This is a reference to an xkcd-post by Randall Munroe, a former NASA employee and space proponent.

http://xkcd.com/1133/ [text at the bottom]

Wow, I've somehow lived through 40 years of math/science/space-geekdom without learning that the pointy thing on top of the Saturn V is a part of an escape system.

http://en.wikipedia.org/wiki/Launch_escape_system

But don't worry, future-people-I-will-argue-with-on-the-Internet, I'm sure that's the final gap in my knowledge base.