@sh1mmer reminds us that we all want to understand Infinity. And you can’t take anything away from Infinity, man.
Woah!
var bignum = 1e300;
var ∞ = 1e400; //Infinity
alert(∞ - bignum); //Infinity
Also note: @sh1mmer is from the future wherein Unicode entities are valid for variable identifiers. Rename above to something sane in our old school present day interpreters.