A treatment of the twin paradox based on the assumption of an instantaneous acceleration

2012 ◽  
Vol 90 (10) ◽  
pp. 925-930
Author(s):  
Marcelo Carvalho
Keyword(s):  
Boundary Conditions ◽  
Lorentz Transformation ◽  
Relative Motion ◽  
Twin Paradox ◽  
Lorentz Transformations ◽  
Relative Speed ◽  
Relative Movement ◽  
Two Stages ◽  
Instantaneous Acceleration

We investigate the twin paradox assuming the acceleration acts instantaneously on one of the twins and that its effect is just to revert the relative movement of the twins keeping the same relative speed. The relative motion of the twins is then split in two stages: one where they move away and another when they approach each other. Each stage is described by specific Lorentz transformations that obey certain boundary conditions related to the reversion of motion. We then show how the paradox arises from the particular form of the Lorentz transformation describing the approaching movement of the twins.

scholarly journals Relativistic Thermodynamic State Functions from a Time Dilation Perspective

2020 ◽  
Author(s):  
Mirza Wasif Baig
Keyword(s):  
Heat Flux ◽  
Lorentz Transformation ◽  
Special Theory ◽  
Time Dilation ◽  
Twin Paradox ◽  
Lorentz Transformations ◽  
Theory Of Relativity ◽  
Thermodynamic State ◽  
Classical Thermodynamics ◽  
State Functions

To embrace the special theory of relativity with classical thermodynamics correct Lorentz transformations of thermodynamic state functions are formulated. All of these Lorentz transformations of state functions equally support the time dilation phenomenon which is experimentally verified fact. Relativistic Boltzmann constant proves entropy to be the Lorentz variant. Twin paradox thought experiments for heat engines prove heat flux to be Lorentz variant. Lorentz transformation of entropy and heat flux proves temperature Lorentz invariant. All thermodynamic state functions are proved to be Lorentz variant which is shown in accord with Lorentz transformation of thermodynamic work.

scholarly journals The “twin paradox”: the role of acceleration

2019 ◽  
Vol 97 (10) ◽  
pp. 1049-1063
Author(s):  
J. Gamboa ◽  
F. Mendez ◽  
M.B. Paranjape ◽  
Benoit Sirois
Keyword(s):  
Reference Frame ◽  
Relative Motion ◽  
Complete Resolution ◽  
Proper Time ◽  
The Other ◽  
Twin Paradox ◽  
Age Difference ◽  
Inertial Reference Frame

The “twin paradox” corresponds to the situation where two twins begin at rest in an inertial reference frame, one of them takes a journey, normally very fast and to a distant place, and then returns to the twin at rest. The “twin paradox” evokes the idea that each twin would say that it should be the other who is younger because of their relative motion. A complete resolution of the paradox corresponds to the calculation of the elapsed proper time of each twin, by each twin, and the subsequent observation that they actually get the same answer, that the travelling twin is indeedthe younger twin. Acceleration has a role to play; indeed, if one tries to calculate the age difference from the point of the view of the travelling twin, then the role of the acceleration is crucial and cannot be dismissed. In this tutorial, we show in complete and pedagogical detail, how to do the necessary calculations according to each twin using simple transformations of coordinates.

Zur Beschreibung der Coulomb-Wechselwirkung in der Quantenelektrodynamik

1969 ◽  
Vol 24 (7) ◽  
pp. 1151-1160 ◽  
Author(s):  
Arnd Wülfing
Keyword(s):  
Lorentz Transformation ◽  
Quantum Electrodynamics ◽  
Scattering Theory ◽  
Coulomb Gauge ◽  
Lorentz Transformations ◽  
Gauge Transformations

Abstract The covariance of the scattering theory in the formulations of quantum electrodynamics by GUPTA and BLEULER, by VALATIN, and in the formulation with COULOMB gauge is reinvestigated. The effect of gauge transformations and the effect of time disordering, both generally connected with a Lorentz transformation, compensate each other. For the potential in the GUPTA-BLEULER formulation there exist two different generators of Lorentz transformations.

Neural responses to relative speed in the primary visual cortex of rhesus monkey

2003 ◽  
Vol 20 (1) ◽  
pp. 77-84 ◽  
Author(s):  
AN CAO ◽  
PETER H. SCHILLER
Keyword(s):  
Visual Cortex ◽  
Primary Visual Cortex ◽  
Relative Motion ◽  
Motion Parallax ◽  
Relative Speed ◽  
Neural Responses ◽  
Tuning Curves ◽  
V1 Neurons ◽  
Cortex Area ◽  
Ground Segmentation

Relative motion information, especially relative speed between different input patterns, is required for solving many complex tasks of the visual system, such as depth perception by motion parallax and motion-induced figure/ground segmentation. However, little is known about the neural substrate for processing relative speed information. To explore the neural mechanisms for relative speed, we recorded single-unit responses to relative motion in the primary visual cortex (area V1) of rhesus monkeys while presenting sets of random-dot arrays moving at different speeds. We found that most V1 neurons were sensitive to the existence of a discontinuity in speed, that is, they showed higher responses when relative motion was presented compared to homogenous field motion. Seventy percent of the neurons in our sample responded predominantly to relative rather than to absolute speed. Relative speed tuning curves were similar at different center–surround velocity combinations. These relative motion-sensitive neurons in macaque area V1 probably contribute to figure/ground segmentation and motion discontinuity detection.

scholarly journals Research of particle movement on cylinder outer surface during its progressive oscillations in horizontal planes

2020 ◽  
Vol 11 (4) ◽  
pp. 101-105
Author(s):  
T. M. Volina ◽  
◽  
S. F. Pylypaka ◽  
Keyword(s):  
Numerical Methods ◽  
Differential Equations ◽  
Relative Motion ◽  
Outer Surface ◽  
Horizontal Plane ◽  
External Surface ◽  
Relative Movement ◽  
Particle Movement ◽  
Angle Of Friction ◽  
Oscillatory Movement

The differential equations of relative movement of a particle on the external surface of the inclined cylinder which carries out oscillatory movement were received in the article. All points of the cylinder describe circles in horizontal planes. The equations were solved by numerical methods and the trajectories of the relative motion of the particle on the surface of the cylinder are constructed. Graphs of other kinematic characteristics as a function of time are given. Partial cases when the axis of the cylinder is located horizontally or at an angle of friction to the horizontal plane are considered.

scholarly journals Derivation of Generalized Einstein's Equations of Gravitation in Some Non-Inertial Reference Frames Based on the Theory of Vacuum Mechanics

2021 ◽  
Author(s):  
Xiao-Song Wang
Keyword(s):  
General Relativity ◽  
Reference Frame ◽  
Lorentz Transformation ◽  
Special Class ◽  
Wave Equations ◽  
Reference Frames ◽  
Lorentz Transformations ◽  
Einstein’S Equations ◽  
Einstein's Equations

When solving the Einstein's equations for an isolated system of masses, V. Fock introduces harmonic reference frame and obtains an unambiguous solution. Further, he concludes that there exists a harmonic reference frame which is determined uniquely apart from a Lorentz transformation if suitable supplementary conditions are imposed. It is known that wave equations keep the same form under Lorentz transformations. Thus, we speculate that Fock's special harmonic reference frames may have provided us a clue to derive the Einstein's equations in some special class of non-inertial reference frames. Following this clue, generalized Einstein's equations in some special non-inertial reference frames are derived based on the theory of vacuum mechanics. If the field is weak and the reference frame is quasi-inertial, these generalized Einstein's equations reduce to Einstein's equations. Thus, this theory may also explain all the experiments which support the theory of general relativity. There exist some differences between this theory and the theory of general relativity.

scholarly journals Buckling and Vibration Performance of a Composite Laminated Plate with Elastic Boundaries Subjected to Local Thermal Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Yonggan Sun
Keyword(s):  
Boundary Conditions ◽  
Thermal Loading ◽  
Shear Deformation Theory ◽  
Laminated Plates ◽  
Laminated Plate ◽  
Practical Applications ◽  
Composite Laminated Plate ◽  
Heated Area ◽  
Two Stages ◽  
Fixed Boundaries

In this paper, a model is established for the calculation of the vibrations of a composite laminated plate with elastic boundary conditions subjected to local thermal loading. The model is based on first-order shear deformation theory using the finite element method. The influence of boundary conditions, heating area, and heating location on buckling and vibrations of a composite laminated plate was investigated, and there were two stages in which the critical temperature increased sharply during the transition from free boundary to simply supported and rigid fixed boundaries. The thermal buckling of locally heated laminated plates is generally not checked in practical applications unless the heated area exceeds approximately 10% of the total area of the plates. The stronger the boundary constraint is, the greater the influence of the heated area is on the vibrational frequencies of the composite laminated plate.

scholarly journals Lorentz Transformation of Electromagnetic Systems and the 4/3 Problem

1991 ◽  
Vol 46 (5) ◽  
pp. 377-383 ◽  
Author(s):  
E. Comay
Keyword(s):  
Spherical Shell ◽  
Special Relativity ◽  
Stress Tensor ◽  
Electromagnetic Fields ◽  
Lorentz Transformation ◽  
Momentum Flux ◽  
Lorentz Transformations ◽  
Definition Of

AbstractLorentz transformations of two macroscopic devices are discussed. In each case, the overall momentum flux into every static element of matter vanishes. It is shown that a Lorentz transformation of the energy-momentum 4-vector of each system agrees with special relativity. In particular, using the ordinary definition of 4-momentum of electromagnetic fields, it is proved by means of a particular form of Poincare's stress tensor, that there is no 4/3 factor in the transformation of the entire momentum of a uniformly charged spherical shell

scholarly journals Derivation of a general lorentz transformation without rotation

1969 ◽  
Vol 10 (1-2) ◽  
pp. 141-144
Author(s):  
A. H. Klotz
Keyword(s):  
Lorentz Transformation ◽  
Lorentz Transformations ◽  
Thomas Precession

An elementary, purely algebraic derivation of the most general Lorentz transformations without spacial rotation and of the Thomas precession is given.

scholarly journals Lorentz Group Action on Ellips Space

2017 ◽  
Vol 1 (2) ◽  
pp. 55
Author(s):  
Muhammad Ardhi Khalif
Keyword(s):  
Lorentz Transformation ◽  
Group Action ◽  
Lorentz Group ◽  
Cartesian Product ◽  
Lorentz Transformations ◽  
Speed Parameter ◽  
Rotation Transformation ◽  
Definition Of

<p style="text-align: justify;">The ellips space <em>E </em>has been constructed as cartesian product R+ <em>× </em>R+ <em>× </em>[ <em>π </em>2 <em>, </em><em>π </em>2 ]. Its elements, (<em>a, b, θ</em>), is called as an ellipse with eccentricity is <em> </em>= p1 <em>− </em><em>b</em>2<em>/a</em>2 if <em>b &lt; a </em>and is <em> </em>= p1 <em>− </em><em>a</em>2<em>/b</em>2 if <em>a &gt; b</em>. The points (<em>a, b, π/</em>2) is equal to (<em>b, a, </em>0). The action of subgrup <em>SO</em><em>oz</em>(3<em>, </em>1) of Lorentz group <em>SO</em><em>o</em>(3<em>, </em>1), containing Lorentz transformations on <em>x</em><em>−</em><em>y </em>plane and rotations about <em>z </em>axes, on <em>E </em>is defined as Lorentz transformation or rotation transformation of points in an ellipse. The action is effective since there are no rigid points in <em>E</em>. The action is also not free and transitive. These properties means that Lorentz transformations change any ellips into another ellips. Although mathematically we can move from an ellipse to another one with the bigger eccentrity but it is imposible physically. This is occured because we donot include the speed parameter into the definition of an ellipse in <em>E</em>.</p>

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