We report experimental evidence that light storage, understood as the controlled release of a light pulse by an atomic sample dependent on the past presence of a writing pulse, is not restricted to small-group-velocity media but can also occur in a negative-group-velocity medium. We present a numerical modeling in close agreement with our observations and a simple physical picture applicable to...

The aim of this paper is to show experimentally the possibility to assess acoustic pressure holograms using a light membrane and a scanning laser vibrometer. The velocity of a light membrane placed in an acoustic field can be measured without contact by means of a laser vibrometer. The ideal membrane must be optically reflective, acoustically transparent (as light as possible), impermeable, and...

As we all know, when the relative velocity of two inertial reference frames ∑ and ∑′ is less than the speed of light, the relations of xμ with x ′ μ, a particle mass m with its velocity υ, and a particle mass with its energy are all given by Einstein’s special relativity. In this paper, we will give new relation of xμ and x ′ μ when the relative velocity of ∑ and ∑′ frame is larger than the spe...

Background: An imbalance of the cerebrovascular response during functional activation of the brain has been postulated as a factor in the pathophysiology of migraine. The purpose of this study was to determine the transcranial doppler sonography (TDS) diagnostic value for the cerebral flow velocity changes in the interictal phase of classic migraine. Methods: This study was carried out on 46 pa...

Fourier decomposition is employed to compare observed light and velocity curves of classical Cepheids with light and velocity curves generated by two sets of hydrodynamic models-the Carson-opacity models of Vemury and Stothers (VS) and a set of models constructed with Los Alamos opacities and dynamical zoning (LOS). In spite of the fact that a number of the theoretical light and (particularly) ...