This year's Flame Challenge question from Stonybrook is "What is sound?". The answers will be judged by 11-year-olds from around the world. Sounds like fun to me.
http://www.centerforcommunicatingscience.org/flame-challenge-2016-entry-form/
I'm going to place my bet on Eric Heller: http://www.whyyouhearwhatyouhear.com/