In the coming days, as the Sun makes its way across the sky, moving towards the north with each passing day, depending upon where you live, the Sun will pass through the Zenith. This is Zero Shadow Day. Zenith is the point exactly above your head wherever you stand. Since the Earth is a sphere-globe, this point varies from place to place with respect to the sky.
Shadow Goes Missing
At any other point, with the Sun facing you at an angle, your shadow will be cast on the ground around you. As the sun reaches higher in the sky, the length of the shadow reduces and, on this day, when the sun is exactly above your head, it casts a shadow exactly below you. Since you stand on this shadow, you don’t really see your shadow making your shadow invisible… or Zero shadow.
With the Earth tilted at an angle of 23.5 degrees (as the globes are made), as the earth moves around the Sun, the sun appears to move from north to south, appearing at zenith on two days of the year for all people living between the Tropic of Cancer and Tropic of Capricorn. The two days occur in April-May and August every year, with August being the monsoon and April, a summer month, the chances of observing Zero Shadow Days are higher during this time.
This is one of the easiest astronomical phenomena that can be observed without the use of any instrument.
When and Where?
People at Mangaluru will observe Zero Shadows at 12:28pm on 24th of April and at Udupi on 25th April at 12:29pm. People in Bengaluru will have their Zero Shadow moment on the 24th of April at 12:18pm.
The following are the dates of Zero Shadow day for the rest of Karnataka:
| 22 Apr : Mysore, Madikeri 23 Apr : Mandya, Puttur 24 Apr : Mangalore (D.K.), Hassan, Bengaluru 25 Apr : Udupi, Chikamagaluru, Tumkur, Chikkaballapura 26 Apr : Kundapura, Thirthahalli, Gauribidanur 27 Apr : Bhatkal, Shivamogga, Channagiri 28 Apr : Honnavara, Kumta, Shikaripura, Chitradurga 29 Apr : Gokarna, Sirsi, Ranebennur, Davanagere 30 Apr : Karwar, Haveri01 May : Hubli, Hospet, Bellari 02 May : Dharwad, Gadag, Koppala 03 May : Belagavi, Sindhanur 04 May : Gokak, Bagalkot, Raichur 06 May : Yadgir 07 May : Vijayapura 09 May : Kalburgi 10 May : Hunmabad 11 May : Bidar |
The shadows for the above place will disappear for a minute between 12:15pm for eastern and 12:35pm for western parts of the state.
In order to observe Zero Shadow, an object needs to have an equal or increasing width from top to bottom, like a Cylinder, Cube or a Cone. Poles, Traffic Cones or an Inverted Glass Tumbler. Humans have a broader upper body than our lower half and hence would cast a very small amount of shadow which will be minimum on Zero Shadow Day.
To know more about Zero Shadow Day beyond Karnataka and for Exciting animations check out the ZSD App
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