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

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.]

💡 Research Summary

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Erasmo Recami’s paper “Modern Aspects of Ancient Greek Physics” argues that the contributions of early Greek thinkers contain surprisingly modern scientific ideas that have been obscured by translations performed mainly by scholars in the humanities. The author points out that such translations often miss the physical significance of the original texts because the translators lack a deep understanding of physics. To illustrate this, Recami highlights two passages: one from Plutarch (c. 100 AD) and another from Posidonius (c. 135–51 BC).

Plutarch’s statement that the Moon “does not fall because of its motion and the dash associated with its revolution” is essentially a qualitative description of the balance between gravitational attraction and the centrifugal effect of orbital motion. He notes that a body falls only when its natural motion is not counter‑acted, anticipating the modern concept of inertia and the idea that an object in uniform circular motion experiences a continuous outward tendency that balances the inward pull of gravity. Plutarch’s surprise at a stationary Moon further reveals an intuitive grasp of orbital dynamics that predates Newton by more than a millennium.

Posidonius, on the other hand, writes that “matter is endowed with a cohesion that keeps it together and against which the surrounding vacuum has no power.” This reflects an early notion of internal binding forces—what we would now call cohesive energy or the strong interaction—that render matter resistant to the emptiness of space. His description of the cosmos as an “immense force” that causes matter to alternately contract and expand anticipates, in a very rough way, modern ideas about cosmic cycles, dark energy, and the dynamic evolution of the universe.

Recami treats these passages not as poetic metaphors but as genuine attempts to explain natural phenomena using physical reasoning. He argues that the Greeks were already seeking universal laws governing nature, a pursuit that aligns with the core mission of modern physics. While the Greeks lacked the sophisticated mathematics of later centuries, their qualitative insights correspond to concepts such as conservation, symmetry, and the interplay between forces that underlie contemporary theories.

The paper also critiques the conventional view that ancient Greek physics was purely qualitative or “philosophical.” Recami demonstrates that embedded within the philosophical discourse are quantitative hints—references to motion, speed, and force—that could be extracted and reformulated with modern mathematical language. He calls for a systematic re‑translation of Greek scientific texts by physicists who possess both linguistic competence and scientific expertise. Such an effort would not only correct historical misunderstandings but also enrich physics education by providing students with a richer narrative of how scientific ideas evolve.

Beyond historical correction, Recami suggests that revisiting Greek thought can inspire current research. The Greeks’ holistic approach to nature, their willingness to treat the cosmos as a single, ordered system, resonates with today’s work on complex systems, statistical mechanics, and attempts at a unified theory of quantum gravity. For instance, Posidonius’ cyclical view of contraction and expansion mirrors modern cosmological models that contemplate a universe undergoing phases of inflation, expansion, and possible future contraction.

In conclusion, Recami’s article makes a compelling case that ancient Greek physics contains proto‑modern concepts of inertia, gravitation, cohesion, and cosmic dynamics. By re‑examining these ideas through the lens of contemporary physics, scholars can both recover a more accurate picture of the history of science and potentially uncover fresh perspectives that inform present‑day theoretical work. The paper thus serves as a call to action for physicists to engage directly with the original Greek sources, to translate them with scientific rigor, and to integrate the insights they contain into the broader narrative of scientific progress.