The following is a timeline of gravitational physics and general relativity.
Before 1500 3rd century B.C. – Aristarchus of Samos proposes the heliocentric model.
1500s 1543 – Nicolaus Copernicus publishes On the Revolutions of Heavenly Spheres. 1583 – Galileo Galilei deduces the period relationship of a pendulum from observations (according to later biographer). 1586 – Simon Stevin demonstrates that two objects of different masses accelerate at the same rate when dropped. 1589 – Galileo Galilei describes a hydrostatic balance for measuring specific gravity. 1590 – Galileo Galilei formulates modified Aristotelian theory of motion (later retracted) based on density rather than weight of objects.
1600s
1602-1608 – Galileo Galilei experiments with pendulum motion and inclined planes; deduces his law of free fall; and discovers that projectiles travel along parabolic trajectories. 1609 – Johannes Kepler announces his first two laws of planetary motion. 1610 – Johannes Kepler states the dark night paradox. 1610 – Galileo Galilei publishes The Sidereal Messenger, detailing his astronomical discoveries made with a telescope. 1619 – Johannes Kepler unveils his third law of planetary motion. 1665-66 – Isaac Newton introduces an inverse-square law of universal gravitation uniting terrestrial and celestial theories of motion and uses it to predict the orbit of the Moon and the parabolic arc of projectiles (the latter using his generalization of the binomial theorem). 1673 – Christiaan Huygens publishes his The Pendulum Clock, describing the motion of pendulums and the formula for centripetal acceleration during uniform circular motion, known to Isaac Newton since the 1660s. 1676-9 – Ole Rømer makes the first scientific determination of the speed of light. 1684 – Isaac Newton proves that planets moving under an inverse-square force law will obey Kepler's laws in a letter to Edmond Halley. 1686 – Isaac Newton uses a fixed length pendulum with weights of varying composition to test the weak equivalence principle to 1 part in 1000. 1686 – Isaac Newton publishes his Mathematical Principles of Natural Philosophy, where he develops his calculus, states his laws of motion and gravitation, proves the shell theorem, describes his rotating bucket thought experiment, explains the tides, and calculates the figure of the Earth. 1692 – Richard Bentley states his cosmological paradox in a letter to Newton.
1700s 1705 – Edmond Halley predicts the return of Halley's comet in 1758, the first use of Newton's laws by someone other than Newton himself. 1728 – Isaac Newton posthumously publishes his cannonball thought experiment.De mundi systemate, Isaac Newton, London: J. Tonson, J. Osborn, & T. Longman, 1728. 1730s – Alexis Clairault examines equipotential surfaces and develops the notions of partial differentiation and exact differentials. 1742 – Colin Maclaurin studies a self-gravitating uniform liquid drop at equilibrium, the Maclaurin spheroid.Maclaurin, Colin. A Treatise of Fluxions: In Two Books. 1. Vol. 1. Ruddimans, 1742. 1740s – Jean le Rond d'Alembert and Leonhard Euler independently examine the precession of the equinoxes and nutation of the Earth. In the process, they develop the dynamics of rigid bodies. 1740s-1750s – Leonhard Euler and Alexis Clairault independently derive the equations of motion for the three-body problem and apply them to the Moon. 1755 – Immanuel Kant advances Emanuel Swedenborg's nebular hypothesis on the origin of the Solar System. For details of Kant's position, see Stephen Palmquist, "Kant's Cosmogony Re-Evaluated", Studies in History and Philosophy of Science 18:3 (September 1987), pp.255–269.
1765 – Leonhard Euler discovers the first three Lagrange points. (16MB) 1767 – Leonhard Euler solves Euler's restricted three-body problem.Euler L, Nov. Comm. Acad. Imp. Petropolitanae, 10, pp. 207–242, 11, pp. 152–184; Mémoires de l'Acad. de Berlin, 11, 228–249. 1772 – Joseph-Louis Lagrange discovers the two remaining Lagrange points. 1770s – Pierre-Simon de Laplace develops equations for the tides that take into account both gravitation and rotation. 1770s-1780s – Joseph-Louis Lagrange and Pierre-Simon de Laplace investigate the stability of the Solar System. 1780s – Adrien-Marie Legendre and Pierre-Simon de Laplace study the gravitational attraction of spheroids in spherical coordinates and introduce the Legendre polynomials. 1781 – William Herschel discovers the planet Uranus. 1783 – John Michell speculates that a star could be so massive that its gravitational field would prevent light from escaping. Pierre-Simon de Laplace proposes the same thing in 1795. 1796 – Pierre-Simon de Laplace independently introduces the nebular hypothesis. 1798 – Henry Cavendish tests Newton's law of universal gravitation using a torsion balance, leading to the first accurate value for the gravitational constant and the mean density of the Earth. 1799-1825 – Pierre-Simon de Laplace publishes his Treatise on Celestial Mechanics, in five volumes.
1800s 1846 – Urbain Le Verrier and John Couch Adams independently show that the orbit of Uranus is perturbed by another planet, Neptune, promptly discovered by Johann Gottfried Galle. 1849 – Armand Fizeau makes the first terrestrial determination of the speed of light. 1855 – Le Verrier observes a 38 arc-second per century excess precession of Mercury's orbit and attributes it to another planet, inside Mercury's orbit. The planet, called Vulcan, was never found. Le Verrier's figure is revised by Simon Newcomb to 43 arc-second per century in 1882. 1876 – William Kingdon Clifford suggests that the motion of matter may be due to changes in the geometry of space.s:On the Space Theory of Matter 1880 – Aurel Voss discovers the contracted Bianchi identities, subsequently rediscovered independently by Gregorio Ricci-Curbastro in 1889 and Luigi Bianchi in 1902. 1884 – William Thomson (Lord Kelvin) lectures on the issues with the wave theory of light with regards to the luminiferous ether. 1887 – Albert A. Michelson and Edward W. Morley report a null result in their experiment to detect the ether drift. 1888 – Oliver Heaviside calculates the electromagnetic field of a moving point charge at constant velocity, and realizes, with some help by George Frederick Charles Searle, that the field contracts in the direction of motion. 1889 – Loránd Eötvös uses a torsion balance to test the weak equivalence principle to 1 part in one billion. 1892 – George Francis FitzGerald explains his hypothesis that the Michelson-Morley interferometer contracts in the direction of motion through the luminiferous ether to Oliver Lodge. 1893 – Ernst Mach states Mach's principle, the first constructive critique of the idea of Newtonian absolute space. 1897 – Henri Poincaré questions whether absolute space, absolute time, and Euclidean geometry are applicable to physics.
1900s
1902 – Paul Gerber explains the movement of the perihelion of Mercury using finite speed of gravity. (Originally published in Programmabhandlung des städtischen Realgymnasiums zu Stargard i. Pomm., 1902) His formula, at least approximately, matches the later model from Einstein's general relativity, but Gerber's theory was incorrect. 1902 – Henri Poincaré questions the concept of simultaneity in his book, Science and Hypothesis. 1904 – Hendrik Antoon Lorentz publishes the Lorentz transformations, so named by Henri Poincaré. 1902 – Henri Poincaré shows that the Lorentz transformations form a mathematical group, called the Lorentz group, and derives the relativistic formula for adding velocities. 1905 – Albert Einstein completes his special theory of relativity and examines relativistic aberration and the transverse Doppler effect. 1905 – Albert Einstein discovers the equivalence of mass and energy, in modern form. He notes that it may be tested using radioactive substances. He returns to the problem multiple times later. 1906 – Max Planck coins the term Relativtheorie. Albert Einstein later uses the term Relativitätstheorie in a conversation with Paul Ehrenfest. He originally prefers calling it Invariance Theory. 1906 – Max Planck discovers the energy-momentum relation and formulates a variational principle for special relativity. 1907 – Albert Einstein introduces the principle of equivalence of gravitational and inertial mass and uses it to predict gravitational lensing and gravitational redshift, historically known as the Einstein shift. 1907-8 – Hermann Minkowski introduces the Minkowski spacetime and expresses electromagnetic field strengths as a second-rank tensor. He also coins the terms spacelike, timelike, light cone, and world line. His paper is published posthumously. 1909 – Max Born proposes his notion of rigidity. 1909 – Paul Ehrenfest states the Ehrenfest paradox.
1910s
1911 – Max von Laue publishes the first textbook on special relativity. 1911 – Albert Einstein explains the need to replace both special relativity and Newton's theory of gravity; he realizes that the principle of equivalence only holds locally, not globally. 1912 – Friedrich Kottler applies the notion of tensors to curved spacetime. 1915-16 – Albert Einstein completes his general theory of relativity. He explains the perihelion of Mercury and calculates gravitational lensing correctly and introduces the post-Newtonian approximation. 1915 – David Hilbert independently introduces the Einstein-Hilbert action. Hilbert also recognizes the connection between the Einstein equations and the Gauss-Bonnet theorem. 1916 – Karl Schwarzschild publishes the Schwarzschild metric about a month after Einstein published his general theory of relativity. This was the first solution to the Einstein field equations other than the trivial flat space solution.Eisenstaedt, "The Early Interpretation of the Schwarzschild Solution," in D. Howard and J. Stachel (eds), Einstein and the History of General Relativity: Einstein Studies, Vol. 1, pp. 213-234. Boston: Birkhauser, 1989. 1916 – Hans Reissner obtains the Reissner–Nordström solution, rediscovered in 1918 by Gunnar Nordström. 1916 – Albert Einstein predicts the existence of gravitational waves, traveling at the speed of light. 1916 – Willem de Sitter predicts the geodetic effect. 1917 – Albert Einstein applies his field equations to the entire Universe. Physical cosmology is born. 1916-20 – Arthur Eddington studies the internal constitution of the stars.The Internal Constitution of the Stars A. S. Eddington The Scientific Monthly Vol. 11, No. 4 (Oct., 1920), pp. 297–303 1918 – Albert Einstein derives the quadrupole formula for gravitational radiation. 1918 – Emmy Noether publishes Noether's theorem and resolves the issue of local energy conservation in general relativity. 1918 – Felix Klein applies the calculus of variations to deduce the conservation laws of general relativity. 1918 – Josef Lense and Hans Thirring find the gravitomagnetic frame-dragging of gyroscopes in the equations of general relativity. [On the Effect of Rotating Distant Masses in Einstein's Theory of Gravitation] [Correction to my paper "On the Effect of Rotating Distant Masses in Einstein's Theory of Gravitation"] [On the Influence of the Proper Rotation of Central Bodies on the Motions of Planets and Moons According to Einstein's Theory of Gravitation] 1919 – Arthur Eddington leads a solar eclipse expedition which detects gravitational deflection of light by the Sun, which, despite opinion to the contrary, survives modern scrutiny. Other teams fail for reasons of war and politics.
1920s
1921 – Theodor Kaluza demonstrates that a five-dimensional version of Einstein's equations unifies gravitation and electromagnetism. This idea is later extended by Oskar Klein to incorporate quantum mechanics. 1922 – Alexander Friedmann derives the Friedmann equations. Translated in: