Facets of Time in Physics
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Implications for a Future Information Theory Based on Vacuum 1 Microtopology
Getting Something Out of Nothing: Implications for a Future Information Theory Based on Vacuum 1 Microtopology William Michael Kallfelz 2 Committee for Philosophy and the Sciences University of Maryland at College Park Abstract (word count: 194) Submitted October 3, 2005 Published in IANANO Conference Proceedings : October 31-November 4, 2005 3 Contemporary theoretical physicists H. S. Green and David R. Finkelstein have recently advanced theories depicting space-time as a singular limit, or condensate, formed from fundamentally quantum micro topological units of information, or process (denoted respectively by ‘qubits,’ or ‘chronons.’) H. S. Green (2000) characterizes the manifold of space-time as a parafermionic statistical algebra generated fundamentally by qubits. David Finkelstein (2004a-c) models the space-time manifold as singular limit of a regular structure represented by a Clifford algebra, whose generators γ α represent ‘chronons,’ i.e., elementary quantum processes. Both of these theories are in principle experimentally testable. Green writes that his parafermionic embeddings “hav[e] an important advantage over their classical counterparts [in] that they have a direct physical interpretation and their parameters are in principle observable.” (166) David Finkelstein discusses in detail unique empirical ramifications of his theory in (2004b,c) which most notably include the removal of quantum field-theoretic divergences. Since the work of Shannon and Hawking, associations with entropy, information, and gravity emerged in the study of Hawking radiation. Nowadays, the theories of Green and Finkelstein suggest that the study of space-time lies in the development of technologies better able to probe its microtopology in controlled laboratory conditions. 1 Total word count, including abstract & footnotes: 3,509. -
Supervised Language Modeling for Temporal Resolution of Texts
Supervised Language Modeling for Temporal Resolution of Texts Abhimanu Kumar Matthew Lease Jason Baldridge Dept. of Computer Science School of Information Department of Linguistics University of Texas at Austin University of Texas at Austin University of Texas at Austin [email protected] [email protected] [email protected] ABSTRACT describe any form of communication without cables (e.g. internet We investigate temporal resolution of documents, such as deter- access). As such, the word wireless embodies implicit time cues, mining the date of publication of a story based on its text. We a notion we might generalize by inferring its complete temporal describe and evaluate a model that build histograms encoding the distribution as well as that of all other words. By harnessing many probability of different temporal periods for a document. We con- such implicit cues in combination across a document, we might fur- struct histograms based on the Kullback-Leibler Divergence be- ther infer a unique temporal distribution for the overall document. tween the language model for a test document and supervised lan- As in prior document dating studies, we partition the timeline guage models for each interval. Initial results indicate this language (and document collection) to infer an unique language model (LM) modeling approach is effective for predicting the dates of publica- underlying each time period [10, 14]. While prior work consid- tion of short stories, which contain few explicit mentions of years. ered texts from the past 10-20 years, our work is more historically- oriented, predicting publication dates for historical works of fiction. -
Time Dilation of Accelerated Clocks
Astrophysical Institute Neunhof Circular se07117, February 2016 1 Time Dilation of accelerated Clocks The definitions of proper time and proper length in General Rela- tivity Theory are presented. Time dilation and length contraction are explicitly computed for the example of clocks and rulers which are at rest in a rotating reference frame, and hence accelerated versus inertial reference frames. Experimental proofs of this time dilation, in particular the observation of the decay rates of acceler- ated muons, are discussed. As an illustration of the equivalence principle, we show that the general relativistic equation of motion of objects, which are at rest in a rotating reference frame, reduces to Newtons equation of motion of the same objects at rest in an inertial reference system and subject to a gravitational field. We close with some remarks on real versus ideal clocks, and the “clock hypothesis”. 1. Coordinate Diffeomorphisms In flat Minkowski space, we place a rectangular three-dimensional grid of fiducial marks in three-dimensional position space, and assign cartesian coordinate values x1, x2, x3 to each fiducial mark. The values of the xi are constants for each fiducial mark, i. e. the fiducial marks are at rest in the coordinate frame, which they define. Now we stretch and/or compress and/or skew and/or rotate the grid of fiducial marks locally and/or globally, and/or re-name the fiducial marks, e. g. change from cartesian coordinates to spherical coordinates or whatever other coordinates. All movements and renamings of the fiducial marks are subject to the constraint that the map from the initial grid to the deformed and/or renamed grid must be differentiable and invertible (i. -
COORDINATE TIME in the VICINITY of the EARTH D. W. Allan' and N
COORDINATE TIME IN THE VICINITY OF THE EARTH D. W. Allan’ and N. Ashby’ 1. Time and Frequency Division, National Bureau of Standards Boulder, Colorado 80303 2. Department of Physics, Campus Box 390 University of Colorado, Boulder, Colorado 80309 ABSTRACT. Atomic clock accuracies continue to improve rapidly, requir- ing the inclusion of general relativity for unambiguous time and fre- quency clock comparisons. Atomic clocks are now placed on space vehi- cles and there are many new applications of time and frequency metrology. This paper addresses theoretical and practical limitations in the accuracy of atomic clock comparisons arising from relativity, and demonstrates that accuracies of time and frequency comparison can approach a few picoseconds and a few parts in respectively. 1. INTRODUCTION Recent experience has shown that the accuracy of atomic clocks has improved by about an order of magnitude every seven years. It has therefore been necessary to include relativistic effects in the reali- zation of state-of-the-art time and frequency comparisons for at least the last decade. There is a growing need for agreement about proce- dures for incorporating relativistic effects in all disciplines which use modern time and frequency metrology techniques. The areas of need include sophisticated communication and navigation systems and funda- mental areas of research such as geodesy and radio astrometry. Significant progress has recently been made in arriving at defini- tions €or coordinate time that are practical, and in experimental veri- fication of the self-consistency of these procedures. International Atomic Time (TAI) and Universal Coordinated Time (UTC) have been defin- ed as coordinate time scales to assist in the unambiguous comparison of time and frequency in the vicinity of the Earth. -
Time Scales and Time Differences
SECTION 2 TIME SCALES AND TIME DIFFERENCES Contents 2.1 Introduction .....................................................................................2–3 2.2 Time Scales .......................................................................................2–3 2.2.1 Ephemeris Time (ET) .......................................................2–3 2.2.2 International Atomic Time (TAI) ...................................2–3 2.2.3 Universal Time (UT1 and UT1R)....................................2–4 2.2.4 Coordinated Universal Time (UTC)..............................2–5 2.2.5 GPS or TOPEX Master Time (GPS or TPX)...................2–5 2.2.6 Station Time (ST) ..............................................................2–5 2.3 Time Differences..............................................................................2–6 2.3.1 ET − TAI.............................................................................2–6 2.3.1.1 The Metric Tensor and the Metric...................2–6 2.3.1.2 Solar-System Barycentric Frame of Reference............................................................2–10 2.3.1.2.1 Tracking Station on Earth .................2–13 2.3.1.2.2 Earth Satellite ......................................2–16 2.3.1.2.3 Approximate Expression...................2–17 2.3.1.3 Geocentric Frame of Reference.......................2–18 2–1 SECTION 2 2.3.1.3.1 Tracking Station on Earth .................2–19 2.3.1.3.2 Earth Satellite ......................................2–20 2.3.2 TAI − UTC .........................................................................2–20 -
Arxiv:Quant-Ph/0206117V3 1 Sep 2002
Preprint NSF-ITP-02-62 A SIMPLE QUANTUM EQUATION FOR DECOHERENCE AND DISSIPATION (†) Erasmo Recami Facolt`adi Ingegneria, Universit`astatale di Bergamo, Dalmine (BG), Italy; INFN—Sezione di Milano, Milan, Italy; and Kavli Institute for Theoretical Physics, UCSB, CA 93106, USA. Ruy H. A. Farias LNLS - Synchrotron Light National Laboratory; Campinas, S.P.; Brazil. [email protected] Abstract – Within the density matrix formalism, it is shown that a simple way to get decoherence is through the introduction of a “quantum” of time (chronon): which implies replacing the differential Liouville–von Neumann equation with a finite-difference version of it. In this way, one is given the possibility of using a rather simple quantum equation to describe the decoherence effects due to dissipation. Namely, the mere introduction (not of a “time-lattice”, but simply) of a “chronon” allows us to go on from differential to finite-difference equations; and in particular to write down the quantum-theoretical equations (Schroedinger equation, Liouville–von Neumann equation,...) in three different ways: “retarded”, “symmetrical”, and “advanced”. One of such three formulations —the arXiv:quant-ph/0206117v3 1 Sep 2002 retarded one— describes in an elementary way a system which is exchanging (and losing) energy with the environment; and in its density-matrix version, indeed, it can be easily shown that all non-diagonal terms go to zero very rapidly. keywords: quantum decoherence, interaction with the environment, dissipation, quan- tum measurement theory, finite-difference equations, chronon, Caldirola, density-matrix formalism, Liouville–von Neumann equation (†) This reasearch was supported in part by the N.S.F. under Grant No.PHY99-07949; and by INFN and Murst/Miur (Italy). -
Observer with a Constant Proper Acceleration Cannot Be Treated Within the Theory of Special Relativity and That Theory of General Relativity Is Absolutely Necessary
Observer with a constant proper acceleration Claude Semay∗ Groupe de Physique Nucl´eaire Th´eorique, Universit´ede Mons-Hainaut, Acad´emie universitaire Wallonie-Bruxelles, Place du Parc 20, BE-7000 Mons, Belgium (Dated: February 2, 2008) Abstract Relying on the equivalence principle, a first approach of the general theory of relativity is pre- sented using the spacetime metric of an observer with a constant proper acceleration. Within this non inertial frame, the equation of motion of a freely moving object is studied and the equation of motion of a second accelerated observer with the same proper acceleration is examined. A com- parison of the metric of the accelerated observer with the metric due to a gravitational field is also performed. PACS numbers: 03.30.+p,04.20.-q arXiv:physics/0601179v1 [physics.ed-ph] 23 Jan 2006 ∗FNRS Research Associate; E-mail: [email protected] Typeset by REVTEX 1 I. INTRODUCTION The study of a motion with a constant proper acceleration is a classical exercise of special relativity that can be found in many textbooks [1, 2, 3]. With its analytical solution, it is possible to show that the limit speed of light is asymptotically reached despite the constant proper acceleration. The very prominent notion of event horizon can be introduced in a simple context and the problem of the twin paradox can also be analysed. In many articles of popularisation, it is sometimes stated that the point of view of an observer with a constant proper acceleration cannot be treated within the theory of special relativity and that theory of general relativity is absolutely necessary. -
Coordinate Systems in De Sitter Spacetime Bachelor Thesis A.C
Coordinate systems in De Sitter spacetime Bachelor thesis A.C. Ripken July 19, 2013 Radboud University Nijmegen Radboud Honours Academy Abstract The De Sitter metric is a solution for the Einstein equation with positive cosmological constant, modelling an expanding universe. The De Sitter metric has a coordinate sin- gularity corresponding to an event horizon. The physical properties of this horizon are studied. The Klein-Gordon equation is generalized for curved spacetime, and solved in various coordinate systems in De Sitter space. Contact Name Chris Ripken Email [email protected] Student number 4049489 Study Physicsandmathematics Supervisor Name prof.dr.R.H.PKleiss Email [email protected] Department Theoretical High Energy Physics Adress Heyendaalseweg 135, Nijmegen Cover illustration Projection of two-dimensional De Sitter spacetime embedded in Minkowski space. Three coordinate systems are used: global coordinates, static coordinates, and static coordinates rotated in the (x1,x2)-plane. Contents Preface 3 1 Introduction 4 1.1 TheEinsteinfieldequations . 4 1.2 Thegeodesicequations. 6 1.3 DeSitterspace ................................. 7 1.4 TheKlein-Gordonequation . 10 2 Coordinate transformations 12 2.1 Transformations to non-singular coordinates . ......... 12 2.2 Transformationsofthestaticmetric . ..... 15 2.3 Atranslationoftheorigin . 22 3 Geodesics 25 4 The Klein-Gordon equation 28 4.1 Flatspace.................................... 28 4.2 Staticcoordinates ............................... 30 4.3 Flatslicingcoordinates. 32 5 Conclusion 39 Bibliography 40 A Maple code 41 A.1 Theprocedure‘riemann’. 41 A.2 Flatslicingcoordinates. 50 A.3 Transformationsofthestaticmetric . ..... 50 A.4 Geodesics .................................... 51 A.5 TheKleinGordonequation . 52 1 Preface For ages, people have studied the motion of objects. These objects could be close to home, like marbles on a table, or far away, like planets and stars. -
The Flow of Time in the Theory of Relativity Mario Bacelar Valente
The flow of time in the theory of relativity Mario Bacelar Valente Abstract Dennis Dieks advanced the view that the idea of flow of time is implemented in the theory of relativity. The ‘flow’ results from the successive happening/becoming of events along the time-like worldline of a material system. This leads to a view of now as local to each worldline. Each past event of the worldline has occurred once as a now- point, and we take there to be an ever-changing present now-point ‘marking’ the unfolding of a physical system. In Dieks’ approach there is no preferred worldline and only along each worldline is there a Newtonian-like linear order between successive now-points. We have a flow of time per worldline. Also there is no global temporal order of the now-points of different worldlines. There is, as much, what Dieks calls a partial order. However Dieks needs for a consistency reason to impose a limitation on the assignment of the now-points along different worldlines. In this work it is made the claim that Dieks’ consistency requirement is, in fact, inbuilt in the theory as a spatial relation between physical systems and processes. Furthermore, in this work we will consider (very) particular cases of assignments of now-points restricted by this spatial relation, in which the now-points taken to be simultaneous are not relative to the adopted inertial reference frame. 1 Introduction When we consider any experiment related to the theory of relativity,1 like the Michelson-Morley experiment (see, e.g., Møller 1955, 26-8), we can always describe it in terms of an intuitive notion of passage or flow of time: light is send through the two arms of the interferometer at a particular moment – the now of the experimenter –, and the process of light propagation takes time to occur, as can be measured by a clock calibrated to the adopted time scale. -
Space-Time Reference Systems
Space-Time reference systems Michael Soffel Dresden Technical University What are Space-Time Reference Systems (RS)? Science talks about events (e.g., observations): something that happens during a short interval of time in some small volume of space Both space and time are considered to be continous combined they are described by a ST manifold A Space-Time RS basically is a ST coordinate system (t,x) describing the ST position of events in a certain part of space-time In practice such a coordinate system has to be realized in nature with certain observations; the realization is then called the corresponding Reference Frame Newton‘s space and time In Newton‘s ST things are quite simple: Time is absolute as is Space -> there exists a class of preferred inertial coordinates (t, x) that have direct physical meaning, i.e., observables can be obtained directly from the coordinate picture of the physical system. Example: ∆τ = ∆t (proper) time coordinate time indicated by some clock Newton‘s absolute space Newtonian astrometry physically preferred global inertial coordinates observables are directly related to the inertial coordinates Example: observed angle θ between two incident light-rays 1 and 2 x (t) = x0 + c n (t – t ) ii i 0 cos θ = n. n 1 2 Is Newton‘s conception of Time and Space in accordance with nature? NO! The reason for that is related with properties of light propagation upon which time measurements are based Presently: The (SI) second is the duration of 9 192 631 770 periods of radiation that corresponds to a certain transition -
1 Temporal Arrows in Space-Time Temporality
Temporal Arrows in Space-Time Temporality (…) has nothing to do with mechanics. It has to do with statistical mechanics, thermodynamics (…).C. Rovelli, in Dieks, 2006, 35 Abstract The prevailing current of thought in both physics and philosophy is that relativistic space-time provides no means for the objective measurement of the passage of time. Kurt Gödel, for instance, denied the possibility of an objective lapse of time, both in the Special and the General theory of relativity. From this failure many writers have inferred that a static block universe is the only acceptable conceptual consequence of a four-dimensional world. The aim of this paper is to investigate how arrows of time could be measured objectively in space-time. In order to carry out this investigation it is proposed to consider both local and global arrows of time. In particular the investigation will focus on a) invariant thermodynamic parameters in both the Special and the General theory for local regions of space-time (passage of time); b) the evolution of the universe under appropriate boundary conditions for the whole of space-time (arrow of time), as envisaged in modern quantum cosmology. The upshot of this investigation is that a number of invariant physical indicators in space-time can be found, which would allow observers to measure the lapse of time and to infer both the existence of an objective passage and an arrow of time. Keywords Arrows of time; entropy; four-dimensional world; invariance; space-time; thermodynamics 1 I. Introduction Philosophical debates about the nature of space-time often centre on questions of its ontology, i.e. -
Electro-Gravity Via Geometric Chronon Field
Physical Science International Journal 7(3): 152-185, 2015, Article no.PSIJ.2015.066 ISSN: 2348-0130 SCIENCEDOMAIN international www.sciencedomain.org Electro-Gravity via Geometric Chronon Field Eytan H. Suchard1* 1Geometry and Algorithms, Applied Neural Biometrics, Israel. Author’s contribution The sole author designed, analyzed and interpreted and prepared the manuscript. Article Information DOI: 10.9734/PSIJ/2015/18291 Editor(s): (1) Shi-Hai Dong, Department of Physics School of Physics and Mathematics National Polytechnic Institute, Mexico. (2) David F. Mota, Institute of Theoretical Astrophysics, University of Oslo, Norway. Reviewers: (1) Auffray Jean-Paul, New York University, New York, USA. (2) Anonymous, Sãopaulo State University, Brazil. (3) Anonymous, Neijiang Normal University, China. (4) Anonymous, Italy. (5) Anonymous, Hebei University, China. Complete Peer review History: http://sciencedomain.org/review-history/9858 Received 13th April 2015 th Original Research Article Accepted 9 June 2015 Published 19th June 2015 ABSTRACT Aim: To develop a model of matter that will account for electro-gravity. Interacting particles with non-gravitational fields can be seen as clocks whose trajectory is not Minkowsky geodesic. A field, in which each such small enough clock is not geodesic, can be described by a scalar field of time, whose gradient has non-zero curvature. This way the scalar field adds information to space-time, which is not anticipated by the metric tensor alone. The scalar field can’t be realized as a coordinate because it can be measured from a reference sub-manifold along different curves. In a “Big Bang” manifold, the field is simply an upper limit on measurable time by interacting clocks, backwards from each event to the big bang singularity as a limit only.