The symbol for infinity, “∞”, represents limitless or unboundedness, and it originates from the Latin word “infinitas” meaning “without end.” Its shape resembles a sideways figure eight. This mathematical sign is used in mathematics to denote endlessness, such as in calculus and set theory. Infinity isn’t a number but a concept. It’s used to represent concepts like infinite series and limits.

The origin

Some ancient cultures, such as the ancient Greeks and Indians, had conceptualizations of infinity, albeit not in the precise mathematical sense we understand today.

In ancient Greece, philosophers such as Zeno of Elea famously explored paradoxes related to infinity, such as Zeno’s paradox of motion, which challenged the idea of continuous motion by presenting scenarios where an infinite number of tasks must be completed to traverse a finite distance. Greek mathematicians like Pythagoras and Euclid also contemplated the idea of the infinite in geometry, particularly in the context of infinite lines and geometric series.

In ancient India, the concept of infinity was deeply intertwined with religious and philosophical beliefs. Indian mathematicians and philosophers, particularly those in the Jain and Hindu traditions, explored the idea of infinite time cycles and the infinite divisibility of space. The Indian mathematical texts, such as the Vedas and the Siddhantas, contain discussions on large numbers, infinite series, and the concept of “ananta,” meaning endlessness or infinity.

However, the formal symbol for infinity as we recognize it today emerged during the Renaissance period in Europe. This era marked a revival in mathematical inquiry and the development of symbolic notation, leading to the introduction of the ∞ symbol by mathematicians like John Wallis. This symbol provided a concise representation of the concept of infinity, helping mathematicians in expressing infinite processes and quantities in a more accessible manner.

Interesting fact

In mathematics, there exists a mind-bending concept known as “different sizes of infinity.” While infinity itself may seem boundless and singular, mathematicians have uncovered that there are actually varying levels, or sizes, of infinity.

This concept was introduced by the German mathematician Georg Cantor in the late 19th century. Cantor showed that not all infinite sets are the same size by developing a theory of infinite cardinal numbers.