Related papers: $c$ at the belfry
The properties of light in the presence of electromagnetic and gravitational fields are compared. Once one takes account of the fact that clock rates vary with distance from a massive object, it is argued that in an absolute sense light…
With a Michelson interferometer using a phase-conjugate mirror (PCM) that reverses the uniform phase shift in a light path, we can conduct a first-order experiment of Special Relativity. Utilization of the PCM changes the basic concepts of…
We present a new, model-independent method to reconstruct the temporal evolution of the speed of light $c(z)$ using astronomical observations. After validating our pipeline using mock datasets, we apply our method to the latest BAO and…
A spherically symmetric and static metric that describes physical coordinates is introduced. It is defined to be a metric that gives coordinate independent results for physically observable quantities without a further coordinate…
The thought experiment (called the clock paradox or the twin paradox)proposed by Langevin in 1911 of two observers, one staying on Earth and the other making a trip toward a star with a velocity near the light velocity is very well known…
Probing the speed of light is as an important test of General Relativity but the measurements of $c$ using objects in the distant universe have been almost completely unexplored. In this letter, we propose an idea to use the multiple…
The concepts of Fourier optics were established in France in the 1940s by Pierre-Michel Duffieux, and laid the foundations of an extensive series of activities in the French research community that have touched on nearly every aspect of…
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…
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,…
In this paper, we describe in detail the BMV (Bir\'efringence Magn\'etique du Vide) experiment, a novel apparatus to study the propagation of light in a transverse magnetic field. It is based on a very high finesse Fabry-Perot cavity and on…
We present a Michelson-Morley type experiment for testing the isotropy of the speed of light in vacuum and matter. The experiment compares the resonance frequency of an actively rotated monolithic optical cryogenic sapphire resonator…
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 a recent experiment, Salart et al. addressed the important issues of the speed of hypothetical communication and of reference frames in Bell-type experiments. The authors report that they "performed a Bell experiment using entangled…
The time delay of light as it passes by a massive object, first calculated by Shapiro in 1964, is a hallmark of the curvature of space-time. To date, all measurements of the Shapiro time delay have been made over solar-system distance…
We describe a highly unusual microlensing event, OGLE-1999-BUL-19, which exhibits multiple peaks in its light curve. The Einstein radius crossing time for this event is approximately one year, which is unusually long. We show that the…
In science, one observes correlations and invents theoretical models that describe them. In all sciences, besides quantum physics, all correlations are described by either of two mechanisms. Either a first event influences a second one by…
Proposed by Maxwell in 1879 detector of aether seems, at a superficial glance, a simple device. For example, Michelson in 1881 thought that he built an instrument that (when you turn it in the horizontal plane) will measure in vacuum…
We report on spectroscopy and time-of-flight measurements using an 18 keV fast-pulsed photoelectron source of adjustable intensity, ranging from single photoelectrons per pulse to 5 photoelectrons per microsecond at pulse repetition rates…
The paper shows that, conceptually and operationally, the speed of light as measured locally in the inertial comoving frame of a point on the rim of a rotating disk, is different from the one measured globally for a round trip along the…
In 1746 Euler publishes E88 -- Nova theoria lucis et colorum (A new theory of light and colors) in five chapters. This is an annotated translation of Chapter II - De formatione ac propagatione pulsuum (On the formation and propagation of…