Āryabhaṭa, Varāhamihira and Kālidāsa

Āryabhaṭa lived around 500 CE in Kusumapura (near Patna), a famous place of learning. He wrote a short book on maths and astronomy, the *Āryabhaṭīya*.

His big ideas:

• formulas for the movements of the Sun, Moon and planets
• the Earth spins on its axis, and that's why we have day and night (an amazing idea for the year 500!)
• a good estimate of the size of the Earth
• the correct reason for solar and lunar eclipses

He even worked out the length of a year:

Only about 24 minutes off, worked out 1,500 years ago! Some calculation methods you learn at school were first written down by him.

Varāhamihira, from the same time, was a mathematician, astronomer and astrologer in Ujjayinī, another famous city of learning. His Bṛihat Samhitā is like an encyclopedia: astronomy, astrology, weather forecasting, architecture, town planning, even farming. He observed the world, reasoned carefully and used old knowledge: a true pioneer of science.

We know little about Kālidāsa's life. Legends say people once laughed at him, which pushed him to work hard and change his life. He became a master of Sanskrit poetry.

In his *Meghadūtam* ('The Cloud Messenger'), a yakṣha banished from home asks a passing cloud to carry a message to his beloved. As the cloud travels, the poem describes the landscapes and weather of north India, place after place, all the way to her.

Āyurveda, India's traditional medicine, has roots going back centuries BCE. In the Gupta period it was codified (written in an organised way): the Charaka Saṃhitā and Suśhruta Saṃhitā got their final shape. They cover naming and diagnosing diseases, treatments, diet, making medicines and advanced surgery. Āyurveda stresses whole-person healing, linking mind, body and nature.