Changes can be described in space and time
Let us turn back here to our basic metaphor: the dynamics of movement. The concepts of time and space are also derived from our observations of movement; this framework determines our perception of changes in space and time. Motion picture gives this everyday experience in one and two spatial dimensions and in time. As it was mentioned earlier, these processes are primarily modelled with differential equations, in partial differential equation formulae according to the number of dimensions. These primarily describe changes in time and space, as the spreading of spilt liquid (see figure), but all those phenomena can be represented this way too which work in a complex way, as the result of multiple effects.