Newtonian Dynamics and Gravitation
The first great conceptual synthesis in modern sciencewas the creation of a system of mechanics and a law of gravitation by the English physicist Isaac Newton , published in his Principia (Mathematical Principles of Natural Philosophy) of 1687. His “system of the world” was based on a universal attraction between any two point objects described by a force on each, along the line joining them, directly proportional to the product of their masses and inversely proportional to the square of the distance between them. He also presented the differential and integral calculus, mathematical tools that became indispensable to theoretical science. On this foundation, Newton derived and generalized the laws of Kepler , showing that orbits could be conic sections other than ellipses. Nonperiodic comets are well-known examples of objects with parabolic or hyperbolic orbits. The constant in Kepler’s third law, relating the squares of orbital periods to the cubes of semimajor axes, was found to depe...