Bengaluru witnessed an unusual celestial event today, Aug. 18. Called a Shadowless Day, the phenomenon occurs when the sun aligns overhead, causing the shadow to almost disappear.
Shadowless Day is a unique astronomical event that occurs twice a year for locations between Tropic of Cancer and Tropic of Capricorn, in the latitude range of 23.5 to -23.5 degrees.
The exact timing of this event in Bengaluru is at 12:24 pm, when the sun is at its zenith, the highest point in its daily path across the sky.
During this time, observers will notice their shadows gradually fade until they are almost invisible.
This fascinating sight happened once this year in Bengaluru, on April 25, at 12:17 pm.
The Astronomical Society of India explains that the sun is never exactly directly overhead because the Earth’s axis is tilted 23.5 degrees from the plane of its orbit around the Sun. This tilt is responsible for the variation of seasons we experience throughout the year.
Shadowless Day has important cultural and educational value. It provides an opportunity to teach people about the Earth’s axial tilt, its orbit around the Sun, and the changing angles of sunlight throughout the year.
Hands-on activities are performed to demonstrate the variable shadow lengths of objects and collaborative measurements of the Earth’s diameter.
In addition to the scientific meaning, the Dark Day also has a symbolic meaning in astrology. The absence of a shadow represents a moment of equilibrium, a concept of great importance in astrological interpretations.
Whether viewed from a scientific or astrological perspective, Shadowless Day offers a unique opportunity to interact with the natural world and gain a deeper understanding of our planet’s constant relationship with the sun.
Sibu Kumar Tripathi
August 18, 2023