Infinity in mathematics is considered as a number and represented as ∞. It is an endlessness and limitless concept which describes something without any bound or larger than any number. Sometimes it is also known as lemniscate, has a shape of number 8 on its side.
Various theories are propounded for infinity like Ancient cultures had various ideas about the nature of infinity. They did not describe it as a symbol like in mathematics, but explained it as a philosophical concept.
1. Even a verse from Isavasyopanishad (ईशावास्योपनिषद्) explains the concept of Infinity - the doctrine of Bhuma
The drift of the statement is that infinity is unchanging and this mantra is a figurative way of saying that nothing proceeds from infinity. Even the idea of something proceeding from infinity is based on its essential character of infinity.
2.The symbol of infinity which has been used now a day has a long history. It was first appeared in the ornaments of the cross of Saint Boniface, who promotes Christianity in the Frankish Empire in the 8th century through a missionary. It was wrapped around the Latin cross.
3. In the past also Infinity symbol conveyed a lot of meanings to various people. According to several sources, it was also used in ancient India and Tibet to represent perfection and dualism. It also stood for the unity of man and a woman. Even in occult tarot it signifies balance between the opposite forces. In an ancient symbol of the Ouroboros, the dragon eats its tail in the shape of an infinity symbol. That is Ouroboros itself is a sign of the infinite and drawn in the shape of 8.
4. In the 17th century infinity symbol got its mathematical meaning. In 1655 it was first used by John Wallis but he never said that why he used 8 on its side as a symbol of infinity. In fact, this type of similar symbol was used by Romans to express large numbers. Like 1000 was written like this CIƆ which means “many”.
In mathematics, Calculus, Leibniz speculated infinite numbers and their use in mathematics.
In Real analysis also the symbol infinity is used to denote an unbounded limit.
Even in Complex analysis the symbol infinity denotes an unsigned infinite limit etc.
5.The infinity symbol appears in the Tarot, as a part of the Magician card. Like in the Pamela Colman rider Waite version has a lemniscate floating boldly infinitive symbol above his head and in other decks, the brim of his hat conceals the shape.