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          This picture was  nominated as a  featured picture candidate in April 2006 and  July 2007. | 
         
        
        
        
        
       
        Summary 
        One of the most perfect spheres ever created by humans. A fused quartz gyroscope for the Gravity Probe B experiment which differs from a perfect sphere by no more than a mere 40 atoms of thickness as it refracts the image of  Albert Einstein in the background.
         Licensing 
        
         
          
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           This file is in the  public domain because it was solely created by  NASA. NASA copyright policy states that "NASA material is not protected by copyright unless noted". (See  Template:PD-USGov,  NASA copyright policy page or  JPL Image Use Policy.) | 
           
            
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        Imagen tomada de  en.wikipedia.org/wiki/Image:Einstein_gyro_gravity_probe_b.jpg
        
        
        
       File usage
       
        The following pages on Schools Wikipedia link to this image (list may be incomplete):
        
        
       
       This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. If the file has been modified from its original state, some details may not fully reflect the modified file.
        
       
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