MAXWELL E GLI ANELLI DI SATURNO

While still a student at Cambridge University, James Clerk Maxwell attention was attracted by Saturn Rings. To discover how these celestial bodies are composed, he constructed various mathematical models; each model was derived under different assumptions, such as: the rings constitute a unique rigid cap, or the rings are made by a gas nebula, and so on. The adopted rationale was to construct the models and then validate them by comparing their characteristics with “the facts”, as Maxwell wrote, namely with the observation of reality. For the validation, Maxwell resorted to the notion of stability. Indeed, being the rings operating since millennia, it was argued that the stability property had to be satisfied. In the opposite, the model had to be rejected, together with the underlying assumption. This approach, which anticipates the current identification techniques, is summarized by the author with this masterful statement: … by rejecting every hypothesis which leads to conclusions at variance with the facts, we may learn more on the nature of these distant bodies than the telescope can yet ascertain. With his approach, Maxwell came to the conclusion that the rings are constituted by various rigid parts disconnected each other rotating around the planet, a fact which has been confirmed by space missions of our days.