/Matter_wave Cuántica sin fórmulashttp://eltamiz.com/cuantica-sin-formulas/ Did the 'God Particle' Create Matter?http://www.icr.org/article/did-god-particle-create-matter/ Neutrino velocity consistent with speed of lighthttp://www.symmetrymagazine.org/breaking/2012/06/08/neutrino-velocity-consistent-with-speed-of-light/Einstein can breathe a sigh of relief – neutrinos obey the cosmic speed limit after all. July issue of symmetry now onlinehttp://www.symmetrymagazine.org/breaking/2012/07/02/july-issue-of-symmetry-now-online/As excitement builds over what physicists may or may not say about their hunt for the Higgs boson, symmetry goes beyond the “Hamlet question” of whether or not the Higgs exists to ask: What happens next? Stephen Hawking loses Higgs boson particle bet - videohttp://www.guardian.co.uk/science/video/2012/jul/05/stephen-hawking-higgs-boson-bet-video?CMP=twt_gu FTL NEUTRINO RESEARCH 'ALMOST CERTAINLY WRONG'http://news.discovery.com/space/faster-than-light-neutrino-theory-almost-certainly-wrong-111012.html Particles Found to Travel Faster Than Speed of Lighthttp://www.scientificamerican.com/article.cfm?id=particles-found-to-travel&WT.mc_id=SA_WR_20110929 CERN confirms speedy neutrinos follow laws of physics after allhttp://news.cnet.com/8301-11386_3-57449418-76/cern-confirms-speedy-neutrinos-follow-laws-of-physics-after-all/ Into the Subatomic Junglehttp://www.youtube.com/watch?v=up-fbMd_ziU&feature=youtu.be Splitting the unsplittablehttp://www.nanowerk.com/news/newsid=25486.php The Collider, the Particle and a Theory About Fatehttp://www.nytimes.com/2009/10/13/science/space/13lhc.html?_r=2 At a Workshop; and Higgs Papers Are Outhttp://profmattstrassler.com/2012/08/02/at-a-workshop-and-higgs-papers-are-out/ Mis Enlaceshttp://delicious.com/ajlopez/quantum Nos leemos! Angel "Java" Lopezhttp://www.ajlopez.comhttp://twitter.com/ajlopez
Por ajlopez, en: Ciencia

### Publicado el 11 de Abril, 2013, 14:32

 Ya mencioné a Herman Weyl y su libro The Theory of Groups and Quantum Mechanics en Hermann Weyl, fisica y matematicas. Hacia el final de la introducción, encuentro: Our generation is witness to a development of physical knowledge such as has not been seen since the days of Kepler, Galileo and , and mathematics has scarcely ever experienced such a stormy epoch. Mathematical thought removes the spirit from its worldly haunts to solitude and renounces the unveiling of the secrets of Nature. But as recompense, mathematics is less bound to the course of worldly events than physics. While the quantum theory can be traced back only as far as 1900, the origin of the theory of groups is lost in a past scarcely accessible to history; the earliest works of art show that the symmetry groups of plane figures were even then already known, although the theory of these was only given definite form in the latter part of the eighteenth and in the nineteenth centuries. F. Klein considered the group concept. as most characteristic of nineteenth century mathematics. Es interesante ver cómo algo como la teoría de grupos tuvo una larga historia, aunque hay que reconocer que como teoría matemática aparece realmente en el siglo XIX. Igual, es de destacar que tenemos otro ejemplo de matemáticas desarrolladas ANTES de tener una aplicación física. Until the present, its most important application to natural science lay in the description of the symmetry of crystals, but it has recently been recognized that group theory is of fundamental importance for quantum physics; it here reveals the essential features which are not contingent on a special form of the dynamical laws nor on special assumptions concerning the forces involved. We may well expect that it is just this part of quantum physics which is most certain of a lasting place. Y ahora menciona dos grupos que van a tener un rol en su libro: Two groups, the group of rotations in 3-dimensional space and the permutation group, play here the principal role, for the laws governing the possible electronic configurations grouped about the stationary nucleus of an atom or an ion are spherically symmetric with respect to the nucleus, and since the various electrons of which the atom or ion is composed are identical, these possible configurations are invariant under a permutation of the individual electrons. Y otro tema que aparece, cuando los grupos se relacionan con la física: sus representaciones por transformaciones lineales: The investigation of groups first becomes a connected and complete theory in the theory of the representaration of groups by linear transformations, and it is exactly this mathematically most important part which is necessary for an adequate description of the quantum mechanical relations. All quantum numbers, with the exception of the so-called prirtcipal quantum number, are indices characterizing representations of groups. Nunca traté todavía el tema de representaciones de grupos por transformaciones lineales. Pero es interesante encontrar esta temprana referencia en Weyl, que luego llegaría a aplicarse más allá de la teoría cuántica que menciona. Ver Group RepresentationCharacter theoryGroup RepresentationsGroup Representation Theory ahí leo lo principal: Informally, a representation of a group is a way of writing it down as a group of matrices Nos leemos! Angel "Java" Lopezhttp://www.ajlopez.comhttp://twitter.com/ajlopez
Por ajlopez, en: Ciencia

### Publicado el 6 de Abril, 2013, 14:11

 Hoy volví a leer notas y apuntes sobre cuántica, y enlaces que tengo seleccionados. También sobre la historia del desarrollo de la mecánica cuántica. Para llegar a esos enlaces de hoy, sigo publicando otra tanda, para seguir con la serie PARTICULAS SUBATOMICAS Y PARTICULAS ELEMENTALEShttp://platea.pntic.mec.es/jdelucas/particulaselementales.htm The quark model http://jazz.physik.unibas.ch/~irakli/files/Publications/quarks/rpv41i11p1707.pdf The Richard Feynman Trilogy: The Physicist Captured in Three Filmshttp://www.openculture.com/2012/01/the_richard_feynman_film_trilogy.html Lecture 1 | Modern Physics: Quantum Mechanics (Stanford)http://www.youtube.com/watch?v=2h1E3YJMKfA Roger Penrose Says Physics Is Wrong, From String Theory to Quantum Mechanicshttp://m.discovermagazine.com/2009/sep/06-discover-interview-roger-penrose-says-physics-is-wrong-string-theory-quantum-mechanics Quantum decision affects results of measurements taken earlier in timhttp://arstechnica.com/science/2012/04/decision-to-entangle-effects-results-of-measurements-taken-beforehand/ Explaining electron spin and Pauli exclusion principle to childrenhttp://commonsensequantum.blogspot.com.ar/2010/10/explaining-electron-spin-and-pauli.html String theory officially useful, may not represent realityhttp://arstechnica.com/science/2009/02/string-theory-officially-useful-may-not-represent-reality/ Unknotting knot theoryhttp://www.sciencenews.org/view/generic/id/38237/title/Unknotting_knot_theory  Advanced Propulsion Physics: Harnessing the Quantum Vacuum http://nextbigfuture.com/2012/04/quantum-vacuum-propulsion.html OPERA"s Timing Issue Confirmed? Yes!http://profmattstrassler.com/2012/03/30/operas-timing-issue-confirmed/ Higgs vs Popper: Falsification Falsified.http://www.quantumdiaries.org/2012/03/23/higgs-vs-popper-falsification-falsified/ Pinpointing Planck"s Constant with GPShttp://physics.aps.org/synopsis-for/10.1103/PhysRevLett.108.110801 The Quantum Conspiracy: What Popularizers of QM Don't Want You to Knowhttp://www.youtube.com/watch?v=dEaecUuEqfc&feature=relmfu Quantum Mysteries Disentangledhttp://www.flownet.com/ron/QM.pdf Emmy Noether and The Fabric of Realityhttp://www.youtube.com/watch?v=1_MpQG2xXVo&feature=related Researchers send 'wireless' message using neutrinoshttp://phys.org/news/2012-03-wireless-message-neutrinos.html Científicos envían por primera vez un mensaje con un haz de neutrinos http://www.abadiadigital.com/articulo/cientificos-envian-por-primera-vez-un-mensaje-con-un-haz-de-neutrinos/ El CERN consigue medir la antimateriahttp://www.muyinteresante.es/el-cern-consigue-medir-la-antimateria CERN: The Standard Model Of Particle Physicshttp://www.youtube.com/watch?v=V0KjXsGRvoA All on the Higgs for (nearly) everyonehttp://www.quantumdiaries.org/2012/03/02/all-on-the-higgs-for-nearly-everyone/ Quantum computers: introhttp://motls.blogspot.com.ar/2012/02/quantum-computers-intro.html Mis Enlaceshttp://delicious.com/ajlopez/quantum Nos leemos! Angel "Java" Lopezhttp://www.ajlopez.comhttp://twitter.com/ajlopez
Por ajlopez, en: Ciencia

### Publicado el 11 de Marzo, 2013, 13:20

 Ayer me encuentro con este texto de Pascal, que quiero compartir: "... From this, we see that by a particular prerogative, not only does each man advance day by day in the sciences, but all men together make continual progress as the universe ages, because the same thing happens in the aging of mankind as a whole as happens during the aging of a single man. Thus, the entire body of mankind, over many centuries, must be considered as a single man, who lives forever and continues to learn [...]. Those whom we call the ancients were truly new in all things, and form the childhood of mankind; as we have added to their knowledge the experience of the centuries which followed them, it is in ourselves that we should seek the antiquity which we dream of in others.'' Está en su prefacio al Tratado del Vacío. Eso es lo que tiene la ciencia humana, el progreso acumulativo, y desde hace unos siglos, la colaboración que se extiende en siglos para resolver un problema. Como el caso del propio vacío, tema del libro. Se lo niega desde Aristóteles a Descartes, y luego Pascal y cía (Torricelli, por ejemplo), poniéndolo como existente. Hubo un tiempo donde el avance de la ciencia (o proto-ciencia) fue lento. Pero hace unos pocos siglos, se mejoró la comunicación de los descubrimientos y fue más fácil usar el progreso de otros para avanzar en un tema. Hoy las comunicaciones son aún mejor, y tenemos hasta difusión en línea de lo que se va descubriendo y proponiendo. Otro ejemplo, además de la ciencia, es la historia de las matemáticas. Encuentro este texto citado en "Invitation to the Mathematics of Fermat-Wiles", de Yves Hellegouarch. El libro trata el largo camino a la solución del famoso último teorema de Fermat. Ese camino debe considerarse como la construcción de una hermosa catedral del conocimiento humano. El autor mismo colaboró en parte de ese camino. Viendo hacia atrás, Fermat y Pascal son ahora los hombres que eran "new in all things". Nos leemos! Angel "Java" Lopezhttp://www.ajlopez.comhttp://twitter.com/ajlopez
Por ajlopez, en: Ciencia

### Publicado el 23 de Febrero, 2013, 10:14

Por ajlopez, en: Ciencia

### Publicado el 17 de Febrero, 2013, 15:26

Por ajlopez, en: Ciencia

### Publicado el 12 de Febrero, 2013, 15:15

Por ajlopez, en: Ciencia

### Publicado el 6 de Febrero, 2013, 14:30

Por ajlopez, en: Ciencia

### Publicado el 26 de Enero, 2013, 6:27

Por ajlopez, en: Ciencia

### Publicado el 16 de Diciembre, 2012, 14:21

Por ajlopez, en: Ciencia

### Publicado el 9 de Diciembre, 2012, 15:00

Por ajlopez, en: Ciencia

### Publicado el 6 de Diciembre, 2012, 14:01

Por ajlopez, en: Ciencia

### Publicado el 27 de Noviembre, 2012, 13:37

 Anterior Post Más enlaces que he estado coleccionado, visitando (algunos pendientes de revisión), sobre un tema que nos lleva desde la física de altas energías a la cosmología, a la epistemología y a pensar sobre el método científico. Para mí, la teoría de cuerdas es un modelo demasiado amplio, que ha tenido aceptación porque permite evitar infinitos. Pero nos debe todavía una corroboración por experiencia o experimento. String Theory Basicshttp://www.superstringtheory.com/basics/index.html String theory officially useful, may not represent realityhttp://arstechnica.com/science/news/2009/02/string-theory-officially-useful-may-not-represent-reality.ars Physical reality of string theory demonstratedhttp://esciencenews.com/articles/2009/07/06/physical.reality.string.theory.demonstrated South Pole Neutrino Detector Could Yield Evidences of String Theoryhttp://phys.org/news10295.html A Scientist Takes On Gravity - NYTimes.comhttp://www.nytimes.com/2010/07/13/science/13gravity.html?_r=1It"s hard to imagine a more fundamental and ubiquitous aspect of life on the Earth than gravity, from the moment you first took a step and fell on your diapered bottom to the slow terminal sagging of flesh and dreams. But what if it"s all an illusion, a sort of cosmic frill, or a side effect of something else going on at deeper levels of reality? New Scientist Is string theory in trouble? - Interviewhttp://www.newscientist.com/channel/fundamentals/mg18825305.800.html Unknotting knot theoryhttp://www.sciencenews.org/view/generic/id/38237/title/Unknotting_knot_theoryNew techniques are beginning to unravel the mysteries of knots, revealing a great mathematical superstructure in the process M-theoryhttp://en.wikipedia.org/wiki/M-theoryIn theoretical physics, M-theory is an extension of string theory in which 11 dimensions are identified. Because the dimensionality exceeds that of superstring theories in 10 dimensions, proponents believe that the 11-dimensional theory unites all five string theories (and supersedes them). Introduction to M-Theoryhttp://en.wikipedia.org/wiki/Introduction_to_M-theory Brian Greene on string theory | Video on TED.comhttp://www.ted.com/index.php/talks/brian_greene_on_string_theory.html Physicist Brian Greene explains superstring theory, the idea that minscule strands of energy vibrating in 11 dimensions create every particle and force in the universe. Science in Two Minutes or Lesshttp://discovermagazine.com/twominutesorlessString theory contest winners announced Visualizing up to ten dimensions - Boing Boinghttp://www.boingboing.net/2009/08/18/visualizing-up-to-te.htmlThis is a short animation that takes the viewer through a progressive description of all (and all possible) dimensions, up to and including the 10th. It is an elegant introduction to the fundamentals of string theory and a mind-blowing toe-dip into the pool of the metaphysical The Official String Theory Web Sitehttp://www.superstringtheory.com/ Edward Witten on String theoryhttp://www.3quarksdaily.com/3quarksdaily/2012/04/edward-witten-on-string-theory.html The accidental universe: Science's crisis of faith—By Alan P. Lightmanhttp://www.harpers.org/archive/2011/12/0083720 Abstruse Goose » The 13.7 Billion Year Experimenthttp://abstrusegoose.com/424 AdS/CFT correspondence - Wikipedia, the free encyclopediahttp://en.wikipedia.org/wiki/AdS/CFT_correspondenceThis is a KEY relation. Only for Mathematics? Or Physics? Originally proposed by argentinean physics Juan Maldacena M-theory, the theory formerly known as Stringshttp://www.damtp.cam.ac.uk/research/gr/public/qg_ss.html Electric charge in string theoryhttp://physics.stackexchange.com/questions/5665/electric-charge-in-string-theory The mass of an elementary particle in string theory is related with the way the string vibrates. The more frantically a string vibrates the more energy it posses and hence the more massive it is. My question is how is the electric charge of a particle is described in S.T. How is the opposite charges described? More specifically, I would like to know how a particle and its antiparticle are conceptualized? String and M-theory: answering the criticshttp://www.math.columbia.edu/~woit/wordpress/?p=4219 Welcome to the Multiversehttp://www.math.columbia.edu/~woit/wordpress/?p=4043...that multiverse mania is driven by string theory... Quest to Find a Menagerie of Exotic Particles : Discovery Newshttp://news.discovery.com/space/the-quest-to-find-a-menagerie-of-exotic-particles.htmlThe hypothetical "X" particle recently suggested as a dark matter candidate by scientists at Brookhaven isn't the only exotic particle that physicists have proposed in recent years. Quantum Field Theory (Stanford Encyclopedia of Philosophy)http://plato.stanford.edu/entries/quantum-field-theory/ My Linkshttp://delicious.com/ajlopez/stringtheory
Por ajlopez, en: Ciencia

### Publicado el 23 de Noviembre, 2012, 13:20

Por ajlopez, en: Ciencia