Chandas is the science of Vedic metres — the rhythmic patterns that structure Vedic hymns. Understanding metre is essential for correct recitation and for appreciating the mathematical beauty embedded in the Vedas.
Pingala's treatise (~3rd century BCE) systematically analyzes all possible metres. It contains the earliest known description of binary numbers (laghu/guru as 0/1), the Fibonacci sequence (known as "Matra-meru"), and combinatorial mathematics. His work anticipates discoveries attributed to Pascal, Fibonacci, and Leibniz by centuries.
Gayatri (24 syllables, 3 padas of 8), Ushnik (28), Anushtubh (32 — the most common Sanskrit verse form), Brihati (36), Pankti (40), Trishtubh (44 — the most common Rigvedic metre), and Jagati (48). Each metre has a presiding deity and is suited to particular types of content.
Pingala's method for systematically enumerating all possible metrical combinations produces what is now called Pascal's Triangle — centuries before Pascal. This demonstrates how the study of Vedic metre led to fundamental mathematical discoveries.