Gravitational Wave Observations

Amal Kumar Raychaudhuri and the Raychaudhuri Equation


From UPSC perspective, the following things are important :

Prelims level: Raychaudhuri Equation

Mains level: NA


Central Idea

  • Amal Kumar Raychaudhuri, an Indian physicist, overcame obstacles and restrictions to make a profound contribution to the field of general relativity.

A.K. Raychaudhuri: Early Life  

  • Born in Barisal, now in Bangladesh, in 1923.
  • Educated in Kolkata.
  • Developed a deep interest in general relativity during his time at the Indian Association of Cultivation of Science (IACS).

Challenges Faced

  • While passionate about general relativity, Raychaudhuri was instructed by the director of IACS, Meghnad Saha, to work on topics of the director’s choosing or leave.
  • Raychaudhuri, with limited career options, complied with Saha’s directive but continued to explore the mysteries of gravity in his spare time.

Theoretical Breakthrough: The Raychaudhuri Equation

  • Raychaudhuri focused on the problem of singularities in general relativity, specifically points where gravity could become infinitely strong.
  • Developed a unique approach that bypassed complex mathematical challenges.
  • Introduced the Raychaudhuri equation, a simple and elegant formula that showed the inevitable convergence of matter in curved spacetime.
  • The equation hinted strongly at the existence of singularities, a critical aspect of general relativity.

Influence on Renowned Physicists

  • Raychaudhuri’s equation played a pivotal role in the work of Stephen Hawking and Roger Penrose.
  • Hawking’s area theorem, demonstrating that the surface area of black holes never decreases, relied on the Raychaudhuri equation.

Recognition and Legacy

  • Despite his groundbreaking work, Raychaudhuri received limited recognition in India.
  • He faced obstacles in career advancement, including rejection by Calcutta University.
  • Raychaudhuri eventually joined Presidency College, Kolkata, where he became a revered teacher, inspiring future generations of physicists.

Get an IAS/IPS ranker as your 1: 1 personal mentor for UPSC 2024

Attend Now

Notify of
Inline Feedbacks
View all comments


Join us across Social Media platforms.

💥Mentorship New Batch Launch
💥Mentorship New Batch Launch