One-way Speed Of Light Research Articles

Relativistic analysis of the Michelson-Gale experimental result.

The result of the Michelson-Gale experiment, which shows fringe shifts by the interference between two light beams traversing a rectangular loop in opposite directions, has been nonrelativistically analyzed based on the Galilean transformation. We relativistically analyze it via the transformation under the constant light speed (TCL) and via the framework of Mansouri and Sexl (MS). The TCL provides a coordinate transformation between the isotropic frame and a rotating frame, in which the two-way speed of light is a constant c irrespective of direction on the surface that has the same radius of rotation. When using TCL, we assume that the Solar System is isotropic so that the one-way speed of light is c in it. On the contrary, considering its movement, the analysis is carried out without the assumption of isotropy based on the MS framework. The analysis results via the TCL and via the MS framework correspond to each other and are in agreement with the result of the experiment. It is shown that the difference between the travel times of the counter-propagating light beams, which results in the fringe shift, takes place due to the two factors, the anisotropy of the one-way speed of light in inertial frames and the different rotation radii at different latitudes on the Earth surface.

Theoretical Model of an Experiment to Test the Isotropy of the Speed of Light

The value for the speed of light ‘c’ = 299792458 m/s is widely known and used in theoretical physics, experimental physics, astronomy and astrophysics. However, this is the roundtrip speed from the source to the detector and back. The roundtrip speed of light has been verified thoroughly by several experiments to be a constant. Still, the equality of the one-way speed of light with the roundtrip speed of light, or the isotropy of the one-way speed of light, has never been verified. It is impossible to measure the one-way speed of light unless an absolute (standard) simultaneity is to be found. Yet, testing the isotropy of the one-way speed of light using a mathematical structure that resembles an isosceles triangle is still possible. Since the roundtrip speed of light has already proven to be isotropic, there are values only with which the one-way speed of light can travel in a path, maintaining the roundtrip speed of light to be isotropic. These values serve as limits to the maximum speed that the one-way speed of light can have in its direction of propagation in its path, from which two light pulses from both ends of its path send to the same clock, thereby evading the need for synchronization and allowing the possibility to test the constancy of the one-way speed of light.

Measuring one way speed of light

In this paper, we present a method for measuring the one-way speed of light. In order to achieve this, it is necessary to solve two problems. The rst problem is how to synchronize the clocks at the source and the detector, and the second problem is to prove that the slow movement of one of the clocks does not significantly a ect the already established synchronization between the two clocks.

The concept of a mechanical system for measuring the one-way speed of light

The work presents the concept of a device for the measurement of the one-way speed of light. The minimum parameters of this device have also been determined based on the Special Theory of Ether without transverse contraction. The Special Theory of Ether is a relativistic theory of kinemat-ics with a universal frame of reference in which light propagates and is an alternative explanation for the null result of the Michelson-Morley experiment. An experiment based on the proposed device can be one of the ways to falsify the Special Theory of Relativity and Special Theory of Ether.

How to Solve the Clock Synchronization Problem to Measure the One-Way Speed of Light and Change a Second-Order Experiment to First-Order

How to Solve the Clock Synchronization Problem to Measure the One-Way Speed of Light and Change a Second-Order Experiment to First-Order

The Existence of a Universal Frame of Reference, in Which it Propagates Light, is Still an Unresolved Problem of Physics

Abstract: This article shows that the existence of a universal frame of reference, in which light propagates, is still an unresolved problem of physics. The analyzed articles show that the rejection of the idea of ether due to Michelson-Morley’s and Kennedy-Thorndike’s experiments was too hasty. The zero results of these experiments can be explained by the theory with a universal frame of reference, in which light propagates. The fact that one-way speed of light has never been accurately measured and that there is a well-documented effect showing the anisotropy of space from the perspective of our frame of reference, which is the dipolar anisotropy of cosmic microwave background radiation, further substantiates theories with a universal frame of reference. The article shows that the null result of the Michelson-Morley and Kennedy-Thorndike experiments does not determine the Lorentz symmetry. Keywords: Lorentz transformation, Coordinate and time transformation, Universal frame of reference, Anisotropy of cosmic microwave background radiation, One-way speed of light.

Doppler effect and one-way speed of light

The Doppler effect is one of the most important and most elementary phenomenon in nature. If we accept that fact, then there is no need to use any other theories to understand its essence. There is only one Doppler effect, regardless of whether the signal between the sender and the receiver travels directly or through a medium. Therefore, there is only one formula that is valid in all cases. The goal of this paper is to determine that formula. Using the obtained results, we will show that the one-way speed of light can be measured by physical experiment.

Testing light speed invariance by measuring the one-way light speed on Earth

We show that the one-way speed of light, along an open contour AB on the uniformly rotating Earth, is observable. Our approach exploits the property of the Sagnac effect that can measure the Earth's local angular velocity and, correspondingly, the peripheral speed of the contour AB relative to Earth Centered Inertial (ECI) frame. Light speed variations, measured on the rotating Earth, may be related to the velocity w of the ECI frame relative to a hypothetical preferred frame. Since it is possible to test Einstein's postulate of a universal light speed, standard special relativity is confirmed to be a viable falsifiable theory.

One-Way Speed of Light Experiment (Quantum Entanglement Approach)

Since Einstein stated the constancy of the speed of light to be a mere “stipulation … to arrive at a definition of simultaneity”, theorists argued that it could be possible for the speed of light to differ in different directions since there are many anisotropies like the amount of matter vs antimatter. However, this assumption has not been confirmed yet. No experiment has been proposed that measures the one-way speed of light; all experiments to date measure the round-trip speed of light. The experiment proposed in this paper seeks to measure the one-way speed of light by using an entanglement-controlled stopwatch while remaining blind (during the experiment) on whether the speed of light is isotropic or anisotropic, thereby answering the century-long question.

Optical data implies a null simultaneity test theory parameter in rotating frames

The simultaneity framework describes the relativistic interaction of time with space. The two major proposed simultaneity frameworks are differential simultaneity, in which time is offset with distance in “moving” or rotating frames for each “stationary” observer, and absolute simultaneity, in which time is not offset with distance. We use the Mansouri and Sexl test theory to analyze the simultaneity framework in rotating frames in the absence of spacetime curvature. The Mansouri and Sexl test theory has four parameters. Three parameters describe relativistic effects. The fourth parameter, [Formula: see text], was described as a convention on clock synchronization. We show that [Formula: see text] is not a convention, but is instead a descriptor of the simultaneity framework whose value can be determined from the extent of anisotropy in the unidirectional one-way speed of light. In rotating frames, one-way light speed anisotropy is described by the Sagnac effect equation. We show that four published Sagnac equations form a relativistic series based on relativistic kinematics and simultaneity framework. Only the conventional Sagnac effect equation, and its associated isotropic two-way speed of light, is found to match high-resolution optical data. Using the conventional Sagnac effect equation, we show that [Formula: see text] has a null value in rotating frames, which implies absolute simultaneity. Introducing the empirical Mansouri and Sexl parameter values into the test theory equations generates the rotational form of the absolute Lorentz transformation, implying that this transformation accurately describes rotational relativistic effects.

Assessment of the relativistic rotational transformations

Rotational transformations describe relativistic effects in rotating frames. There are four major kinematic rotational transformations: the Langevin metric; Post transformation; Franklin transformation; and the rotational form of the absolute Lorentz transformation. The four transformations exhibit different combinations of relativistic effects and simultaneity frameworks, and generate different predictions for relativistic phenomena. Here, the predictions of the four rotational transformations are compared with recent optical data that has sufficient resolution to distinguish the transformations. We show that the rotational absolute Lorentz transformation matches diverse relativistic optical and non-optical rotational data. These include experimental observations of length contraction, directional time dilation, anisotropic one-way speed of light, isotropic two-way speed of light, and the conventional Sagnac effect. In contrast, the other three transformations do not match the full range of rotating-frame relativistic observations.

The one-way speed of light and the Milne universe

Abstract In Einstein’s special theory of relativity, all observers measure the speed of light, c, to be the same. However, this refers to the round-trip speed, where a clock at the origin times the outward and return trip of light reflecting off a distant mirror. Measuring the one-way speed of light is fraught with issues of clock synchronisation, and, as long as the average speed of light remains c, the speeds on the outward and return legs could be different. One objection to this anisotropic speed of light is that views of the distant universe would be different in different directions, especially with regard to the ages of observed objects and the smoothness of the Cosmic Microwave Background. In this paper, we explore this in the Milne universe, the limiting case of a Friedmann–Robertson–Walker universe containing no matter, radiation, or dark energy. Given that this universe is empty, it can be mapped onto flat Minkowski space-time and so can be explored in terms of the one-way speed of light. The conclusion is that the presence of an anisotropic speed of light leads to anisotropic time dilation effects, and hence observers in the Milne universe would be presented with an isotropic view of the distant cosmos.

On the Very Idea of Distant Correlations

Contemporary debate over laws of nature centers around Humean supervenience, the thesis that everything supervenes on the distribution of non-nomic facts. The key ingredient of this thesis is the idea that nomic-like concepts—law, chance, causation, etc.—are expressible in terms of the regularities of non-nomic facts. Inherent to this idea is the tacit conviction that regularities, “constant conjunctions” of non-nomic facts do supervene on the distribution of non-nomic facts. This paper raises a challenge for this conviction. It will be pointed out that the notion of regularity, understood as statistical correlation, has a necessary conceptual component not clearly identified before—I shall call this the “conjunctive relation” of the correlated events. On the other hand, it will be argued that there exists no unambiguous, non-circular way in which this relation could be determined. In this regard, the notion of correlation is similar to that of distant simultaneity where the necessary conceptual component is the one-way speed of light, whose value doesn’t seem to be determined by matters of (non-nomic) facts.

Simultaneity in cylindrical spacetime

In cylindrical spacetime which is flat like Minkowski spacetime but is spatially closed, two twins can part and reunite, while none of them go through any acceleration. Still, the twins are aged differently upon their reunion (except for some special occasions). The key to understanding what happens in cylindrical spacetime lies in clock synchrony. In cylindrical spacetime, the Round-trip Axiom (that two light signals sent simultaneously in opposite directions along a closed path return simultaneously) fails to hold, and so distant clocks cannot be consistently synchronized following the standard procedure proposed by Einstein except for those under some privileged motion. We propose an alternative method of synchrony utilizing the one-way speed of light traveling around the universe, which can be measured with one clock and varies from inertial frame to inertial frame. This alternative synchrony renders simultaneity not relative but absolute and makes it possible to consistently describe both the local and global phenomena in cylindrical spacetime.

Why the Sagnac effect favors absolute over relative simultaneity

We consider a thought experiment, equivalent to the Sagnac effect, where a light signal performs a round trip over a closed path. If special relativity (SR) adopts Einstein synchronization, the result of the experiment shows that the local light speed cannot be c in every section of the closed path. No inconsistencies are found when adopting absolute synchronization. Since Einstein and absolute synchronizations can be discriminated, the conventionality of the one-way speed of light holds no longer. Thus, as sustained by specialists, it might be a viable formulation of SR that reinstates the conservation of simultaneity, even though it allows for relativistic effects, such as time dilation. Such an approach may lead to the discovery of new effects and a better understanding of relativistic theories.

Measuring the One-Way Speed of Light

This paper describes a method for determining the one-way speed of light.
 
 My thesis is that the one-way speed of light is NOT constant in a moving frame of reference, and that the one-way speed of light in any moving frame of reference is anisotropic, in that its one-way measured speed varies depending on the direction of travel of light relative to the direction of travel and velocity of the moving frame of reference.
 
 Using the disclosed method for measuring the one-way speed of light, a method is proposed for how to use this knowledge to synchronize clocks, and how to calculate the absolute velocity and direction of movement of a moving frame of reference through absolute spacetime using the measured one-way speed of light as the only point of reference.

Thought experiment discriminating special relativity from preferred frame theories

In relativistic theories the effect of nonconservation of simultaneity can be separated from that of the Lorentz-Fitzgerald contraction. Since with absolute synchronization simultaneity is conserved, we show that a simple kinematic test may discriminate absolute from Einstein synchronization, settling the century-long debate on the conventionality of the one-way speed of light. An immediate consequence is that Einstein’s postulate of a universal light speed can actually be tested and the unique physical meaning of special relativity (SR) is restored. Only an experiment can corroborate SR or identify the preferred frame of reference.

The light speed versus the observer: the Kennedy\u2013Thorndike test from GRAAL-ESRF

High precision tests of the light speed constancy for all observers as a empirical basis of Special Relativity have continuously been among the goals of advanced experimental studies. Based on the Compton edge method proposed by us (Gurzadyan and Margarian in Phys Scr 53:513, 1996), a constraint on the one-way light speed isotropy and Lorentz invariance violation has been obtained at the dedicated GRAAL experiment at European Synchrotron Radiation Facility (ESRF, Grenoble) (Gurzadyan et al. in Mod Phys Lett A 20:1, 2005, Nuovo Cimento 122:515, 2007, Proceedings of the XII M. Grossmann meeting on general relativity, vol B. World Scientific, p 1495. arXiv:1004.2867, 2012; Bocquet et al. in Phys Rev Lett 104:241601, 2010). Using the GRAAL data we now get a new constraint on one of the key tests of Special Relativity—the Kennedy–Thorndike experiment (Kennedy and Thorndike in Phys Rev 42:400, 1932) in probing light speed invariance with respect to the velocity of the observer (apparatus). Our analysis takes advantage of GRAAL’s setup where two separate energy scales are involved: first, via the position of the Compton edge determining the light speed in the reference frame of incident 6 GeV electrons within the tagging system, second, in the calorimeter via the 1.27 MeV photons of the ^{22}Na source. The two energy scales are engaged to each other through production of eta mesons by tagged laser Compton backscattered gamma -rays. The accuracy of the calibration and stability of energies reached in each section enable us to obtain the limit of 7 times 10^{-12} for the Kennedy–Thorndike test, which improves the currently existing limits by three orders of magnitude.

Theoretical analysis of generalized Sagnac effect in the standard synchronization

The Sagnac effect has been shown in inertial frames as well as rotating frames. We solve the problem of the generalized Sagnac effect in the standard synchronization of clocks. The speed of a light beam that traverses an optical fiber loop is measured with respect to the proper time of the light detector, and is shown to be other than the constant c, though it appears to be c if measured by the time standard-synchronized. The fiber loop, which can have an arbitrary shape, is described by an infinite number of straight lines such that it can be handled by the general framework of Mansouri and Sexl (MS). For a complete analysis of the Sagnac effect, the motion of the laboratory should be taken into account. The MS framework is introduced to deal with its motion relative to a preferred reference frame. Though the one-way speed of light is other than c, its two-way speed is shown to be c with respect to the proper time. The theoretical analysis of the generalized Sagnac effect corresponds to the experimental results, and shows the usefulness of the standard synchronization. The introduction of the standard synchrony can make mathematical manipulation easy and can allow us to deal with relative motions between inertial frames without information on their velocities relative to the preferred frame.

Einstein’s physical chronogeometry

In Einstein’s physical geometry, the geometry of space and the uniformity of time are taken to be non-conventional. However, due to the stipulation of the isotropy of the one-way speed of light in the synchronization of clocks (or definition of simultaneity), as it stands, Einstein’s views do not seem to apply to the whole of the Minkowski space-time. In this work we will see how Einstein’s views can be applied to the Minkowski space-time. In this way, when adopting Einstein’s views, chronogeometry is a physical chronogeometry.