What is a Flame?

This is what Alan Alda (from M*A*S*H) wanted to know when he was 11 years old.  He asked a teacher who told him, “it’s oxidation.”  This explanation didn’t help Mr. Alda, who continues to be fascinated with science.  So fascinated that he helps to put on the World Science Festival which is taking place in New York as I write this post.  And a part of this festival is a contest: The Flame Challenge.  The entries in this contest have to explain to 11 year old judges the answer to the question: What is a flame?  I have checked out the finalists and the answers are quite entertaining and informative.  You be the judge!  Who answers it best?  Leave your ideas below in the comments section.  The winner will be announced on Saturday, June 2.