Axiom of Choice 

The best axiom in all of mathematics. The Axiom states: The infinite Cartesian Product of non empty sets is non-empty.

I used the Axiom of Choice to Prove the Banach-Tarski Paradox last night.

Axiom of Choice by Vincent Guingona October 13, 2004

Axiom of Choice 

A mathematical (and philosophical) theory. Introduced in the early 20th century, it states that if you have a bunch of stuff, you can pick one thing from that stuff, and if you have many different groups of things, you can select one from each group.

This was controversial at the time.

Math is weird.

I have a two bowls of Cap'n Crunch. It took mathematicians until 1904 to figure out that I can take a Crunchberry from each. This is the Axiom of Choice.

Axiom of Choice by Carter? April 8, 2012