Although many of the solitons described in previous chapters were discovered and studied in the 20th century, they could have been discovered and understood by physicists of the previous century. What I have in mind, of course, is the distinction between classical (19th century) and quantum physics (20th century). It happened that the quantum revolution in physics started at the frontier of the two centuries. At the end of 1900 the German physicist Max Planck (1858–1947) boldly introduced the notion of quanta of energy in the processes of emission of light by atoms. He also introduced a new fundamental constant in physics, the Planck constant h . The significance of this revolutionary step was not recognized until much later. Planck himself did not realize that he had started one of the greatest revolutions in physics. These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
Abstract We have been hovering on the edge of quantum theory, with one toe dip- ping into its dangerously infested pool. It is time to take the plunge. To appreciate the significance of the impact of this extraordinary theory we need to note that until the end of the nineteenth century waves unambiguously waved and particles were unambiguously particulate. Unfortunately for naive understanding, though, this distinction did not survive the turn of the century. From a scatter of observations towards the end of that century a virus entered classical physics. A few decades into the twentieth century the disease it brought had destroyed classical physics completely.