ONE WAY SPEED of LIGHT

2018

The speed of light has been repeatedly measured considering the time a photon spends travelling from an initial point to another and then coming back to the initial point, the so called two-way speed of light. Experiments aiming to measure the speed of light when it travels strictly an initial point to another, the so called one-way speed of light, have also been proposed. Here we will discuss the conceptual basics some of these experiments, proposing what seems to be a new feasible procedure to measure the one-way speed of light. According to Special Relativity it is expected that the measurable value will match the observed value for the two-way speed of light.

Journal of Modern Physics Vol.15 No.13, 2024

The self-rotating motion of the earth makes it possible to test the constancy of the speed of light in all directions by measuring the one-way speed of light. The review of the implemented experiments to test the constancy of the speed of light, based on the theory of the absolute system of reference, yields some indications that the speed of light is affected by the self-rotational motion of the earth. Newest experiments based either on the methodology of standing waves or on the Compton edge effect cannot contribute in this field of research. A proposed experiment to measuring the one-way speed of light, and the corresponding relativistic predictions, are discussed.

American Journal of Physics, 2009

A constructive formulation of the one-way speed of light Am.

JOURNAL OF ADVANCES IN PHYSICS, 2023

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 first 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 affect the already established synchronization between the two clocks.

Einstein in 1905 introduced the constancy of the speed of light as a postulate, but in so doing removed the 19 th century idea that the speed of light can be explained physically. So one might ask the question, why is the speed of light the speed that it is, and not something else? Einstein's theory provides no answer for this question. As a philosophical exercise, we consider if relativity genuinely disproved the alternative hypothesis, that light can be modeled as a wave propagating through a medium that is static with respect to the universe. We further consider if this alternative model can remain consistent with the experimentally observed speed of light. We examine herein the mathematical arguments of Herbert Ives regarding slow clock transport with respect to such a hypothetical " preferred frame " for the velocity of light, and find that this leads to a prediction of clock biases which obfuscate any one-way speed of light differences expected from a Galilean addition of velocities. As such the Lorentzian model followed by Ives can be seen as equivalent to relativity, but differing in the conventions regarding the synchronization of clocks. Finally, we explore how clocks positioned in a static frame of reference might be used to make the anticipated one-way speed of light visible experimentally.

2013

Abstract: In 1898 Henri Poincaré stated the physical impossibility of measuring the oneway velocity of light. In the present note, we present a proposal for two experimental processes that may overcome the so-called Poincaré’s curse. KEY WORDS: Special relativity, one-way velocity of light, clock calibration. 1.

This paper presents the outcome of an experiment based on an improved version of Fizeau's coupled-slotted-discs that tests the fundamental postulates of Special Relativity for the one-way speed of light propagation. According to our methodology, important phenomena-a limit on and the diurnal regularity of the variation of the speed of light due to the movements of the Earth (assuming that the speed of light follows a Galilean transformation)-can be tested by the present experiment. However, these measurements do not indicate any significant diurnal variation. Consequently, the limit of the present outcome on the variation of the speed of light is insignificant. Assuming that the speed of light is not invariant and performing a rigorous statistical analysis, the limit established is approximately 1/50 of the previous Fizeau-type experiment with 95% confidence level. These outcomes are consistent with the assumptions of Einstein's Special Relativity.

Iris Journal of Astronomy and Satellite Communications, 2024

In the current paper we set the theoretical foundations for justifying the fact that one-way light speed in vacuum has to be isotropic. Once we establish the theoretical foundations for one-way light speed isotropy, we proceed with describing the experimental setup for measuring one-way light speed. The specialty literature is full of reasons why measuring one-way light speed is not possible, in the second half of this paper we show why this is not true. We also describe two different approaches, one based on Einstein clock synchronization, and one based on clock transport for measuring one-way light speed.

Journal of Student Research

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.

2023

We propose a setup allowing the physical testing of a “one way” or rather anisotropic/directionally dependent speed of light. A foundational yet unsolved measurement problem proposed to be impossible, we demonstrate the basis for a setup that is immediately practicable. Our insight is simply that the pythagorean theorem allows for a tiny geometric indiscrepancy in path length versus time over a 2d geometry, most likely the maximum indiscrepancy allowed. While some have claimed that an anisotropic speed of light would introduce fundamental problems with the lorentz transformation and equivalence principle, we demonstrate measuring such is simply a conjugate to length contraction. Finally we suggest how this may be used to test the isotropy of dark energy.