In the following link is a slow motion video of a maple tree seed falling (you have to wait till the 7th second). From the Wiki article on Action http://en.wikipedia.org/wiki/Action_(physics) "In physics, action is an attribute of the dynamics of a physical system. It is a mathematical functional which takes the trajectory, also called path or history, of the system as its argument and has a real number as its result. Action has the dimension of energy × time, and its unit is joule-seconds in the International System of Units (SI). Generally, the action takes different values for different paths. Classical mechanics postulates that the path actually followed by a physical system is that for which the action is minimized, or, more strictly, is stationary." If we consider the falling seed and the air through which it falls as the dynamical system how can we use the above quote to help explain how the seed falls in the above video? Thanks for any help!