Infinite sets are not all created equal, however. There are actually many different sizes or levels of infinity; some infinite sets are vastly larger than other infinite sets. The theory of infinite sets was developed in the late nineteenth century by the brilliant mathematician Georg Cantor.

Why all infinities are equal?

Cantor showed that there's a one-to-one correspondence between the elements of each of these infinite sets. Because of this, Cantor concluded that all three sets are the same size. Mathematicians call sets of this size “countable,” because you can assign one counting number to each element in each set.

How many different infinities are there?

Three main types of infinity may be distinguished: the mathematical, the physical, and the metaphysical.