Prahalad Chunnilal Vaidya (P.C.Vaidya; 23 May 1918 – 12 March 2010), was an Indian physicist and mathematician, renowned for his instrumental work in the general theory of relativity.

Apart from his scientific career, he was also an educationist and a follower of Gandhian philosophy in post-independence India, specifically in his domicile state Gujarat.

Vaidya's first stint at teaching was at the Dharmendra Singhji College in Rajkot, where he joined as a lecturer in 1940, soon after completing his MSc examinations.

Due to differences with the new management, Vaidya resigned in 1941 and subsequently started with freedom fighter Prithvi Singh Azad at the Ahimsak Vyayam Sangh institute of physical education, where he was the principal for non-violent struggle training programme for youths.

Vaidya was living with his wife Vidya and six-month-old daughter Kumud and surviving solely on his earlier savings.

[citation needed] After his research stint at BHU, he went to a number of places to teach mathematics, including science institutions in Surat, Rajkot and Mumbai.

Due to accommodation constraints, he left Mumbai, and continued the rest of his academic career in Gujarat.

It was only ten months that he spent at BHU at that time, during which the revolutionary idea of developing a spacetime geometry was born within him, which would describe the gravitational potentials in the exterior of a radiating star.

His discovery of the Vaidya Metric gave him a worldwide reputation at the age of 24, even before the beginning of his professional career.

Vaidya Metric applies to a set Einstein's equations that describes the gravitational field of a star which has a sizeable radiation.

In other words, it was an idea of a null co-ordinate, which eventually played extremely significant role in subsequent research in gravitation theory during forthcoming decades.

The result was the Indian Association for General Relativity and Gravitation (IAGRG),[6] and Professor V. V. Narlikar assumed the position of founder President.

At his suggestion, Vikram Sarabhai laid foundation of mathematics laboratory in Ahmedabad, a pioneering institute of its kind in India.

Since its inception, it has been continually read in numerous schools and colleges, and has inspired generations of mathematics teachers and students alike.

According to his close aides, even during peak years of his scientific career, he exercised extreme prudence and wisdom in using his influence for personal gains of his family, or people related to him.

He tried to reach to farthest rural areas, and aimed the society's efforts to empower teachers and eradicate fear of the subject from students' minds.