English
Related papers

Related papers: $c$ at the belfry

200 papers

Recently there has been a lot of intersest in the superluminal phenomena, and time varying velocity of light cosmological models. More than two decades ago at Einstein centenary symposium, Nagpur I had put forward space-time interaction…

General Relativity and Quantum Cosmology · Physics 2007-05-23 S. C. Tiwari

In this paper, we present an analysis of the outcomes of long-baseline neutrino experiments based on the consideration of frameworks. Our analysis suggests that the time difference between the time-of-flights corresponding to the speed of…

General Physics · Physics 2012-05-15 Md. Farid Ahmed

Multiple scattering of light by resonant vapor is characterized by Levy-type superdiffusion with a step size distribution $P(x) \propto 1/x^{1+{\alpha}}$, with $0 < {\alpha} < 2$. The Levy parameter ${\alpha}$ was measured from $P(x)$,…

Physics textbooks assert that in the famous interferometer 1887 experiment to detect absolute motion Michelson and Morley saw no rotation-induced fringe shifts - the signature of absolute motion; it was a null experiment. However this is…

General Physics · Physics 2007-05-23 Reginald T. Cahill

In the Friedmann-Lema\^itre-Robertson-Walker metric, a varying speed of light (VSL) reflects a change in the clock rate across hypersurfaces, described by the lapse function. This variation is not a dynamical field evolution but a…

General Physics · Physics 2025-05-23 Seokcheon Lee

The recent, precise Michelson-Morley experiment performed by Muller et al. suggests a tiny anisotropy of the speed of light. I propose a quantitative explanation of the observed effect based on the interpretation of gravity as a density…

General Relativity and Quantum Cosmology · Physics 2007-05-23 M. Consoli

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…

Physics Education · Physics 2007-05-23 Joel Lepak , M. Crescimanno

Observations of interplanetary scintillation (IPS - the scintillation of compact radio sources due to density variations in the solar wind) enable the velocity of the solar wind to be determined, and its bulk density to be estimated,…

Solar and Stellar Astrophysics · Physics 2022-10-06 R. A. Fallows , K. Iwai , B. V. Jackson , P. Zhang , M. M. Bisi , P. Zucca

In 1676 Olaus R{\o}mer presented the first observational evidence for a finite light velocity $\cem$. He formed his estimate by attributing the periodically varying discrepancy between the observed and expected occultation times of the…

General Relativity and Quantum Cosmology · Physics 2015-06-15 Lee Samuel Finn , Joseph D. Romano

Current constraints on photon velocity variability are summarized and displayed in terms of an energy dependent vacuum refraction index. It is shown that the energy-momentum balance of high energy Compton scattering is very sensitive to the…

High Energy Physics - Experiment · Physics 2012-11-13 V. Gharibyan

In the famous Solvay 1927 conference, Einstein discussed a gedanken experiment involving a single photon diffracted at an aperture and impinging on a screen. He devised the example to support De Broglie's hypothesis of the pilot wave, and…

Quantum Physics · Physics 2026-04-02 Alejandro A. Hnilo

Betelgeuse has gone through a sudden shift in its brightness and dimmed mysteriously. This is likely caused by a hot blob of plasma ejected from Betelgeuse and then cooled to obscuring dust. If true, it is a remarkable opportunity to…

When the electrons stored in the ring of the European Synchrotron Radiation Facility (ESRF, Grenoble) scatter on a laser beam (Compton scattering in flight) the lower energy of the scattered electron spectra, the Compton Edge (CE), is given…

The square inverse law with distance plays an important role in many fields of physics covering electromagnetism, optics or acoustics. However, as every law in physics has its range of validity. We propose an open-inquiry laboratory where…

Physics Education · Physics 2025-09-18 Cecilia Stari , Marcos Abreu , Martín Monteiro , Arturo C. Marti

Classical Doppler Effect of light propagation can be calculated by making any one of the two assumptions a) Light propagates at the speed c with respect to the source or b) Light propagates at the speed c with respect to the receptor. We…

General Physics · Physics 2022-10-31 Chandru Iyer , G. M. Prabhu

Edmond Becquerel's process of making photochromatic images, which are the first colours photographs, is still poorly understood. In particular, the origin of the colours of these images gave rise to a long-lasting debate, starting from the…

In a previous work we have shown that the null result of the Michelson-Morley experiment in vacuum is deeply connected with the notion of time. The same is true for the the postulate of constancy of the two-way speed of light in vacuum in…

Physics Education · Physics 2007-05-23 Rodrigo de Abreu , Vasco Guerra

Motivated by a recent experiment [J. Eschner {\it et al.}, Nature {\bf 413}, 495 (2001)], we now present a theoretical study on the fluorescence of an atom in front of a mirror. On the assumption that the presence of the distant mirror and…

Quantum Physics · Physics 2009-11-07 Almut Beige , Jiannis Pachos , Herbert Walther

A hundred years ago, two British expeditions measured the deflection of starlight by the sun's gravitational field, confirming the prediction made by Einstein's General theory of Relativity. One hundred years later many physicists around…

History and Philosophy of Physics · Physics 2020-01-15 Jorge L. Cervantes-Cota , Salvador Galindo-Uribarri , George F. Smoot

Hall and Abouraddy [1] have reported first experimental observation of optical de Broglie-Mackinnon wave packets, which is a seminal achievement in the study of so-called non-diffracting optical pulses. These wave packets propagate in free…

Optics · Physics 2024-03-06 Peeter Saari , Ioannis M. Besieris