Encyclopedia > Arago spot

  Article Content

Arago spot

An Arago spot is a bright point which, owing to diffraction, appears at the center of the shadow of a circular object in light from a point source[?]. The diffraction pattern of a circular object has considerable interest due to the historical part it played in the wave theory of light. Siméon Poisson deduced from Augustin Fresnel's theory the necessity of a bright spot at the centre of the shadow of a circular opaque obstacle. With this counterintuitive result Poisson hoped to disprove the wave theory; however Dominique Arago experimentally verifed the prediction and today the demonstration goes by the name "Poisson's (Arago's) spot".



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Westhampton Beach, New York

... 65 years of age or older. The median age is 44 years. For every 100 females there are 93.5 males. For every 100 females age 18 and over, there are 92.2 males. Th ...

 
 
 
This page was created in 27.6 ms