History of Astronomy – Jantar Mantar Jaipur – the biggest observatory ever built without a telescope, by Thomas Obitz

The Jantar Mantar was built between 1728 and 1734 by Maharajah Sawii Jai Singh II, at the centre of his new capital Jaipur, just next to the palace. It employed 20 permanent astronomers mapping the skies with the naked eye, supported by a collection of huge instruments. The large sundial, the Samrat Yantra, is more than 20m high and has a resolution of 2 seconds.

Jai Singh was a ruler passionate about science, in particular mathematics and astronomy, and he built five observatories all over India. The one in Jaipur is the largest and the most well-preserved.

The presentation will discuss the instruments, the work performed at the Jantar Mantar, the role of astronomy and astrology in Indian and Mughal culture, and the pleasure of visiting India.

Thomas Obitz is an amateur astronomer with a strong interest in astrophysics and specifically heliophysics. He has been a member of the astronomical…