Space-time on the rotating disk

1951 ◽  
Vol 47 (1) ◽  
pp. 177-189 ◽  
Author(s):  
Behram Kurşunogğlu
Keyword(s):  
Rotating Disk ◽  
Space Time ◽  
Strained State ◽  
Velocity Of Light ◽  
Unstrained State ◽  
Image Position ◽  
The Waves

1. Introduction. In a recent paper Clark (1) has dealt with the problem of the rotating disk, the material of which is such that the waves of dilatation in this particular material travel with the velocity of light. The material of the disk is supposed to be under an isotropic stress p when in a strained state, and the relation between stress p and the dilatation Δ is found to be connected by an expressionwhere a = density in the unstrained state, and Δ is given byUi (i = 1, 2, 3) are the components of the strain.

The problem of a rotating incompressible disk

1949 ◽  
Vol 45 (3) ◽  
pp. 405-410 ◽  
Author(s):  
G. L. Clark
Keyword(s):  
Strained State ◽  
Velocity Of Light ◽  
Unstrained State ◽  
Image Position ◽  
The Waves

In this paper an investigation is made of the properties of material which is under isotropic stress p when in a strained state, and is such that the relation between the stress and the dilatation Δ iswhere α is the density, assumed constant in the unstrained state, and c is the velocity of light. It is shown that in this material the waves of dilatation travel with the velocity of light and that a disk or cylinder composed of this kind of matter suffers no change in radius when it is made to rotate.It is suggested that it is not unreasonable to attach the label incompressible to matter having these properties.

scholarly journals CHARGED PARTICLES AND THE ELECTRO-MAGNETIC FIELD IN NONINERTIAL FRAMES OF MINKOWSKI SPACE–TIME II: "APPLICATIONS: ROTATING FRAMES, SAGNAC EFFECT, FARADAY ROTATION, WRAP-UP EFFECT"

2010 ◽  
Vol 07 (02) ◽  
pp. 185-213 ◽  
Author(s):  
DAVID ALBA ◽  
LUCA LUSANNA
Keyword(s):  
Minkowski Space ◽  
Faraday Rotation ◽  
Rotating Disk ◽  
Space Time ◽  
Sagnac Effect ◽  
Electro Magnetic Field ◽  
Minkowski Space Time ◽  
Relativistic Extension ◽  
Rotating Frames ◽  
Electro Magnetic

We apply the theory of noninertial frames in Minkowski space–time, developed in the previous paper, to various relevant physical systems. We give the 3 + 1 description without coordinate singularities of the rotating disk and the Sagnac effect, with added comments on pulsar magnetosphere and on a relativistic extension of the Earth-fixed coordinate system. Then we study properties of Maxwell equations in noninertial frames like the wrap-up effect and the Faraday rotation in astrophysics.

Evasive Epiphanies in Ekphrastic Epigram

Ramus ◽  
2002 ◽  
Vol 31 (1-2) ◽  
pp. 33-50 ◽  
Author(s):  
Verity Platt
Keyword(s):  
Literary Context ◽  
Presence And Absence ◽  
Image Position ◽  
The Waves ◽  
Divine Truth

(Greek Anthology 16.160, attributed to ‘Plato’)Paphian Cytherea came through the waves to Knidos,Wishing to see her own image.Having viewed it from all sides in its open shrine,She cried, ‘Where did Praxiteles see me naked?’‘Through a glass, darkly:’ not just a hackneyed, Biblical phrase summing up our inability to apprehend God, but a pithy visualisation of the gap between divine truth and our perception of it. Yet Paul's words might also stand as an image for the trope of ekphrasis, the bewildering textual prism through which the frustrated reader attempts to view an enclosed and distant image. In this paper I will attempt to unite these two themes; one, the complexities of viewing and representing the divine, and two, the unrequited desire engendered by the ekphrastic text. Both of these rely upon an interplay of presence and absence which is, in a literary context, brilliantly communicated by the series of epigrams in the Greek Anthology dealing with images of gods, particularly, if we are to speak of desire, those which address images of Aphrodite.

On the existence theory for irrotational water waves

1978 ◽  
Vol 83 (1) ◽  
pp. 137-157 ◽  
Author(s):  
G. Keady ◽  
J. Norbury
Keyword(s):  
Water Waves ◽  
Volume Flow Rate ◽  
Ideal Liquid ◽  
Flow Speed ◽  
Existence Theory ◽  
Wave Solutions ◽  
Maximum Angle ◽  
Steady Plane ◽  
Image Position ◽  
The Waves

AbstractThis paper concerns steady plane periodic waves on the surface of an ideal liquid flowing above a horizontal bottom. The flow is irrotational. The volume flow rate is denoted by Q, the velocity potential by ø, the period in ø of the waves by 2L, and the maximum angle of inclination between the tangent to the surface and the horizontal by θm.Krasovskii (12) established that, at each fixed Q and L, there exist wave solutions for each value of θm strictly between zero and ⅙π. We establish that, at each fixed Q and L, there exist wave solutions for each value of qc strictly between c and zero. Here qc is the flow speed at the crest, andwhere g is the acceleration due to gravity. Krasovskii's set of solutions is included in the set that we obtain.

scholarly journals D-FOAM PHENOMENOLOGY: DARK ENERGY, THE VELOCITY OF LIGHT AND A POSSIBLE D-VOID

2011 ◽  
Vol 26 (13) ◽  
pp. 2243-2262 ◽  
Author(s):  
JOHN ELLIS ◽  
NICK E. MAVROMATOS ◽  
DIMITRI V. NANOPOULOS
Keyword(s):  
Refractive Index ◽  
Dark Energy ◽  
Energy Density ◽  
Particle Density ◽  
Space Time ◽  
Dark Energy Density ◽  
Present Epoch ◽  
Brane Model ◽  
Velocity Of Light ◽  
Reduced Density

In a D-brane model of cosmology and space–time foam, there are contributions to the dark energy that depend on the D-brane 10-velocities and on the density of D-particle defects in the ten-dimensional bulk. The latter may also reduce the speeds of energetic photons, establishing a phenomenological connection with astrophysical probes of the universality of the velocity of light. Specifically, the cosmological dark energy density measured at the present epoch may be linked to the apparent retardation of energetic photons propagating from nearby AGN's. However, this nascent field of "D-foam phenomenology" may be complicated by variations in the D-particle density encountered at different cosmological epochs. A reduced density of D-particles encountered at redshifts z ~ 1 — a "D-void" — would increase the dark energy while suppressing the vacuum refractive index, and thereby might reconcile the AGN measurements with the relatively small retardation seen for the energetic photons propagating from GRB 090510, as measured by the Fermi satellite.

scholarly journals BRANS–DICKE COSMOLOGY IN AN ANISOTROPIC MODEL WHEN VELOCITY OF LIGHT VARIES

2002 ◽  
Vol 11 (06) ◽  
pp. 921-932 ◽  
Author(s):  
SUBENOY CHAKRABORTY ◽  
NARAYAN CHANDRA CHAKRABORTY ◽  
UJJAL DEBNATH
Keyword(s):  
Scalar Field ◽  
Asymptotic Behaviour ◽  
Space Time ◽  
Anisotropic Model ◽  
Time Model ◽  
Velocity Of Light ◽  
Space Time Model ◽  
Flatness Problem

In this paper, we have studied Brans–Dicke (BD) Cosmology in an anisotropic Kantowski–Sachs space–time model; considering variation of the velocity of light. We have addressed the flatness problem considering both cases namely (i) when the Brans–Dicke scalar field φ is constant (ii) when φ varies, specially for radiation dominated era perturbatively and non-perturbatively and asymptotic behaviour have been studied.

Effect of scale on solute dispersion in saturated porous media

1984 ◽  
Vol 16 (1) ◽  
pp. 18-18 ◽  
Author(s):  
Vijay K. Gupta ◽  
R. N. Bhatiacharya
Keyword(s):  
Differential Equation ◽  
Porous Media ◽  
Time Scale ◽  
Space Time ◽  
Saturated Porous Media ◽  
Solute Dispersion ◽  
Image Position ◽  
Steady Velocity ◽  
Fokker Planck

Consider a saturated porous m edium in which water is flowing slowly with a steady velocity. Suppose at some space-time scale the concentration C(x, r) of a non-reactive dilute solute is governed by the following Fokker-Planck differential equation:

Experimental Analysis and Flow Visualization of a Thin Liquid Film on a Stationary and Rotating Disk

1991 ◽  
Vol 113 (1) ◽  
pp. 73-80 ◽  
Author(s):  
S. Thomas ◽  
A. Faghri ◽  
W. Hankey
Keyword(s):  
Free Surface ◽  
Film Thickness ◽  
Liquid Film ◽  
Flow Visualization ◽  
Thin Liquid Film ◽  
Rotating Disk ◽  
Radial Spreading ◽  
Frictional Forces ◽  
The Mean ◽  
The Waves

The mean thickness of a thin liquid film of deionized water with a free surface on a stationary and rotating horizontal disk has been measured with a nonobtrusive capacitance technique. The measurements were taken when the rotational speed ranged from 0–300 rpm and the flow rate varied from 7.0–15.0 lpm. A flow visualization study of the thin film was also performed to determine the characteristics of the waves on the free surface. When the disk was stationary, a circular hydraulic jump was present on the disk. Upstream from the jump, the film thickness was determined by the inertial and frictional forces on the fluid, and the radial spreading of the film. The surface tension at the edge of the disk affected the film thickness downstream from the jump. For the rotating disk, the film thickness was dependent upon the inertial and frictional forces near the center of the disk and the centrifugal forces near the edge of the disk.

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