For those living between the latitude of 23.5 degree south (the tropic of Capricorn) and 23.5 degree north (the tropic of Cancer), this unique illusion will take place in the coming days when the sun is right overhead and for a short time the shadow of a vertical object is right below the base- as if it has disappeared.
Informing that this phenomenon occurs twice a year, Mumbai-based Nehru Planetarium Director Arvind Paranjpye told PTI over phone that it was "very exciting" to watch your very shadow disappear for a brief interval.
"All one needs to do is to keep a vertical object in the sun and watch its shadow falling right below it- vanishing for about a minute or so. This is a very enjoyable phenomenon to watch that carries a high value of edutainment", he said.
Attributing the phenomenon to the solstices, known as Uttarayan and Dakshinayan, Paranjpye said as the earth is tilted by about 23.5 degree towards vertical plane during this time, when it revolves around the sun, seasons take place on plain.
"One could see the position of the rising (or setting) sun shifting day by day repeatedly northwards and southwards. In India it is popularly known as 'Uttarayan' and 'Dakshinayan'. During these two-and-a-half cycles come a day when the sun shines directly over head. At that time the shadow of a vertical object is right below. Giving the impression that the shadow has disappeared", Paranjpye said.
One can experience this optical illusion in the next seven to eight days at Pune (May 13 and May 14), Mumbai (May 15), Ahemadnagar (May 19) and cities, namely Aurangabad, Jalna and Nashik---all in Maharashtra, on May 20 at around 12:30 PM.
Paranjpye further said that those living between the north of tropic of Cancer (between +23.5 and +90 degree latitude) and south of tropic of Capricorn (between -23.5 and -90 degree latitude) will not experience the phenomenon.
