11.5: Scientific Revolution

Figure of the heavenly bodies — An illustration of the Ptolemaic geocentric system by Portuguese cosmographer and cartographer Bartolomeu Velho, 1568 (Bibliothèque Nationale, Paris) Source: https://commons.wikimedia.org/wiki/F...Velho_1568.jpg

Roots of the Scientific Revolution

The word "revolution" connotes a period of turmoil and social upheaval where ideas about the world change severely and a completely new era of academic thought is ushered in. Therefore, the Scientific Revolution (1543 – 1687) describes quite accurately what took place in the scientific community. Medieval scientific philosophy was abandoned in favor of the new methods proposed by Bacon, Galileo, Descartes, and Newton. The importance of experimentation to the scientific method was reaffirmed. The importance of God to science was for the most part invalidated. Last, the pursuit of science itself (rather than philosophy) gained validity on its own terms. The change to the medieval idea of science occurred for four reasons:

1. Seventeenth-century scientists and philosophers were able to collaborate with members of the mathematical and astronomical communities to effect advances in all fields.
2. Scientists realized the inadequacy of medieval experimental methods for their work and so felt the need to devise new methods (some of which we use today).
3. Academics had access to a legacy of European, Greek, and Middle Eastern scientific philosophy they could use as a starting point (either by disproving or building on the theorems).
4. Groups like the British Royal Society helped validate science as a field by providing an outlet for the publication of scientists' work.

These changes were not immediate, nor did they directly create the experimental method used today. But they did represent a step toward Enlightenment thinking (with an emphasis on reason) that was revolutionary for the time.

Science and Philosophy Before the Revolution

At the end of the sixteenth century, "natural philosopher" carried much more academic clout. So, the majority of the research on scientific theory was conducted not in the scientific realm, but in philosophy, where "scientific methods" like empiricism and teleology were promoted.

In the 17th century, empiricism and teleology existed as remnants of medieval thought that were utilized by philosophers. Empiricism is a theory that reality consists solely of what one physically experiences. Teleology is the idea that phenomena exist only because they have a purpose, i.e. because God wills them to do so. Both these theories did not have a need for fact-gathering, hypothesis writing, and controlled experimentation.

Robert Boyle (1627–1691), an Irish-born English scientist, was an early supporter of the scientific method and the founder of modern chemistry. Source: https://commons.wikimedia.org/wiki/F...bert_Boyle.jpg

The defining feature of the scientific revolution lies in how much scientific thought changed during a period of only a century. Modern experimental methods incorporate Francis Bacon's focus on the use of controlled experiments and inductive reasoning, Galileo's emphasis on incorporation of established laws from all disciplines (math, astronomy, chemistry, biology, physics) in coming to a conclusion through mechanism, and Newton's method of composition. Each successive method strengthened the validity of the next.

Francis Bacon (1561-1626)

Bacon represents the first step away from sixteenth-century thinking, in that he denied the validity of empiricism. He preferred inductive reasoning (drawing a general conclusion from a set of specific observations) to deductive reasoning (making an inference based on widely-accepted facts or premises).

He emphasized the necessity of fact-gathering as a first step in the scientific method, which could then be followed by carefully recorded and controlled (unbiased) experimentation. Further, experimentation should not be conducted to simply "see what happens" but "as a way of answering specific questions." Moreover, the main purpose of science was the betterment of human society and that experimentation should be applied to hard, real situations rather than to Aristotelian abstract ideas. His work influenced advances in chemistry and biology through the 18th century.

Justus Sustermans - Portrait of Galileo Galilei, 1636

Galileo Galilei (1564-1642)

Galileo argued that "an explanation of a scientific problem is truly begun when it is reduced to its basic terms of matter and motion," because only the most basic events occur because of one axiom.

For example, one can demonstrate the concept of "acceleration" in the laboratory with a ball and a slanted board. However, according to Galileo's reasoning, one would have to utilize the concepts of many different disciplines: the physics-based concepts of time and distance, the idea of gravity, force, and mass, or even the chemical composition of the element that is accelerating. All of these components could be individually broken down to their smallest elements in order for a scientist to fully understand the item as a whole.

This "mechanic" or "systemic" approach partially removed the burden of fact-gathering emphasized by Bacon. Galileo's experimental method aided advances in chemistry and biology by allowing biologists to explain the work of a muscle or any body function using existing ideas of motion, matter, energy, and other basic principles.

Robert Boyle (1627-1691)

Even though he made progress in the field of chemistry through Baconian experimentation, Boyle remained drawn to teleological explanations for scientific phenomena. For example, Boyle believed that because God establish some rules of motion and nature, phenomena must exist to serve a certain purpose within that established order.

Sir Isaac Newton (1643-1747)

Newton composed a set of four rules for scientific reasoning stated in his famed Principia. His analytical method and laws lent well to experimentation with mathematical physics, where conclusions "could then be confirmed by direct observation. " Newton also refined Galileo's experimental method by making experiments and observations, followed by inducted conclusions that could only be overturned by the realization of other, more substantiated truths. Essentially, through his physical and mathematical approach to experimental design, Newton established a clear distinction between "natural philosophy" and "physical science. "

All of these natural philosophers built upon the work of their contemporaries. This collaboration became even simpler with the establishment of professional societies for scientists that published journals and provided forums for scientific discussion.

Astronomy

In Aristotelian metaphysics, abstractions dominated. All entities were understood as following rules based on their essences. Each substance had a proper or natural place. In astronomy, space was divided into two main regions. The stars resided in the higher region and were fixed in space. The planets and the moon resided in the lower region and revolved around the Earth. The sun also revolved around the Earth. Celestial and earthly motion was understood in terms of bodies seeking their natural resting places.

By the completion of the Scientific Revolution, most Aristotelian notions were overthrown. Space was reconceived as isotropic and non-hierarchical. Matter was seen as compositionally consistent throughout the universe. Motion was understood in terms of forces acting upon otherwise inert bodies. Finally, with Isaac Newton, a single constant called "gravity" was introduced as the fundamental operative force of the entire universe.

Copernicus

Nicolaus Copernicus (1473–1543) was a mathematician, lawyer, physician, and classicist. He was also a polyglot, a fluent speaker and writer in several languages, including Latin, Polish, German, Greek, and Italian. Most importantly for posterity, Copernicus was the astronomer credited with founding the field of modern astronomy.

Copernicus's major work, On the Revolutions of the Heavenly Spheres, was published in 1543, the year of his death. In this great work, he made a radical transformation of the system developed by Ptolemy (ca. 87–150 CE). Contrary to the Ptolemaic system, Copernicus posited a heliocentric model wherein the Earth and other planets, including Mercury, Venus, Mars, Jupiter, and Saturn, were carried by spheres around a stationary sun.

De revolutionibus, p. 9. Heliocentric model of the solar system in Copernicus' manuscript Source: https://en.Wikipedia.org/wiki/File:D...script_p9b.jpg

In the Ptolemaic system, the Earth had been figured as the stationary center of the universe around which the planets and sun revolved. In the Copernican system, on the other hand, the Earth was merely "another planet," that is, a "wandering star. "

Because his philosophy and theology held that God created only perfect order and harmony, Copernicus envisioned the planetary revolutions as perfectly circular. In order to account for some locations of planets and moons, he retained the auxiliary theory of epicycles that had been a part of the Ptolemaic system. In Copernicus's use of epicycles, the planets also circled the Earth while circling the sun.

Like a majority of Europeans of his time, Copernicus was an adherent of the Catholic Church. Yet a heliocentric universe ran contrary to the Christian, Earth-centered cosmology. That's why his On the Revolutions of the Heavenly Spheres was not published until the end of his life.

While Copernicus's ideas were revolutionary at the time, they did not cause a revolution in the study of astronomy until taken up by Galileo Galilei and Johannes Kepler several years later.

Jan Matejko-Astronomer Copernicus-Conversation with God Oil painting by the Polish artist Jan Matejko, finished in 1873, depicting Nicolaus Copernicus observing the heavens from a balcony by a tower near the cathedral in Frombork. Source: https://en.Wikipedia.org/wiki/Jan_Ma...n_with_God.jpg

Kepler

While accepting the central feature of Copernicus's model—a stationary sun and revolving planets—Johannes Kepler (1571- 1640) threw out the idea of epicycles. In their place, he introduced a wholly new conception of the universe that is still essentially accepted today. In his book The New Astronomy (1609), his "elliptical thesis" boldly declared that the planets, including the Earth, revolve around a stationary sun in ellipses, rather than in perfect circles.

Under Aristotle's metaphysics, an object's movement toward its "natural" resting place accounted for its motion. Kepler introduced the modern notion of physical forces as the causes of motion. For Kepler, a planet or other lifeless object is without an internal or active force of its own. Motion is derived only from external forces acting on the object. This particular insight was essential for Isaac Newton's breakthrough formulation of the law of gravity.

Attribution: Material modified from CK-12 6.3 The Scientific Revolution