ABSTRACT

Chapter 2 Schrodinger’s wave mechanics I Quantum mechanics — a new approach to describing atomic m atter If experimental evidence conflicts with an accepted scientific theory, adjustments to the theory can usually be made, but only up to a point. As mounting experimental evidence becomes overwhelming, scientists sometimes have to revolutionize their ideas with a new theory capable of accommodating experimental observations comfortably. Perhaps the most significant scientific revolution since the time of Newton, began at around the turn of the twentieth century and peaked in the mid1920s, with the advent of Schrodinger’s formulation of quantum mechanics. The need for a revolutionary theory of microscopic nature began to be recognized as the results of experimental atomic physics accreted into a body of evidence which, scientists eventually realized, undermined many of the basic ideas of classical mechanics. (Figure 2.1.)

The challenge to classical mechanics could hardly have been more formidable, for the world of classical mechanics is deterministic. Classical mechanics supposes that, while the mathematical difficulties are often insurmountable, it is in principle possible, given sufficient information about the present, to predict the future exactly, that is, to predict the progress of any experiment with absolute certainty. The evidence from atomic physics implied that this was not true of microscopic nature. In microscopic nature, identical conditions do not produce identical results.