Related papers: Foucault's method in new settings
In this paper, we demonstrate a low-cost method to measure the speed of light. It uses instruments which are readily available in any undergraduate laboratory in a developing country and some components which are inexpensive. The method is…
A small tabletop experiment for a direct measurement of the speed of light to an accuracy of few percent is described. The experiment is accessible to a wide spectrum of undergraduate students, in particular to students not majoring in…
The speed of light in vacuum, one of the most important and precisely measured natural constants, is fixed by convention to $c=299 792 458$ m/s. Advanced theories predict possible deviations from this universal value, or even quantum…
A powerful test of fundamental physics consists on probing the variability of fundamental constants in Nature. Although they have been measured on Earth laboratories and in our Solar neighbourhood with extremely high precision, it is…
We report on a very simple and inexpensive method for determining the speed of an electrical wave in a transmission line. The method consists of analyzing the roundtrip time for ethernet packets between two computers. It involves minimal…
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…
An experimental setup capable, in principle, to test the isotropy of the {\em one way} propagation of light to 1 part in $10^8$ (or better), is suggested.
The Varying Speed of Light (VSL) model describes how the speed of light in a vacuum changes with cosmological redshift. Despite numerous models, there is little observational evidence for this variation. While the speed of light can be…
In this contribution the question of the isotropy of the one-way speed of light from an experimental perspective is addressed. In particular, we analyze two experimental methods commonly used in its determination. The analysis is aimed at…
We develop a new model-independent method to probe the constancy of the speed of light $c$. In our method, the degeneracy between the cosmic curvature and the speed of light can be eliminated, which makes the test more natural and general.…
Recent attempts at measuring the variation of $c$ using an assortment of standard candles and the redshift-dependent Hubble expansion rate inferred from the currently available catalog of cosmic chronometers have tended to show that the…
In this paper we extend a new method to measure possible variation of the speed of light by using Baryon Acoustic Oscillations and the Hubble function presented in our earlier paper [V. Salzano, M. P. D\c{a}browski, and R. Lazkoz, Phys.…
One of the main issues in measuring the speed of light when it only travels from one spatial position into another position, known as the one-way speed of light, is that the clocks belonging to each separated spatial position are not and,…
We empirically determined the speed of light by measuring the variation in longitudinal mode frequencies, or the beat frequencies, of an adjustable-length, open-cavity helium-neon laser as a function of its cavity length. The TEM$_{00}$…
We report the first direct photon velocity measurements for extragalactic objects. A fiber-optic, photon time-of-flight instrument, optimized for relatively dim sources ($m 12$), is used to measure the velocity of visible photons emanating…
The isotropy of the speed of light - the fundamental postulate of Special Relativity (SR) constrains conceptions of time, space and the existence of a preferred cosmological reference frame. Consequently, this phenomenon has been subject to…
A formulation of the one-way speed of light in three-dimensional Euclidean space is derived by a constructive approach. This formulation is consistent with the result of the Michelson-Morley experiment in that the harmonic mean of the…
Traditional methods for measuring the speed of light in dispersive media have been based on the detection of interference between light waves emitted from the same source. In the present study the elapsed times for single photons to move…
The possible time variation of the fundamental constants of nature has been an active subject of research in modern physics. In this paper, we propose a new method to investigate such possible time variation of the speed of light $c$ using…
In this paper, we discuss some of the consequences of the CGPM (1983) definition of meter and, in particular, we discuss giving the speed of light an exact value. It is shown that this act touches the fundamental paradigms, such as the…