Sir Issac Newton and Galileo Galilei were two of the most leading scientist of 17th century. Even though the two were never able to work together unfortunately as Issac Newton was born in the year of 1642, the same year that Galileo passed away, between them there was certainly a storm of scientific revolution. Both Galileo and Newton made great contribution to Philosophy of Science and their work are still influencing us till today. There are definitely a lot of similarity between these two great philosophers.
Galileo made major contributions to the fields of physics, astronomy, cosmology, mathematics and philosophy. A key term that would describe Galileo’s idea of philosophy of science is observation. Curious with the world around him, Galileo designed an improved telescope which allowed him to view the universe closer and more precisely, from the surface of the moon to the rings of Saturn. Galileo also had great contributions to the beginning phases of laws of motion. The Aristotelian law of free fall stated that the speed of objects falling depends on its weight, i.e. the heavier an object is, the faster it falls, but Galileo disagreed. He was certain that heavy objects fall faster because air resistance slows down lighter objects, with the ideal case in which the resistance is eliminated, the speed of two falling objects of different weight would be the same. Having done many scientific experiments of the rate in which objects fell to prove his idea, Galileo eventually developed the concept of inertia. He was the first to formulate the law of inertia which was later generalized and expanded by Newton. Before Galileo, it had been thought that all horizontal motion required a direct cause, but Galileo deduced from his experiments that a body in motion would remain in motion unless a force caused it to come to rest. This is the Principle of Inertia. Fundamental to his scientific task, Galileo used the Principle of Inertia to explain how it is possible that, if Earth is really spinning on its axis and orbiting the Sun, we do not sense that motion to support his belief of Heliocentrism.
English physicist, philosopher, Mathematician Issac Newton (1642-1726) expanded on the work of Galileo. When Newton arrived in Cambridge in 1661, the movement now known as the Scientific Revolution was well advanced, and many of the works basic to modern science had appeared. Like thousands of other undergraduates, Newton began his higher education by immersing himself in Aristotle’s work but the revolution was happening and nothing was able to stop Newton from discovering works of philosopher who disagreed with Aristotle. Newton expanded and organized Galileo’s principle of motion and formulated three laws of motion, arguably the most important and definitely one of the most basic and well-known laws of Physics. In 1687, he presented the laws for the first time in his seminal work Principia Mathematica Philosophiae Naturalis.
The first law states: An object at rest remains at rest, and an object in motion remains in motion at constant speed and in a straight line unless acted on by unbalanced external force.
The Second law: The acceleration of an object depends on the mass of the object and the amount of force applied (F=ma).
The third law: Whenever one object exerts a force on another object, the second object exerts an equal and opposite reaction on the first.
Newton succeeded in using these laws to explain why the orbits of the planets are ellipses rather than circles and proved much more than what he expected. It is not an exaggeration to say our modern physics is based on Newton’s law of motions. Also worth mentioning, Newton stated his four “Rules of Reasoning in Philosophy” which reflects his idea of how science should be done:
- No more causes of natural things should be admitted than are both true and sufficient to explain their phenomena.
- Therefore, the causes assigned to natural effects of the same kind must be, so far as possible, the same.
- Those qualities of bodies that cannot be intended and remitted and that belong to all bodies on which experiments can be made, should be taken as qualities of all bodies universally.
- In experimental philosophy, propositions gathered from phenomena by induction should be considered either exactly or very nearly true not withstanding any contrary hypotheses, until yet other phenomena make such propositions either more exact or liable to exception.
Newton lay down the foundation of scientific reasoning and he believed it is wise to use reasoning and evidence to prove hypothesis.
Contradictory to many people who are not familiar with Newton might think, Newton is a devout Christian. He saw the Universe as a manifestation of the infinite power of God, and science was a portal into God’s mind. He wrote,“And so that the systems of the fixed stars will not fall upon one another as a result of their gravity, he has placed them at immense distances from one another.He rules all things, not as the world soul but as the lord of all.” (Newton, General Scholium). He considered science as a portal to God’s mind, which is magnificent and beyond human imagination. We can only approach God by trying to make sense of his perfect work, the world in which we live; As we know, Galileo had conflicts with the Roman Catholic Church but he was also a believer of God. He was not aimed to deny the church but to deny Aristotelianism, or to better put it, it was a war against the dogmatic ruling of the church. He did not deny God, but believed that not everything contrary to the Bible must be held undoubtedly false. He wrote, “I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use.” (Galileo, Letter to the Grand Duchess Christina of Tuscany) He wholeheartedly believed that our reasoning is more convincing than what was written in the Bible. Evidently, the two scientist/philosopher believed in reasoning and observation. They both believed that there is order in the creation of God and it was their mission to endeavor to seek understanding of this order. If something is proven logically and scientifically, it became impossible to deny it.