When you need to find out what time it is, you look at your wall clock. That clock on the wall (and now your fancy wristwatch or smartphone watch!) tells you what time you need to get up, what time you need to have your meals and what time you have to hit the bed. But a clock wasn’t discovered before the 14th century. Ever wondered, how people figured out the time before clocks? Well, they used sundials.
A sundial is a device that uses the position of the sun in the sky to tell the time. And if you thought that it would not be accurate, you would be wrong. Our ancient astronomers were so amazingly good at their work that these sundials would predict the correct time with just a few seconds of difference. And do you know, what is even more amazing is that the largest of these devices in the world, Samrat Yantra, is installed in India in our very own pink city, Jaipur.
Samrat Yantra has been there for over 300 years
The Samrat Yantra in Jaipur, Rajasthan, is part of the famous Jantar Mantar observatory, built in the 18th century. Meaning the "great king of instruments", Samrat Yantra is over 27 metres high and is the largest sundial in the world.
The sundial’s face is angled at 27 degrees, the latitude of Jaipur. As the sun’s rays fall on it, the shadow of the yantra tells the correct time of the day with an accuracy of only 2 seconds difference from the local Jaipur time. A small dome-like structure known as chatri at the tip of this instrument can predict the climatic change, location of the stars, eclipses or arrival of monsoon.
Who built the sundial?
The Jantar Mantar was built by the Hindu king, Sawai Jai Singh II and is one of the most sophisticated ancient astronomical observatories, hosting the largest sundial in the world. The observatory was probably completed around 1734. There are 19 instruments in the observatory which are built primarily of stone and marble. The observatory was in use until 1800.
Infact, recognising the immense architectural, historical, and astronomical significance of the observatory, it was declared a World Heritage Site by UNESCO in 2010.
There are other instruments that perform various functions like inferring data on the celestial objects and constellations and their positions and movements, as well as predicting the timing of eclipses. If you will look at the accuracy with which these ancient instruments represent astronomical data, it would amaze you.