Aspetti Moderni della Fisica Greca [Modern Aspects of Ancient Greek Physics]

Abstract: Plutarchus, circa 100 AD, in his early book on "astrophysics" --in which he exposed, in a sense, a general theory of gravitation-- wrote the noticeable passage: <<The Moon gets the guarantee of not falling down just from its motion and from the dash associated with its revolution, exactly as stones in slings cannot fall due to their circular whirling motion; in fact, each thing is dragged by its mere natural motion only if it isn't deviated by something else. The Moon, therefore, is not dragged down by its weight, because its natural tendency is frustrated by its revolution. And, on the contrary, it would be really amazing if it could remain at rest always at the same place, like the Earth>>. While Posidonius (circa 135-51 BC) had written: <<Matter is endowed with a cohesion that keeps it together and against which the surrounding vacuum has no power. Indeed, the material world is supported by an immense force, and alternately contracts and expands in the vacuum following its own physical processes, now consumed by fire, now, instead, giving rise to a new creation of the cosmos>>. These two examples show how "modern" was part of the ancient Greek physics, frequently overlooked since it is sometimes known through the praiseworthy translations of scholars often competent in humanities, more than in science. [A more extended English summary appears at the beginning of this article, which is in Italian.]