Geoffrey R. Dolby, PhD One of the principal characteristics of a scientific theory is that it be falsifiable. It must contain predictions about the real world which can be put to experimental test. Another very important characteristic of a good theory is that it should take full cognisance of the literature of the discipline in which it is embedded, and that it should be able to explain, at least as well as its competitors, those experimental results which workers in the discipline accept without dispute. Readers of John Parks' book will be left in no doubt that his theory of the feed ing...