String Theory Talk Agenda Science in the news String Theory Talk! Higgs Boson Discussion (brief) Introduction 4 fundamental forces of nature Weak Nuclear Force: Quantum Flavordynamis Strong Nuclear Force: Quantum Chromodynamics Gravity Electromagnetism: Quantum Electrodynamics Weak Interaction Affect all fermions (half spin particles) Theorized to be caused by exchange of W and Z bosons. The heaviness of these bosons account for the small range of the weak interaction. Strong Interaction Strongest force, shortest range. Holds together protons and neutrons. Held together by gluons. Caused by meson exchange. Helps overcome electrostatic repulsion. Relationship between quarks and gluons is known as quantum chromodynamics. Pecei Quinn Theory Yangsmill Equations Gravity Theorized to be caused by the exchange of gravitons. Defined by the universal law of gravitation: Electromagnetism Magnetic Field: Caused by a charge in motion Electric field: Caused by presence of an electric charge Strong in short distances. Elementary Particles You cannot break it down any further. Even protons and neutrons can be broken down. Three main types: Quarks: Fundamental constituent of matter. Combine to form large particles called hadrons. They cant be found in isolation. Various properties. Six types known as flavors. Leptons: Does not undergo strong interactions but is subject to the pauli exclusion principle. Electron is a lepton. Two types: Electron-like (charged) Neutrally charged (neutrinos) Exchange Particles: Higgs, mesons, gravitons, etc. Govern the four forces. Pauli Exclusion Principle Particles with the same quantum state cannot occupy the same place. String Theory Why is it called the Theory of Everything? Because it is the one theory that can tie together all four fundamental forces of nature. It can bridge the gap between Relativity and Newtonian Mechanics. It can explain how light behaves both as a wave and a particle. (quantum-photoelectric effect) String Theory (or the Theory of Everything) By Alex Smith The Basics of String Theory Why is it called String Theory? Where did String Theory come from, and where is it now? What are some of the requirements of String Theory? What does String Theory solve? Do we have any proof? What are the strings of String Theory? Miniscule vibrating strands of energy of energy. Fundamental unit of the universe. Different ways of vibrating yield different particles. MUCH smaller than any particle. The parts of String Theory The Standard Model Describes all known particles. Now complete with the discovery of the Higgs Boson. However, fails to explain gravity or the existence of Dark matter. Quantum Mechanics Describes the three strong fundamental forces in the universe: Electromagnetism, Strong Nuclear Force, and the Weak Nuclear Force. General Relativity The explanation of Gravity, the weakest fundamental force. String Theory Combines these three to create an all-encompassing picture of reality Odds and Ends of String Theory It requires multiple Dimensions. Requires 10 spatial dimensions and one dimension of time. These can be either curled up at every point in space, or the multiverse can be of a higher dimension and we are living in a 3-D membrane, where the strings are attached String theory needs there to be supersymmetry with the particles to work. Every particle has a supersymetric partner that is much heavier. The purpose of String Theory Solves Quantum Gravity It explains why gravity is so weak: it escapes off of our membrane and into the higher-dimensional multiverse. Unites the Fundamental Forces All fundamental forces are united into a single theory to describe everything. The Holy Grail for scientists. One Small Problem There is currently no proof for string theory, despite the several decades of its existence The theory provides no observable predictions. You cant claim it as truth if there is nothing to prove. So far, supersymmetry is yet undiscovered, but this would not prove String Theory, or the existence of the Graviton. The Fuzzball THE STRING THEORY VERSION OF A BLACK HOLE BY MAX FONTANA Definition A Fuzzball is, in superstring theory, the true quantum description of a black hole This theory helps solve two fundamental problems in the modern definition of a black hole The Information Paradox The singularity at the heart of the black hole Idea was conceived by Samir Mathur of Ohio State University and postdoctoral researcher Oleg Lunin in 2002 Event Horizon The physical surface Space-time is distorted around the event horizon Light bends around it The escape velocity is equal to the speed of light Known as The Point of No Return because it is impossible for anything to escape the black hole past this point Information Paradox The quantum mechanical law of reversibility states that quantum information cannot be lost in any process A black holes singularity has no composition, meaning that the composition of quantum information would be lost The information paradox states that all quantum information of matter and energy that falls into a black hole would entirely vanish due to the zero-volume singularity at the heart of the black hole The Fuzzball theory corrects this by suggesting that the strings that fall into the fuzzball contribute to its makeup, thus no quantum information is lost Singularity at the Heart In the classic definition of a black hole, the heart is a region of gravitational singularity, where space-time curvature becomes infinite due to the infinitely intense gravitational field in a zero volume region The Fuzzball Theory proposes that the entire area within the event horizon is a ball of strings Therefore, there would be no infinite gravitational energy in a zero volume area space-time curve, becomes infinite in a black hole Physical Properties Whereas a black hole is described as having a distinct event horizon, a fuzzball would be like a mist This mist is only about a few Planck lengths long Small fuzzballs are theorized to form from extremely dense neutron stars, where the neutrons will have melted down to the quarks, which are strings in string theory A fuzzball is a black hole, and space-time, light, and anything that gets near its event horizon acts similarly Fuzzballs and black holes are unrelated only at the quantum level Physical Properties The volume of a fuzzball is a function of the Schwarzschild radius, which is equivalent to about 3,000 meters per solar mass The density of a fuzzball decreases as the inverse square of their mass (Mass*2) = (Diameter*2) = (Volume*8 ) = (Density/4) A typical 6.8 solar-mass fuzzball would have a mean density of 4.010 17 kg/m 3 A piece of such a fuzzball the size of a drop of water would weigh about 20,000,000 metric tons on Earth Fuzzballs become less dense as their mass increases because of fractional tension. When matter or energy fall into a fuzzball, strings fuse together instead of being added to the amount of strings already in the fuzzball Thus, the quantum information from the strings falling into the fuzzball become part of larger, more complex strings, resolving the information paradox Sources Mathur, Samir D. "The Fuzzball Proposal for Black Holes: An Elementary Review." Cornell University Library, 3 Feb Web. CERN. "The Black Hole Information Problem and the Fuzzball Proposal I." CERN, Geneva, 11 Feb Web. CERN. "The Black Hole Information Problem and the Fuzzball Proposal III." CERN, Geneva, 12 Feb Web. Thank you for coming! Other presentations will be uploaded shortly.