chapter  Chapter 15
6 Pages

The Arrow of Time

WithDerek York

Time flows onwards, never stopping and never turning back. The image showing the greater entropy represents the later universe. This capacity of entropy to point unerringly in the direction of time’s flow, was called ‘the arrow of time’ by Sir Arthur Eddington. The fundamental laws of motion in physics all work equally well with time running backwards or forwards; so none of the motions in the back-to-front movies was breaking Newton’s or Schrodinger’s laws. Certainly the evolution and continuing existence of life on this planet represents an increase in order with time for those molecules involved in all our bodies and plants. The jigsaw puzzle has modelled the evolution of our universe. It began in a highly ordered state and gradually became more and more disordered. The jigsaw puzzle became more and more disordered because there are many, many more ways for a system to become disordered than there are for it to order itself.