Aryabhatta:
1. Aryabhatta (476-550CE) was the first of the major mathematician-astronomers from the classical age of Indian mathematics and Indian astronomy.
2. His major work, Aryabhatiya is a compendium of mathematics and astronomy.
3. Aryabhatiya covers several branches of mathematics such as algebra, arithmetic, plane and spherical trigonometry.
4. Aryabhatta discovered the position of nine planets and expressed that these likewise rotate around the sun.
5. He also provided the circumference and measurement of the Earth and the radius of the orbits of 9 planets.
6. Aryabhatta pronounced that the moon has no light of its own.
7. He concluded that the earth is round. He also stated that it rotates on its own axis, which is why we have days and nights.
8. He concentrated on a few geometric and trigonometric parts of the celestial sphere that are still used to study stars.
9. In his old age, Aryabhatta composed another treatise ‘ Aryabahatta – Siddhanta’. It is the booklet for everyday astronomical calculation for performing rituals, To this very day, astronomical dat provided in this text is used for preparing panchangs (Hindu Calendars).
10. India’s first Satellite Aryabhatta was named after him.
Varahamihira:
1. Varahamihira (505-587CE) was an Indian astronomer, mathematician and astrologer from Ujjain.
2. Varahamihira is considered to be one of the Nine gems (Navarathnas) of the court of ancient ruler Yashodarman.
3. His knowledge of westren astrology was thorough but he was also very intrested in astrology and horoschope
4. His father was a worshipper of the Sun God and it was he who taught astrology.
5. Varahamihira was a scientist. He declared that the earth was spherical. He was the first to claim that some ‘force’ might be keeping bodies stuck to the round earth. This force is now called gravity.
6. He proposed that the moon and the planets are lustrous not because of their own light but due to Sunlight.
7. His book Panchasiddhantika on mathematical astronomy is one of the most important sources for the history of Hindu Astronomy.
8. His encyclopedia Brihat-Samhita with 106 chapters include subjects planetary movements, eclipses, rainfall, clouds, growth of crops, various rituals.
Brahmagupta – (598-668 CE):
1. Brahmagupta was an Indian mathematician and astronomer. He wrote some important works on both mathematics and astronomy.
2. His most famous work is “Brahmasphutasiddanta”.
3. Brahmagupta explained how to find the cube and cuberoot.
4. He was the earliest known mathematician to treat zero as a number in its own right.
5. He dedicated a substantial portion of his work to geometry and trigonometry
6. He explains that since the Moon is closer to the Earth than the Sun, the degree of the illuminated part of the moon depends on the relative position of the sun and the moon. This can be computed from the size of the angle between the bodies.
7. In his treatise Khandakhadyaka, explored the longitudes of the planets, diurnal rotation, lunar and solar eclipses, rising and settings etc.
