The Students of Department of Physics traced the shadow of various objects at
different times on April
24, 2019 as there will be no shadow exactly at 12.07 noon when the sun will be
exactly at zenith. 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 be exactly
under any object, making it look like there are no shadows. The
apparent path of the Sun goes from 23.5 degrees south of our equator to 23.5
degrees north of it through the year, so every place on the Earth between the Tropics of Cancer and Tropics of
Capricorn, will have two days in a year where the Sun will be directly overhead
once during `Uttarayan’ (summer
solstice - when sun begins its movement
away from the Tropic of Capricorn, towards the Northern Hemisphere) and
once during `Dakshinayan’ (winter solstice - period when Sun travels back from Cancer to Capricorn that is from North
to South). These are called Zero Shadow Days or ZSDs for that location. For India these days happen during the time
period from April to September.
