Great Idea 3

Idea 3: Newton’s laws of motion

             In 1687, Issac Newton in his seminal work "Philosophiæ Naturalis Principia Mathematica" (Mathematical Principles of Natural Philosophy)  formalized the description of how massive bodies move under the influence of external forces, and presented his three laws of motion.

In formulating his three laws, Newton simplified the treatment of massive bodies by considering them to be mathematical points with no size or rotation. This allowed him to ignore factors such as friction, air resistance, temperature, material properties, etc., and concentrate on phenomena that can be described solely in terms of mass, length and time. 
    
    Thus Newton developed a special kind of relation between abstract mathematical constructs and the physical systems that we observe in the world around us by means of experiment and critical observation. The heart of the radical Newtonian style is the construction on the mind of a mathematical system that has some important features in common with the physical world; this system is then modified when the deductions and conclusions drawn from it are tested against the physical universe. 

    Newton's laws were verified by experiment and observation for over 200 years, and they are excellent approximations at the scales and speeds of everyday life. Newton's laws of motion, together with his law of universal gravitation and the mathematical techniques of calculus, provided for the first time a unified quantitative explanation for a wide range of physical phenomena.