The four (six if you count levels Zero and Five) levels of
coolness are
fundamental properties of all
things. These levels are entirely
integral – just as
electrons around a
nucleus jump up and down by entire
orbits, never gradually, there is no such thing as "Cool Level 3.5."
All things which do not have a basic uncool aspect are Cool Level One. This is because the universe is, in fact, a wondrous and awesome place, even if this is often forgotten in our society. Even if it is not obvious at first glance, there is at least one positive point to be made about most things, when considered at length. So, Cool Level One is the default.
Cool Level Four is the pinnacle. Scientists have theorized the existence of a Cool Level Five, but no examples have been found on Earth. It is possible that societal factors, not all of which have been identified, actually sabotage the creation of any thing of utmost Coolness, but that the ideal state could exist in analien culture. The search for rarified Coolness is a prime motivation for the search for extraterrestrial intelligence.
While Cool Levels are an absolute, they are mutable with time, and people's perceptions of them vary, sometimes greatly. There is no objective measure, no acid test of Coolness, but as a person grows wise in the ways of the popular culture, he or she tends to come to conclusions that tend to be borne out by other, similarly-advanced pop culture sages.
The following is the Harris Yardstick of Cool, not without its flaws, but suitable for most introductory discussions on the topic.
Level Five: Ideal. No undisputed examples found on Earth. May not exist, or be capable of existing. Meditation upon the qualities necessary to achieve Cool Five can be used to achieve enlightenment. (This may have been Rasterman's method.)
Level Four: Great coolness. Over time, things of Cool Four tends toward universal recognition, even among those who could care less about pop culture. (They exist, I swear!) The archetypical example of Cool Four is Star Wars, particularly Darth Vader.
Level Three: Very cool. Most Disney animated features exist at this level, but the rest of their output is either Cool One or Zero. Some claim that anime defaults to Cool Three. I have written two papers in which I prove this is not so (a piece of tripe called "Capricorn" weighs heavily in my arguments), but not many seem to agree with me. Everything is probably Cool Three.
Level Two: Somewhat cool. Better than it is bad. Seinfeld is probably at Cool Two, since, although it possesses sterling qualities of narrative invention, it is, after all, a sitcom. The upcoming live action Tick series will probably make the breakthrough to Cool Three, featuring, as it does, a superhero.
Level One: Default cool. The overwhelming bulk of popular culture fits into this mold. It is not hated by the Cool Cognoscenti, but neither is it especially loved, except by limited cliques.
Level Zero: Uncool. The Scale of Cool only attempts to measure positive qualities. Uncool things deserve a scale of their own, which we leave others to devise. Brittany Spears exemplifies Cool Zero. Note that a Brittany Spears fan would likely rate her at Cool Three or even Four, but almost anyone else would not. Sages of Coolness attempt to see past their own localized prejudices in order to glimpse the Great Cool Beyond.
To summarize:
Cool Four: Star Wars.
Cool Three: Star Trek.
Cool Two: Stargate.
Cool One: Star Kid.
Cool Zero: Stars (Circus Of The).