Time-dependence in homogeneous catalysis. 2. The general actions of time-dependent ("mechanical") and energy-Dependent ("thermodynamic") catalysts
[extract] 6.1 INTRODUCTION In Chapter 1, we described two fundamental types of action that are observed in physical science. The first is created by the laws of thermodynamics, which describe, in essence, how changes in energy create actions or set processes in train. Because the field of thermodynamics today extends far beyond this most elementary description and to avoid any possible confusion, we have termed actions or processes of this type energy-dependent in character. An example of an energy-dependent action is that of a ball falling to Earth under the influence of gravity. The gravitational field is invisible and intangible. However, it induces movement. We can often only perceive energy gradients in the physical effect that they create.