Isaac Newton biography

Halley persuaded him to work out the problem mathematically and offered to pay all costs so that the ideas might be published.

Publishing 'Principia'

In 1687, after 18 months of intense and effectively non-stop work, Newton published Philosophiae, Natrualis, Principia Mathematica (Mathematical Principles of Natural Philosophy). Said to be the single-most influential book on physics and possibly all of science, it is most often known as Principia and contains information on nearly all of the essential concepts of physics, except energy.

The work offers an exact quantitative description of bodies in motion in three basic laws: 1) A stationary body will stay stationary unless an external force is applied to it; 2) Force is equal to mass times acceleration, and a change in motion is proportional to the force applied; and 3) For every action, there is an equal and opposite reaction. These three laws not only helped explain elliptical planetary orbits but nearly every other motion in the universe: how the planets are kept in orbit by the pull of the sun’s gravity; how the moon revolves around earth and the moons of Jupiter revolve around it; how comets revolve in elliptical orbits around the sun.

The laws also allowed Newton to calculate the mass of each planet, calculate the flattening of the Earth at the polls and the bulge at the equator, and how gravitational pull of the sun and moon create the Earth’s tides. In Newton's account, gravity kept the universe balanced, made it work, and brought heaven and earth together in one great equation.

Upon the publication of the first edition of Principia, Robert Hooke immediately accused Newton of plagiarism, claiming that he had discovered the theory of inverse squares and that Newton had stolen his work. The charge was unfounded, as most scientists knew, for Hooke had only theorized on the idea and had never brought it to any level of proof. However, Newton was furious and strongly defended his discoveries.

He withdrew all references to Hooke in his notes and threatened to withdraw from publishing the subsequent edition of Principia altogether. Halley, who had invested much of himself in Newton's work, tried to make peace between the two men. While Newton begrudgingly agreed to insert a joint acknowledgement of Hooke's work (shared with Wren and Halley) in his discussion of the law of inverse squares, it did nothing to placate Hooke.

As the years went on, Hooke's life began to unravel. His beloved niece and companion died the same year that Principia was published, in 1687. As Newton's reputation and fame grew, Hooke's declined, causing him to become even more bitter and loathsome toward his rival. To the bitter end, Hooke took every opportunity he could to offend Newton. Knowing that is rival would soon be elected president of the society, Hooke refused to retire until the year of his death, in 1703.

International Prominence

Principia immediately raised Newton to international prominence, and he thereafter became more involved in public affairs.