A mysterious portal to the stars built in India 300 years ago

On a clear and warm afternoon a week after the spring equinox, I walked through the frenzy of Johri Bazaar, Jaipur’s main market, with its coral walls, delicate latticework and Mughal arches.

It might be a bad time to be sightseeing in Rajasthan’s desert capital, but it was perfect. Measuring time by shadows of the sun.

I was heading towards Jantar Mantar, India’s mysterious portal to the stars.

At first glance, this open-air complex – strange triangular walls and staircases seem omnipresent: it is neither as ornate as the surrounding city palace nor as elaborate as the venerable Govind Dev Ji Temple and nearby Hawa Mahal.

The 300-year-old ‘Yantram’, a collection of 20 scientific sculptures – which measure the positions of the stars and planets and accurately tell time – has puzzled me since my childhood in Jaipur, how they looked. Giant versions of the delicate tools I had in my school geometry kit.

But after many years, as a professional architect, I was able to better understand its use.

They are unique architectural solutions for understanding the dynamics of astronomy, as well as important tools for traditional Hindu astrologers to draw birth charts and predict auspicious dates.

Star-aligned cities

In 1727, when the king of the region, Sawai Jai Singh, envisioned Jaipur as his capital and the country’s first planned city, he wanted to design it according to the principles of Vastu Shastra, based on nature, astronomy and astrology. For architecture and location.

He realized that he would need accurate and accessible instruments to properly align Jaipur with the stars, assist in astrological practices, and predict key weather events for crops.

However, after sending research teams to Central Asia and Europe to collect data based on the knowledge of Islamic and European scientists, Sawai Jai Singh found discrepancies between the readings of brass instruments commonly used at the time.

To improve accuracy, he increased the size of the instruments, stabilized them by reducing moving parts, and made them resistant to wear and weather by making them from local marble and stone.

He used these findings to build five open-air observatories in the Indian cities of Jaipur, Delhi, Ujjain, Varanasi and Mathura.

Four survive: one demolished at Mathura.

But the one at Jaipur, completed in 1734, was the largest and most complete.

Today, it is a UNESCO World Heritage Site because it is the best-preserved laboratory in India, but also, as the UNESCO inscription explains, represents innovations in architecture, astronomy and cosmology, as well as learning and tradition. From Western, Middle Eastern, Asian and African cultures.

Celestial Mathematics

In Sanskrit, ‘jandar’ means tools and ‘mandar’ means calculator, so each of the yantras in the complex has a mathematical purpose: sundials to mark some local time and indicate the sun’s position in the hemisphere; Others measure the movements of the constellations and planets, identify zodiac signs and guide predictions.

Most important of all is a huge Samabandi sundial called the Samrat Yantra, a 27-meter-high triangular wall with two slender semicircular ramps like wings from its sides.

Standing below it, my guide pointed to a shadow on a curve that moved precisely 1 millimeter every second and indicated the local time within two seconds.

Another yantra, Jai Prakash, measures the path of the Sun through Indian Vedic zodiac signs to determine horoscope.

Its bowl-shaped structure, set on the ground, is like an inverted map of the sky, and a small metal plate hung from a crossbar casts a shadow to show the position of a chosen star or planet.

“I used these tools frequently during my two-year master’s program,” says Neha Sharma, a PhD in Jyotish Shastra (Vedic Astrology) from the University of Rajasthan.

“Learning to read and calculate with these instruments is a mandatory part of the curriculum for anyone who wants to pursue astrology as a career option.”

More than a curiosity

Most of the modern scientific world viewed the Jandar Mantar observatories as a curiosity until renowned Indian astrophysicist Nandiwada Ratnasree argued that the structures were still relevant.

As Director of Nehru Planetarium, Delhi (from 1999 till his death in 2021), he encouraged students to get hands-on experience in station astronomy at various Jandar Mantars and lobbied for their education and international recognition.

“It was Nandiwada Ratnasree who brought Jandar Mantar to the attention of the scientific fraternity,” says Rima Huja, archaeologist and consulting director of the Maharaja Sawai Man Singh II Museum at City Palace.

“He was instrumental in getting Jandar Mantar Jaipur recognized as a UNESCO World Heritage Site.”

Jandar Manatar continues to gain fame not only for its architectural finesse but also for its traditional style.

“On the surface, the Jandar Mantar does not look like indigenous architecture,” says conservation architect Kavitha Jain.

“But if you look closely, the tall sundial is confirmed by creating curved voids. The tools used in the construction, the Hindu canopies on top of the marble and stone evoke local architectural values” .

Today, students, scientists and tourists from many disciplines and cultures around the world understand that Jaipur’s Jandar Mantar is more than just a historical monument.

Located in the heart of an ancient city that flourishes of forts and palaces, its monolithic structures continue to reflect the universe and create a lasting legacy.

This story was originally published on BBC Travel.