Varāhamihira, also called Varāha or Mihira, was a Hindu astronomer and polymath who lived in Ujjain. He was born in the Avanti region, roughly corresponding to modern-day Malwa, to Adityadasa. According to one of his own works, he was educated at Kapitthaka. The Indian tradition believes him to be one of the "Nine Jewels" of the court of ruler Yashodharman Vikramaditya of Malwa. However, this claim appears for the first time in a much later text and scholars consider this claim to be doubtful because neither Varahamihira and Vikramaditya lived in the same century nor did Varahamihira live in the same century as some of the other names in the "nine jewels" list such as the much older Kalidasa. Varāhamihira's most notable work was Brihat Samhita, an encyclopedic work on architecture, temples, planetary motions, eclipses, timekeeping, astrology, seasons, cloud formation, rainfall, agriculture, mathematics, gemology, perfumes and many other topics. According to Varahamihira, in some verses he was merely summarizing earlier existing literature on astronomy, Shilpa Sastra and temple architecture, yet his presentation of different theories and models of design are among the earliest texts that have survived. The chapters of the Brihat Samhita and verses of Varahamihira were quoted by the Persian traveler and scholar Al Biruni. Varāhamihira is also credited with writing several authoritative texts on astronomy and astrology. He learned the Greek language, and praised the Greeks in his text for being "well trained in the sciences". Some scholars consider him to be the strong candidate as the one who understood and introduced the zodiac signs, predictive calculations for auspicious ceremonies and astrological computations to the Indian subcontinent from the Greek literature.
Works
Pancha-Siddhantika
Varahamihira's main work is the book dated ca. 575 CE, which gives us information about older Indian texts which are now lost. The work is a treatise on mathematical astronomy and it summarises five earlier astronomical treatises by five authors, namely the Surya Siddhanta, Romaka Siddhanta, Paulisa Siddhanta, Vasishtha Siddhanta and Paitamaha Siddhanta. It is a compendium of Vedanga Jyotisha as well as Hellenistic astronomy. Varahamihira was the first one to mention that the ayanamsa, or the shifting of the equinox is 50.32 seconds.
Brihat-Samhita
Another important contribution of Varahamihira is the encyclopedic Brihat-Samhita. Although the book is mostly about divination, it also includes a wide range of subjects other than divination. It covers wide-ranging subjects of human interest, including astronomy, planetary movements, eclipses, rainfall, clouds, architecture, growth of crops, manufacture of perfume, matrimony, domestic relations, gems, pearls, and rituals. The volume expounds on gemstone evaluation criterion found in the Garuda Purana, and elaborates on the sacred Nine Pearls from the same text. It contains 106 chapters and is known as the "great compilation".
On Astrology
He was also an astrologer. His son Prithuyasas also contributed to Hindu astrology; his book Hora Sara is a famous book on horoscopy. Khana, the medieval Bengali poet astrologer, is believed to be the daughter-in-law of Varahamihira.
Influences
The Romaka Siddhanta and the Paulisa Siddhanta were two works of Western origin which influenced Varahamihira's thought. Paulisa Siddhanta is often mistakenly thought to be a single work and attributed to Paul of Alexandria. However, this notion has been rejected by other scholars in the field, notably by David Pingree who stated that "...the identification of Paulus Alexandrinus with the author of the Pauliśa Siddhānta is totally false". Number of his writings share similarities with the earlier texts like Vedanga Jyotisha. A comment in the Brihat-Samhita, quoting Garga, an earlier astronomer, says: "The Greeks, though barbaric, must be honored since they have shown tremendous interest in our science.....".
Contributions
Trigonometry
Varahamihira improved the accuracy of the sine tables of Aryabhata.
Combinatorics
He was among the first mathematicians to discover a version of what is now known as the Pascal's triangle. He used it to calculate the binomial coefficients. He also records the first known 4×4 magic square.
Optics
Among Varahamihira's contribution to physics is his statement that reflection is caused by the back-scattering of particles and refraction by the ability of the particles to penetrate inner spaces of the material, much like fluids that move through porous objects.
