Very impressive video, about the breaking all the stones part,
thats newton's third law, every action has an equal but opposite
reaction.
When the guy breaks all the bricks, he only experiences the
reaction equal to the force he applied to the
surface of the brick but if he fails to break any
single brick, the reaction would hit him twice as hard due to both
the force he applied to the surface of the first brick as well as
the force that went through the slabs of bricks up to the unbroken
1. 
