The Beginning of the Quantum Story

Abstract

By the end of the nineteenth century, most physicists felt rather good about the state of their art. In fact, some felt that their successors would spend their time simply taking measurements to the next decimal place. There were reasons for this complacent attitude. Most of the astronomical data about the motion of the planets, as well as the behavior of ordinary mechanical systems, could be explained using Newton’s laws of motion and his law of universal gravitation. The empirical laws concerning electric and magnetic fields had been discovered and fused together by Maxwell, and his prediction of the existence of electromagnetic waves had been experimentally verified by Heinrich Hertz: The nature of light was no longer a mystery. More important, the same laws used to explain the behavior of macroscopic systems were also able to explain the behavior of submicroscopic objects (atoms and molecules). This came about with the development of the techniques of statistical mechanics. By applying Newton’s laws statistically the ideal gas law, PV = nRT could be derived. Similarly, the specific heat of gases could be predicted in agreement with the available experimental data.