Poisson's spot

Poisson's spot

also called  Arago's spot 

      diffraction pattern produced by a small spherical object in the path of parallel light rays. French physicist Augustin-Jean Fresnel (Fresnel, Augustin-Jean) presented much of his work on diffraction as an entry to a competition on the subject sponsored by the French Academy of Sciences (Sciences, Academy of) in 1818. The committee of judges included a number of prominent advocates of Isaac Newton (Newton, Sir Isaac)'s corpuscular model of light, one of whom, Siméon-Denis Poisson (Poisson, Siméon-Denis), pointed out that Fresnel's model predicted a seemingly absurd result: If a parallel beam of light falls on a small spherical obstacle, there will be a bright spot at the centre of the circular shadow—a spot nearly as bright as if the obstacle were not there at all. An experiment was subsequently performed by the French physicist François Arago, and Poisson's spot was seen, vindicating Fresnel and giving support for the wave model of light.

Glenn Stark
 

* * *


Universalium. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • Poisson (disambiguation) — Poisson (meaning fish in French) may refer to:* Siméon Denis Poisson (1781 1840), French mathematician, geometer and physicist, after whom a number of mathematical concepts and physical phenomena are named, including: ** Poisson distribution, a… …   Wikipedia

  • Poisson-Fleck — Der Poisson Fleck ist ein Beugungsphänomen der Optik und beschreibt den hellen Fleck in der Mitte einer Beugungsfigur bei Beugung von Licht an einem kreisrunden lichtundurchlässigen Objekt. Alle Punkte eines Kreises haben den gleichen Abstand zu… …   Deutsch Wikipedia

  • Siméon Denis Poisson — Infobox Scientist box width = 300px name = Siméon Poisson image size = 200px caption = Siméon Denis Poisson (1781 1840) birth date = 21 June 1781 birth place = Pithiviers, France death date = 25 April 1840 death place = Sceaux, France residence …   Wikipedia

  • Arago spot — In optics, an Arago spot is a bright point which appears at the center of the shadow of a circular object in light from a point source. It is also sometimes called a Poisson spot. [Citation | last =Pedrotti | first =Frank L. | last2 =Pedrotti |… …   Wikipedia

  • light — light1 lightful, adj. lightfully, adv. /luyt/, n., adj., lighter, lightest, v., lighted or lit, lighting. n. 1. something that makes things visible or affords illumination: All colors depend on light. 2. Physics …   Universalium

  • science, philosophy of — Branch of philosophy that attempts to elucidate the nature of scientific inquiry observational procedures, patterns of argument, methods of representation and calculation, metaphysical presuppositions and evaluate the grounds of their validity… …   Universalium

  • Laser beam profiler — A laser beam profiler captures, displays, and records the spatial intensity profile of a laser beam at a particular plane transverse to the beam propagation path. Since there are many types of lasers ultraviolet, visible, infrared, continuous… …   Wikipedia

  • Giacomo F. Maraldi — Giacomo Filippo Maraldi (August 21,1665 ndash; December 1,1729) was an French Italian astronomer and mathematician. His name is also given as Jacques Philippe Maraldi.Born in Perinaldo (modern Liguria) he was the nephew of Giovanni Cassini, and… …   Wikipedia

  • CrimeStat — Primary File page of CrimeStat CrimeStat is a Windows based spatial statistic software program that conducts spatial and statistical analysis and is designed to interface with a Geographic Information System. The program is developed by Ned… …   Wikipedia

  • Institut national de prévention et d'éducation pour la santé — Logo de l INPES. L Inpes ou Institut national de prévention et d éducation pour la santé est un établissement public administratif (EPA) français placé sous la tutelle du ministère chargé de la Santé. Créé par la loi du 4 mars 2002 relative aux… …   Wikipédia en Français

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”