“that there isn’t just one kind of infinity. There is an infinity of infinities, and some infinities are more infinite than others. Mathematicians call this cardinality. The smallest kind of infinity is called aleph-null. This is the infinity you get when you take the set of all whole numbers. But it is possible to prove that there are more decimals than there are integers, so the infinity of the set of all decimals is of a greater type, called beth-one. And if you start with the set of all decimals and take the set of all subsets of this set, you get an even greater infinity known as beth-two. And you can continue to do this indefinitely.”