This video won an international competition in which contestants were invited to explain to an 11-year-old what a flame is.
As the website for “The Flame Challenge: Explaining Science to an 11-Year-Old” explains:
When he was 11 years old, Alan Alda asked his teacher, “What is a flame?” She replied: “It’s oxidation.” Alda went on to win fame as an actor and writer, became an advocate for clear communication of science, and helped found the Center for Communicating Science at Stony Brook University. He never stopped being curious, and he never forgot how disappointing that non-answer answer was.
Many years later, Alan Alda launched the Flame Challenge. The winner, Ben Ames, is an American working on his PhD in quantum optics.