Timeline of gravitational physics and relativity

The following is a timeline of gravitational physics and general relativity.

Before 1500

3rd century BC - Aristarchus of Samos proposes heliocentric model, measures the distance to the Moon and its size

1500s

1543 – Nicolaus Copernicus places the Sun at the gravitational center, starting a revolution in science
1583 – Galileo Galilei induces the period relationship of a pendulum from observations (according to later biographer).
1586 – Simon Stevin demonstrates that two objects of different mass accelerate at the same rate when dropped.
1589 – Galileo Galilei describes a hydrostatic balance for measuring specific gravity.
1590 – Galileo Galilei formulates modified Aristotelean theory of motion (later retracted) based on density rather than weight of objects.

1600s

1602 – Galileo Galilei conducts experiments on pendulum motion.
1604 – Galileo Galilei conducts experiments with inclined planes and induces the law of falling objects.
1607 – Galileo Galilei arrives a mathematical formulation of the law of falling objects based on his earlier experiments.
1608 – Galileo Galilei discovers the parabolic arc of projectiles through experiment.
1609 – Johannes Kepler describes the motion of planets around the Sun, now known as Kepler's laws of planetary motion.
1640 – Ismaël Bullialdus suggests an inverse-square gravitational force law.
1665 – Isaac Newton introduces an inverse-square universal law of gravitation uniting terrestrial and celestial theories of motion and uses it to predict the orbit of the Moon and the parabolic arc of projectiles.
1684 – Isaac Newton proves that planets moving under an inverse-square force law will obey Kepler's laws
1686 – Isaac Newton uses a fixed length pendulum with weights of varying composition to test the weak equivalence principle to 1 part in 1000

1700s

1798 – Henry Cavendish measures the force of gravity between two masses, leading to the first accurate value for the gravitational constant

1800s

1846 – Urbain Le Verrier and John Couch Adams, studying Uranus' orbit, independently prove that another, farther planet must exist. Neptune was found at the predicted moment and position.
1855 – Le Verrier observes a 35 arcsecond per century excess precession of Mercury's orbit and attributes it to another planet, inside Mercury's orbit. The planet was never found. See Vulcan.
1876 – William Kingdon Clifford suggests that the motion of matter may be due to changes in the geometry of space
1882 – Simon Newcomb observes a 43 arcsecond per century excess precession of Mercury's orbit
1887 – Albert A. Michelson and Edward W. Morley in their famous experiment do not detect the ether drift
1889 – Loránd Eötvös uses a torsion balance to test the weak equivalence principle to 1 part in one billion
1893 – Ernst Mach states Mach's principle; first constructive attack on the idea of Newtonian absolute space
1898 – Henri Poincaré states that simultaneity is relative
1899 – Hendrik Antoon Lorentz published Lorentz transformations

1900s

1904 – Henri Poincaré presents the principle of relativity for electromagnetism
1905 – Albert Einstein completes his theory of special relativity and states the law of mass-energy conservation: E=mc2
1907 – Albert Einstein introduces the principle of equivalence of gravitation and inertia and uses it to predict the gravitational redshift
1915 – Albert Einstein completes his theory of general relativity. The new theory explains Mercury's strange motions that baffled Urbain Le Verrier.
1915 – 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.
1916 – Albert Einstein shows that the field equations of general relativity admit wavelike solutions
1918 – J. Lense and Hans Thirring find the gravitomagnetic precession of gyroscopes in the equations of general relativity
1919 – Arthur Eddington leads a solar eclipse expedition which claims to detect gravitational deflection of light by the Sun
1921 – Theodor Kaluza demonstrates that a five-dimensional version of Einstein's equations unifies gravitation and electromagnetism
1937 – Fritz Zwicky states that galaxies could act as gravitational lenses
1937 – Albert Einstein, Leopold Infeld, and Banesh Hoffmann show that the geodesic equations of general relativity can be deduced from its field equations

1950s

1953 – P. C. Vaidya Newtonian time in general relativity, Nature, 171, p260.
1956 – John Lighton Synge publishes the first relativity text emphasizing spacetime diagrams and geometrical methods,
1957 – Felix A. E. Pirani uses Petrov classification to understand gravitational radiation,
1957 – Richard Feynman introduces sticky bead argument,
1957 – John Wheeler discusses the breakdown of classical general relativity near singularities and the need for quantum gravity
1959 – Pound–Rebka experiment, first precision test of gravitational redshift,
1959 – Lluís Bel introduces Bel–Robinson tensor and the Bel decomposition of the Riemann tensor,
1959 – Arthur Komar introduces the Komar mass,
1959 – Richard Arnowitt, Stanley Deser and Charles W. Misner developed ADM formalism.

1960s

1960 – Martin Kruskal and George Szekeres independently introduce the Kruskal–Szekeres coordinates for the Schwarzschild vacuum,
1960 – Shapiro effect confirmed,
1960 – Thomas Matthews and Allan R. Sandage associate 3C 48 with a point-like optical image, show radio source can be at most 15 light minutes in diameter,
1960 – Carl H. Brans and Robert H. Dicke introduce Brans–Dicke theory, the first viable alternative theory with a clear physical motivation,
1960 – Ivor M. Robinson and Andrzej Trautman discover the Robinson-Trautman null dust solution[1]
1961 – Pascual Jordan and Jürgen Ehlers develop the kinematic decomposition of a timelike congruence,
1960 – Robert Pound and Glen Rebka test the gravitational redshift predicted by the equivalence principle to approximately 1%
1962 – Roger Penrose and Ezra T. Newman introduce the Newman–Penrose formalism,
1962 – Ehlers and Wolfgang Kundt classify the symmetries of Pp-wave spacetimes,
1962: –Joshua Goldberg and Rainer K. Sachs prove the Goldberg–Sachs theorem,
1962 – Ehlers introduces Ehlers transformations, a new solution generating method,
1962 – Cornelius Lanczos introduces the Lanczos potential for the Weyl tensor,
1962 – Richard Arnowitt, Stanley Deser, and Charles W. Misner introduce the ADM reformulation and global hyperbolicity,
1962 – Yvonne Choquet-Bruhat on Cauchy problem and global hyperbolicity,
1962 – Istvan Ozsvath and Englbert Schücking rediscover the circularly polarized monochromomatic gravitational wave,
1962 – Hans Adolph Buchdahl discovers Buchdahl's theorem,
1962 – Hermann Bondi introduces Bondi mass,
1962 – Robert Dicke, Peter Roll, and R. Krotkov use a torsion fiber balance to test the weak equivalence principle to 2 parts in 100 billion,
1962 - Hermann Bondi, M. G. van der Burg, A. W. Metzner, and Rainer K. Sachs introduce the asymptotic symmetry group of asymptotically flat, Lorentzian spacetimes at null (i.e., light-like) infinity.
1963 – Roy Kerr discovers the Kerr vacuum solution of Einstein's field equations,
1963 – Redshifts of 3C 273 and other quasars show they are very distant; hence very luminous,
1963 – Newman, T. Unti and L.A. Tamburino introduce the NUT vacuum solution,
1963 – Roger Penrose introduces Penrose diagrams and Penrose limits,
1963 – First Texas Symposium on Relativistic Astrophysics held in Dallas, 16–18 December,
1964 – R. W. Sharp and Misner introduce the Misner–Sharp mass,
1964 – M. A. Melvin discovers the Melvin electrovacuum solution (aka the Melvin magnetic universe),
1964 – Irwin Shapiro predicts a gravitational time delay of radiation travel as a test of general relativity
1965 – Roger Penrose proves first of the singularity theorems,
1965 – Newman and others discover the Kerr–Newman electrovacuum solution,
1965 – Penrose discovers the structure of the light cones in gravitational plane wave spacetimes,
1965 – Kerr and Alfred Schild introduce Kerr-Schild spacetime,
1965 – Subrahmanyan Chandrasekhar determines a stability criterion,
1965 – Arno Penzias and Robert Wilson discover the cosmic microwave background radiation,
1965 – Joseph Weber puts the first Weber bar gravitational wave detector into operation
1966 – Sachs and Ronald Kantowski discover the Kantowski-Sachs dust solution,
1967 – Jocelyn Bell and Antony Hewish discover pulsars,
1967 – Robert H. Boyer and R. W. Lindquist introduce Boyer–Lindquist coordinates for the Kerr vacuum,
1967 – Bryce DeWitt publishes on canonical quantum gravity,
1967 – Werner Israel proves the no-hair theorem,
1967 – Kenneth Nordtvedt develops PPN formalism,
1967 – Mendel Sachs publishes factorization of Einstein's field equations,
1967 – Hans Stephani discovers the Stephani dust solution,
1968 – F. J. Ernst discovers the Ernst equation,
1968 – B. Kent Harrison discovers the Harrison transformation, a solution-generating method,
1968 – Brandon Carter solves the geodesic equations for Kerr–Newmann electrovacuum,
1968 – Hugo D. Wahlquist discovers the Wahlquist fluid,
1968 – Irwin Shapiro presents the first detection of the Shapiro delay
1968 – Kenneth Nordtvedt studies a possible violation of the weak equivalence principle for self-gravitating bodies and proposes a new test of the weak equivalence principle based on observing the relative motion of the Earth and Moon in the Sun's gravitational field
1969 – William B. Bonnor introduces the Bonnor beam,
1969 – Joseph Weber reports observation of gravitational waves[2] (a claim now generally discounted),
1969 – Penrose proposes the (weak) cosmic censorship hypothesis and the Penrose process,
1969 – Stephen W. Hawking proves area theorem for black holes,
1969 – Misner introduces the mixmaster universe,

1970s

1970 – Frank J. Zerilli derives the Zerilli equation,
1970 – Vladimir A. Belinskiǐ, Isaak Markovich Khalatnikov, and Evgeny Lifshitz introduce the BKL conjecture,
1970 – Chandrasekhar pushes on to 5/2 post-Newtonian order,
1970 – Hawking and Penrose prove trapped surfaces must arise in black holes,
1970 – the Kinnersley-Walker photon rocket,
1970 – Peter Szekeres introduces colliding plane waves,
1971 – Peter C. Aichelburg and Roman U. Sexl introduce the Aichelburg–Sexl ultraboost,
1971 – Introduction of the Khan–Penrose vacuum, a simple explicit colliding plane wave spacetime,
1971 – Robert H. Gowdy introduces the Gowdy vacuum solutions (cosmological models containing circulating gravitational waves),
1971 – Cygnus X-1, the first solid black hole candidate, discovered by Uhuru satellite,
1971 – William H. Press discovers black hole ringing by numerical simulation,
1971 – Harrison and Estabrook algorithm for solving systems of PDEs,
1971 – James W. York introduces conformal method generating initial data for ADM initial value formulation,
1971 – Robert Geroch introduces Geroch group and a solution generating method,
1972 – Jacob Bekenstein proposes that black holes have a non-decreasing entropy which can be identified with the area,
1972 – Carter, Hawking and James M. Bardeen propose the four laws of black hole mechanics,
1972 – Sachs introduces optical scalars and proves peeling theorem,
1972 – Rainer Weiss proposes concept of interferometric gravitational wave detector,
1972 – J. C. Hafele and R. E. Keating perform Hafele–Keating experiment,
1972 – Richard H. Price studies gravitational collapse with numerical simulations,
1972 – Saul Teukolsky derives the Teukolsky equation,
1972 – Yakov B. Zel'dovich predicts the transmutation of electromagnetic and gravitational radiation,
1973 – P. C. Vaidya and L. K. Patel introduce the Kerr–Vaidya null dust solution,
1973 – Publication by Charles W. Misner, Kip S. Thorne and John A. Wheeler of the treatise Gravitation, the first modern textbook on general relativity,
1973 – Publication by Stephen W. Hawking and George Ellis of the monograph The Large Scale Structure of Space-Time,
1973 – Geroch introduces the GHP formalism,
1974 – Russell Hulse and Joseph Hooton Taylor, Jr. discover the Hulse–Taylor binary pulsar,
1974 – James W. York and Niall Ó Murchadha present the analysis of the initial value formulation and examine the stability of its solutions,
1974 – R. O. Hansen introduces Hansen–Geroch multipole moments,
1974: –Tullio Regge introduces the Regge calculus,
1974 – Hawking discovers Hawking radiation,
1975 – Chandrasekhar and Steven Detweiler compute quasinormal modes,
1975 – Szekeres and D. A. Szafron discover the Szekeres–Szafron dust solutions,
1976 – Penrose introduces Penrose limits (every null geodesic in a Lorentzian spacetime behaves like a plane wave),
1976 – Gravity Probe A experiment confirmed slowing the flow of time caused by gravity matching the predicted effects to an accuracy of about 70 parts per million.
1976 – Robert Vessot and Martin Levine use a hydrogen maser clock on a Scout D rocket to test the gravitational redshift predicted by the equivalence principle to approximately 0.007%
1978 – Penrose introduces the notion of a thunderbolt,
1978 – Belinskiǐ and Zakharov show how to solve Einstein's field equations using the inverse scattering transform; the first gravitational solitons,
1979 – Richard Schoen and Shing-Tung Yau prove the positive mass theorem.
1979 – Dennis Walsh, Robert Carswell, and Ray Weymann discover the gravitationally lensed quasar Q0957+561

After 1980

1982 – Joseph Taylor and Joel Weisberg show that the rate of energy loss from the binary pulsar PSR B1913+16 agrees with that predicted by the general relativistic quadrupole formula to within 5%
2002 – First data collection of the Laser Interferometer Gravitational-Wave Observatory (LIGO).
2005 – The first stable numerical solutions of a binary black hole orbit are calculated independently by three different research groups.
2007 – End of Gravity Probe B experiment.
2015 – Advanced LIGO reports the first direct detections of gravitational waves (GW150914 and GW151226).
2017 – Advanced LIGO and Fermi Gamma-ray Space Telescope constrain the speed of gravity to 1 part in \( 10^{15} \) of the speed of light with GW170817.
2019 – The Event Horizon Telescope images the shadow of supermassive black hole M87*