[Homeopathy and structure of water: a physical model].

Background: Formerly, the author has suggested a relatively simple water model. There, the dynamical structure of a typical water cluster was investigated, being represented by the movement of a ball in an abstract energy landscape.

Objective: Now the above-mentioned model is investigated in more detail to answer the following question: Are essential claims of homeopathy concerning potentiation (diluting and shaking) in agreement with science?

Methods: Equations of motion are employed that represent vibrations of clusters. For the computer experiments, the formalism of Nosé-Hoover is used, the surrounding water being interpreted as a heat bath. Diluting corresponds to a shift of the energy landscape towards the pure solvent (water), shaking is accompanied by an increase of the contact to the heat bath.

Results: There is a tendency of the ball to be caught in local valleys of the energy landscape (metastable states) if the temperature is not too high and if the liquid is not shaken. Thus, even for a given landscape there are a variety of structures being durable for some time.

Conclusions: The computer experiments suggest that the repeated process of potentiation eventually results in a specific metastable state of the pure solvent. The initial substance helps to obtain this goal, but is no longer necessary at last.