A Theory without Space & Time

Einstein would have like a theory with no space and no time; he added that he didn’t know how to do it (Klein & Spiro,1996). I guess that Einstein was not excited by the job, all the more that getting rid of space and time requires having accurate definitions beforehand. This is the case today, but, if it’s quite easy to proceed, we can’t ensure that the replacement leads to significant progress in the theory. It’s no doubt paradoxical that Einstein never defined time and space, neither did contemporary researchers like Stephen Hawking. The lack of definitions about space and time is a real disadvantage, insofar as defining something is saying what it is; otherwise, we don’t know what we’re talking about. For example, what is the physical nature of space as such? What are the physical properties of time? Is time a phenomenon or a concept? In addition, a good definition is supposed to bring some theoretical extensions. For this purpose, the definitions of the second and the meter will be clarified; the signification of the covariance of the parameters in a relativistic situation will be reminded. Our target, getting rid of time and space, is based on two ideas:• Given that the international unit of time is defined in relation to the frequency of the cesium, the term which is related to time will be replaced by a term related to the frequency.• The cesium wavelength is a fundamental constant; it’s of course covariant. It turns out that any length is proportional to the cesium wavelength; the proportionality coefficient, which is a multiple of the cesium wavelength, is invariant. The splitting in two parts is not only an arithmetical trick, it allows circumscribing the covariance

Apprentissage de la thérapie manuelle par le mental training chez les étudiants en physiothérapie: étude pilote randomisée contrôlée en cross-over

L’apprentissage de gestes techniques grâce au mental training a fait ses preuves chez les sportifs, les musiciens et les chirurgiens. Ces derniers ont développé des protocoles de mental training pour certaines interventions chirurgicales telles que la laparoscopie en se basant sur le modèle PETTLEP. Concernant la physiothérapie, aucune étude n’a encore été recensée concernant l’apprentissage de la thérapie manuelle à l’aide du mental training

Quantum state tomography of slow and stored light

Quantum information can be transferred from a beam of light to a cloud of atoms and controllably released at a later time. These quantum memory devices are fundamental to applications in quantum information science, quantum computing, and quantum communication. We propose a technique for measuring the quantum state of light that has been stored and released from a quantum memory system. This technique does not require careful mode matching can in fact be used to optimize the measured field mode without a priori knowledge of the stored light

Perception, Action, and Roelofs Effect: A Mere Illusion of Dissociation

A prominent and influential hypothesis of vision suggests the existence of two separate visual systems within the brain, one creating our perception of the world and another guiding our actions within it. The induced Roelofs effect has been described as providing strong evidence for this perception/action dissociation: When a small visual target is surrounded by a large frame positioned so that the frame's center is offset from the observer's midline, the perceived location of the target is shifted in the direction opposite the frame's offset. In spite of this perceptual mislocalization, however, the observer can accurately guide movements to the target location. Thus, perception is prone to the illusion while actions seem immune. Here we demonstrate that the Roelofs illusion is caused by a frame-induced transient distortion of the observer's apparent midline. We further demonstrate that actions guided to targets within this same distorted egocentric reference frame are fully expected to be accurate, since the errors of target localization will exactly cancel the errors of motor guidance. These findings provide a mechanistic explanation for the various perceptual and motor effects of the induced Roelofs illusion without requiring the existence of separate neural systems for perception and action. Given this, the behavioral dissociation that accompanies the Roelofs effect cannot be considered evidence of a dissociation of perception and action. This indicates a general need to re-evaluate the broad class of evidence purported to support this hypothesized dissociation

Manual chronostasis: Tactile perception precedes physical contact

When saccading to a silent clock, observers sometimes think that the second hand has paused momentarily. This effect has been termed chronostasis and occurs because observers overestimate the time that they have seen the object of an eye movement. They seem to extrapolate its appearance back to just prior to the onset of the saccade rather than the time that it is actually fixated on the retina. Here, we describe a similar effect following an arm movement: subjects overestimate the time that their hand has been in contact with a newly touched object. The illusion's magnitude suggests backward extrapolation of tactile perception to a moment during the preceding reach. The illusion does not occur if the arm movement triggers a change in a continuously visible visual target: the time of onset of the change is estimated correctly. We hypothesize that chronostasis-like effects occur when movement produces uncertainty about the onset of a sensory event. Under these circumstances, the time at which neurons with receptive fields that shift in the temporal vicinity of a movement change their mappings may be used as a time marker for the onset of perceptual properties that are only established later