HISTORY TIME LINE
QUICK REFERENCE FOR "HISTORY THAT SHAPED OUR HOME"
300 BC; Greek Philosophers Plato and Aristotle models Geocentric Theory with Earth as a Sphere. Aristotle publishes in his book “On the Heavens”.
3rd century BC - Aristarchus of Samos proposes heliocentric model, measures the distance to the Moon and its size
200 BC; Greek Aristarchus of Samos placed Earth and other planets in motion around the central Sun but rejected by Aristotleans.
140 CE; Cladius Ptolemy of Alexandria devised complex system of “epicycles” to account for retrograde (going backwards) motion of the planets. Published his theories in book called “Almagest”
200 CE; Ptolemic System developed by Cladius Ptolemaus. “Alamagest”. Geocentric Theory
1270; Roman Catholic church adopts priest Thomas Aquinas theory of a “God-ordained and man-centered” universe which declared the glory of God.
1453; Guttenberg Printing Press developed
1543; Nicholas Copernicus publishes “On the Revolution of Heavenly Spheres” in his last year of his life which postulates a heliocentric, Sun centered, solar system where Earth and planets are revolving around the Sun. “For who would place this lamp of a very beautiful temple in another or better place than this, wherefrom it can illuminate everything at the same time?”
1580; Tycho Brahe, A Danish Astronomer, claimed the most accurate measurement of planet and stars yet still was uncertain of a heliocentric or geocentric model. Was first to suggest a non-circular orbit of planets.
1582 Gregorian Calendar replaces Julian Calendar by Roman Catholic Church by Pope Gregory.
1583 – Galileo Galilei induces the period relationship of a pendulum from observation (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.
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; Galileo Galilei grinds his own glass and makes telescope. Observes Venus moons going around Venus “proving” the Heliocentrism. Publishes his work in Italian so all laymen can read instead of scholar Roman Latin. Recants at Roman Inquisition and banished to _____.
1609 - Johannes Kepler describes to motion of planets around the Sun, now known as Kepler's laws of planetary motion.
1619; Johannes Kepler, German Astronomer student of Tycho Brahe “proved” Heliocentric theory by identifying planet orbits as elliptical and not circular
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 Moonand 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
1687; Sir Isaac Newton, English Astronomer and President of the Royal Society of England, stated “Law of Universal Gravitation” which mathematically showed the force that kept the Earth and planets going around the Sun as well as what kept the oceans in and air from flying away. Wrote the book “Principia Mathematica.
1758 Edmund Halley successfully predicted, using Newton equations, the return of a comet last seen
1798 – Henry Cavendish measures the force of gravity between two masses, leading to the first accurate value for the gravitational constant
1822; Congregation of the Holy Office remove heliocentric books from the Vatican banned book list.
1838; Friedrich Bessel measures “Stellar Parrallax” method to measure first distance of star, 61 Cygni.
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 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
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
in 1915, Albert Einstein (1879 – 1955) published the general theory of relativity, in which gravity is not a force but it is a consequence of the curvature of space-time.
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
- 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.
- 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: Joseph Weber reports observation of gravitational waves (a claim now generally discounted),
- 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
- 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 Gravitational 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 spacetimes,
- 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: 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,
- 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
- 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 observations of Laser Interferometer Gravitational-Wave Observatory (LIGO), seeking direct detection of gravitational waves.
- 2007 – End of Gravity Probe B experiment.