~~Equinox (samaraathri) day~~

From my dad

    Today Mar 21, 2011, is the Equinox day. Skywatchers and space enthusiasts will take measurements of the shortest shadow at noon, and also calculate the latitude of the place.  The word ‘equinox' is derived from the Latin words aequus (equal) and nox (night). It means equal day and night. 

          However, in reality, the day is longer than the night at an equinox. This is because the sun is not a single point of light, but appears to be a disc. So when the centre of the sun is still below the horizon, the upper limb already emits light, he said. Furthermore, the atmosphere refracts light downwards, so even when the upper limb is still below the horizon, its rays already reach around the horizon to the ground. These effects together make the day about 14 minutes longer than the night at the equator, and more towards the poles.