Zero Shadow Day in Bengaluru on April 25

Indian Institute of Astrophysics is organising a public talk followed by hands-on activities to demonstrate Zero Shadow Day at its campus on April 25

Zero Shadow Day occurs when the Sun is directly overhead, and hence any vertical object will cast no shadow. | Photo Credit: the hindu

It’s Zero Shadow Day in Bengaluru on April 25. At 12.17 p.m., the Sun will be directly overhead and hence any vertical object will cast no shadow.

“This happens for places between the Tropic of Cancer and Tropic of Capricorn and is on April 25 and 18 August for Bengaluru,” said the Indian Institute of Astrophysics.

“To celebrate this, we are organising a public talk followed by hands-on activities to demonstrate Zero Shadow Day at our campus. The latter will involve observing the effect of the changing shadow length of objects as well as measuring the length of the shadow by the visiting public. We will also be coordinating with a school at a different location to collaboratively measure the Earth’s diameter. The moment of zero shadows when the Sun is directly overhead in Bengaluru, i.e., local noon, is at 12:17 afternoon,” it added.

As per the Astronomical Society of India, this annual celestial phenomenon occurs twice a year for places between +23.5 and -23.5 degrees latitude. The Sun is almost never exactly overhead at noon but usually transits a bit lower in altitude, a bit to the north or a bit to the south.