Is Twitter Earth’s mood ring?

It's Friday and we're happy. How do we know? Not because that Rebbecca Black song is running through our heads telling us how much we're looking forward to the "fun fun fun fun" weekend, but because Twitter says so.

Sociologists at Cornell University analyzed 500 million tweets from 84 different countries, searching for words that were indicative of a positive mood. What they found, according to the Associated Press, was that people wake up in a good mood and are -- shocker! -- generally happiest on the weekend.

Even in countries like the United Arab Emirates, where Friday and Saturday are considered the weekend, the researchers were able to identify a happier mood during that time as well.

Some may scoff at the reported initial morning happiness, but perhaps most of these tweeters have had their first cup of coffee by the time of their first tweets.

The study showed that moods declined midweek, toward the middle of the day and during winter months.

The study by Scott Golder and Michael Macy, appropriately ran in today's edition of the journal Science. New Scientist notes this is not the first time Twitter has been analyzed to identify mood, but this is the first time it has been done on a global scale.

This video is from a previous study, mentioned by New Scientist, that tracked mood via Twitter in the U.S.: