Thoughts on a New Definition of Momentum That Makes Physics
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Schrödinger Equation)
Lecture 37 (Schrödinger Equation) Physics 2310-01 Spring 2020 Douglas Fields Reduced Mass • OK, so the Bohr model of the atom gives energy levels: • But, this has one problem – it was developed assuming the acceleration of the electron was given as an object revolving around a fixed point. • In fact, the proton is also free to move. • The acceleration of the electron must then take this into account. • Since we know from Newton’s third law that: • If we want to relate the real acceleration of the electron to the force on the electron, we have to take into account the motion of the proton too. Reduced Mass • So, the relative acceleration of the electron to the proton is just: • Then, the force relation becomes: • And the energy levels become: Reduced Mass • The reduced mass is close to the electron mass, but the 0.0054% difference is measurable in hydrogen and important in the energy levels of muonium (a hydrogen atom with a muon instead of an electron) since the muon mass is 200 times heavier than the electron. • Or, in general: Hydrogen-like atoms • For single electron atoms with more than one proton in the nucleus, we can use the Bohr energy levels with a minor change: e4 → Z2e4. • For instance, for He+ , Uncertainty Revisited • Let’s go back to the wave function for a travelling plane wave: • Notice that we derived an uncertainty relationship between k and x that ended being an uncertainty relation between p and x (since p=ћk): Uncertainty Revisited • Well it turns out that the same relation holds for ω and t, and therefore for E and t: • We see this playing an important role in the lifetime of excited states. -
Arxiv:0809.1003V5 [Hep-Ph] 5 Oct 2010 Htnadgaio Aslimits Mass Graviton and Photon I.Scr N Pcltv Htnms Limits Mass Photon Speculative and Secure III
October 7, 2010 Photon and Graviton Mass Limits Alfred Scharff Goldhaber∗,† and Michael Martin Nieto† ∗C. N. Yang Institute for Theoretical Physics, SUNY Stony Brook, NY 11794-3840 USA and †Theoretical Division (MS B285), Los Alamos National Laboratory, Los Alamos, NM 87545 USA Efforts to place limits on deviations from canonical formulations of electromagnetism and gravity have probed length scales increasing dramatically over time. Historically, these studies have passed through three stages: (1) Testing the power in the inverse-square laws of Newton and Coulomb, (2) Seeking a nonzero value for the rest mass of photon or graviton, (3) Considering more degrees of freedom, allowing mass while preserving explicit gauge or general-coordinate invariance. Since our previous review the lower limit on the photon Compton wavelength has improved by four orders of magnitude, to about one astronomical unit, and rapid current progress in astronomy makes further advance likely. For gravity there have been vigorous debates about even the concept of graviton rest mass. Meanwhile there are striking observations of astronomical motions that do not fit Einstein gravity with visible sources. “Cold dark matter” (slow, invisible classical particles) fits well at large scales. “Modified Newtonian dynamics” provides the best phenomenology at galactic scales. Satisfying this phenomenology is a requirement if dark matter, perhaps as invisible classical fields, could be correct here too. “Dark energy” might be explained by a graviton-mass-like effect, with associated Compton wavelength comparable to the radius of the visible universe. We summarize significant mass limits in a table. Contents B. Einstein’s general theory of relativity and beyond? 20 C. -
Uniting the Wave and the Particle in Quantum Mechanics
Uniting the wave and the particle in quantum mechanics Peter Holland1 (final version published in Quantum Stud.: Math. Found., 5th October 2019) Abstract We present a unified field theory of wave and particle in quantum mechanics. This emerges from an investigation of three weaknesses in the de Broglie-Bohm theory: its reliance on the quantum probability formula to justify the particle guidance equation; its insouciance regarding the absence of reciprocal action of the particle on the guiding wavefunction; and its lack of a unified model to represent its inseparable components. Following the author’s previous work, these problems are examined within an analytical framework by requiring that the wave-particle composite exhibits no observable differences with a quantum system. This scheme is implemented by appealing to symmetries (global gauge and spacetime translations) and imposing equality of the corresponding conserved Noether densities (matter, energy and momentum) with their Schrödinger counterparts. In conjunction with the condition of time reversal covariance this implies the de Broglie-Bohm law for the particle where the quantum potential mediates the wave-particle interaction (we also show how the time reversal assumption may be replaced by a statistical condition). The method clarifies the nature of the composite’s mass, and its energy and momentum conservation laws. Our principal result is the unification of the Schrödinger equation and the de Broglie-Bohm law in a single inhomogeneous equation whose solution amalgamates the wavefunction and a singular soliton model of the particle in a unified spacetime field. The wavefunction suffers no reaction from the particle since it is the homogeneous part of the unified field to whose source the particle contributes via the quantum potential. -
Compton Effect
Module 5 : MODERN PHYSICS Lecture 25 : Compton Effect Objectives In this course you will learn the following Scattering of radiation from an electron (Compton effect). Compton effect provides a direct confirmation of particle nature of radiation. Why photoelectric effect cannot be exhited by a free electron. Compton Effect Photoelectric effect provides evidence that energy is quantized. In order to establish the particle nature of radiation, it is necessary that photons must carry momentum. In 1922, Arthur Compton studied the scattering of x-rays of known frequency from graphite and looked at the recoil electrons and the scattered x-rays. According to wave theory, when an electromagnetic wave of frequency is incident on an atom, it would cause electrons to oscillate. The electrons would absorb energy from the wave and re-radiate electromagnetic wave of a frequency . The frequency of scattered radiation would depend on the amount of energy absorbed from the wave, i.e. on the intensity of incident radiation and the duration of the exposure of electrons to the radiation and not on the frequency of the incident radiation. Compton found that the wavelength of the scattered radiation does not depend on the intensity of incident radiation but it depends on the angle of scattering and the wavelength of the incident beam. The wavelength of the radiation scattered at an angle is given by .where is the rest mass of the electron. The constant is known as the Compton wavelength of the electron and it has a value 0.0024 nm. The spectrum of radiation at an angle consists of two peaks, one at and the other at . -
1 the Principle of Wave–Particle Duality: an Overview
3 1 The Principle of Wave–Particle Duality: An Overview 1.1 Introduction In the year 1900, physics entered a period of deep crisis as a number of peculiar phenomena, for which no classical explanation was possible, began to appear one after the other, starting with the famous problem of blackbody radiation. By 1923, when the “dust had settled,” it became apparent that these peculiarities had a common explanation. They revealed a novel fundamental principle of nature that wascompletelyatoddswiththeframeworkofclassicalphysics:thecelebrated principle of wave–particle duality, which can be phrased as follows. The principle of wave–particle duality: All physical entities have a dual character; they are waves and particles at the same time. Everything we used to regard as being exclusively a wave has, at the same time, a corpuscular character, while everything we thought of as strictly a particle behaves also as a wave. The relations between these two classically irreconcilable points of view—particle versus wave—are , h, E = hf p = (1.1) or, equivalently, E h f = ,= . (1.2) h p In expressions (1.1) we start off with what we traditionally considered to be solely a wave—an electromagnetic (EM) wave, for example—and we associate its wave characteristics f and (frequency and wavelength) with the corpuscular charac- teristics E and p (energy and momentum) of the corresponding particle. Conversely, in expressions (1.2), we begin with what we once regarded as purely a particle—say, an electron—and we associate its corpuscular characteristics E and p with the wave characteristics f and of the corresponding wave. -
Path Integral Quantum Monte Carlo Study of Coupling and Proximity Effects in Superfluid Helium-4
Path Integral Quantum Monte Carlo Study of Coupling and Proximity Effects in Superfluid Helium-4 A Thesis Presented by Max T. Graves to The Faculty of the Graduate College of The University of Vermont In Partial Fullfillment of the Requirements for the Degree of Master of Science Specializing in Materials Science October, 2014 Accepted by the Faculty of the Graduate College, The University of Vermont, in partial fulfillment of the requirements for the degree of Master of Science in Materials Science. Thesis Examination Committee: Advisor Adrian Del Maestro, Ph.D. Valeri Kotov, Ph.D. Frederic Sansoz, Ph.D. Chairperson Chris Danforth, Ph.D. Dean, Graduate College Cynthia J. Forehand, Ph.D. Date: August 29, 2014 Abstract When bulk helium-4 is cooled below T = 2.18 K, it undergoes a phase transition to a su- perfluid, characterized by a complex wave function with a macroscopic phase and exhibits inviscid, quantized flow. The macroscopic phase coherence can be probed in a container filled with helium-4, by reducing one or more of its dimensions until they are smaller than the coherence length, the spatial distance over which order propagates. As this dimensional reduction occurs, enhanced thermal and quantum fluctuations push the transition to the su- perfluid state to lower temperatures. However, this trend can be countered via the proximity effect, where a bulk 3-dimensional (3d) superfluid is coupled to a low (2d) dimensional su- perfluid via a weak link producing superfluid correlations in the film at temperatures above the Kosterlitz-Thouless temperature. Recent experiments probing the coupling between 3d and 2d superfluid helium-4 have uncovered an anomalously large proximity effect, leading to an enhanced superfluid density that cannot be explained using the correlation length alone. -
Matter-Wave Diffraction of Quantum Magical Helium Clusters Oleg Kornilov * and J
s e r u t a e f Matter-wave diffraction of quantum magical helium clusters Oleg Kornilov * and J. Peter Toennies , Max-Planck-Institut für Dynamik und Selbstorganisation, Bunsenstraße 10 • D-37073 Göttingen • Germany. * Present address: Chemical Sciences Division, Lawrence Berkeley National Lab., University of California • Berkeley, CA 94720 • USA. DOI: 10.1051/epn:2007003 ack in 1868 the element helium was discovered in and named Finally, helium clusters are the only clusters which are defi - Bafter the sun (Gr.“helios”), an extremely hot environment with nitely liquid. This property led to the development of a new temperatures of millions of degrees. Ironically today helium has experimental technique of inserting foreign molecules into large become one of the prime objects of condensed matter research at helium clusters, which serve as ultra-cold nano-containers. The temperatures down to 10 -6 Kelvin. With its two very tightly bound virtually unhindered rotations of the trapped molecules as indi - electrons in a 1S shell it is virtually inaccessible to lasers and does cated by their sharp clearly resolved spectral lines in the infrared not have any chemistry. It is the only substance which remains liq - has been shown to be a new microscopic manifestation of super - uid down to 0 Kelvin. Moreover, owing to its light weight and very fluidity [3], thus linking cluster properties back to the bulk weak van der Waals interaction, helium is the only liquid to exhib - behavior of liquid helium. it one of the most striking macroscopic quantum effects: Today one of the aims of modern helium cluster research is to superfluidity. -
The Graviton Compton Mass As Dark Energy
Gravitation, Mathematical Physics and Field Theory Revista Mexicana de F´ısica 67 040703 1–5 JULY-AUGUST 2021 The graviton Compton mass as dark energy T. Matosa and L. L.-Parrillab aDepartamento de F´ısica, Centro de Investigacion´ y de Estudios Avanzados del IPN, Apartado Postal 14-740, 07000, CDMX, Mexico.´ bInstituto de Ciencias Nucleares, Universidad Nacional Autonoma´ de Mexico,´ Circuito Exterior C.U., Apartado Postal 70-543, 04510, CDMX, Mexico.´ Received 3 January 2021; accepted 18 February 2021 One of the greatest challenges of science is to understand the current accelerated expansion of the Universe. In this work, we show that by considering the quantum nature of the gravitational field, its wavelength can be associated with an effective Compton mass. We propose that this mass can be interpreted as dark energy, with a Compton wavelength given by the size of the observable Universe, implying that the dark energy varies depending on this size. If we do so, we find that: 1.- Even without any free constant for dark energy, the evolution of the Hubble parameter is exactly the same as for the LCDM model, so this model has the same predictions as LCDM. 2.- The density rate of the dark energy is ¤ = 0:69 which is a very similar value as the one found by the Planck satellite ¤ = 0:684. 3.- The dark energy has this value because it corresponds to the actual size of the radius of the Universe, thus the coincidence problem has a very natural explanation. 4.- It, is possible to find also a natural explanation to why observations inferred from the local distance ladder find the value H0 = 73 km/s/Mpc for the Hubble constant. -
Lecture 3: Wave Properties of Matter
3 WAVE PROPERTIES OF MATTER 1 3 Wave properties of matter In Lecture 1 we mapped out some of the principal interactions between photons and matter (elec- trons). At the quantum level, individual photons and electrons are described as particles in the various relationships used to describe phenomena such as the photo{electric effect and Compton scattering. We are building up a map of quantum interactions (Table 1). Under certain circum- particle wave electron Thomson's experiment Photo{electric effect Compton effect low{energy photon photo{electric effect interference diffraction high{energy photon Compton effect Pair production Table 1: A simple map of quantum behaviour. stances, low energy photons can act as particles or as waves. Importantly, such photons never display both wave{like and particle{like properties in the same experiment (Two-slit experiment). The blank spaces in Table 1 provide the directions we must investigate in order to complete our simple quantum map: can high energy photons, X{ and γ{rays, act as waves, and can electrons { classically viewed as matter particles { also act in a wave{like manner? • X{ray diffraction { high energy photons can behave as waves. • De Broglie suggests a relationship between momentum (mass) and wavelength { a wave{like description of matter? • Electron scattering and transmission electron diffraction photography confirm wave phenom- ena in electrons. • A wave mechanics primer. • The uncertainty principle derived using wave physics. • Bohr's complementarity principle and an introduction to the two slit experiment. • The Copenhagen interpretation of quantum theory. • A wave description of a particle in a box leads to quantised energy states. -
The Principle of Relativity and the De Broglie Relation Abstract
The principle of relativity and the De Broglie relation Julio G¨u´emez∗ Department of Applied Physics, Faculty of Sciences, University of Cantabria, Av. de Los Castros, 39005 Santander, Spain Manuel Fiolhaisy Physics Department and CFisUC, University of Coimbra, 3004-516 Coimbra, Portugal Luis A. Fern´andezz Department of Mathematics, Statistics and Computation, Faculty of Sciences, University of Cantabria, Av. de Los Castros, 39005 Santander, Spain (Dated: February 5, 2016) Abstract The De Broglie relation is revisited in connection with an ab initio relativistic description of particles and waves, which was the same treatment that historically led to that famous relation. In the same context of the Minkowski four-vectors formalism, we also discuss the phase and the group velocity of a matter wave, explicitly showing that, under a Lorentz transformation, both transform as ordinary velocities. We show that such a transformation rule is a necessary condition for the covariance of the De Broglie relation, and stress the pedagogical value of the Einstein-Minkowski- Lorentz relativistic context in the presentation of the De Broglie relation. 1 I. INTRODUCTION The motivation for this paper is to emphasize the advantage of discussing the De Broglie relation in the framework of special relativity, formulated with Minkowski's four-vectors, as actually was done by De Broglie himself.1 The De Broglie relation, usually written as h λ = ; (1) p which introduces the concept of a wavelength λ, for a \material wave" associated with a massive particle (such as an electron), with linear momentum p and h being Planck's constant. Equation (1) is typically presented in the first or the second semester of a physics major, in a curricular unit of introduction to modern physics. -
High Energy Physics Quantum Information Science Awards Abstracts
High Energy Physics Quantum Information Science Awards Abstracts Towards Directional Detection of WIMP Dark Matter using Spectroscopy of Quantum Defects in Diamond Ronald Walsworth, David Phillips, and Alexander Sushkov Challenges and Opportunities in Noise‐Aware Implementations of Quantum Field Theories on Near‐Term Quantum Computing Hardware Raphael Pooser, Patrick Dreher, and Lex Kemper Quantum Sensors for Wide Band Axion Dark Matter Detection Peter S Barry, Andrew Sonnenschein, Clarence Chang, Jiansong Gao, Steve Kuhlmann, Noah Kurinsky, and Joel Ullom The Dark Matter Radio‐: A Quantum‐Enhanced Dark Matter Search Kent Irwin and Peter Graham Quantum Sensors for Light-field Dark Matter Searches Kent Irwin, Peter Graham, Alexander Sushkov, Dmitry Budke, and Derek Kimball The Geometry and Flow of Quantum Information: From Quantum Gravity to Quantum Technology Raphael Bousso1, Ehud Altman1, Ning Bao1, Patrick Hayden, Christopher Monroe, Yasunori Nomura1, Xiao‐Liang Qi, Monika Schleier‐Smith, Brian Swingle3, Norman Yao1, and Michael Zaletel Algebraic Approach Towards Quantum Information in Quantum Field Theory and Holography Daniel Harlow, Aram Harrow and Hong Liu Interplay of Quantum Information, Thermodynamics, and Gravity in the Early Universe Nishant Agarwal, Adolfo del Campo, Archana Kamal, and Sarah Shandera Quantum Computing for Neutrino‐nucleus Dynamics Joseph Carlson, Rajan Gupta, Andy C.N. Li, Gabriel Perdue, and Alessandro Roggero Quantum‐Enhanced Metrology with Trapped Ions for Fundamental Physics Salman Habib, Kaifeng Cui1, -
Compton Wavelength, Bohr Radius, Balmer's Formula and G-Factors
Compton wavelength, Bohr radius, Balmer's formula and g-factors Raji Heyrovska J. Heyrovský Institute of Physical Chemistry, Academy of Sciences of the Czech Republic, Dolejškova 3, 182 23 Prague 8, Czech Republic. [email protected] Abstract. The Balmer formula for the spectrum of atomic hydrogen is shown to be analogous to that in Compton effect and is written in terms of the difference between the absorbed and emitted wavelengths. The g-factors come into play when the atom is subjected to disturbances (like changes in the magnetic and electric fields), and the electron and proton get displaced from their fixed positions giving rise to Zeeman effect, Stark effect, etc. The Bohr radius (aB) of the ground state of a hydrogen atom, the ionization energy (EH) and the Compton wavelengths, λC,e (= h/mec = 2πre) and λC,p (= h/mpc = 2πrp) of the electron and proton respectively, (see [1] for an introduction and literature), are related by the following equations, 2 EH = (1/2)(hc/λH) = (1/2)(e /κ)/aB (1) 2 2 (λC,e + λC,p) = α2πaB = α λH = α /2RH (2) (λC,e + λC,p) = (λout - λin)C,e + (λout - λin)C,p (3) α = vω/c = (re + rp)/aB = 2πaB/λH (4) aB = (αλH/2π) = c(re + rp)/vω = c(τe + τp) = cτB (5) where λH is the wavelength of the ionizing radiation, κ = 4πεo, εo is 2 the electrical permittivity of vacuum, h (= 2πħ = e /2εoαc) is the 2 Planck constant, ħ (= e /κvω) is the angular momentum of spin, α (= vω/c) is the fine structure constant, vω is the velocity of spin [2], re ( = ħ/mec) and rp ( = ħ/mpc) are the radii of the electron and