I was sitting around the camp fire and there was a periodic sound of cracking and pieces of the burning wood flew off. My question is what is the mechanism for the cracking of the wood? I was thinking it was a pocket of air in the wood or something, but that still doesn't explain why the piece of wood flew well over a meter high. Could this be a chemical reaction causing this?
Wet wood crackles. Dry wood does not.
Water in the wood boils. The steam builds up pressure because it is trapped inside. The wood explodes, releasing the steam and flying pieces.