The Infinity Symbol Has an Official Name

While we recognize it instantly as the symbol for infinity, the familiar horizontal figure eight has a more formal name: the lemniscate. This term, derived from the Latin word for "decorated with ribbons," aptly describes its continuous, looping shape. Its first documented use in a mathematical sense was in 1655 by English mathematician John Wallis, who was exploring the concept of infinitesimals—quantities that are endlessly small—which laid groundwork for the development of calculus.

The true mystery, however, is why Wallis chose this specific symbol, as he never explained his reasoning. Scholars have proposed several compelling theories. One popular idea is that he adapted it from a variant of the Roman numeral for 1000 (originally CIƆ), which was sometimes used colloquially to mean "many" or an uncountable number. Another fascinating hypothesis connects it to the ouroboros, the ancient symbol of a serpent devouring its own tail. This powerful image, representing eternity and endless cycles, would have been a fitting, if esoteric, choice for the mathematical concept of the infinite.