This book reflects on the mind and thought of Isaac Newton, one of the greatest physicists, through his writings. Principia and Opticks are the masterpieces of his accomplishments, but we get a glimpse of him through his letters to friends, fellow physicists, and philosophers of his time. The influence of Christian church in his thought is significant and found in numerous writings, which invokes God as the Supreme Being who gave us the laws of physics; the laws of motion, gravitation and geometry, to create the physical reality we experience. Albert Einstein also invoked God in many of his discussions, but Einstein thought God as an entity, but Newton's view of Christian God illustrates the influence of faith and belief on people of his time. In spite of this, many of his peers' interpreted Newtonian mechanics proves the independent nature of our world. The concept of absolute space, absolute time and absolute motion was criticized by theologians, including Bishop Berkeley and Leibniz, who regarded them as relative. But his newfound rationalism inspired many 18th century and future physicists that paved the way for more radical and newer way of scientific thinking that progressively diminished the impact of religious beliefs in scientific thought. Recently Stephen Hawking, a highly respected physicist of our time, stated that there is no God and no heaven. The truth of scientific enquiry is accepted by more people than ever before.
The first two chapters of this book discuss the principles of Newtonian dynamics and methods in philosophy. The third chapter is most interesting as it deals with physical reality. The influence of Newton's faith is clearly evident in his discussions, when he describes the solar system consisting of sun, planets and comets could only proceed from the counsel and dominion of one Intelligent and Powerful Being. He also implied that God kept stars at immense distance preventing them to fall on each other by their strong gravity. Gravity is also implied to play a role in keeping the sea and heavens. The subtle spirit is known pervade and lies hid in all gross bodies by the force and action of which spirit the particles of bodies attract one another at near distances and cohere, if contiguous; and electric bodies operate to greater distances as well as repelling as attracting the neighboring corpuscles. The vibrations of the spirit in the living bodies are suggested to propagate along the solid nerve filaments from muscles to the brain that make the animals move. In his letter to Richard Bentley, the Bishop of Worcester, Newton writes that "the power that is placed in sun in the center of six primary planets. Why there is one body in our system qualified to give light and heat to all the rest, I know no reason but because the Author of the system thought that it is convenient." In another part of the same letter, he states the geometrical arrangements and orbits of the planets around sun, "argues that cause to be not blind and fortuitous, but very well skilled in mechanics and geometry." In another letter, Newton ascribes the sun and planetary motions; "for this as well as other reasons, I am compelled to ascribe the frame of this system to an Intelligent Agent." In his letter to Thomas Burnett, Newton discusses the science of genesis and creationism, and when light may have been created in the six days of creation; Newton's arguments surrounds the physics of motion and gravity, which are thought to have been created by God.
In the fourth chapter, theory of light and colors, the most interesting part of this discussion is on "ether and gravity," which starts from page 112. Newton also had lengthy correspondence with another famous chemist of his time, Robert Boyle, which is also discussed in this book
This book does not get into the personal nature of Newton where many have commented on his mean and erratic behavior. He was a Lucasian Professor of Mathematics at Cambridge, and later appointed as a warden of the Royal Mint. Newton successfully prosecuted 28 counterfeiters, and sent one to gallows. He made himself a justice of the peace in all the counties, and then conducted more than 100 cross-examinations of witnesses, informers, and suspects as a prosecutor. Disguised as a habitué of bars and taverns, he gathered evidence himself. Newton's quarrel with Leibniz (another famous mathematician of his time), about atheism to the discovery of calculus, is very briefly discussed.
Newton's Principia is one of the most difficult books to read, even with the notation s modernized by author Florian Cajori in his 1928 book. Newton described physics so elliptically that most readers could not fill in the missing steps. Philosopher John Locke, who was not mathematically inclined, asked his mathematical friends if Newton's work is reliable before he took pains to read and understand the book. In light of this, it is a nice feeling to read this book, which is clearly described.
1. The Principia (Great Minds)
2. Newton's Principia for the Common Reader
3. Philosophiae Naturalis Principia Mathematica (Latin Edition)
4. Isaac Newton
5. Opticks Or, a Treatise of the Reflections, Refractions, Inflections, and Colours of Light