Aryabhata, a renowned 5th-century astronomer, proposed the theory of the Earth's rotation on its axis, contradicting the prevailing belief of a stationary Earth.

The quadrant, a quarter-circle instrument, was widely used by ancient Indian astronomers for measuring the altitudes of celestial bodies and determining their positions.

Aryabhata devised a method for calculating the circumference of the Earth using the concept of the Earth's shadow during a lunar eclipse.

The Surya Siddhanta is an ancient Indian astronomical treatise that presents a comprehensive understanding of the solar system, planetary motions, and eclipses.

Brahmagupta, a 7th-century astronomer, proposed the concept of gravity as a force that attracts objects towards the Earth's center.

Maharaja Jai Singh II constructed five Jantar Mantars, astronomical observatories, in various cities across India, including Delhi, Jaipur, and Varanasi.

S. Chandrasekhar, an Indian-American astrophysicist, made significant contributions to the theory of relativity, particularly in the study of white dwarf stars.

C. V. Raman, an Indian physicist, won the Nobel Prize in Physics in 1930 for his discovery of the Raman effect, which involves the inelastic scattering of light.

Homi J. Bhabha, an Indian physicist, conducted extensive research on cosmic rays, studying their properties and interactions.

Homi J. Bhabha founded the Tata Institute of Fundamental Research (TIFR) in Mumbai, India, which became a leading center for research in physics and mathematics.

Vikram Sarabhai, an Indian physicist, made significant contributions to the field of nuclear physics, particularly in the areas of cosmic ray research and nuclear reactor design.

Ashoke Sen, an Indian physicist, is renowned for his contributions to string theory, particularly in the study of black holes and their entropy.

Raja Ramanna, an Indian physicist, made significant contributions to the field of quantum mechanics, particularly in the study of nuclear reactions and particle physics.

C. N. R. Rao, an Indian chemist and physicist, is renowned for his contributions to condensed matter physics, particularly in the study of materials and their properties.

Jayant Narlikar, an Indian astrophysicist, is known for his contributions to cosmology and gravitational physics, including the theory of Hoyle-Narlikar.