History of general relativity - AbsoluteAstronomy.com

Overview

General relativity or the general theory of relativity is the geometric theory of gravitation published by Albert Einstein in 1916. It is the current description of gravitation in modern physics...

(GR) is a theory of gravitation that was developed by Albert Einstein between 1907 and 1915, with contributions by many others after 1915. According to general relativity, the observed gravitational attraction between masses results from the warping of space and time by those masses.

Before the advent of general relativity, Newton's law of universal gravitation had been accepted for more than two hundred years as a valid description of the gravitational force between masses, even though Newton himself did not regard the theory as the final word on the nature of gravity. Within a century of Newton's formulation, careful astronomical observation revealed unexplainable variations between the theory and the observations. Under Newton's model, gravity was the result of an attractive force between massive objects. Although even Newton was bothered by the unknown nature of that force, the basic framework was extremely successful at describing motion.

However, experiments and observations show that Einstein's description accounts for several effects that are unexplained by Newton's law, such as minute anomalies in the orbits of Mercury and other planets. General relativity also predicts novel effects of gravity, such as gravitational waves, gravitational lensing and an effect of gravity on time known as gravitational time dilation. Many of these predictions have been confirmed by experiment, while others are the subject of ongoing research. For example, although there is indirect evidence for gravitational waves, direct evidence of their existence is still being sought by several teams of scientists in experiments such as the LIGO

LIGO

LIGO, which stands for the Laser Interferometer Gravitational-Wave Observatory, is a large-scale physics experiment aiming to directly detect gravitational waves. Cofounded in 1992 by Kip Thorne and Ronald Drever of Caltech and Rainer Weiss of MIT, LIGO is a joint project between scientists at MIT,...

and GEO 600

GEO 600

GEO 600 is a gravitational wave detector located near Sarstedt, Germany. This instrument, and its sister interferometric detectors, when operational, are some of the most sensitive gravitational wave detectors ever designed...

projects.

General relativity has developed into an essential tool in modern astrophysics. It provides the foundation for the current understanding of black holes, regions of space where gravitational attraction is so strong that not even light can escape. Their strong gravity is thought to be responsible for the intense radiation emitted by certain types of astronomical objects (such as active galactic nuclei or microquasars). General relativity is also part of the framework of the standard Big Bang model of cosmology.

Early investigations

As Einstein later said, the reason for the development of general relativity was the preference of inertial motion within special relativity

Special relativity

Special relativity is the physical theory of measurement in an inertial frame of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".It generalizes Galileo's...

, while a theory which from the outset prefers no state of motion (even accelerated ones) appeared more satisfactory to him. So, while still working at the patent office in 1907, Einstein had what he would call his "happiest thought". He realized that the principle of relativity could be extended to gravitational fields.

Consequently, in 1907 (published 1908) he wrote an article on acceleration under special relativity

Special relativity

.
In that article, he argued that free fall

Free fall

Free fall is any motion of a body where gravity is the only force acting upon it, at least initially. These conditions produce an inertial trajectory so long as gravity remains the only force. Since this definition does not specify velocity, it also applies to objects initially moving upward...

is really inertial motion, and that for a freefalling observer the rules of special relativity must apply. This argument is called the Equivalence principle

Equivalence principle

In the physics of general relativity, the equivalence principle is any of several related concepts dealing with the equivalence of gravitational and inertial mass, and to Albert Einstein's assertion that the gravitational "force" as experienced locally while standing on a massive body is actually...

. In the same article, Einstein also predicted the phenomenon of gravitational time dilation

Gravitational time dilation

Gravitational time dilation is the effect of time passing at different rates in regions of different gravitational potential; the lower the gravitational potential, the more slowly time passes...

.

In 1911, Einstein published another article expanding on the 1907 article.
There, he thought about the case of a uniformly accelerated box not in a gravitational field, and noted that it would be indistinguishable from a box sitting still in an unchanging gravitational field. He used special relativity to see that the rate of clocks at the top of a box accelerating upward would be faster than the rate of clocks at the bottom. He concludes that the rates of clocks depend on their position in a gravitational field, and that the difference in rate is proportional to the gravitational potential to first approximation.

Also the deflection of light by massive bodies was predicted. Although the approximation was crude, it allowed him to calculate that the deflection is nonzero. German astronomer Erwin Finlay-Freundlich

Erwin Finlay-Freundlich

Erwin Finlay-Freundlich was a German astronomer, a pupil of Felix Klein. He was born in Biebrich, Germany. Freundlich was a working associate of Albert Einstein and introduced experiments for which the general theory of relativity could be tested by astronomical observations based on the...

publicized Einstein's challenge to scientists around the world. This urged astronomers to detect the deflection of light during a solar eclipse

Solar eclipse

As seen from the Earth, a solar eclipse occurs when the Moon passes between the Sun and the Earth, and the Moon fully or partially blocks the Sun as viewed from a location on Earth. This can happen only during a new moon, when the Sun and the Moon are in conjunction as seen from Earth. At least...

, and gave Einstein confidence that the scalar theory of gravity proposed by Gunnar Nordström

Gunnar Nordström

Gunnar Nordström was a Finnish theoretical physicist best remembered for his theory of gravitation, which was an early competitor of general relativity...

was incorrect. But the actual value for the deflection that he calculated was too small by a factor of two, because the approximation he used doesn't work well for things moving at near the speed of light. When Einstein finished the full theory of general relativity, he would rectify this error and predict the correct amount of light deflection by the sun.

Another of Einstein's notable thought experiments about the nature of the gravitational field is that of the rotating disk (a variant of the Ehrenfest paradox

Ehrenfest paradox

The Ehrenfest paradox concerns the rotation of a "rigid" disc in the theory of relativity.In its original formulation as presented by Paul Ehrenfest 1909 in the Physikalische Zeitschrift, it discusses an ideally rigid cylinder that is made to rotate about its axis of symmetry...

). He imagined an observer making experiments on a rotating turntable. He noted that such an observer would find a different value for the mathematical constant π than the one predicted by Euclidean geometry. The reason is that the radius of a circle would be measured with an uncontracted ruler, but, according to special relativity, the circumference would seem to be longer because the ruler would be contracted. Since Einstein believed that the laws of physics were local, described by local fields, he concluded from this that spacetime could be locally curved. This led him to study Riemannian geometry

Riemannian geometry

Riemannian geometry is the branch of differential geometry that studies Riemannian manifolds, smooth manifolds with a Riemannian metric, i.e. with an inner product on the tangent space at each point which varies smoothly from point to point. This gives, in particular, local notions of angle, length...

, and to formulate general relativity in this language.

Developing general relativity

In 1912, Einstein returned to Switzerland to accept a professorship at his alma mater, the ETH. Once back in Zurich, he immediately visited his old ETH classmate Marcel Grossmann

Marcel Grossmann

Marcel Grossmann was a mathematician of Jewish ancestry, and a friend and classmate of Albert Einstein. He became a Professor of Mathematics at the Federal Polytechnic Institute in Zurich, today the ETH Zurich, specializing in descriptive geometry....

, now a professor of mathematics, who introduced him to Riemannian geometry and, more generally, to differential geometry. On the recommendation of Italian mathematician Tullio Levi-Civita

Tullio Levi-Civita

Tullio Levi-Civita, FRS was an Italian mathematician, most famous for his work on absolute differential calculus and its applications to the theory of relativity, but who also made significant contributions in other areas. He was a pupil of Gregorio Ricci-Curbastro, the inventor of tensor calculus...

, Einstein began exploring the usefulness of general covariance

General covariance

In theoretical physics, general covariance is the invariance of the form of physical laws under arbitrary differentiable coordinate transformations...

(essentially the use of tensor

Tensor

Tensors are geometric objects that describe linear relations between vectors, scalars, and other tensors. Elementary examples include the dot product, the cross product, and linear maps. Vectors and scalars themselves are also tensors. A tensor can be represented as a multi-dimensional array of...

s) for his gravitational theory. For a while Einstein thought that there were problems with the approach, but he later returned to it and, by late 1915, had published his general theory of relativity in the form in which it is used today. This theory explains gravitation as distortion of the structure of spacetime

Spacetime

In physics, spacetime is any mathematical model that combines space and time into a single continuum. Spacetime is usually interpreted with space as being three-dimensional and time playing the role of a fourth dimension that is of a different sort from the spatial dimensions...

by matter, affecting the inertia

Inertia

Inertia is the resistance of any physical object to a change in its state of motion or rest, or the tendency of an object to resist any change in its motion. It is proportional to an object's mass. The principle of inertia is one of the fundamental principles of classical physics which are used to...

l motion of other matter.
During World War I, the work of Central Powers

Central Powers

The Central Powers were one of the two warring factions in World War I , composed of the German Empire, the Austro-Hungarian Empire, the Ottoman Empire, and the Kingdom of Bulgaria...

scientists was available only to Central Powers academics, for national security reasons. Some of Einstein's work did reach the United Kingdom and the United States through the efforts of the Austrian Paul Ehrenfest

Paul Ehrenfest

Paul Ehrenfest was an Austrian and Dutch physicist, who made major contributions to the field of statistical mechanics and its relations with quantum mechanics, including the theory of phase transition and the Ehrenfest theorem.- Biography :Paul Ehrenfest was born and grew up in Vienna in a Jewish...

and physicists in the Netherlands, especially 1902 Nobel Prize-winner Hendrik Lorentz

Hendrik Lorentz

Hendrik Antoon Lorentz 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...

and Willem de Sitter

Willem de Sitter

Willem de Sitter was a Dutch mathematician, physicist and astronomer.-Life and work:Born in Sneek, De Sitter studied mathematics at the University of Groningen and then joined the Groningen astronomical laboratory. He worked at the Cape Observatory in South Africa...

of Leiden University

Leiden University

Leiden University , located in the city of Leiden, is the oldest university in the Netherlands. The university was founded in 1575 by William, Prince of Orange, leader of the Dutch Revolt in the Eighty Years' War. The royal Dutch House of Orange-Nassau and Leiden University still have a close...

. After the war ended, Einstein maintained his relationship with Leiden University, accepting a contract as an Extraordinary Professor; for ten years, from 1920 to 1930, he travelled to Holland regularly to lecture.

In 1917, several astronomers accepted Einstein 's 1911 challenge from Prague. The Mount Wilson Observatory

Mount Wilson Observatory

The Mount Wilson Observatory is an astronomical observatory in Los Angeles County, California, United States. The MWO is located on Mount Wilson, a 5,715 foot peak in the San Gabriel Mountains near Pasadena, northeast of Los Angeles...

in California, U.S., published a solar spectroscopic analysis that showed no gravitational redshift. In 1918, the Lick Observatory

Lick Observatory

The Lick Observatory is an astronomical observatory, owned and operated by the University of California. It is situated on the summit of Mount Hamilton, in the Diablo Range just east of San Jose, California, USA...

, also in California, announced that it too had disproved Einstein's prediction, although its findings were not published.

However, in May 1919, a team led by the British astronomer Arthur Stanley Eddington

Arthur Stanley Eddington

Sir Arthur Stanley Eddington, OM, FRS was a British astrophysicist of the early 20th century. He was also a philosopher of science and a popularizer of science...

claimed to have confirmed Einstein's prediction of gravitational deflection of starlight by the Sun while photographing a solar eclipse with dual expeditions in Sobral

Sobral, Ceará

Sobral is a city in the state of Ceará, Brazil.Sobral is the second largest municipality of Ceará, after Fortaleza. Its economy is based on agriculture, services and some manufacturing industries...

, northern Brazil

Brazil

Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...

, and Príncipe

Príncipe

Príncipe is the northern and smaller of the two major islands of the country of São Tomé and Príncipe lying off the west coast of Africa. It has an area of 136 km² and a population of approximately 5,000. The island is a heavily eroded volcano over three million years old, surrounded by other...

, a west African island. Nobel laureate Max Born

Max Born

Max Born was a German-born physicist and mathematician who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics and supervised the work of a number of notable physicists in the 1920s and 30s...

praised general relativity as the "greatest feat of human thinking about nature"; fellow laureate Paul Dirac

Paul Dirac

Paul Adrien Maurice Dirac, OM, FRS was an English theoretical physicist who made fundamental contributions to the early development of both quantum mechanics and quantum electrodynamics...

was quoted saying it was "probably the greatest scientific discovery ever made".
The international media guaranteed Einstein's global renown.

There have been claims that scrutiny of the specific photographs taken on the Eddington expedition showed the experimental uncertainty to be comparable to the same magnitude as the effect Eddington claimed to have demonstrated, and that a 1962 British expedition concluded that the method was inherently unreliable. The deflection of light during a solar eclipse was confirmed by later, more accurate observations. Some resented the newcomer's fame, notably among some German physicists, who later started the Deutsche Physik
Deutsche Physik
Deutsche Physik or Aryan Physics was a nationalist movement in the German physics community in the early 1930s against the work of Albert Einstein, labeled "Jewish Physics"...

(German Physics) movement.

General covariance and the hole argument

By 1912, Einstein was actively seeking a theory in which gravitation

Gravitation

Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped...

was explained as a geometric phenomenon. At the urging of Tullio Levi-Civita

Tullio Levi-Civita

, Einstein began by exploring the use of general covariance

General covariance

In theoretical physics, general covariance is the invariance of the form of physical laws under arbitrary differentiable coordinate transformations...

(which is essentially the use of curvature tensors) to create a gravitational theory. However, in 1913 Einstein abandoned that approach, arguing that it is inconsistent based on the "hole argument

Hole argument

In general relativity, the hole argument is a "paradox" which much troubled Albert Einstein while developing his famous field equation.It is incorrectly interpreted by some philosophers as an argument against manifold substantialism, a doctrine that the manifold of events in spacetime are a...

". In 1914 and much of 1915, Einstein was trying to create field equations based on another approach. When that approach was proven to be inconsistent, Einstein revisited the concept of general covariance and discovered that the hole argument was flawed.

The development of the Einstein field equations

When Einstein realized that general covariance was actually tenable, he quickly completed the development of the field equations that are named after him. However, he made a now-famous mistake. The field equations he published in October 1915 were

,

where

is the Ricci tensor, and

the energy-momentum tensor. This predicted the non-Newtonian

Classical mechanics

In physics, classical mechanics is one of the two major sub-fields of mechanics, which is concerned with the set of physical laws describing the motion of bodies under the action of a system of forces...

perihelion precession of Mercury

Mercury (planet)

Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...

, and so had Einstein very excited. However, it was soon realized that they were inconsistent with the local conservation of energy-momentum unless the universe had a constant density of mass-energy-momentum. In other words, air, rock and even a vacuum should all have the same density. This inconsistency with observation sent Einstein back to the drawing board. However, the solution was all but obvious, and in November 1915 Einstein published the actual Einstein field equations:

,

where

is the Ricci scalar and

the metric tensor

Metric tensor

In the mathematical field of differential geometry, a metric tensor is a type of function defined on a manifold which takes as input a pair of tangent vectors v and w and produces a real number g in a way that generalizes many of the familiar properties of the dot product of vectors in Euclidean...

. With the publication of the field equations, the issue became one of solving them for various cases and interpreting the solutions. This and experimental verification have dominated general relativity research ever since.

Einstein and Hilbert

Although Einstein is credited with finding the field equations, the German mathematician David Hilbert

David Hilbert

David Hilbert was a German mathematician. He is recognized as one of the most influential and universal mathematicians of the 19th and early 20th centuries. Hilbert discovered and developed a broad range of fundamental ideas in many areas, including invariant theory and the axiomatization of...

published them in an article before Einstein's article. This has resulted in accusations of plagiarism

Plagiarism

Plagiarism is defined in dictionaries as the "wrongful appropriation," "close imitation," or "purloining and publication" of another author's "language, thoughts, ideas, or expressions," and the representation of them as one's own original work, but the notion remains problematic with nebulous...

against Einstein (never from Hilbert), and assertions that the field equations should be called the "Einstein-Hilbert field equations". However, Hilbert did not press his claim for priority and some have asserted that Einstein submitted the correct equations before Hilbert amended his own work to include them. This suggests that Einstein developed the correct field equations first, though Hilbert may have reached them later independently (or even learned of them afterwards through his correspondence with Einstein). However, others have criticized those assertions.

Sir Arthur Eddington

In the early years after Einstein's theory was published, Sir Arthur Eddington lent his considerable prestige in the British scientific establishment in an effort to champion the work of this German scientist. Because the theory was so complex and abstruse (even today it is popularly considered the pinnacle of scientific thinking; in the early years it was even more so), it was rumored that only three people in the world understood it. There was an illuminating, though probably apocryphal, anecdote about this. As related by Ludwik Silberstein

Ludwik Silberstein

Ludwik Silberstein was a Polish-American physicist who helped make special relativity and general relativity staples of university coursework...

, during one of Eddington's lectures he asked "Professor Eddington, you must be one of three persons in the world who understands general relativity." Eddington paused, unable to answer. Silberstein continued "Don't be modest, Eddington!" Finally, Eddington replied "On the contrary, I'm trying to think who the third person is."

The Schwarzschild solution

Since the field equations are non-linear, Einstein assumed that they were insoluble. However, in 1916 Karl Schwarzschild

Karl Schwarzschild

Karl Schwarzschild was a German physicist. He is also the father of astrophysicist Martin Schwarzschild.He is best known for providing the first exact solution to the Einstein field equations of general relativity, for the limited case of a single spherical non-rotating mass, which he accomplished...

discovered an exact solution

Exact solution

In mathematics and especially physics, an exact solution is a solution to a problem that encapsulates the whole mathematics or physics of the problem without using an approximation.-References:*...

for the case of a spherically symmetric spacetime

Spacetime

surrounding a massive object in spherical coordinates. This is now known as the Schwarzschild solution. Since then, many other exact solutions have been found.

The expanding universe and the cosmological constant

In 1922, Alexander Friedmann found a solution in which the universe may expand or contract, and later Georges Lemaître

Georges Lemaître

Monsignor Georges Henri Joseph Édouard Lemaître was a Belgian priest, astronomer and professor of physics at the Catholic University of Louvain. He was the first person to propose the theory of the expansion of the Universe, widely misattributed to Edwin Hubble...

derived a solution for an expanding universe. However, Einstein believed that the universe was apparently static, and since a static cosmology was not supported by the general relativistic field equations, he added a cosmological constant

Cosmological constant

In physical cosmology, the cosmological constant was proposed by Albert Einstein as a modification of his original theory of general relativity to achieve a stationary universe...

Λ to the field equations, which became

.

This permitted the creation of steady-state solutions, but they were unstable: the slightest perturbation of a static state would result in the universe expanding or contracting. In 1929, Edwin Hubble

Edwin Hubble

Edwin Powell Hubble was an American astronomer who profoundly changed the understanding of the universe by confirming the existence of galaxies other than the Milky Way - our own galaxy...

found evidence for the idea that the universe is expanding. This resulted in Einstein dropping the cosmological constant, referring to it as "the biggest blunder in my career". At the time, it was an ad hoc

Ad hoc

Ad hoc is a Latin phrase meaning "for this". It generally signifies a solution designed for a specific problem or task, non-generalizable, and not intended to be able to be adapted to other purposes. Compare A priori....

hypothesis to add in the cosmological constant, as it was only intended to justify one result (a static universe).

Testing the theory

The perihelion precession of Mercury was the first evidence that general relativity is correct. Sir Arthur Stanley Eddington

Arthur Stanley Eddington

Sir Arthur Stanley Eddington, OM, FRS was a British astrophysicist of the early 20th century. He was also a philosopher of science and a popularizer of science...

's 1919 expedition in which he confirmed Einstein's prediction for the deflection of light by the Sun during the total solar eclipse of 29 May 1919 helped to cement the status of general relativity as a likely true theory. Since then many observations have confirmed the correctness of general relativity. These include studies of binary pulsar

Binary pulsar

A binary pulsar is a pulsar with a binary companion, often a white dwarf or neutron star. Binary pulsars are one of the few objects which allow physicists to test general relativity in the case of a strong gravitational field...

s, observations of radio signals passing the limb of the Sun, and even the GPS system. For more information, see the Tests of general relativity

Tests of general relativity

At its introduction in 1915, the general theory of relativity did not have a solid empirical foundation. It was known that it correctly accounted for the "anomalous" precession of the perihelion of Mercury and on philosophical grounds it was considered satisfying that it was able to unify Newton's...

article.

Alternative theories

There have been various attempts to find modifications to general relativity. The most famous of these are the Brans-Dicke theory

Brans-Dicke theory

In theoretical physics, the Brans–Dicke theory of gravitation is a theoretical framework to explain gravitation. It is a well-known competitor of Einstein's more popular theory of general relativity...

(also known as scalar-tensor theory

Scalar-tensor theory

In theoretical physics, a scalar-tensor theory is a theory that includes both a scalar field and a tensor field to represent a certain interaction...

), and Rosen's bimetric theory. Both of these theories proposed changes to the field equations of general relativity, and both suffer from these changes permitting the presence of bipolar gravitational radiation. As a result, Rosen's original theory has been refuted by observations of binary pulsars. As for Brans-Dicke (which has a tunable parameter ω such that ω = ∞ is the same as general relativity), the amount by which it can differ from general relativity has been severely constrained by these observations.

In addition, general relativity is inconsistent with quantum mechanics

Quantum mechanics

Quantum mechanics, also known as quantum physics or quantum theory, is a branch of physics providing a mathematical description of much of the dual particle-like and wave-like behavior and interactions of energy and matter. It departs from classical mechanics primarily at the atomic and subatomic...

, the physical theory that describes the wave-particle duality of matter, and quantum mechanics does not currently describe gravitational attraction at relevant (microscopic) scales. There is a great deal of speculation in the physics community as to the modifications that might be needed to both general relativity and quantum mechanics in order to unite them consistently. The speculative theory that unites general relativity and quantum mechanics is usually called quantum gravity

Quantum gravity

Quantum gravity is the field of theoretical physics which attempts to develop scientific models that unify quantum mechanics with general relativity...

, prominent examples of which include String Theory

String theory

String theory is an active research framework in particle physics that attempts to reconcile quantum mechanics and general relativity. It is a contender for a theory of everything , a manner of describing the known fundamental forces and matter in a mathematically complete system...

and Loop Quantum Gravity

Loop quantum gravity

Loop quantum gravity , also known as loop gravity and quantum geometry, is a proposed quantum theory of spacetime which attempts to reconcile the theories of quantum mechanics and general relativity...

More about GR history

The study of general relativity, entered the mainstream of theoretical physics

Theoretical physics

Theoretical physics is a branch of physics which employs mathematical models and abstractions of physics to rationalize, explain and predict natural phenomena...

. Terms were introduced, including black hole

Black hole

A black hole is a region of spacetime from which nothing, not even light, can escape. The theory of general relativity predicts that a sufficiently compact mass will deform spacetime to form a black hole. Around a black hole there is a mathematically defined surface called an event horizon that...

s and 'gravitational singularity

Gravitational singularity

A gravitational singularity or spacetime singularity is a location where the quantities that are used to measure the gravitational field become infinite in a way that does not depend on the coordinate system...

'. At the same time, the study of physical cosmology

Physical cosmology

Physical cosmology, as a branch of astronomy, is the study of the largest-scale structures and dynamics of the universe and is concerned with fundamental questions about its formation and evolution. For most of human history, it was a branch of metaphysics and religion...

entered the mainstream including the Big Bang

Big Bang

The Big Bang theory is the prevailing cosmological model that explains the early development of the Universe. According to the Big Bang theory, the Universe was once in an extremely hot and dense state which expanded rapidly. This rapid expansion caused the young Universe to cool and resulted in...

Role of curvature in general relativity;
Theoretical importance of the black holes;
Importance of geometrical machinery and levels of mathematical structure, especially local
Local spacetime structure
Local spacetime structure refers to the structure of spacetime on a local level, i.e. only considering those points in an open region of a point. This notion is useful in many areas of physics, most notably in Einstein's theory of general relativity....

versus global spacetime structure;
Overall legitimacy of cosmology
Cosmology
Cosmology is the discipline that deals with the nature of the Universe as a whole. Cosmologists seek to understand the origin, evolution, structure, and ultimate fate of the Universe at large, as well as the natural laws that keep it in order...

by the wider physics community.

A competitor to general relativity (the Brans-Dicke theory), and the first "precision tests" of gravitation theories. Discoveries in observational astronomy are:

Quasar
Quasar
A quasi-stellar radio source is a very energetic and distant active galactic nucleus. Quasars are extremely luminous and were first identified as being high redshift sources of electromagnetic energy, including radio waves and visible light, that were point-like, similar to stars, rather than...

s (objects the size of the solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...

and as luminous as a hundred modern galaxies
Galaxy
A galaxy is a massive, gravitationally bound system that consists of stars and stellar remnants, an interstellar medium of gas and dust, and an important but poorly understood component tentatively dubbed dark matter. The word galaxy is derived from the Greek galaxias , literally "milky", a...

, so distant that they date from the early years of the universe);
Pulsar
Pulsar
A pulsar is a highly magnetized, rotating neutron star that emits a beam of electromagnetic radiation. The radiation can only be observed when the beam of emission is pointing towards the Earth. This is called the lighthouse effect and gives rise to the pulsed nature that gives pulsars their name...

s (soon interpreted as spinning neutron stars);
The first credible candidate black hole, Cygnus X-1
Cygnus X-1
Cygnus X-1 is a well-known galactic X-ray source in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 2.3 Wm−2Hz−1...

;
The cosmic background radiation, hard evidence of the Big Bang and the subsequent expansion of the universe.

1950s

1953: P. C. Vaidya
P. C. Vaidya
Prahalad Chunnilal Vaidya , was an Indian physicist and mathematician, renowned for his instrumental work in general theory of relativity...

Newtonian time in general relativity, Nature, 171, p260.
1956: John Lighton Synge
John Lighton Synge
John Lighton Synge was an Irish mathematician and physicist.-Background:Synge was born 1897 in Dublin, Ireland, in a Protestant family and educated at St. Andrew's College, Dublin. He entered Trinity College, Dublin in 1915...

publishes the first relativity text emphasizing spacetime diagrams
Minkowski diagram
The Minkowski diagram was developed in 1908 by Hermann Minkowski and provides an illustration of the properties of space and time in the special theory of relativity. It allows a quantitative understanding of the corresponding phenomena like time dilation and length contraction without mathematical...

and geometrical methods,
1957: Felix A. E. Pirani uses Petrov classification
Petrov classification
In differential geometry and theoretical physics, the Petrov classification describes the possible algebraic symmetries of the Weyl tensor at each event in a Lorentzian manifold....

to understand gravitational radiation,
1957: Richard Feynman
Richard Feynman
Richard Phillips Feynman was an American physicist known for his work in the path integral formulation of quantum mechanics, the theory of quantum electrodynamics and the physics of the superfluidity of supercooled liquid helium, as well as in particle physics...

introduces sticky bead argument
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...

,
1959: Pound–Rebka experiment, first precision test of gravitational redshift,
1959: Lluis Bel introduces Bel–Robinson tensor and the Bel decomposition
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 four pieces. It was introduced in 1959 by the physicist Lluis Bel....

of the Riemann tensor,
1959: Arthur Komar introduces the Komar mass
Komar mass
The Komar mass 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 can be written so that they are independent of time...

,

1960s

1960: Martin Kruskal
Martin Kruskal
Martin David Kruskal 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 from nonlinear analysis to asymptotic analysis...

and George Szekeres
George Szekeres
George Szekeres AM 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 of Budapest. He worked six years in Budapest as an analytical chemist. He married Esther Klein in 1936...

independently introduce the Kruskal-Szekeres coordinates
Kruskal-Szekeres coordinates
In general relativity Kruskal–Szekeres coordinates, named for Martin Kruskal and George Szekeres, are a coordinate system for the Schwarzschild geometry for a black hole...

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
Carl H. Brans
Carl Henry Brans is an American mathematical physicist best known for his research into the theoretical underpinnings of gravitation elucidated in his most widely publicized work, the Brans–Dicke theory....

and Robert H. Dicke
Robert H. Dicke
Robert Henry Dicke was an American physicist who made important contributions to the fields of astrophysics, atomic physics, cosmology and gravity.-Biography:...

introduce Brans-Dicke theory, the first viable alternative theory with a clear physical motivation,
1960: Joseph Weber
Joseph Weber
Joseph Weber 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 .-Early education:...

reports observation of gravitational waves (a claim now generally discounted),
1960: Ivor M. Robinson and Andrzej Trautman
Andrzej Trautman
Andrzej Mariusz Trautman is a leading mathematical physicist who has made important contributions to classical gravitation in general and to general relativity in particular....

discover the Robinson-Trautman null dust solution
Null dust solution
In mathematical physics, a null dust solution is a Lorentzian manifold in which the Einstein tensor is null...
1961: Pascual Jordan
Pascual Jordan
-Further reading:...

and Jürgen Ehlers
Jürgen Ehlers
Jürgen Ehlers was a German physicist who made notable contributions to the current understanding of Albert Einstein's theory of general relativity...

develop the kinematic decomposition of a timelike congruence,
1962: Roger Penrose
Roger Penrose
Sir Roger Penrose OM FRS is an English mathematical physicist and Emeritus Rouse Ball Professor of Mathematics at the Mathematical Institute, University of Oxford and Emeritus Fellow of Wadham College...

and Ezra T. Newman
Ezra T. Newman
Ezra Ted Newman is an American physicist, known for his many contributions to general relativity theory. He is Professor Emeritus at the University of Pittsburgh...

introduce the Newman-Penrose formalism
Newman-Penrose Formalism
The Newman-Penrose Formalism is a set of notation developed by Ezra T. Newman and Roger Penrose for General Relativity. Their notation is an effort to treat General Relativity in terms of spinor notation, which introduces complex forms of the usual variables used in GR.The NP formalism is itself a...

,
1962: Ehlers and Wolfgang Kundt classify the symmetries of Pp-wave spacetimes,
1962: Joshua Goldberg and Rainer K. Sachs prove the Goldberg-Sachs theorem
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....

,
1962: Ehlers introduces Ehlers transformations, a new solution generating method,
1962: Cornelius Lanczos
Cornelius Lanczos
Cornelius Lanczos Löwy Kornél was a Hungarian-Jewish mathematician and physicist, who was born on February 2, 1893, and died on June 25, 1974....

introduces the Lanczos potential
Lanczos tensor
There are two different tensors sometimes referred to as the Lanczos tensor :* A tensor in the theory of quadratic Lagrangians, which vanishes in four dimensions....

for the Weyl tensor
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 force that a body feels when moving along a geodesic...

,
1962: R. Arnowitt, Stanley Deser
Stanley Deser
Stanley Deser is an American physicist known for his contributions to general relativity. Currently, he is the Ancell Professor of Physics at Brandeis University in Waltham, Massachusetts....

, and Charles W. Misner
Charles W. Misner
Charles W. Misner 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 and numerical relativity....

introduce the ADM reformulation and global hyperbolicity,
1962: Yvonne Choquet-Bruhat
Yvonne Choquet-Bruhat
Yvonne Choquet-Bruhat is a French mathematician and physicist. She was the first woman to be elected to the Académie des Sciences Française and is a Grand Officier of the Légion d'honneur....

on Cauchy problem and global hyperbolicity,
1962: Istvan Ozsvath and Englbert Schücking rediscover the circularly polarized monochromomatic gravitational wave
Ozváth-Schücking metric
In Einstein's theory of general relativity, the Ozsváth–Schücking metric, or the Ozsváth–Schücking solution, is a rotating vacuum solution to the field equations, published by István Ozsváth and Engelbert Schücking in 1962...

,
1962: Hans Adolph Buchdahl discovers Buchdahl's theorem,
1962: Hermann Bondi
Hermann Bondi
Sir Hermann Bondi, KCB, FRS was an Anglo-Austrian mathematician and cosmologist. He is best known for developing the steady-state theory of the universe with Fred Hoyle and Thomas Gold as an alternative to the Big Bang theory, but his most lasting legacy will probably be his important...

introduces Bondi mass,
1963: Roy Kerr
Roy Kerr
Roy Patrick Kerr CNZM is a New Zealand mathematician who is best known for discovering the Kerr vacuum, an exact solution to the Einstein field equation of general relativity...

discovers the Kerr vacuum solution
Kerr metric
The Kerr metric describes the geometry of empty spacetime around an uncharged axially-symmetric black-hole with an event horizon which is topologically a sphere. The Kerr metric is an exact solution of the Einstein field equations of general relativity; these equations are highly non-linear, which...

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
Roger Penrose
Sir Roger Penrose OM FRS is an English mathematical physicist and Emeritus Rouse Ball Professor of Mathematics at the Mathematical Institute, University of Oxford and Emeritus Fellow of Wadham College...

introduces Penrose diagram
Penrose diagram
In theoretical physics, a Penrose diagram is a two-dimensional diagram that captures the causal relations between different points in spacetime...

s 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),
1965: Roger Penrose proves first of the singularity theorems
Penrose-Hawking singularity theorems
The Penrose–Hawking singularity theorems are a set of results in general relativity which attempt to answer the question of when gravitation produces singularities.A singularity in solutions of the Einstein field equations is one of two things:...

,
1965: Newman and others discover the Kerr-Newman electrovacuum solution,
1965: Penrose discovers the structure of the light cones in gravitational plane wave
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 byds^2=[a+2bxy]du^2+2dudv+dx^2+dy^2...

spacetimes,
1965: Kerr and Alfred Schild
Alfred Schild
Alfred Schild was a leading American physicist, well-known for his contributions to the Golden age of general relativity ....

introduce Kerr-Schild spacetimes,
1965: Subrahmanyan Chandrasekhar
Subrahmanyan Chandrasekhar
Subrahmanyan Chandrasekhar, FRS ) was an Indian origin American astrophysicist who, with William A. Fowler, won the 1983 Nobel Prize for Physics for key discoveries that led to the currently accepted theory on the later evolutionary stages of massive stars...

determines a stability criterion,
1965: Arno Penzias and Robert Wilson
Robert Woodrow Wilson
For the American President, see Woodrow Wilson.Robert Woodrow Wilson is an American astronomer, 1978 Nobel laureate in physics, who with Arno Allan Penzias discovered in 1964 the cosmic microwave background radiation...

discover the cosmic microwave background radiation
Cosmic microwave background radiation
In cosmology, cosmic microwave background radiation is thermal radiation filling the observable universe almost uniformly....

,
1966: Sachs and Ronald Kantowski
Ronald Kantowski
Ronald Kantowski is a theoretical cosmologist, well known in the field of general relativity as the author, together with Rainer K. Sachs, of the Kantowski/Sachs dust solutions to the Einstein field equation. These are a widely used family of inhomogeneous cosmological models.Kantowski received his...

discover the Kantowski-Sachs dust solution,
1967: Jocelyn Bell and Antony Hewish
Antony Hewish
Antony Hewish FRS is a British radio astronomer who won the Nobel Prize for Physics in 1974 for his work on the development of radio aperture synthesis and its role in the discovery of pulsars...

discover pulsars,
1967: Robert H. Boyer and R. W. Lindquist introduce Boyer-Lindquist coordinates
Boyer-Lindquist coordinates
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 coordinate transformation from Boyer–Lindquist coordinates r, \theta, \phi to cartesian coordinates x, y, z is given bywhereThe Hamiltonian for test...

for the Kerr vacuum,
1967: Bryce DeWitt
Bryce DeWitt
Bryce Seligman DeWitt was a theoretical physicist renowned for advancing gravity and field theories.-Biography:...

publishes on canonical quantum gravity
Quantum gravity
Quantum gravity is the field of theoretical physics which attempts to develop scientific models that unify quantum mechanics with general relativity...

,
1967: Werner Israel
Werner Israel
Werner Israel, OC, FRSC, FRS is a Canadian physicist.Born in Berlin, Germany and raised in Cape Town, South Africa, he received his B.Sc. in 1951 and his M.Sc. in 1954 from the University of Cape Town. He received his Ph.D...

proves the no hair theorem
No hair theorem
The no-hair theorem postulates that all black hole solutions of the Einstein-Maxwell equations of gravitation and electromagnetism in general relativity can be completely characterized by only three externally observable classical parameters: mass, electric charge, and angular momentum...

,
1967: Kenneth Nordtvedt develops PPN formalism,
1967: Mendel Sachs
Mendel Sachs
Mendel Sachs is a US theoretical physicist who was Professor of Physics at the State University of New York Buffalo .- Education and career :...

publishes factorization of Einstein's field equations,
1967: Hans Stephani discovers the Stephani dust solution,
1968: F. J. Ernst discovers the Ernst equation
Ernst equation
In mathematics, the Ernst equation is the non-linear partial differential equation\displaystyle \Re = ^2+^2.It is used to produce exact solutions of Einstein's equations....

,
1968: B. Kent Harrison discovers the Harrison transformation, a solution-generating method,
1968: Brandon Carter
Brandon Carter
Brandon Carter, FRS 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 the Meudon campus of the Laboratoire Univers et Théories, part of...

solves the geodesic equations for Kerr-Newmann electrovacuum,
1968: Hugo D. Wahlquist discovers the Wahlquist fluid,
1969: William B. Bonnor
William B. Bonnor
William Bowen Bonnor is a mathematician and gravitation physicist best known for his research into astrophysics, cosmology and general relativity. For most of his academic career he has been a professor of mathematics at the University of London....

introduces the Bonnor beam
Bonnor beam
In general relativity, the Bonnor beam is an exact solution which models an infinitely long, straight beam of light. It is an explicit example of a pp-wave spacetime. It is named after William B...

,
1969: Penrose proposes the (weak) cosmic censorship hypothesis
Cosmic censorship hypothesis
The weak and the strong cosmic censorship hypotheses are two mathematical conjectures about the structure of singularities arising in general relativity....

and the Penrose process
Penrose process
The Penrose process is a process theorised by Roger Penrose wherein energy can be extracted from a rotating black hole...

,
1969: Stephen W. Hawking proves area theorem for black holes,
1969: Misner introduces the mixmaster universe
Mixmaster universe
The Mixmaster Universe is a solution to Einstein's field equations of general relativity studied by Charles Misner in an effort to better understand the dynamics of the early universe...

,

1970s

1970: Franco J. Zerilli derives the Zerilli equation,
1970: Vladimir A. Belinskiǐ, Isaak Markovich Khalatnikov
Isaak Markovich Khalatnikov
Isaak Markovich Khalatnikov is a leading Soviet physicist, well known for his role in developing the BKL conjecture in general relativity.Khalatnikov was born in Dnipropetrovsk and graduated from Dnipropetrovsk State University with a degree in Physics in 1941. He has been a member of the...

, and Evgeny Lifshitz
Evgeny Lifshitz
Evgeny Mikhailovich Lifshitz was a leading Soviet physicist of Jewish origin and the brother of physicist Ilya Mikhailovich Lifshitz. Lifshitz is well known in general relativity for coauthoring the BKL conjecture concerning the nature of a generic curvature...

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
Peter C. Aichelburg
Peter C. Aichelburg is an Austrian physicist well-known for his contributions to general relativity, particularly the Aichelburg-Sexl ultraboost of the Schwarzschild vacuum....

and Roman U. Sexl introduce the Aichelburg-Sexl ultraboost
Aichelburg-Sexl ultraboost
In general relativity, the Aichelburg–Sexl ultraboost is an exact solution which models the physical experience of an observer moving past a spherically symmetric gravitating object at nearly the speed of light. It was introduced by Peter C. Aichelburg and Roman U...

,
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
Cygnus X-1 is a well-known galactic X-ray source in the constellation Cygnus. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources seen from Earth, producing a peak X-ray flux density of 2.3 Wm−2Hz−1...

, the first solid black hole candidate, discovered by Uhuru satellite
Uhuru (satellite)
Uhuru was the first satellite launched specifically for the purpose of X-ray astronomy. It was also known as the X-ray Explorer Satellite, SAS-A , SAS 1, or Explorer 42.The observatory was launched on 12 December 1970 into an initial orbit of about 560 km apogee, 520 km...

,
1971: William H. Press
William H. Press
William H. Press is an astrophysicist, theoretical physicist, and computational biologist. He is a member of the United States National Academy of Sciences, the American Academy of Arts and Sciences, and the Council on Foreign Relations. Other honors include the 1981 Helen B...

discovers black hole ringing by numerical simulation
Numerical relativity
Numerical relativity is one of the branches of general relativity that uses numerical methods and algorithms to solve and analyze problems. To this end, supercomputers are often employed to study black holes, gravitational waves, neutron stars and many other phenomena governed by Einstein's Theory...

,
1971: Harrison and Estabrook algorithm for solving systems of PDEs,
1971: James W. York
James W. York
James W. York, Jr. is an American mathematical physicist who is well known for his many important contributions to the theory of general relativity...

introduces conformal method generating initial data for ADM initial value formulation,
1971: Robert Geroch
Robert Geroch
Robert Geroch is a 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 in mathematics and physics. He was the Ph.D. supervisor for Abhay Ashtekar.Geroch obtained his Ph.D...

introduces Geroch group
Geroch group
The Geroch group is an inifinite-dimensional symmetry group of axisymmetric, stationary vacuum spacetimes that are solutions of Einstein's equations of general relativity. It is generated by two non-commuting subgroups: the Matznerg–Misner group The Geroch group is an inifinite-dimensional...

and a solution generating method,
1972: Jacob Bekenstein
Jacob Bekenstein
Jacob David Bekenstein is an Israeli theoretical physicist who has contributed to the foundation of black hole thermodynamics and to other aspects of the connections between information and gravitation.-Biography:...

proposes that black holes have a non-decreasing entropy
Entropy
Entropy is a thermodynamic property that can be used to determine the energy available for useful work in a thermodynamic process, such as in energy conversion devices, engines, or machines. Such devices can only be driven by convertible energy, and have a theoretical maximum efficiency when...

which can be identified with the area,
1972: Carter, Hawking and James M. Bardeen
James M. Bardeen
James Maxwell Bardeen is 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 exact solution of the Einstein field equation.Bardeen graduated from Harvard in 1960 and...

propose the four laws of black hole mechanics,
1972: Sachs introduces optical scalars
Optical scalars
In general relativity, optical scalars are a set of scalars that describe various properties of null geodesic congruences. The three optical scalars used in general relativity are expansion, shear and twist and were first defined and used by Sachs...

and proves peeling theorem,
1972: Rainer Weiss
Rainer Weiss
Rainer Weiss is professor of physics emeritus at MIT.- Early life and education :Weiss was born in Berlin, Germany, in 1932. Fleeing political unrest, his family moved first to Prague, in late 1932, and then to the United States, in 1938; his youth was spent in New York City, where he attended...

proposes concept of interferometric gravitational wave detector,
1972: J. C. Hafele and R. E. Keating perform Hafele-Keating experiment
Hafele-Keating experiment
The Hafele–Keating experiment was a test of the theory of relativity. In October 1971, Joseph C. Hafele, a physicist, and Richard E. Keating, an astronomer, took four cesium-beam atomic clocks aboard commercial airliners and flew twice around the world, first eastward, then westward, and compared...

,
1972: Richard H. Price
Richard H. Price
Richard H. Price is an American physicist specializing in general relativity.Price graduated from Stuyvesant High School in 1960, and went on to earn a dual degree in physics and engineering from Cornell University in 1965. He earned his Ph.D. in 1971 from Caltech under the supervision of Kip...

studies gravitational collapse
Gravitational collapse
Gravitational collapse is the inward fall of a body due to the influence of its own gravity. In any stable body, this gravitational force is counterbalanced by the internal pressure of the body, in the opposite direction to the force of gravity...

with numerical simulations,
1972: Saul Teukolsky
Saul Teukolsky
Saul Teukolsky is a theoretical astrophysicist and a professor of Physics and Astronomy at Cornell University. His major research interests include general relativity, relativistic astrophysics, and computational astrophysics.-Biography:...

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
Charles W. Misner 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 and numerical relativity....

, Kip S. Thorne and John A. Wheeler of the treatise Gravitation
Gravitation (book)
In physics, Gravitation is a very important reference book on Einstein's theory of gravity by Charles W. Misner, Kip S. Thorne, and John Archibald Wheeler. Often considered the "Bible" of General Relativity by researchers for its prominence. It is frequently called MTW after its authors' initials....

, 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
GHP formalism
The GHP formalism is a technique used in the mathematics of general relativity that involves singling out a pair of null directions at each point of spacetime....

,
1974: Russell Hulse and Joseph Hooton Taylor, Jr.
Joseph Hooton Taylor, Jr.
Joseph Hooton Taylor, Jr. is an American astrophysicist and Nobel Prize in Physics laureate for his discovery with Russell Alan Hulse of a "new type of pulsar, a discovery that has opened up new possibilities for the study of gravitation."...

discover the Hulse-Taylor binary pulsar
PSR 1913+16
PSR B1913+16 is a pulsar which together with another neutron star is in orbit around a common center of mass, thus forming a binary star system. In 1974 it was discovered by Russell Alan Hulse and Joseph Hooton Taylor, Jr., of Princeton University...

,
1974: James W. York
James W. York
James W. York, Jr. is an American mathematical physicist who is well known for his many important contributions to the theory of general relativity...

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 Regge
Tullio Regge is an Italian theoretical physicist. He obtained a degree in physics from the University of Turin in 1952, and a Ph.D. in physics from the University of Rochester in 1957 under the direction of Robert Marshak. From 1958 to 1959 Regge held a post at the Max Planck Institute for...

introduces the Regge calculus
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 the early 1960s....

,
1974: Hawking discovers Hawking radiation
Hawking radiation
Hawking radiation is a thermal radiation with a black body spectrum predicted to be emitted by black holes due to quantum effects. It is named after the physicist Stephen Hawking, who provided a theoretical argument for its existence in 1974, and sometimes also after the physicist Jacob Bekenstein...

,
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),
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
Inverse scattering transform
In mathematics, the inverse scattering transform is a method for solving some non-linear partial differential equations. It is one of the most important developments in mathematical physics in the past 40 years...

; the first gravitational solitons,
1979: Richard Schoen
Richard Schoen
Richard Melvin Schoen is an American mathematician. Born in Fort Recovery, Ohio, he received his PhD in 1977 from Stanford University where he is currently the Anne T. and Robert M. Bass Professor of Humanities and Sciences...

and Shing-Tung Yau
Shing-Tung Yau
Shing-Tung Yau is a Chinese American mathematician working in differential geometry. He was born in Shantou, Guangdong Province, China into a family of scholars from Jiaoling, Guangdong Province....

prove the positive mass theorem
Positive energy theorem
In general relativity, the positive energy theorem states that, assuming the dominant energy condition, the mass of an asymptotically flat spacetime is non-negative; furthermore, the mass is zero only for Minkowski spacetime...

.