ZERO SHADOW DAY

About: 

• What is it? 
  • A sub-solar point is when the sun is directly overhead at a particular latitude. 
    
    
  • When the sun is at the zenith (the highest point in the sky) its rays will be hitting a particular point exactly perpendicular to the surface. 
    
    
  • This will make the shadow of that person/object exactly under him/her/it, making it look like there are no shadows. 
    
    
  
  
  
• When and where observed? 
  • There are two zero shadow days every year in May and July/August, observed in places that lie between tropic of cancer and tropic of Capricorn.
    
    
  • One falls during the Uttarayan (when the Sun moves northwards), and the other is during Dakshinayan (when the Sun moves southwards).
    
    
  
  
  
• How long does it lasts? This phenomenon lasts for a small part of a second, but the effect can be seen for a minute to a minute-and-a-half.