Hi, so glad to be here. This is my first posting. I'm just a 61 year-old dummy, so please help! If a rubber ball is dropped to a hard surface the impact will compress the rubber, storing some of the kinetic energy as potential elastic energy. The rebound will come from this stored potential elastic energy. If the ball is dropped straight down I presume this elastic force is stored in the ball mostly in an axis normal to the ground, ie. the ball is smushed out making it just a little fatter at its' "equater" than at its' poles (the axis of impact). If I've got this bouncing ball thing right so far, can this idea of storing potential energy mostly along the axis of impact be carried over to air molecules? Do air molecules impacting a surface, like the walls of a containing vessel, hold potential energy (for the rebound) mostly in the axis of impact (normal to the impact surface)? Let's change the world.....does anybody out there know the answer? Thank you in advance!