The following is a
timeline
A timeline is a display of a list of events in chronological order. It is typically a graphic design showing a long bar labelled with dates paralleling it, and usually contemporaneous events.
Timelines can use any suitable scale represen ...
of
gravitational physics
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the strong ...
and
general relativity
General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics ...
.
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
Galileo di Vincenzo Bonaiuti de' Galilei (15 February 1564 – 8 January 1642) was an Italian astronomer, physicist and engineer, sometimes described as a polymath. Commonly referred to as Galileo, his name was pronounced (, ). He wa ...
induces the period relationship of a
pendulum
A pendulum is a weight suspended from a pivot so that it can swing freely. When a pendulum is displaced sideways from its resting, equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward th ...
from observations (according to later biographer).
* 1586 –
Simon Stevin
Simon Stevin (; 1548–1620), sometimes called Stevinus, was a Flemish mathematician, scientist and music theorist. He made various contributions in many areas of science and engineering, both theoretical and practical. He also translated vario ...
demonstrates that two objects of different mass accelerate at the same rate when dropped.
* 1589 – Galileo Galilei describes a
hydrostatic balance
In fluid mechanics, hydrostatic equilibrium (hydrostatic balance, hydrostasy) is the condition of a fluid or plastic solid at rest, which occurs when external forces, such as gravity, are balanced by a pressure-gradient force. In the planetary ...
for measuring
specific gravity
Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its densest ...
.
* 1590 – Galileo Galilei formulates modified
Aristotelean theory of motion (later retracted) based on
density
Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...
rather than weight of objects.
1600s
* 1602 – Galileo Galilei conducts experiments on pendulum motion.
* 1604 – Galileo Galilei conducts experiments with
inclined plane
An inclined plane, also known as a ramp, is a flat supporting surface tilted at an angle from the vertical direction, with one end higher than the other, used as an aid for raising or lowering a load. The inclined plane is one of the six clas ...
s and induces the law of falling objects.
* 1607 – Galileo Galilei derives 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
Ismaël Boulliau (; Latin: Ismaël Bullialdus; 28 September 1605 – 25 November 1694) was a 17th-century French astronomer and mathematician who was also interested in history, theology, classical studies, and philology. He was an active m ...
suggests an inverse-square gravitational force law.
* 1665 –
Isaac Newton
Sir Isaac Newton (25 December 1642 – 20 March 1726/27) was an English mathematician, physicist, astronomer, alchemist, theologian, and author (described in his time as a " natural philosopher"), widely recognised as one of the grea ...
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
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...
and the parabolic arc of projectiles.
* 1684 – Isaac Newton proves that
planet
A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a you ...
s moving under an inverse-square force law will obey
Kepler's laws
In astronomy, Kepler's laws of planetary motion, published by Johannes Kepler between 1609 and 1619, describe the orbits of planets around the Sun. The laws modified the heliocentric theory of Nicolaus Copernicus, replacing its circular orbi ...
* 1686 – Isaac Newton uses a fixed length
pendulum
A pendulum is a weight suspended from a pivot so that it can swing freely. When a pendulum is displaced sideways from its resting, equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward th ...
with weights of varying composition to test the
weak equivalence principle
In the theory of general relativity, the equivalence principle is the equivalence of gravitational and inertial mass, and Albert Einstein's observation that the gravitational "force" as experienced locally while standing on a massive body (suc ...
to 1 part in 1000
1700s
* 1798 –
Henry Cavendish
Henry Cavendish ( ; 10 October 1731 – 24 February 1810) was an English natural philosopher and scientist who was an important experimental and theoretical chemist and physicist. He is noted for his discovery of hydrogen, which he termed "infl ...
measures the force of gravity between two masses, leading to the first accurate value for the
gravitational constant
1800s
* 1846 –
Urbain Le Verrier
Urbain Jean Joseph Le Verrier FRS (FOR) H FRSE (; 11 March 1811 – 23 September 1877) was a French astronomer and mathematician who specialized in celestial mechanics and is best known for predicting the existence and position of Neptune usin ...
and
John Couch Adams
John Couch Adams (; 5 June 1819 – 21 January 1892) was a British mathematician and astronomer. He was born in Laneast, near Launceston, Cornwall, and died in Cambridge.
His most famous achievement was predicting the existence and position o ...
, studying
Uranus
Uranus is the seventh planet from the Sun. Its name is a reference to the Greek god of the sky, Uranus ( Caelus), who, according to Greek mythology, was the great-grandfather of Ares (Mars), grandfather of Zeus (Jupiter) and father of ...
' 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
Precession is a change in the orientation of the rotational axis of a rotating body. In an appropriate reference frame it can be defined as a change in the first Euler angle, whereas the third Euler angle defines the rotation itself. In oth ...
of
Mercury's
orbit
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as ...
and attributes it to another planet, inside Mercury's orbit. The planet was never found. See
Vulcan
Vulcan may refer to:
Mythology
* Vulcan (mythology), the god of fire, volcanoes, metalworking, and the forge in Roman mythology
Arts, entertainment and media Film and television
* Vulcan (''Star Trek''), name of a fictional race and their home p ...
.
* 1876 –
William Kingdon Clifford suggests that the motion of matter may be due to changes in the geometry of space
* 1882 –
Simon Newcomb
Simon Newcomb (March 12, 1835 – July 11, 1909) was a Canadian–American astronomer, applied mathematician, and autodidactic polymath. He served as Professor of Mathematics in the United States Navy and at Johns Hopkins University. Born in N ...
observes a 43 arcsecond per century excess precession of Mercury's orbit
* 1887 –
Albert A. Michelson
Albert Abraham Michelson FFRS HFRSE (surname pronunciation anglicized as "Michael-son", December 19, 1852 – May 9, 1931) was a German-born American physicist of Polish/Jewish origin, known for his work on measuring the speed of light and esp ...
and
Edward W. Morley in
their famous experiment do not detect the
ether
In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again be ...
drift
* 1889 –
Loránd Eötvös
Baron Loránd Eötvös de Vásárosnamény (or Loránd Eötvös, , '' hu, vásárosnaményi báró Eötvös Loránd Ágoston''; 27 July 1848 – 8 April 1919), also called Baron Roland von Eötvös in English literature, was a Hungarian physicist ...
uses a
torsion balance
A torsion spring is a spring that works by twisting its end along its axis; that is, a flexible elastic object that stores mechanical energy when it is twisted. When it is twisted, it exerts a torque in the opposite direction, proportional ...
to test the
weak equivalence principle
In the theory of general relativity, the equivalence principle is the equivalence of gravitational and inertial mass, and Albert Einstein's observation that the gravitational "force" as experienced locally while standing on a massive body (suc ...
to 1 part in one billion
* 1893 –
Ernst Mach states
Mach's principle
In theoretical physics, particularly in discussions of gravitation theories, Mach's principle (or Mach's conjecture) is the name given by Einstein to an imprecise hypothesis often credited to the physicist and philosopher Ernst Mach. The hypothe ...
; first constructive attack on the idea of Newtonian absolute space
* 1898 –
Henri Poincaré states that simultaneity is relative
* 1899 –
Hendrik Antoon Lorentz
Hendrik Antoon Lorentz (; 18 July 1853 – 4 February 1928) was a Dutch physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and theoretical explanation of the Zeeman effect. He also derived the Lorent ...
published Lorentz transformations
1900s
* 1902 –
Paul Gerber explains the movement of the perihelion of Mercury using finite speed of gravity. His formula, at least approximately, matches the later model from Einstein's general relativity, but Gerber's theory was incorrect.
* 1904 –
Henri Poincaré presents the principle of relativity for
electromagnetism
In physics, electromagnetism is an interaction that occurs between particles with electric charge. It is the second-strongest of the four fundamental interactions, after the strong force, and it is the dominant force in the interactions of ...
* 1905 –
Albert Einstein
Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...
completes his theory of
special relativity
In physics, the special theory of relativity, or special relativity for short, is a scientific theory regarding the relationship between space and time. In Albert Einstein's original treatment, the theory is based on two postulates:
# The laws ...
and states the
law of mass-energy conservation: E=mc
2
* 1907 –
Albert Einstein
Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...
introduces the principle of equivalence of gravitation and inertia and uses it to predict the
gravitational redshift
In physics and general relativity, gravitational redshift (known as Einstein shift in older literature) is the phenomenon that electromagnetic waves or photons travelling out of a gravitational well (seem to) lose energy. This loss of energy ...
* 1915 –
Albert Einstein
Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...
completes his theory of
general relativity
General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics ...
. The new theory explains
Mercury's strange motions that baffled
Urbain Le Verrier
Urbain Jean Joseph Le Verrier FRS (FOR) H FRSE (; 11 March 1811 – 23 September 1877) was a French astronomer and mathematician who specialized in celestial mechanics and is best known for predicting the existence and position of Neptune usin ...
.
* 1915 –
Karl Schwarzschild
Karl Schwarzschild (; 9 October 1873 – 11 May 1916) was a German physicist and astronomer.
Schwarzschild provided the first exact solution to the Einstein field equations of general relativity, for the limited case of a single spherical non-r ...
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
Albert Einstein ( ; ; 14 March 1879 – 18 April 1955) was a German-born theoretical physicist, widely acknowledged to be one of the greatest and most influential physicists of all time. Einstein is best known for developing the theory ...
shows that the field equations of general relativity admit wavelike solutions
* 1918 –
Josef Lense
Josef Lense (28 October 1890 in Vienna – 28 December 1985 in Munich) was an Austrian physicist.
In 1914 Lense obtained his doctorate under Samuel Oppenheim. From 1927-28 he was Professor ordinarius and from 1928–1946 Professor extraord ...
and
Hans Thirring
Hans Thirring (March 23, 1888 – March 22, 1976) was an Austrian theoretical physicist, professor, and father of the physicist Walter Thirring. He won the Haitinger Prize of the Austrian Academy of Sciences in 1920.
Together with the mathemat ...
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
Theodor Franz Eduard Kaluza (; 9 November 1885 – 19 January 1954) was a German mathematician and physicist known for the Kaluza–Klein theory, involving field equations in five-dimensional space-time. His idea that fundamental forces can be ...
demonstrates that a five-dimensional version of Einstein's equations unifies
gravitation and
electromagnetism
In physics, electromagnetism is an interaction that occurs between particles with electric charge. It is the second-strongest of the four fundamental interactions, after the strong force, and it is the dominant force in the interactions of ...
* 1937 –
Fritz Zwicky
Fritz Zwicky (; ; February 14, 1898 – February 8, 1974) was a Swiss astronomer. He worked most of his life at the California Institute of Technology in the United States of America, where he made many important contributions in theoretical an ...
states that
galaxies could act as
gravitational lens
A gravitational lens is a distribution of matter (such as a cluster of galaxies) between a distant light source and an observer that is capable of bending the light from the source as the light travels toward the observer. This effect is known ...
es
* 1937 – Albert Einstein,
Leopold Infeld
Leopold Infeld (20 August 1898 – 15 January 1968) was a Polish physicist who worked mainly in Poland and Canada (1938–1950). He was a Rockefeller fellow at Cambridge University (1933–1934) and a member of the Polish Academy of Sciences.
Ea ...
, and
Banesh Hoffmann
Banesh Hoffmann (6 September 1906 – 5 August 1986) was a British mathematician and physicist known for his association with Albert Einstein.
Life
Banesh Hoffmann was born in Richmond, Surrey, on 6 September 1906. He studied mathematics and ...
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
John Lighton Synge (; 23 March 1897 – 30 March 1995) was an Irish mathematician and physicist, whose seven-decade career included significant periods in Ireland, Canada, and the USA. He was a prolific author and influential mentor, and is cre ...
publishes the first relativity text emphasizing
spacetime diagrams and
geometrical methods
Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is ...
,
* 1957 –
Felix A. E. Pirani uses
Petrov classification
In differential geometry and theoretical physics, the Petrov classification (also known as Petrov–Pirani–Penrose classification) describes the possible algebraic symmetries of the Weyl tensor at each event in a Lorentzian manifold.
It is mos ...
to understand
gravitational radiation,
* 1957 –
Richard Feynman
Richard Phillips Feynman (; May 11, 1918 – February 15, 1988) was an American theoretical physicist, known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics, the physics of the superfl ...
introduces
sticky bead argument
In general relativity, the sticky bead argument is a simple thought experiment designed to show that gravitational radiation is indeed predicted by general relativity, and can have physical effects. These claims were not widely accepted prior to ...
,
* 1957 –
John Wheeler discusses the breakdown of classical general relativity near
singularities and the need for
quantum gravity
* 1959 –
Pound–Rebka experiment
The Pound–Rebka experiment was an experiment in which gamma rays were emitted from the top of a tower and measured by a receiver at the bottom of the tower. The purpose of the experiment was to test Albert Einstein's theory of general relativit ...
, first precision test of gravitational redshift,
* 1959 – Lluís Bel introduces
Bel–Robinson tensor In general relativity and differential geometry, the Bel–Robinson tensor is a tensor defined in the abstract index notation by:
:T_=C_C_ ^ _ ^ + \frac\epsilon_^ \epsilon_^_ C_ C_^_^
Alternatively,
:T_ = C_C_ ^ _ ^ - \frac g_ C_ C^_^
where C_ is ...
and the
Bel decomposition
In semi-Riemannian geometry, the Bel decomposition, taken with respect to a specific timelike congruence, is a way of breaking up the Riemann tensor of a pseudo-Riemannian manifold into lower order tensors with properties similar to the electric ...
of the
Riemann tensor
In the mathematical field of differential geometry, the Riemann curvature tensor or Riemann–Christoffel tensor (after Bernhard Riemann and Elwin Bruno Christoffel) is the most common way used to express the curvature of Riemannian manifolds. ...
,
* 1959 –
Arthur Komar
Arthur B. Komar (March 26, 1931 – June 3, 2011) was a theoretical physicist, specializing in general relativity and the search for quantum gravity. Arthur Komar made a significant contribution to physics as an educator, research scientist, and a ...
introduces the
Komar mass The Komar mass (named after Arthur Komar) of a system is one of several formal concepts of mass that are used in general relativity. The Komar mass can be defined in any stationary spacetime, which is a spacetime in which all the metric componen ...
,
* 1959 –
Richard Arnowitt,
Stanley Deser and
Charles W. Misner
Charles W. Misner (; born June 13, 1932) is an American physicist and one of the authors of '' Gravitation''. His specialties include general relativity and cosmology. His work has also provided early foundations for studies of quantum gravity ...
developed
ADM formalism
The ADM formalism (named for its authors Richard Arnowitt, Stanley Deser and Charles W. Misner) is a Hamiltonian formulation of general relativity that plays an important role in canonical quantum gravity and numerical relativity. It was first ...
.
1960s
* 1960 –
Martin Kruskal
Martin David Kruskal (; September 28, 1925 – December 26, 2006) was an American mathematician and physicist. He made fundamental contributions in many areas of mathematics and science, ranging from plasma physics to general relativity and ...
and
George Szekeres
George Szekeres AM FAA (; 29 May 1911 – 28 August 2005) was a Hungarian–Australian mathematician.
Early years
Szekeres was born in Budapest, Hungary, as Szekeres György and received his degree in chemistry at the Technical University o ...
independently introduce the
Kruskal–Szekeres coordinates
In general relativity, Kruskal–Szekeres coordinates, named after Martin Kruskal and George Szekeres, are a coordinate system for the Schwarzschild geometry for a black hole. These coordinates have the advantage that they cover the entire space ...
for the
Schwarzschild vacuum,
* 1960 –
Shapiro effect confirmed,
* 1960 – Thomas Matthews and
Allan R. Sandage associate
3C 48
3C48 is a quasar discovered in 1960; it was the second source conclusively identified as such.
3C48 was the first source in the Third Cambridge Catalogue of Radio Sources for which an optical identification was found by Allan Sandage and Thoma ...
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
* 1961 –
Pascual Jordan
Ernst Pascual Jordan (; 18 October 1902 – 31 July 1980) was a German theoretical and mathematical physicist who made significant contributions to quantum mechanics and quantum field theory. He contributed much to the mathematical form of matri ...
and
Jürgen Ehlers
Jürgen Ehlers (; 29 December 1929 – 20 May 2008) was a German physicist who contributed to the understanding of Albert Einstein's theory of general relativity. From graduate and postgraduate work in Pascual Jordan's relativity research group ...
develop the ''kinematic decomposition'' of a
timelike congruence In general relativity, a congruence (more properly, a congruence of curves) is the set of integral curves of a (nowhere vanishing) vector field in a four-dimensional Lorentzian manifold which is interpreted physically as a model of spacetime. Oft ...
,
* 1960 –
Robert Pound Robert Vivian Pound (May 16, 1919 – April 12, 2010) was a Canadian-American physicist who helped discover nuclear magnetic resonance (NMR) and who devised the famous Pound–Rebka experiment supporting general relativity. He became a tenured ...
and
Glen Rebka Glen Anderson Rebka Jr. (September 19, 1931, CincinnatiJanuary 13, 2015, Laramie) was an American physicist.
Biography
Rebka attained a doctorate 1961 at Harvard, where he began study in 1953. Starting from 1961 he was at Yale University and start ...
test the gravitational redshift predicted by the equivalence principle to approximately 1%
* 1962 –
Roger Penrose and
Ezra T. Newman
Ezra Theodore Newman (October 17, 1929 – March 24, 2021) was an American physicist, known for his many contributions to general relativity theory. He was Professor Emeritus at the University of Pittsburgh. Newman was awarded the 2011 Einstein P ...
introduce the
Newman–Penrose formalism
The Newman–Penrose (NP) formalism The original paper by Newman and Penrose, which introduces the formalism, and uses it to derive example results.Ezra T Newman, Roger Penrose. ''Errata: An Approach to Gravitational Radiation by a Method of Sp ...
,
* 1962 – Ehlers and
Wolfgang Kundt classify the symmetries of
Pp-wave spacetimes,
* 1962: –
Joshua Goldberg and
Rainer K. Sachs prove the
Goldberg–Sachs theorem
The Goldberg–Sachs theorem is a result in Einstein's theory of general relativity about vacuum solutions of the Einstein field equations relating the existence of a certain type of congruence with algebraic properties of the Weyl tensor.
More ...
,
* 1962 – Ehlers introduces
Ehlers transformations, a new
solution generating method,
* 1962 –
Cornelius Lanczos
__NOTOC__
Cornelius (Cornel) Lanczos ( hu, Lánczos Kornél, ; born as Kornél Lőwy, until 1906: ''Löwy (Lőwy) Kornél''; February 2, 1893 – June 25, 1974) was a Hungarian-American and later Hungarian-Irish mathematician and physicist. Accor ...
introduces the
Lanczos potential for the
Weyl tensor
In differential geometry, the Weyl curvature tensor, named after Hermann Weyl, is a measure of the curvature of spacetime or, more generally, a pseudo-Riemannian manifold. Like the Riemann curvature tensor, the Weyl tensor expresses the tidal f ...
,
* 1962 –
Richard Arnowitt,
Stanley Deser, and
Charles W. Misner
Charles W. Misner (; born June 13, 1932) is an American physicist and one of the authors of '' Gravitation''. His specialties include general relativity and cosmology. His work has also provided early foundations for studies of quantum gravity ...
introduce the
ADM reformulation and
global hyperbolicity,
* 1962 –
Yvonne Choquet-Bruhat
Yvonne Choquet-Bruhat (; born 29 December 1923) is a French mathematician and physicist. She has made seminal contributions to the study of Einstein's general theory of relativity, by showing that the Einstein equations can be put into the form o ...
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
Sir Hermann Bondi (1 November 1919 – 10 September 2005) was an Austrian- British mathematician and cosmologist.
He is best known for developing the steady state model of the universe with Fred Hoyle and Thomas Gold as an alternative to the ...
introduces
Bondi mass,
* 1962 –
Robert Dicke
Robert Henry Dicke (; May 6, 1916 – March 4, 1997) was an American astronomer and physicist who made important contributions to the fields of astrophysics, atomic physics, cosmology and gravity. He was the Albert Einstein Professor in Scienc ...
,
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
Sir Hermann Bondi (1 November 1919 – 10 September 2005) was an Austrian- British mathematician and cosmologist.
He is best known for developing the steady state model of the universe with Fred Hoyle and Thomas Gold as an alternative to the ...
, M. G. van der Burg, A. W. Metzner, and
Rainer K. Sachs introduce the
asymptotic symmetry group of
asymptotically flat
An asymptotically flat spacetime is a Lorentzian manifold in which, roughly speaking, the curvature vanishes at large distances from some region, so that at large distances, the geometry becomes indistinguishable from that of Minkowski spacetime.
...
, Lorentzian spacetimes at null (''i.e.'', light-like) infinity.
* 1963 –
Roy Kerr
Roy Patrick Kerr (; born 16 May 1934) is a New Zealand mathematician who discovered the Kerr geometry, an exact solution to the Einstein field equation of general relativity. His solution models the gravitational field outside an uncharged ...
discovers the
Kerr vacuum solution of
Einstein's field equations
In the general theory of relativity, the Einstein field equations (EFE; also known as Einstein's equations) relate the geometry of spacetime to the distribution of matter within it.
The equations were published by Einstein in 1915 in the form ...
,
* 1963 – Redshifts of
3C 273
3C 273 is a quasar located in the constellation of Virgo. It was the first quasar ever to be identified.
It is the optically brightest quasar in the sky from Earth ( m ~12.9), and one of the closest with a redshift, ''z'', of 0.158. A lumino ...
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 diagram
In theoretical physics, a Penrose diagram (named after mathematical physicist Roger Penrose) is a two-dimensional diagram capturing the causal relations between different points in spacetime through a conformal treatment of infinity. It is an ext ...
s and
Penrose limits,
* 1963 – First
Texas Symposium on Relativistic Astrophysics
Ivor Robinson (October 7, 1923 – May 27, 2016) was a British-American mathematical physicist, born and educated in England, noted for his important contributions to the theory of relativity. He was a principal organizer of the Texas Symposium o ...
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
Singularity or singular point may refer to:
Science, technology, and mathematics Mathematics
* Mathematical singularity, a point at which a given mathematical object is not defined or not "well-behaved", for example infinite or not differentiab ...
,
* 1965 – Newman and others discover the Kerr–Newman electrovacuum solution,
* 1965 – Penrose discovers the structure of the light cones in
gravitational plane wave
In general relativity, a gravitational plane wave is a special class of a vacuum pp-wave spacetime, and may be defined in terms of Brinkmann coordinates by
ds^2= (u)(x^2-y^2)+2b(u)xyu^2+2dudv+dx^2+dy^2
Here, a(u), b(u) can be any smooth functio ...
spacetimes,
* 1965 – Kerr and
Alfred Schild
Alfred Schild (September 7, 1921 – May 24, 1977) was a leading Austrian American physicist, well known for his contributions to the Golden age of general relativity (1960–1975).
Biography
Schild was born in Istanbul on September 7, 1921. His ...
introduce
Kerr-Schild spacetime,
* 1965 –
Subrahmanyan Chandrasekhar determines a stability criterion,
* 1965 –
Arno Penzias
Arno Allan Penzias (; born April 26, 1933) is an American physicist, radio astronomer and Nobel laureate in physics. Along with Robert Woodrow Wilson, he discovered the cosmic microwave background radiation, which helped establish the Big Bang ...
and
Robert Wilson discover the
cosmic microwave background radiation
In Big Bang cosmology the cosmic microwave background (CMB, CMBR) is electromagnetic radiation that is a remnant from an early stage of the universe, also known as "relic radiation". The CMB is faint cosmic background radiation filling all space ...
,
* 1965 –
Joseph Weber
Joseph Weber (May 17, 1919 – September 30, 2000) was an American physicist. He gave the earliest public lecture on the principles behind the laser and the maser and developed the first gravitational wave detectors (Weber bars).
Early educati ...
puts the first Weber bar
gravitational wave detector into operation
* 1966 – Sachs and
Ronald Kantowski discover the
Kantowski-Sachs dust solution,
* 1967 –
Jocelyn Bell
Dame Susan Jocelyn Bell Burnell (; Bell; born 15 July 1943) is an astrophysicist from Northern Ireland who, as a postgraduate student, discovered the first radio pulsars in 1967. The discovery eventually earned the Nobel Prize in Physics in ...
and
Antony Hewish discover
pulsars
A pulsar (from ''pulsating radio source'') is a highly magnetized rotating neutron star that emits beams of electromagnetic radiation out of its magnetic poles. This radiation can be observed only when a beam of emission is pointing toward E ...
,
* 1967 –
Robert H. Boyer and
R. W. Lindquist introduce
Boyer–Lindquist coordinates In the mathematical description of general relativity, the Boyer–Lindquist coordinates are a generalization of the coordinates used for the metric of a Schwarzschild black hole that can be used to express the metric of a Kerr black hole.
The Ha ...
for the Kerr vacuum,
* 1967 –
Bryce DeWitt
Bryce Seligman DeWitt (January 8, 1923 – September 23, 2004), was an American theoretical physicist noted for his work in gravitation and quantum field theory.
Life
He was born Carl Bryce Seligman, but he and his three brothers, including th ...
publishes on canonical
quantum gravity,
* 1967 –
Werner Israel
Werner Israel, (October 4, 1931 – May 18, 2022) was a physicist, author, researcher, and professor at the University of Victoria.
Biography
Born in Berlin, Germany and raised in Cape Town, South Africa, he first received his B.Sc. in 1951 an ...
proves the
no-hair theorem
The no-hair theorem states that all stationary black hole solutions of the Einstein–Maxwell equations of gravitation and electromagnetism in general relativity can be completely characterized by only three independent ''externally'' observabl ...
,
* 1967 –
Kenneth Nordtvedt develops
PPN formalism
In physics, precisely in the study of the theory of general relativity and many alternatives to it, the post-Newtonian formalism is a calculational tool that expresses Einstein's (nonlinear) equations of gravity in terms of the lowest-order dev ...
,
* 1967 –
Mendel Sachs
Mendel Sachs (; April 13, 1927 – May 5, 2012) was an American theoretical physicist. His scientific work includes the proposal of a unified field theory that brings together the weak force, strong force, electromagnetism, and gravity.
Biography ...
publishes factorization of Einstein's field equations,
* 1967 –
Hans Stephani discovers the
Stephani dust solution,
* 1968 –
F. J. Ernst discovers the
Ernst equation
In mathematics, the Ernst equation is an integrable non-linear partial differential equation, named after the American physicist .
The Ernst equation
The equation reads:
\Re(u)(u_+u_r/r+u_) = (u_r)^2+(u_z)^2.
For its Lax pair and other featur ...
,
* 1968 –
B. Kent Harrison discovers the
Harrison transformation, a solution-generating method,
* 1968 –
Brandon Carter
Brandon Carter, (born 1942) is an Australian theoretical physicist, best known for his work on the properties of black holes and for being the first to name and employ the anthropic principle in its contemporary form. He is a researcher at th ...
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
Joseph Weber (May 17, 1919 – September 30, 2000) was an American physicist. He gave the earliest public lecture on the principles behind the laser and the maser and developed the first gravitational wave detectors (Weber bars).
Early educati ...
reports observation of
gravitational waves
Gravitational waves are waves of the intensity of gravity generated by the accelerated masses of an orbital binary system that propagate as waves outward from their source at the speed of light. They were first proposed by Oliver Heaviside in 1 ...
(a claim now generally discounted),
* 1969 – Penrose proposes the (weak)
cosmic censorship hypothesis The weak and the strong cosmic censorship hypotheses are two mathematical conjectures about the structure of gravitational singularities arising in general relativity.
Singularities that arise in the solutions of Einstein's equations are typically ...
and the
Penrose process
The Penrose process (also called Penrose mechanism) is theorised by Sir Roger Penrose as a means whereby energy can be extracted from a rotating black hole. The process takes advantage of the ergosphere --- a region of spacetime around the black ...
,
* 1969 –
Stephen W. Hawking proves area theorem for black holes,
* 1969 – Misner introduces the
mixmaster universe
Mixmaster may refer to:
Equipment and technology
* Sunbeam Mixmaster, an electric kitchen mixer that was the flagship product of Sunbeam Products
** Mix Diskerud, United States professional soccer player nicknamed after the mixer
* Mixmaster ano ...
,
1970s
* 1970 –
Frank J. Zerilli derives the
Zerilli equation,
* 1970 –
Vladimir A. Belinskiǐ,
Isaak Markovich Khalatnikov
Isaak Markovych Khalatnykov ( uk, Ісаа́к Ма́ркович Хала́тников; 17 October 1919 – 9 January 2021) was a leading Soviet theoretical physicist who has made significant contributions to many areas of theoretical physics, ...
, and
Evgeny Lifshitz
Evgeny Mikhailovich Lifshitz (russian: Евге́ний Миха́йлович Ли́фшиц; February 21, 1915, Kharkiv, Russian Empire – October 29, 1985, Moscow, Russian SFSR) was a leading Soviet physicist and brother of the physicist ...
introduce the
BKL conjecture
A Belinski–Khalatnikov–Lifshitz (BKL) singularity is a model of the dynamic evolution of the universe near the initial gravitational singularity, described by an anisotropic, chaotic solution of the Einstein field equation of gravitati ...
,
* 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 wave
In physics, a collision is any event in which two or more bodies exert forces on each other in a relatively short time. Although the most common use of the word ''collision'' refers to incidents in which two or more objects collide with great f ...
s,
* 1971 –
Peter C. Aichelburg and
Roman U. Sexl introduce the
Aichelburg–Sexl ultraboost
In general relativity, the Aichelburg–Sexl ultraboost is an exact solution which models the spacetime of an observer moving towards or away from a spherically symmetric gravitating object at nearly the speed of light. It was introduced by Pe ...
,
* 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
Cygnus X-1 (abbreviated Cyg X-1) is a galactic X-ray source in the constellation Cygnus and was the first such source widely accepted to be a black hole. It was discovered in 1964 during a rocket flight and is one of the ...
, the first solid black hole candidate, discovered by
Uhuru satellite,
* 1971 –
William H. Press discovers black hole ringing by
numerical simulation
Computer simulation is the process of mathematical modelling, performed on a computer, which is designed to predict the behaviour of, or the outcome of, a real-world or physical system. The reliability of some mathematical models can be dete ...
,
* 1971 – Harrison and Estabrook algorithm for solving systems of PDEs,
* 1971 –
James W. York
James W. York Jr. (born July 3, 1939 in Raleigh, North Carolina) is an American mathematical physicist who contributed to the theory of general relativity. In any physical theory, it is important to understand when solutions to the fundamental fiel ...
introduces
conformal method generating initial data for ADM initial value formulation,
* 1971 –
Robert Geroch
Robert Geroch (born 1 June 1942 in Akron, Ohio) is an American theoretical physicist and professor at the University of Chicago. He has worked prominently on general relativity and mathematical physics and has promoted the use of category theory i ...
introduces
Geroch group The Geroch group is an infinite-dimensional symmetry group of axisymmetric, :wikt:stationary, stationary vacuum spacetimes that are solutions of Einstein's equations of general relativity. It is generated by two commutativity, non-commuting subgrou ...
and a
solution generating method,
* 1972 –
Jacob Bekenstein
Jacob David Bekenstein ( he, יעקב בקנשטיין; May 1, 1947 – August 16, 2015) was an American and Israeli theoretical physicist who made fundamental contributions to the foundation of black hole thermodynamics and to other aspects of ...
proposes that black holes have a non-decreasing
entropy
Entropy is a scientific concept, as well as a measurable physical property, that is most commonly associated with a state of disorder, randomness, or uncertainty. The term and the concept are used in diverse fields, from classical thermodynam ...
which can be identified with the area,
* 1972 – Carter, Hawking and
James M. Bardeen
James Maxwell Bardeen (May 9, 1939 – June 20, 2022) was an American physicist, well known for his work in general relativity, particularly his role in formulating the laws of black hole mechanics. He also discovered the Bardeen vacuum, an e ...
propose the four
laws of black hole mechanics,
* 1972 – Sachs introduces
optical scalars and proves
peeling theorem In general relativity, the peeling theorem describes the asymptotic behavior of the Weyl tensor as one goes tnull infinity Let \gamma be a null geodesic in a spacetime (M, g_) from a point p to null infinity, with affine parameter \lambda. Then the ...
,
* 1972 –
Rainer Weiss
Rainer "Rai" Weiss ( , ; born September 29, 1932) is an American physicist, known for his contributions in gravitational physics and astrophysics. He is a professor of physics emeritus at MIT and an adjunct professor at LSU. He is best known ...
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
Saul Arno Teukolsky (born August 2, 1947) is a theoretical astrophysicist and a professor of Physics and Astronomy at Caltech and Cornell University. His major research interests include general relativity, relativistic astrophysics, and computa ...
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
Charles W. Misner (; born June 13, 1932) is an American physicist and one of the authors of '' Gravitation''. His specialties include general relativity and cosmology. His work has also provided early foundations for studies of quantum gravity ...
,
Kip S. Thorne and
John A. Wheeler
John Archibald Wheeler (July 9, 1911April 13, 2008) was an American theoretical physicist. He was largely responsible for reviving interest in general relativity in the United States after World War II. Wheeler also worked with Niels Bohr in e ...
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
''The'' () is a grammatical article in English, denoting persons or things already mentioned, under discussion, implied or otherwise presumed familiar to listeners, readers, or speakers. It is the definite article in English. ''The'' is the m ...
'',
* 1973 – Geroch introduces the
GHP formalism,
* 1974 –
Russell Hulse
Russell Alan Hulse (born November 28, 1950) is an American physicist and winner of the Nobel Prize in Physics, shared with his thesis advisor Joseph Hooton Taylor Jr., "''for the discovery of a new type of pulsar, a discovery that has opened up n ...
and
Joseph Hooton Taylor, Jr. discover the
Hulse–Taylor binary pulsar,
* 1974 –
James W. York
James W. York Jr. (born July 3, 1939 in Raleigh, North Carolina) is an American mathematical physicist who contributed to the theory of general relativity. In any physical theory, it is important to understand when solutions to the fundamental fiel ...
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
Tullio Eugenio Regge (; July 11, 1931 – October 23, 2014) was an Italian theoretical physicist.
Biography
Regge obtained the ''laurea'' in physics from the University of Turin in 1952 under the direction of Mario Verde and Gleb Wataghin, and ...
introduces the
Regge calculus In general relativity, Regge calculus is a formalism for producing simplicial approximations of spacetimes that are solutions to the Einstein field equation. The calculus was introduced by the Italian theoretician Tullio Regge in 1961. Available ...
,
* 1974 – Hawking discovers
Hawking radiation
Hawking radiation is theoretical black body radiation that is theorized to be released outside a black hole's event horizon because of relativistic quantum effects. It is named after the physicist Stephen Hawking, who developed a theoretical a ...
,
* 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
Gravity Probe A (GP-A) was a space-based experiment to test the equivalence principle, a feature of Einstein's theory of relativity. It was performed jointly by the Smithsonian Astrophysical Observatory and the National Aeronautics and Space ...
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
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...
maser
A maser (, an acronym for microwave amplification by stimulated emission of radiation) is a device that produces coherent electromagnetic waves through amplification by stimulated emission. The first maser was built by Charles H. Townes, Ja ...
clock on a
Scout D rocket
A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...
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
In the general theory of relativity, the Einstein field equations (EFE; also known as Einstein's equations) relate the geometry of spacetime to the distribution of matter within it.
The equations were published by Einstein in 1915 in the form ...
using the
inverse scattering transform In mathematics, the inverse scattering transform is a method for solving some non-linear partial differential equations. The method is a non-linear analogue, and in some sense generalization, of the Fourier transform, which itself is applied to so ...
; the first
gravitational soliton
A gravitational soliton is a soliton solution of the Einstein field equation. It can be separated into two kinds, a soliton of the vacuum Einstein field equation generated by the Belinski–Zakharov transform, and a soliton of the Einstein–Maxwe ...
s,
* 1979 –
Richard Schoen
Richard Melvin Schoen (born October 23, 1950) is an American mathematician known for his work in differential geometry and geometric analysis. He is best known for the resolution of the Yamabe problem in 1984.
Career
Born in Celina, Ohio, and a ...
and
Shing-Tung Yau
Shing-Tung Yau (; ; born April 4, 1949) is a Chinese-American mathematician and the William Caspar Graustein Professor of Mathematics at Harvard University. In April 2022, Yau announced retirement from Harvard to become Chair Professor of mathem ...
prove the
positive mass theorem
The positive energy theorem (also known as the positive mass theorem) refers to a collection of foundational results in general relativity and differential geometry. Its standard form, broadly speaking, asserts that the gravitational energy of an ...
.
* 1979 –
Dennis Walsh
Dennis Walsh (12 June 1933 – 1 June 2005) was an English astronomer. He was an early radio astronomer, as well as an optical astronomer. He was best known for his discovery in 1979 of the first example of a gravitational lens, B0957+561, using ...
,
Robert Carswell, and
Ray Weymann
Ray Weymann is a retired astronomer and astrophysicist, associated with the Carnegie Institution of Washington. His PhD is from Princeton University. He is a founder of the Climate Science Rapid Response Team, a member National Academy of Sci ...
discover the gravitationally lensed
quasar Q0957+561
1980s
* 1982 –
Joseph Taylor and
Joel Weisberg show that the rate of energy loss from the binary
pulsar PSR B1913+16
PSR may refer to:
Organizations
* Pacific School of Religion, Berkeley, California, US
* Palestinian Center for Policy and Survey Research
* Physicians for Social Responsibility, US
;Political parties:
* Revolutionary Socialist Party (Portugal) ( ...
agrees with that predicted by the general relativistic quadrupole formula to within 5%
2000s
* 2002 – First data collection of the
Laser Interferometer Gravitational-Wave Observatory
The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. Two large ...
(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
Gravity Probe B (GP-B) was a satellite-based experiment to test two unverified predictions of general relativity: the geodetic effect and frame-dragging. This was to be accomplished by measuring, very precisely, tiny changes in the direction of ...
experiment.
* 2015 – Advanced
LIGO
The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. Two large ...
reports the first direct detections of gravitational waves (
GW150914
The first direct observation of gravitational waves was made on 14 September 2015 and was announced by the LIGO and Virgo collaborations on 11 February 2016. Previously, gravitational waves had been inferred only indirectly, via their effect on ...
and
GW151226
GW151226 was a gravitational wave signal detected by the LIGO observatory on 25 December 2015 local time (26 Dec 2015 UTC). On 15 June 2016, the LIGO and Virgo collaborations announced that they had verified the signal, making it the second such ...
).
* 2017 – Advanced
LIGO
The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. Two large ...
and
Fermi Gamma-ray Space Telescope
The Fermi Gamma-ray Space Telescope (FGST, also FGRST), formerly called the Gamma-ray Large Area Space Telescope (GLAST), is a space observatory being used to perform gamma-ray astronomy observations from low Earth orbit. Its main instrument is ...
constrain the speed of gravity to 1 part in
of the speed of light with
GW170817
GW 170817 was a gravitational wave (GW) signal observed by the LIGO and Virgo detectors on 17 August 2017, originating from the shell elliptical galaxy . The signal was produced by the last minutes of a binary pair of neutron stars' insp ...
.
* 2019 – The
Event Horizon Telescope
The Event Horizon Telescope (EHT) is a large Astronomical interferometer, telescope array consisting of a global network of radio telescopes. The EHT project combines data from several very-long-baseline interferometry (VLBI) stations around Ear ...
images the shadow of
supermassive black hole
A supermassive black hole (SMBH or sometimes SBH) is the largest type of black hole, with its mass being on the order of hundreds of thousands, or millions to billions of times the mass of the Sun (). Black holes are a class of astronomical ob ...
M87*
* 2022 - The
James Webb Space Telescope publishes its
first image, showing gravitational lensing by the
SMACS 0723 galaxy cluster.
See also
*
Timeline of black hole physics
Timeline of black hole physics
Pre-20th century
* 1640 — Ismaël Bullialdus suggests an inverse-square gravitational force law
* 1676 — Ole Rømer demonstrates that light has a finite speed
* 1684 — Isaac Newton writes do ...
*
Timeline of special relativity and the speed of light
References
External links
Timeline of relativity and gravitation(Tomohiro Harada, Department of Physics, Rikkyo University)
{{DEFAULTSORT:Timeline Of Gravitational Physics And Relativity
Astrophysics
Gravity
Gravitational physics and relativity