Imagine an axe going through a sheet of metal, both made of the same probe. On the basic level of language - the axe goes through the sheet. On the next level of language - due to pressure, delivered by the edge of the blade, the bonds between the molecules of the metal sheet begin to tear. But what happens on the next level ? Why do molecules spread out upon the impact of kinetic force ? Why does the matter that is thinner, tuns out to be more pliable ? Why does the blade edge powered by velocity and mass resists deformation much better, if the pressure to it and the sheet is the same ?