Light needs a surface to bounce off, otherwise   
   light cannot be detected, for example when in a dark room, a light   
   bulb or cfl or LED light is switched on then we can see the furniture, walls   
   in that room because the light is bouncing/reflecting of those o   
   jects/surfaces.   
   When a laser pointer is pointed at a screen or at a target that spot can be   
   detected   
   because the laser beam falls on the target and bounces back and then is   
   detected   
   by a photosensor.   
      
   But, what if it was possible to detect a spot or point of light in just air,   
   without   
   the need of a surface for that spot/point to bounce of.   
   What would be the practical applications of such an invention.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)