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The Speed of Light - A Technical Discussion

Submitted by D. Kiran (EEE IV/IV)

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Editor's note: A discussion on the Constancy of the Speed of Light by Kiran, related to this article, can be found here. Kiran can be contacted at his email address for more information on the topic.

The behavior of the atomic constants and the velocity of light, c, indicate that atomic phenomena, though constant when measured in atomic time, are subject to variation in dynamical time. Electromagnetic and gravitational processes govern atomic and dynamical time respectively. If conservation laws hold, many atomic constants are linked with c. Any change in c affects the atom.

For example, electron orbital speeds are proportional to c, meaning that atomic time intervals are proportional to 1/c. Consequently, the time dependent constants are affected. Therefore Planck's constant, h, may be predicted to vary in proportion to 1/c as should the half-lives of the radioactive elements. Conversely, the gyromagnetic ratio, g, should be proportional to c. And variation in c, macroscopically, therefore reflects in the microcosm of the atom. A systematic, non-linear decay trend is revealed by 163 measurements of c in dynamical time by 16 methods over 300 years. Confirming trends also appear in 475 measurements of 11 other atomic quantities by 25 methods in dynamical time. Analysis of the most accurate atomic data reveals that the trend has a consistent magnitude in all quantities. Lunar orbital decay data indicate continuing c decay with slowing atomic clocks. A decay in c also manifests as a red-shift of light from distant galaxies. These variations have thus been recorded at three different levels of measurements: the microscopic world of the atom, the intermediate level of c measurements, and finally on an astronomical scale. Observationally, this implies that the two clocks measuring cosmic time are running at different rates. Relativity can be shown to be compatible with these results. In addition, gravitational phenomena are demonstrated invariant with changes in c and the atom. Observational evidence also demands consistent atomic behavior universally at any given time, t. This requires the permeability and metric properties of free space to be changing. In relativity, these attributes are governed by the action of the cosmological constant, Lambda, proportional to c squared, whose behavior can be shown to follow an exponentially damped form... This is verified by the c data curve fit. (Note: A dynamical second is defined as 1/31,556,925.9747 of the earth's orbital period and was standard until 1967. Atomic time is defined in terms of one revolution of an electron in the ground state orbit of the hydrogen atom. The atomic standard by the cesium clock is accurate to limits of 8 x 10 (exp -14 ).

"We know that the discovery of the fact that the speed of light, when measured both in the direction of the rotation of the earth and in the direction opposite to that rotation, is invariable" has confronted modern astronomers with the alternative either of accepting the immobility of the earth or else of rejecting the usual notions of time and space. Thus it was that Einstein was led into considering space and time as two relative dimensions, variable in function of the state of movement of the observer, the only constant dimension being the speed of light. The latter would everywhere and always be the same, whereas time and space vary in relation to one another: it is as if space could shrink in favour of time, and inversely...

"That the movement of light is a fundamental 'measure' of the corporeal world we willingly believe, but why should this measure itself be a number, and even a definite number? ...Now, what would happen if the constant character of the speed of light ever came to be doubted---and there is every likelihood that it will be sooner or later---so that the one fixed pivot of Einstein's theory would fall down? The whole modern conception of the universe would immediately dissolve like a mirage."

A cosmological model is discussed which is based on interpretation of the red shift by decrease of the light speed with time everywhere in the Universe beginning with a certain moment of time in the past. The model is described by a metric in which the light speed depends on time and the radius of the curvature of three-dimensional space remains constant (c-metric). It is shown that this metric leads to the same observed facts and formulas of different characteristics that the metric of standard cosmology does but with essentially different physical interpretation. Such a property is the consequence of conformity of spaces being defined by both metrics. The agreement with the fundamental physics laws is achieved by introducing the evolution of a number of other fundamental constants synchronously with the variation of the light speed. The model considered connected the evolution of the Universe with evolution of physical constants and permits explaining some unclear phenomena - for example, a high isotropy of the relict background and superluminal speed in quasars.

Dimensional analysis of Maxwell's equations in a planar electromagnetic wave form implies wave propagation at a speed of c, defined as (e0 m0)-1/2. But such analysis does not specify anything at all about the specific values of e0 or m0. Thus Maxwell's equations say nothing about the specific velocity of propagation neither of an electromagnetic wave, nor of the detectable velocity or range of velocities in any particular observer's frame of reference. The generally accepted frame-invariance of c, and hence e0 and m0, constitutes an assumption. The Lorentz transformations allow the preservation of the form of Maxwell's equations in any inertial frame of reference (IFR) under this assumption, an assumption that Einstein raised to the status of a postulate.

But really it may be only the experimental means by which we measure the speed of light c, or e0 and m0, that produces the observed frame invariance...

First, e was a constant required to make the units square up in coloumbs law. The magnetic permeability, m, was measured in the experimental derivation of the Biot-Savart law for determining the magnetic field. These constants are found in Gauss law, which comes from Coloumb's law for the electric force on static, non-moving electrical charges. Mu shows up in Ampere's law. When the curl is applied to Maxwell's equations this gives rise to the well known classical wave equation, and the constants e and m appear as the speed of the wave. When you multiply them out it turns out to be the speed of light.

This page last modified on 25/03/2002