When it comes to understanding the fundamental laws of the universe, Aristotle’s Physics stands as one of the most enduring and influential works in the history of science. While it may seem outdated compared to modern theories like Newtonian physics or Einstein’s theory of relativity, recent research by Carlo Rovelli suggests that Aristotelian physics is not only correct but also a non-intuitive approximation of Newtonian physics in the domain of motion in fluids. In this article, we will delve into the intricacies of Aristotelian physics, compare it with Newtonian physics, explore why it endured for so long, and discuss some general considerations on inter-theoretical relations.

What is Aristotelian Physics?

Aristotelian physics is the philosophical framework developed by the ancient Greek philosopher, Aristotle, over two millennia ago. Aristotle’s approach to understanding the natural world was based on careful observation, classification, and rationalization. According to Aristotle, everything in the universe was composed of four elements: earth, water, air, and fire.

Aristotle believed that motion was an essential characteristic of all things, and he categorized it into two types: natural and violent motion. Natural motion, according to Aristotle, was inherent to an object based on its natural properties. For example, a rock falls to the ground because it has the natural tendency to seek its proper place – the center of the universe. On the other hand, violent motion was caused by an external force acting upon an object.

This qualitative perspective on motion and the nature of the elements formed the foundation of Aristotelian physics. While lacking the mathematical precision and empirical testing crucial to modern physics, Aristotle’s ideas were based on careful observation and remained influential for centuries.

How Does Aristotelian Physics Compare to Newtonian Physics?

Newtonian physics, formulated by Sir Isaac Newton in the 17th century, revolutionized our understanding of the physical world. Newton introduced the concept of forces and laws describing their behavior, such as the famous laws of motion.

So, how does Aristotelian physics, with its elemental composition and qualitative approach to motion, compare to Newtonian physics? Rovelli’s research suggests that Aristotelian physics can be seen as a correct and non-intuitive approximation of Newtonian physics in the suitable domain of motion in fluids.

Consider the motion of a submerged object in water – a domain where Aristotelian physics is known to excel. According to Aristotle, the element of water tends to flow naturally, and objects placed in it will experience a resistance proportional to their size and shape. This concept aligns with our everyday experience of objects moving through water, where larger and more streamlined objects encounter less resistance and move faster.

Newtonian physics, on the other hand, explains the motion of submerged objects in terms of forces, such as buoyancy and drag. These forces depend on various factors like the volume and density of the object, and the viscosity and density of the fluid. By quantifying these forces mathematically and incorporating differential equations, Newtonian physics provides a more accurate and comprehensive description of the motion of objects in fluids.

However, Rovelli argues that when considering the domain of motion in fluids, Aristotelian physics can be seen as an approximation of the more complex Newtonian framework. While Aristotelian physics lacks the mathematical sophistication and precise predictive power, it still captures essential aspects of the motion of objects in fluids, making it a valuable empirical theory.

Why Did Aristotelian Physics Last Long?

One might wonder why Aristotelian physics persisted for so long if it is merely an approximation of more advanced theories like Newtonian physics. Rovelli asserts that Aristotelian physics endured not because it became dogma, but because it was a remarkably good empirically grounded theory.

Aristotelian physics was successful in explaining a broad range of natural phenomena, including the motion of objects in fluids, the fall of heavy bodies, and the behavior of celestial bodies. The explanatory power of Aristotle’s framework, though limited in its mathematical precision, adequately accounted for the observations made by ancient scientists.

Furthermore, the intuitive appeal and simplicity of Aristotelian physics made it accessible to a wide audience. Aristotle’s ideas resonated with our common experiences of motion and the behavior of objects in everyday life. As a result, it found widespread acceptance and served as the foundation for scientific inquiry for centuries.

What are the General Considerations on Inter-theoretical Relations?

Rovelli’s research on Aristotelian physics brings about some thought-provoking considerations on inter-theoretical relations. In the case of Aristotelian physics and Newtonian physics, we witness how one theory can be seen as an approximation of a more encompassing theory within specific domains of application.

This realization challenges our preconceived notions of progress in scientific knowledge. While we tend to view newer theories as strictly superior to older ones, Rovelli’s work underscores the value of historical theories in capturing essential phenomena within certain contexts. It prompts us to reevaluate our understanding of scientific progress and the relationships between different theories.

Furthermore, Rovelli’s findings highlight the importance of empirical grounding in scientific theories. Aristotelian physics’ longevity can be attributed to its close alignment with empirical observations, despite lacking the mathematical formalism and predictive capabilities of later theories. This reminds us that successful scientific theories should be firmly rooted in empirical data and not solely reliant on mathematical elegance.

In conclusion, Aristotelian physics, often considered outdated and superseded, has reemerged as a fascinating approximation of Newtonian physics in the domain of motion in fluids. Carlo Rovelli’s research challenges our understanding of scientific progress, emphasizes the empirical grounding of theories, and offers intriguing insights into the relationships between different theories. While Aristotelian physics may not represent the pinnacle of scientific knowledge, it continues to contribute to our understanding of the natural world.

“Aristotelian physics lasted long not because it became dogma, but because it is a very good empirically grounded theory.” – Carlo Rovelli

Read the original research article by Carlo Rovelli: Aristotle’s Physics: a Physicists Look