Les tests et effets de la physique quantique Alain Aspect est un physicien français, connu notamment pour avoir conduit le premier test concluant portant sur un des paradoxes fondamentaux de la mécanique quantique, le paradoxe Einstein-Podolsky-Rosen. Ancien élève de l'École Normale Supérieure de Cachan (ex- École Normale Supérieure de l'Enseignement Technique), agrégé de physique (1969), titulaire d'une thèse de troisième cycle en optique (Orsay, 1971), Alain Aspect enseigne 3 ans durant à l'École Normale Supérieure de Yaoundé (Cameroun) où il forme les professeurs de physique et chimie de lycée. En 1974, il entreprend à l'Institut d'Optique d'Orsay un travail expérimental sur les fondements de la mécanique quantique, connu sous le nom de " Tests des Inégalités de Bell ". Les expériences originales présentées dans le cadre de sa thèse d'état, en 1983, font encore autorité.
PhysicsLAB: Converging Lenses Any lens that is "thicker in the center" than on the edges is generally described as a convex lens and will function as a converging lens when it is operating in air. The point where all rays which enter the lens parallel to its axis are brought to a focus is called the principal focus. This position is located behind the lens and is usually labeled as F in ray diagrams. A similar point the same distance in front of the lens is called the lens' secondary focus, F'. The distance from the center of the lens to the principal focus is called the focal length of the lens and is represented by the variable, f. Whenever the actual rays of light that refract through the lens converge behind the lens to form an image, that type of image is called a real image. Since the actual rays of light passing through the lens form these real images, they are also known as "hot" images. Converging Lenses There are three primary rays which are used to locate the images formed by converging lenses.
Phénomènes de résonance | mecadyn Article du 26/02/2012 Récemment sur le Net a circulé cette vidéo d’un hélicoptère se détruisant au sol sous l’effet de vibrations. Ça s’est passé au Brésil il y a quelques jours, peu après l’atterrissage de l’appareil qui transportait 4 personnes. Tous ont été bien secoués mais s’en sont sortis indemnes… Impressionnant, non ? Il s’agit ni plus ni moins d’une instabilité comme celle déjà évoqué dans ce précédent article. À cause du fameux phénomène physique de résonance. Sur cette vidéo est bien expliquée la façon dont les vibrations se transforment en bruit. Et paf, le verre ! Pour l’hélicoptère c’est la même chose ! Logiquement de telles destructions ne doivent pas se produire, grâce à l’ajout d’amortisseurs entre l’hélice et la structure. Si vous ne voulez pas que vos équipements industriels subissent le sort de ces pauvres hélicoptères, une seule adresse, celle de MECADYN WordPress: J'aime chargement… Chef d'entreprise MECADYN
Curiosity Cabinet Over the past 25 years I have accumulated a collection of various gizmos, devices, toys etc. which to me are excellent examples of scientific principles or things that you look at and you say "That's impossible!" except it's staring you in the face. In the hope that others may also find them interesting and with the help of two undergraduates, Jacy Lundberg and Omar Khan, we have created videos of many of the items in the collection. In many cases we have tried to include explanations of how they work or references to where one can find this information. Jacy and Omar are currently seniors in the Boston College pre-medical program. Omar is from Portland, Oregon and Jacy is from Los Angeles, California. In the olden days some people assembled what were known as curiosity cabinets.
Figures Animées pour la Physique Vous y trouverez un grand nombre d'animations et de simulations scientifiques dédiées à la Physique, aux Mathématiques, à l'Astronomie... Ces animations sont des simulations numériques ou géométriques interactives de deux types : Des animations Javascript, symbolisées avec l'icône . Voir la page de mode d'emploi. Voici un résumé du menu, également disponible en haut de cette page : Vous trouverez l'historique du site ici. Movie Sheets - Teacher Submitted Movie Worksheets for the Classroom prettygoodphysics - home HyperPhysics Concepts About HyperPhysics Rationale for Development HyperPhysics is an exploration environment for concepts in physics which employs concept maps and other linking strategies to facilitate smooth navigation. For the most part, it is laid out in small segments or "cards", true to its original development in HyperCard. The entire environment is interconnected with thousands of links, reminiscent of a neural network. The bottom bar of each card contains links to major concept maps for divisions of physics, plus a "go back" feature to allow you to retrace the path of an exploration. Part of the intent for this exploration environment is to provide many opportunities for numerical exploration in the form of active formuli and standard problems implemented in Javascript. New content for HyperPhysics will be posted as it is developed. A resource that was initiated as a resource for local high school physics teachers whom I had taught has expanded into an intensively used website worldwide. HyperPhysics
klight - Mechanics Skip to main content Get your brand new Wikispaces Classroom now and do "back to school" in style. guest Join | Help | Sign In klight Home guest| Join | Help | Sign In Turn off "Getting Started" Loading... VIDEO: Watch as Slinky never stops moving on perpetual escalator machine For decades, the question of how to keep a Slinky in perpetual motion has befuddled scientists and toy owners alike. Now, one man may have the answer to ensure the Slinky fun never stops. Matthias Wandel is a Canadian woodworker who regularly uploads videos to YouTube of him creating innovative toys and devices like marble machines or a "Jenga Pistol" out of wood. Wandel recently tackled the challenge of creating a "Slinky escalator," a device that when operated correctly could keep the toy in motion without it coming a stop. In the video, Wandel crafts the machine from scratch, making adjustments along the way to help keep the Slinky from toppling over. The video has already earned nearly 400,000 views since being uploaded last week. "It's these novel but useless contraptions that get people interested," Wandel wrote on his website.