Ujjayini Meridian

• 23 Jul 2024

Why in News?

According to a new Class-6 NCERT textbook for social science, India had a prime meridian of its own much ahead of the Greenwich meridian and it was called "madhya rekha", which passed through the city of Ujjain in Madhya Pradesh.

Key Points

• Madhya rekhā (or 'middle line') passed through the city of Ujjayinī (today Ujjain), which was a reputed centre for astronomy over many centuries. 
  • Varāhamihira, a famous astronomer, lived and worked there some 1,500 years ago. 
• Indian astronomers were aware of the concepts of latitude and longitude, including the need for a zero or prime meridian. 
• The Ujjayinī meridian became a reference for calculations in all Indian astronomical texts.

Varahamihira (505–587 CE)

• He was a renowned astronomer, mathematician, and astrologer.
• Notable works:
  • Brihat Samhita (comprehensive work on astronomy, astrology, architecture, gemology, agriculture, mathematics, and gemology).
    • He wrote about chief aspects of Jyotisha (astrology) like horoscopy.
    • He was the first to state Panchasiddhantika (book on mathematical astronomy) that the ayanamsa (precession of the equinoxes) lasted for 50.32 seconds. 
  • He first described gravity as an attractive “Force”, which binds various things together.