Una proposta di introduzione storica intuitiva ai concetti entropici

Although irreversibility is an intuitive concept in many respects, formal approaches to entropy in secondary school physics are difficult to understand. The paper illustrates an historical approach based on Sadi Carnot?s hydraulic analogy (1824) between spatial and thermal levels. In analogy with a reversible hydraulic wheel, the search of a physical quantity conserved in an operating reversible engine leads quite naturally to entropy.