the superstring adventure

50 %
50 %
Information about the superstring adventure
Entertainment

Published on October 15, 2007

Author: Lindon

Source: authorstream.com

Adventures with Superstrings:  Adventures with Superstrings Robert Myers (Einstein-Plus: July 7, 2005) Slide2:  “Superstring theory is a piece of 21st century physics that fell into the 20th century” Ed Witten (Princeton): Slide3:  Physics of the 20th century: A grand synthesis and progression of ideas! Slide4:  Einstein: Gravity: It’s all just straight lines! Special Relativity (1905): Space and time are inextricably linked Spacetime General Relativity (1915): Gravity is a manifestation of spacetime curvature. Slide5:  General Relativity: a rich source of new ideas Black holes Gravitational waves Expanding universe Slide6:  General Relativity is rigorously tested!! Deflection of Light by the Sun Gravitational Redshift Precession of the Perihelion of Mercury Time Delay of Light, . . . . . Hulse and Taylor: Nobel Prize in 1993!! Slide7:  General Relativity is rigorously tested!! Global Positioning System (GPS): Accurate positioning requires accounting for affects of general relativity on clocks in orbit and on earth Slide8:  General Relativity is rigorously tested!! Deflection of Light by the Sun Gravitational Redshift Precession of the Perihelion of Mercury Time Delay of Light, . . . . . Hulse and Taylor: Nobel Prize in 1993!! General Relativity is the geometric arena of physics on very large scales: planets, stars, galaxies, cosmology Slide9:  Quantum Mechanics (or Quantum Field Theory) is the probabilistic arena of physics on very small scales de Broglie wavelength: Quantum fluctuations are manifest in behavior of subatomic particles Particles can act like waves! electron beam Planck’s constant Å water jet Slide10:  Elementary Particles ( 10 m ) ─17 Fermions - spin ½ : electron, muon, tauon neutrinos (3 flavors) quarks - up, down, strange, charm, bottom, top Bosons (Force Mediators): photon (electromagnetism) gluon (strong) , Z (weak) spin Higgs particle – spinless or spin 0 Standard Model of Subatomic Physics: above particles plus interactions (and ~20 free parameters) Quantum Field Theory is the probabilistic arena of physics on very small scales Slide11:  Standard Model is rigorously tested!! Individual electrons are tiny magnets precise value of magnetic moment depends on quantum fluctuations Example: Slide12:  Standard Model is rigorously tested!! e.g., magnetic moment of the electron, , is modified by quantum fluctuations e.g., Lamb shift: shift between 2S1/2 and 2P1/2 energy levels of hydrogen atom (f = 1057 MHz) Slide13:  band structure in materials semiconductor technology Bose-Einstein condensation superfluids, superconductors quantum Hall effect, neutron diffraction, electron microscopy, lasers, magnetic resonance imaging, · · · · · · · Quantum Theory: a rich source of new ideas Nobel prizes galore!! Slide14:  Subatomic Physics Elementary Particles ( 10 m ) ─17 Fermions - spin ½ : electron, muon, tauon neutrinos (3 flavors) quarks - up, down, strange, charm, bottom, top Bosons (Force Mediators): photon (electromagnetism) gluon (strong) , Z (weak) spin Higgs particle – spinless or spin 0 a theory of strings! Strings tame the particle zoo! Slide15:  Superstrings: the theory of subatomic physics The essential idea: with sufficient resolution, all elementary particles are one-dimensional objects (strings) all particle types are the same kind of string vibrating or rotating in different ways electron photon Slide16:  Superstrings: the theory of subatomic physics The idea: with sufficient resolution, all elementary particles are one-dimensional objects (strings) all particle types are the same kind of string vibrating or rotating in different ways the spectrum and size of the string states is set by a single scale, Interactions? String Tension: Slide18:  coupling constant, g, determines probability of interaction Slide19:  Superstrings: the theory of subatomic physics with resolution, , all elementary particles are one-dimensional objects (strings) interactions are geometric joining and splitting governed by coupling constant, g with these simple rules get appropriate particle species and interactions to match Standard Model Slide20:  Subatomic Physics Elementary Particles ( 10 m ) --17 Fermions - spin ½ : electron, muon, tauon neutrinos (3 flavors) quarks - up, down, strange, charm, bottom, top Bosons (Force Mediators): photon (electromagnetism) gluon (strong) , Z (weak) spin Higgs particle – spinless or spin 0 a theory of strings! What’s missing here? Graviton (gravity!!) – spin 2 Slide21:  Superstrings: the theory of gravitational physics consistency requires the appearance of massless particle with spin 2 the graviton! at long wavelengths or low momenta, reproduces Einstein’s gravitational equations this is the only known sensible description of scattering of gravitons at very high energies! sets the string length scale: Superstrings naturally provides a unified framework for Quantum Field Theory and General Relativity Newton’s constant Slide22:  SUPERSTRING THEORY Slide23:  Superstring theory: The devil is in the “details” Predicts we live in 10 spacetime dimensions!! Experimental update: we live in 4 dimensions! Big fix: Perhaps we haven’t seen the extra dimensions yet. short wavelengths = high energies needed to resolve curled up dimensions Benefit: richness of four-dimensional physics comes from geometry of the extra dimensions Slide24:  Superstring theory: The devil is in the “details” Predicts we live in 10 spacetime dimensions!! Experimental update: we live in 4 dimensions! Predicts extra particles we haven’t seen yet! (Supersymmetry: each fermion is accompanied by a bosonic partner of the same mass) Big fix: Perhaps we should look harder. Benefit: SUSY tames the high energy (quantum) behavior of the theory Slide25:  Superstring theory: Details, details, details, …. Have five consistent superstring theories: Type I, Type IIA, Type IIB, Heterotic E8 X E8, Heterotic SO(32) Conjecture: all known string theories are different solutions of single fundamental theory M-theory one universe four too many theories?!? Slide26:  Essential ingredients for M-theory conjecture: Dualites: two mathematical descriptions describe identical physical phenomena Eg, T-duality relates large and small circle compactifications Slide27:  Essential ingredients for M-theory conjecture: Dualites: two mathematical descriptions describe identical physical phenomena D-branes: string theory contains other kinds of objects extended in 0, 1, 2, . . . dimensions particles strings membranes p-branes g extremely heavy in weak coupling extremely important in strong coupling Slide28:  Superstring theory: Unique theory of everything M-theory Conjecture: all known string theories are different solutions of single fundamental theory M-theory also includes 11-dimensional supergravity! Slide29:  M-THEORY Contact with experiment is crucial ??Physics at Planck scale?? Slide30:  Superstring theory: a theory looking for a good experiment accelerator experiments: probe 1012 eV and beyond Tevatron, Large Hadron Collider, …. Slide31:  How far away is the Planck scale really? Brane-world scenario: (Some) Extra dimensions may be very large! Advantage: Planck scale may be within reach!! Slide32:  Superstring theory: a theory looking for a good experiment accelerator experiments: probe 1012 eV and beyond Tevatron, Large Hadron Collider, …. cosmological experiments: extreme conditions of early universe may have left stringy imprints Slide33:  Cosmology: extreme conditions of early universe give a window on small scales and high energies Present Past Future String physics is manifest Stringy relics or imprints now? We need to understand the optics of our “microscope” Slide34:  Superstring theory: a theory looking for a good experiment accelerator experiments: probe 10−19 m and beyond Tevatron, Large Hadron Collider, …. cosmological experiments: extreme conditions of early universe may have left stringy imprints Slide35:  Superstrings: a mathematical model of our physical universe Studies of string theory draw upon an enormous range of modern mathematics: complex analysis, group theory, fibre bundles, gerbes, topology, differential geometry, mirror symmetry, K-theory, derived categories, noncommutative geometry We are still groping for the language of string theory! Slide36:  early 1900’s ─ Ernst Mach: “atoms are physically unverifiable entities” early 1990’s ─ individual atoms are manipulated using atomic force microscopy For superstrings, the adventure is still only beginning! Slide37:  “The Elegant Universe” Brian Greene http://www.pbs.org/wgbh/nova/elegant/ The Official String Theory Web Site: http://superstringtheory.com/ More strings on the web: “It’s the 21st century ─ time to feed your brain!” Superstrings! http://www.sukidog.com/jpierre/strings/

Add a comment

Related presentations

Related pages

The Superstring Adventure | Perimeter Institute

An introductory presentation on string theory. ... Jump to Navigation
Read more

Podcast: SciCafe: Adventures in Superstring Theory - AMNH

Theoretical physicist Dr. S. James Gates, Jr. uses mathematics to understand string theory and superstring theory, candidates for a single, unified theory ...
Read more

The Superstring Adventure Robert Myers (PITP; February 11 ...

Slide 1 Slide 2 The Superstring Adventure Robert Myers (PITP; February 11, 2008) Slide 3 New Yorker magazine: Slide 4 Physics of the 20 th century: A grand ...
Read more

The Superstring Adventure | Perimeter Institute

An introductory presentation on string theory. ... Le contenu de cette page n’est pas disponible en français. Veuillez nous en excuser.
Read more

The Superstring Store

Welcome to the Superstring Store ... questions with the excitement of a detective, making science not just a quest but an adventure. ...
Read more

The Superstring Adventure - University of British Columbia

7:30 pm, Monday, February 11, 2008 Fairmont Lounge, St John's College. The Superstring Adventure Rob Myers Perimeter Institute. Theoretical physicists have ...
Read more

PIRSA - Perimeter Institute Recorded Seminar Archive

PERIMETER INSTITUTE RECORDED SEMINAR ARCHIVE. Home | Help | Advanced search | Send Feedback. PIRSA:08070002 ... The Superstring Adventure. Speaker(s): ...
Read more

Theoretical Physics Links - Superstring Theory

Theoretical Physics Links String conferences. Strings 2008; ... The Second Superstring Revolution; String ... The Particle Adventure; The Universe Today;
Read more

PPT – Adventures with Superstrings PowerPoint presentation ...

A grand synthesis and. progression of ideas! Einstein: Gravity: It's all just straight lines! ... Nobel Prize in 1993!! Global Positioning System (GPS ...
Read more