Jantar Mantar: How does it calculate time?
Right in the heart of the national capital stands an astronomical marvel, built by a king who was very, very good at Maths and strategy. We are talking about the Jantar Mantar. It was built by Maharaja Jai Singh II of Jaipur, who was equally good at astronomy and planning warfare, because he enjoyed spending time with numbers and strategy. But just what is the Jantar Mantr and why does it look so strange?
How did the Jantar Mantar get built?
Mughal ruler Muhammad Shah followed the Islamic calendar Zij, like most other rulers. Maharaja Jai Singh II noticed that the calendar did not match the astronomical charts he had drawn up based on observation and very complex calculations. The Sultan asked the Raja to re-do the astronomical calculations. So Jai Singh built 4 Jantar Mantars or massive sundials, to calculate time accurately. The one at Jaipur is the biggest. So the Delhi clock (that’s what it is) was built in 1724 by a king who wanted to make an astronomically perfect calendar. His calendar was adopted by the Sultan, and was followed for over a century thereafter
How does the Jantar Mantar work?
The Jantar Mantar is an observatory cum clock built to gauge and create astronomical charts, and to estimate the time by tracking the movements of the planets, moon and the sun. The Delhi Jantar Mantar is made up of several ‘jantras’ or structures to calculate time, according to the ‘mantra’ or system of calculation. The main sundial at Delhi is 723 feet high at its tallest point, and based on ancient Egyptian Ptolemic structures, keeping in mind the angle and curvature of the horizon and Equator, and according to the angles the sun, moon and Earth makes during eclipses. It still tells time accurately, so it’s a centuries old working calendar!
How does the Jantar Mantar calculate time?
4 of the most famous ‘jantars’ at Delhi are Misra Yantra, Samrat Yantra, Jaiprakash Yantra and Rama Yantra. The Misra Yantra is a combination of 5 smaller yantras. Between them, these structures can calculate: the shortest and longest day of the year, noon at any point on Earth, accurate time down to fractions of seconds, declining angles of other celestial bodies, and even their altitude from Earth.