It was Isaac Newton's Principia that founded the law of universal gravitation on 5th July 1687. It is the same principia that inspired Albert Einstein into formulating the Einstein field equations (the general relativity theory). It is still the same principia, I believe, will lead us to the quantum theory of gravity (Quantum gravity)

According to Newton’s Principia, the force of gravity governs the movement of bodies in the solar system. It is this simple mathematical law which determines the motion of bodies. The force of gravity accurately predicts the planetary orbits, it was used to put the first man on the moon, it predicts the return of comets, the rotation of galaxies, the solar eclipses, artificial satellites, satellite communications and television, the GPS and interplanetary probes. I almost forgot, it is why NASA was established in the first place.

The book has an active table of contents for readers to access each chapter,

LIFE OF SIR ISAAC NEWTONxiv

BOOK I.1

THE MATHEMATICAL PRINCIPLES OF NATURAL PHILOSOPHY.1

AXIOMS, OR LAWS OF MOTION.20

OF THE MOTION OF BODIES.43

SECTION II.65

Of the Invention of Centripetal Forces.65

SECTION III.91

Of the motion of bodies in eccentric conic sections.91

SECTION IV.110

Of the finding of elliptic, parabolic, and hyperbolic orbits, from the focus given.110

SECTION V.123

How the orbits are to be found when neither focus is given.123

SECTION VI.171

How the motions are to be found in given orbits.171

SECTION VII.183

Concerning the rectilinear ascent and descent of bodies.183

SECTION VIII.202

Of the invention of orbits wherein bodies will revolve, being acted upon by any sort of centripetal force.202

SECTION IX.212

Of the motion of bodies in moveable orbits; and of the motion of the apsides.212

SECTION X.230

Of the motion of bodies in given superficies, and of the reciprocal motion of funependulous bodies.230

SECTION XI.255

Of the motions of bodies tending to each other with centripetal forces.255

SECTION XII.300

Of the attractive forces of sphærical bodies.300

SECTION XIII.333

Of the attractive forces of bodies which are not of a sphærical figure.333

SECTION XIV.353

Of the motion of very small bodies when agitated by centripetal forces tending to the several parts of any very great body.353

BOOK II.365

OF THE MOTION OF BODIES.365

SECTION I.365

Of the motion of bodies that are resisted in the ratio of the velocity.365

SECTION II.381

Of the motion of bodies that are resisted in the duplicate ratio of their velocities.381

SECTION III.421

Of the motions of bodies which are resisted partly in the ratio of the velocities, and partly in the duplicate of the same ratio.421

SECTION IV.436

Of the circular motion of bodies in resisting mediums.436

SECTION V.449

Of the density and compression of fluids; and of hydrostatics.449

SECTION VI.469

Of the motion and resistance of funependulous bodies.469

SECTION VII.507

Of the motion of fluids, and the resistance made to projected bodies.507

SECTION VIII.571

Of motion propagated through fluids.571

SECTION IX.600

Of the circular motion of fluids.600

BOOK III.619

RULES OF REASONING IN PHILOSOPHY.621

PHÆNOMENA OR APPEARANCES.625

PROPOSITIONS634

OF THE MOTION OF THE MOON'S NODES.724

END OF THE MATHEMATICAL PRINCIPLES.863

THE SYSTEM OF THE WORLD.865

(less)