The Scientific Revolution: Galileo, Newton, and the Birth of Modern Science
The Scientific Revolution: From Aristotle to Newton
The term “Scientific Revolution,” firmly established in modern historiography since 1954, designates a transformative period in science, spanning from the early 16th to the late 17th century. This era witnessed a revolution in physics and astronomy, extending into the 18th century with advancements in chemistry, biology, and geology.
Galileo and Newton: Pillars of Modern Science
Historians emphasize the pivotal role of Galileo Galilei, who challenged over two millennia of Aristotelian thought. Isaac Newton built upon Galileo’s work, completing his mechanical studies and establishing universal laws, creating a systematized framework that led to the decline of Aristotelian physics.
Galileo developed the fruitful Galilean experimental method, while Newton introduced the vera causa method, a significant methodological advancement. Newton’s method addressed limitations of Galileo’s approach and extended beyond astronomy to fields like geology and biology, influencing concepts like Charles Darwin’s natural selection.
Galilean Mechanics: Challenging Aristotelian Authority
Galileo pioneered the study of mechanics free from Aristotelian preconceptions. Aristotle approached the problem of motion (or change) qualitatively, based on a dual ontology. He distinguished between the supralunar and terrestrial regions, governed by different physical laws. The supralunar region, composed of ether, was immutable. The terrestrial region, subject to continuous change, consisted of a universal subject capable of adopting different forms influenced by four qualities: cold, warm, dry, and wet.
For Aristotle, “movement” meant change or transformation. He identified two types of motion:
- Violent motion: Forced movement away from a body’s natural place, requiring a continuous external cause.
- Natural motion: The tendency of bodies to occupy their natural place, exemplified by falling objects. Galileo refuted this with his famous demonstration at the Tower of Pisa, leading to the law of falling bodies.
Galileo used Archimedes’ hydrostatic principle to model dynamic movement, concluding that homogeneous bodies fall at the same speed due to offsetting gravity and volume differences. His Discorsi laid the foundation for new mechanics:
- Challenging Aristotle’s explanation of free fall with the law of falling bodies, the first law of classical physics.
- Presenting motion as the result of an internal force, paving the way for the principle of inertia.
- Establishing that the speed of a falling body increases with time, not distance.
These contributions solidify Galileo’s position as a father of classical science.