What Does "Cool" Mean?

"John Scalzi Answers the Burning Question - Can SciFI Movies Be Cool?", via Instapundit, is a good short literary essay.

For example, there's "cool," as in "the studied indifference to cultural judgment regarding what you like," which means that you like what you like and you don't care if other people like it. Science fiction fails this definition utterly, because science fiction fans are monumentally uncool -- not because they are geeks and nerds, or at least, not directly because of that, but because generally speaking they really really really want you to love what they love, too, and that sort of insensible urge to share is the opposite of cool. Mind you, scifi fans understand other people don't love what they love, but rather than not caring, they feel a little sorry for those people. Which is a different dynamic altogether.

He then notes that 2001: A Space Odyssey and The Matrix were cool movies.