On the Conceptual Discrimination among Theory, Model and Hypothesis

There have been proposed many theoretical trials to explain curious events in the cold fusion phenomenon (CFP) assuming new ideas independent of knowledge of science developed in 20^th century. In discussion of the CFP, there was ambiguity of concepts of theory, model and hypothesis that made discussion in confusion in CF community and impossible communicate with scientists in other research field. We propose here a standard usage of terminology in relation with historical usage of theory, model and hypothesis. It should be noticed that the proposal is not obligatory, as a matter-of-course.

Theory

A theory is a system of logic based on fundamental principles commonly accepted in modern physics. In the logic of a theory, there are inevitably included restrictions (approximations) to confine field of investigation to make the logic tractable. Therefore, validity of a conclusion obtained in a theory definitely depends on the restrictions (approximations) assumed in the logical development from principles to conclusion. If the logic used in a theory is perfect, scientists who believe in the principles will accept the conclusion of the theory without reservation. BCS theory of superconductivity is a typical example of the theory.

In the case of such complex systems as where the CFP occurs, any theoretical task necessarily depends on restrictions or simplifications of the real system to make the object tractable. We can say there is no successful theory for the CFP at present because of too complex situation of the phenomenon where we cannot imagine physics of fundamental processes in CF material.

It should be noticed two fundamental principles related with many-particle problems in the CFP. The first is well-known impossibility of many-particle problems with more than two particles in classical and quantum mechanics. Any theoretical trial in the CFP is therefore inevitably approximate and assumptions made in it should be presented explicitly. The second is the complexity developed in these several decades which shows uncertainty in prediction of future behavior of such a many-particle system with nonlinear interaction between component particles as CF systems.

When we succeeded to deduce a conclusion not expected from intuition of expert in science, we have to check minutely conditions assumed and logical processes used in the deduction. It is necessary to recognize what is the newness included in the logic used in the deduction.

Model

A model is a system of premises (or assumptions) based on some experimental facts sometimes containing adjustable parameters. Value of a model is solely in its ability to explain other data than those composing the basis of the model. If a model is successful, it shows that the premises (or assumptions) of the model include reality in them even if the premises (or assumptions) contradict an established principle and can be a seed to find out a new principle. Bohr’s model of H-atom is a typical example of the model, which included essence of quantum mechanics.

Even if the logic used to explain facts successfully is flawless, the model is not necessarily accepted by people who do not believe in the facts on which the premises of the model based. This occurred in the history of investigation of the cold fusion phenomenon (CFP).

Hypothesis

A hypothesis or an assumption is a statement to explain an experimental data, which is not directly (or plainly) explained by fundamental principles. A statement of a hypothesis may be deduced from principles or not. In the latter case, the hypothesis may contribute to find out a new principle as in the case of a model. Planck’s quantum hypothesis of harmonic oscillator energy is a typical example of the hypothesis played a decisive role in development of quantum physics.

Sometimes, there occurs a situation where no dependable principles exist to fit for a problem. In such a case, new premise(s) (as assumption(s) or hypothesis (hypotheses) at first) is postulated to explain the problem in hand and the conclusion of the theory based on the assumed premise is tested by comparison with experimental data. When the conclusion is consistent with facts, then the

premise is accepted as a new principle of science and there occurs a revolution of the science. The theory of special relativity by A. Einstein is a typical example of the theory of this type.

(Based on Appendix B of H. Kozima, The Science of the Cold Fusion Phenomenon, Elsevier Science, 2006. ISBN-10: 0-08-045110-1.)