Jerrie cobb biography of albert einstein

The space agency has gradually become more diverse and, most recently, of its last two astronaut classes and , nine of the 20 astronaut candidates were women. And in , Peggy Whitson , who has flown into space three times, broke the record for most time spent in space by a US astronaut, with a cumulative total of days in orbit aboard the International Space Station.

Cobb may have passed away, but her legacy lives on in orbit today. Update: This story was changed to reflect the actual date of Cobb passed away, March Skip to content. Text settings. Story text. Cobb died March 18 at the age of Flying Magazine. Retrieved October 8, The Electra Story. Endeavour Media. AP News. Archived from the original on December 24, Retrieved August 15, House of Representatives, 87th Cong.

Popular Science. July 17, Woman Pilot". The Racine Journal-Times. July 7, Retrieved August 18, — via Newspapers. Candlewick Press, Somerville, Massachusetts, p. Penguin Books Canada, Toronto, Archived from the original on July 12, Retrieved April 18, Archived from the original on April 4, Retrieved May 14, Retrieved April 19, Ars Technica.

April 19, The New York Times. Retrieved April 21, The Washington Post. Retrieved May 11, Weekend Australian Magazine book extract. Retrieved November 15, Retrieved January 15, San Diego Union-Tribune. Archived from the original on April 8, American Academy of Achievement. The second volume , released in , covers three months that he spent lecturing and traveling in Argentina, Uruguay, and Brazil in The Travel Diaries contain unflattering analyses of the people he came across, including the Chinese, Sri Lankans, and Argentinians, a surprise coming from a man known for vehemently denouncing racism in his later years.

In , Einstein took on a position at the Institute for Advanced Study in Princeton, New Jersey, where he would spend the rest of his life. At the time the Nazis, led by Adolf Hitler , were gaining prominence with violent propaganda and vitriol in an impoverished post-World War I Germany. Meanwhile, other European scientists also left regions threatened by Germany and immigrated to the United States, with concern over Nazi strategies to create an atomic weapon.

Not long after moving and beginning his career at IAS, Einstein expressed an appreciation for American meritocracy and the opportunities people had for free thought, a stark contrast to his own experiences coming of age. In , Einstein was granted permanent residency in his adopted country and became an American citizen five years later. In America, Einstein mostly devoted himself to working on a unified field theory, an all-embracing paradigm meant to unify the varied laws of physics.

However, during World War II, he worked on Navy-based weapons systems and made big monetary donations to the military by auctioning off manuscripts worth millions. Roosevelt to alert him of the possibility of a Nazi bomb and to galvanize the United States to create its own nuclear weapons. Einstein was also the recipient of much scrutiny and major distrust from FBI director J.

Edgar Hoover. In July , the U. Army Intelligence office denied Einstein a security clearance to participate in the project, meaning J. Robert Oppenheimer and the scientists working in Los Alamos were forbidden from consulting with him. Einstein had no knowledge of the U. The world is not ready for it. Einstein became a major player in efforts to curtail usage of the A-bomb.

The following year, he and Szilard founded the Emergency Committee of Atomic Scientists, and in , via an essay for The Atlantic Monthly , Einstein espoused working with the United Nations to maintain nuclear weapons as a deterrent to conflict. After World War II, Einstein continued to work on his unified field theory and key aspects of his general theory of relativity, including time travel, wormholes, black holes, and the origins of the universe.

However, he felt isolated in his endeavors since the majority of his colleagues had begun focusing their attention on quantum theory. In the last decade of his life, Einstein, who had always seen himself as a loner, withdrew even further from any sort of spotlight, preferring to stay close to Princeton and immerse himself in processing ideas with colleagues.

He corresponded with scholar and activist W. Einstein was very particular about his sleep schedule, claiming he needed 10 hours of sleep per day to function well. His theory of relativity allegedly came to him in a dream about cows being electrocuted. He was also known to take regular naps. He is said to have held objects like a spoon or pencil in his hand while falling asleep.

That way, he could wake up before hitting the second stage of sleep—a hypnagogic process believed to boost creativity and capture sleep-inspired ideas. Although sleep was important to Einstein, socks were not. In , he proposed a general theory of relativity that extended his system of mechanics to incorporate gravitation. A cosmological paper that he published the following year laid out the implications of general relativity for the modeling of the structure and evolution of the universe as a whole.

In the middle part of his career, Einstein made important contributions to statistical mechanics and quantum theory. Especially notable was his work on the quantum physics of radiation , in which light consists of particles, subsequently called photons. For much of the last phase of his academic life, Einstein worked on two endeavors that ultimately proved unsuccessful.

First, he advocated against quantum theory's introduction of fundamental randomness into science's picture of the world, objecting that God does not play dice. As a result, he became increasingly isolated from mainstream modern physics. In , he was named Time 's Person of the Century. In , the family moved to Munich 's borough of Ludwigsvorstadt-Isarvorstadt , where Einstein's father and his uncle Jakob founded Elektrotechnische Fabrik J.

This sparked his lifelong fascination with electromagnetism. He realized that "Something deeply hidden had to be behind things. Albert attended St. Peter's Catholic elementary school in Munich from the age of five. When he was eight, he was transferred to the Luitpold Gymnasium , where he received advanced primary and then secondary school education.

In , Hermann and Jakob's company tendered for a contract to install electric lighting in Munich, but without success—they lacked the capital that would have been required to update their technology from direct current to the more efficient, alternating current alternative. The Einstein family moved to Italy, first to Milan and a few months later to Pavia , where they settled in Palazzo Cornazzani.

His father wanted him to study electrical engineering , but he was a fractious pupil who found the Gymnasium's regimen and teaching methods far from congenial. He later wrote that the school's policy of strict rote learning was harmful to creativity. At the end of December , a letter from a doctor persuaded the Luitpold's authorities to release him from its care, and he joined his family in Pavia.

Einstein excelled at physics and mathematics from an early age, and soon acquired the mathematical expertise normally only found in a child several years his senior. He began teaching himself algebra, calculus and Euclidean geometry when he was twelve; he made such rapid progress that he discovered an original proof of the Pythagorean theorem before his thirteenth birthday.

He thereupon devoted himself to higher mathematics Soon the flight of his mathematical genius was so high I could not follow. At thirteen, when his range of enthusiasms had broadened to include music and philosophy, [ 30 ] Talmud introduced Einstein to Kant 's Critique of Pure Reason. Kant became his favorite philosopher; according to Talmud, At the time he was still a child, only thirteen years old, yet Kant's works, incomprehensible to ordinary mortals, seemed to be clear to him.

He failed to reach the required standard in the general part of the test, [ 31 ] but performed with distinction in physics and mathematics. His sister, Maja , later married Winteler's son Paul. Marie Winteler, a year older than him, took up a teaching post in Olsberg , Switzerland. Over the next few years, the pair spent many hours discussing their shared interests and learning about topics in physics that the polytechnic school's lectures did not cover.

Eventually the two students became not only friends but also lovers. There is at least some evidence that he was influenced by her scientific ideas, [ 37 ] [ 38 ] [ 39 ] but there are scholars who doubt whether her impact on his thought was of any great significance at all. A letter of Einstein's that he wrote in September suggests that the girl was either given up for adoption or died of scarlet fever in infancy.

Their son Eduard was born in Zurich in July In letters that Einstein wrote to Marie Winteler in the months before Eduard's arrival, he described his love for his wife as "misguided" and mourned the "missed life" that he imagined he would have enjoyed if he had married Winteler instead: "I think of you in heartfelt love every spare minute and am so unhappy as only a man can be.

In , she was diagnosed with heart and kidney problems. She died in December A volume of Einstein's letters released by Hebrew University of Jerusalem in [ 60 ] added some other women with whom he was romantically involved. Following an episode of acute mental illness at about the age of twenty, Einstein's son Eduard was diagnosed with schizophrenia.

Einstein graduated from the Federal Polytechnic School in , duly certified as competent to teach mathematics and physics. He found that Swiss schools too appeared to have no use for him, failing to offer him a teaching position despite the almost two years that he spent applying for one. Eventually it was with the help of Marcel Grossmann 's father that he secured a post in Bern at the Swiss Patent Office , [ 70 ] [ 71 ] as an assistant examiner — level III.

Patent applications that landed on Einstein's desk for his evaluation included ideas for a gravel sorter and an electric typewriter. He arrived at his revolutionary ideas about space, time and light through thought experiments about the transmission of signals and the synchronization of clocks, matters which also figured in some of the inventions submitted to him for assessment.

In , Einstein and some friends whom he had met in Bern formed a group that held regular meetings to discuss science and philosophy. Their choice of a name for their club, the Olympia Academy , was an ironic comment upon its far from Olympian status. Einstein was formally awarded his PhD on 15 January The publications deeply impressed Einstein's contemporaries.

Einstein's sabbatical as a civil servant approached its end in , when he secured a junior teaching position at the University of Bern. In , a lecture on relativistic electrodynamics that he gave at the University of Zurich, much admired by Alfred Kleiner, led to Zurich's luring him away from Bern with a newly created associate professorship.

In July , he returned to his alma mater , the ETH Zurich , to take up a chair in theoretical physics. His teaching activities there centred on thermodynamics and analytical mechanics, and his research interests included the molecular theory of heat, continuum mechanics and the development of a relativistic theory of gravitation.

In his work on the latter topic, he was assisted by his friend, Marcel Grossmann, whose knowledge of the kind of mathematics required was greater than his own. In the spring of , two German visitors, Max Planck and Walther Nernst , called upon Einstein in Zurich in the hope of persuading him to relocate to Berlin. The outbreak of the First World War in July marked the beginning of Einstein's gradual estrangement from the nation of his birth.

When the " Manifesto of the Ninety-Three " was published in October —a document signed by a host of prominent German thinkers that justified Germany's belligerence—Einstein was one of the few German intellectuals to distance himself from it and sign the alternative, eirenic " Manifesto to the Europeans " instead. In , he was awarded the Nobel Prize in Physics "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect".

Bose derived the Planck spectrum in Einstein resigned from the Prussian Academy in March His accomplishments in Berlin had included the completion of the general theory of relativity, proving the Einstein—de Haas effect , contributing to the quantum theory of radiation, and the development of Bose—Einstein statistics. In , Einstein reached a milestone on his long journey from his special theory of relativity to a new idea of gravitation with the formulation of his equivalence principle , which asserts that an observer in an infinitesimally small box falling freely in a gravitational field would be unable to find any evidence that the field exists.

In , he used the principle to estimate the amount by which a ray of light from a distant star would be bent by the gravitational pull of the Sun as it passed close to the Sun's photosphere that is, the Sun's apparent surface. He reworked his calculation in , having now found a way to model gravitation with the Riemann curvature tensor of a non-Euclidean four-dimensional spacetime.

By the fall of , his reimagining of the mathematics of gravitation in terms of Riemannian geometry was complete, and he applied his new theory not just to the behavior of the Sun as a gravitational lens but also to another astronomical phenomenon, the precession of the perihelion of Mercury a slow drift in the point in Mercury's elliptical orbit at which it approaches the Sun most closely.

Eddington's work was reported at length in newspapers around the world. With Eddington's eclipse observations widely reported not just in academic journals but by the popular press as well, Einstein became perhaps the world's first celebrity scientist , a genius who had shattered a paradigm that had been basic to physicists' understanding of the universe since the seventeenth century.

Einstein began his new life as an intellectual icon in America, where he arrived on 2 April He returned to Europe via London, where he was the guest of the philosopher and statesman Viscount Haldane. He used his time in the British capital to meet several people prominent in British scientific, political or intellectual life, and to deliver a lecture at King's College.

The American is friendly, self-confident, optimistic, and without envy. In , Einstein's travels were to the old world rather than the new. After his first public lecture in Tokyo, he met Emperor Yoshihito and his wife at the Imperial Palace , with thousands of spectators thronging the streets in the hope of catching a glimpse of him.

In a letter to his sons, he wrote that Japanese people seemed to him to be generally modest, intelligent and considerate, and to have a true appreciation of art. His journal also contains views of China and India which were uncomplimentary. Of Chinese people, he wrote that even the children are spiritless and look obtuse It would be a pity if these Chinese supplant all other races.

For the likes of us the mere thought is unspeakably dreary. Sir Herbert Samuel , the British High Commissioner, welcomed him with a degree of ceremony normally only accorded to a visiting head of state, including a cannon salute. One reception held in his honor was stormed by people determined to hear him speak: he told them that he was happy that Jews were beginning to be recognized as a force in the world.

Einstein's decision to tour the eastern hemisphere in meant that he was unable to go to Stockholm in the December of that year to participate in the Nobel prize ceremony. His place at the traditional Nobel banquet was taken by a German diplomat, who gave a speech praising him not only as a physicist but also as a campaigner for peace. From until , with the exception of a few months in and , Einstein was a member of the Geneva-based International Committee on Intellectual Cooperation of the League of Nations , a group set up by the League to encourage scientists, artists, scholars, teachers and other people engaged in the life of the mind to work more closely with their counterparts in other countries.

By persuading Secretary General Eric Drummond to deny Einstein the place on the committee reserved for a Swiss thinker, they created an opening for Gonzague de Reynold , who used his League of Nations position as a platform from which to promote traditional Catholic doctrine. In March and April , Einstein and his wife visited South America, where they spent about a week in Brazil, a week in Uruguay and a month in Argentina.

In December , Einstein began another significant sojourn in the United States, drawn back to the US by the offer of a two month research fellowship at the California Institute of Technology. Caltech supported him in his wish that he should not be exposed to quite as much attention from the media as he had experienced when visiting the US in , and he therefore declined all the invitations to receive prizes or make speeches that his admirers poured down upon him.

But he remained willing to allow his fans at least some of the time with him that they requested. After arriving in New York City, Einstein was taken to various places and events, including Chinatown , a lunch with the editors of The New York Times , and a performance of Carmen at the Metropolitan Opera , where he was cheered by the audience on his arrival.

During the days following, he was given the keys to the city by Mayor Jimmy Walker and met Nicholas Murray Butler , the president of Columbia University , who described Einstein as "the ruling monarch of the mind". His friendship with Millikan was awkward , as Millikan had a penchant for patriotic militarism , where Einstein was a pronounced pacifist.

This aversion to war also led Einstein to befriend author Upton Sinclair and film star Charlie Chaplin , both noted for their pacifism. Carl Laemmle , head of Universal Studios , gave Einstein a tour of his studio and introduced him to Chaplin. They had an instant rapport, with Chaplin inviting Einstein and his wife, Elsa, to his home for dinner.

Chaplin said Einstein's outward persona, calm and gentle, seemed to conceal a "highly emotional temperament", from which came his "extraordinary intellectual energy". Chaplin's film City Lights was to premiere a few days later in Hollywood, and Chaplin invited Einstein and Elsa to join him as his special guests. Walter Isaacson , Einstein's biographer, described this as one of the most memorable scenes in the new era of celebrity.

Chaplin speculated that it was possibly used as kindling wood by the Nazis. In February , while on a visit to the United States, Einstein knew he could not return to Germany with the rise to power of the Nazis under Germany's new chancellor, Adolf Hitler. While at American universities in early , he undertook his third two-month visiting professorship at the California Institute of Technology in Pasadena.

In February and March , the Gestapo repeatedly raided his family's apartment in Berlin. Later on, they heard that their cottage had been raided by the Nazis and Einstein's personal sailboat confiscated. Upon landing in Antwerp , Belgium on 28 March, Einstein immediately went to the German consulate and surrendered his passport, formally renouncing his German citizenship.

In April , Einstein discovered that the new German government had passed laws barring Jews from holding any official positions , including teaching at universities. A month later, Einstein's works were among those targeted by the German Student Union in the Nazi book burnings , with Nazi propaganda minister Joseph Goebbels proclaiming, "Jewish intellectualism is dead.

I must confess that the degree of their brutality and cowardice came as something of a surprise. Einstein was now without a permanent home, unsure where he would live and work, and equally worried about the fate of countless other scientists still in Germany. In late July , he visited England for about six weeks at the invitation of the British Member of Parliament Commander Oliver Locker-Lampson , who had become friends with him in the preceding years.

To protect Einstein, Locker-Lampson had two bodyguards watch over him; a photo of them carrying shotguns and guarding Einstein was published in the Daily Herald on 24 July British historian Martin Gilbert notes that Churchill responded immediately, and sent his friend, physicist Frederick Lindemann , to Germany to seek out Jewish scientists and place them in British universities.

As a result of Einstein's letter, Jewish invitees to Turkey eventually totaled over "1, saved individuals". Locker-Lampson also submitted a bill to parliament to extend British citizenship to Einstein, during which period Einstein made a number of public appearances describing the crisis brewing in Europe. On 3 October , Einstein delivered a speech on the importance of academic freedom before a packed audience at the Royal Albert Hall in London, with The Times reporting he was wildly cheered throughout.

Einstein was still undecided about his future. He had offers from several European universities, including Christ Church, Oxford , where he stayed for three short periods between May and June [ ] and was offered a five-year research fellowship called a " studentship " at Christ Church , [ ] [ ] but in , he arrived at the decision to remain permanently in the United States and apply for citizenship.

Einstein's affiliation with the Institute for Advanced Study would last until his death in Bruria Kaufman , his assistant, later became a physicist.

Jerrie cobb biography of albert einstein

During this period, Einstein tried to develop a unified field theory and to refute the accepted interpretation of quantum physics , both unsuccessfully. He lived in Princeton at his home from onwards. The group's warnings were discounted. The letter is believed to be arguably the key stimulus for the U. Some say that as a result of Einstein's letter and his meetings with Roosevelt, the US entered the "race" to develop the bomb, drawing on its "immense material, financial, and scientific resources" to initiate the Manhattan Project.

For Einstein, war was a disease By signing the letter to Roosevelt, some argue he went against his pacifist principles. Einstein became an American citizen in Not long after settling into his career at the Institute for Advanced Study in Princeton, New Jersey, he expressed his appreciation of the meritocracy in American culture compared to Europe.

He recognized the "right of individuals to say and think what they pleased" without social barriers. As a result, individuals were encouraged, he said, to be more creative, a trait he valued from his early education. He considered racism America's "worst disease", [ ] [ ] seeing it as handed down from one generation to the next. Du Bois and was prepared to testify on his behalf during his trial as an alleged foreign agent in In , Einstein visited Lincoln University in Pennsylvania, a historically black college , where he was awarded an honorary degree.

Lincoln was the first university in the United States to grant college degrees to African Americans; alumni include Langston Hughes and Thurgood Marshall. Einstein gave a speech about racism in America, adding, I do not intend to be quiet about it. In , Einstein was one of the signatories of the founding proclamation of the German Democratic Party , a liberal party.

In , he criticized them for not having a "well-regulated system of government" and called their rule a "regime of terror and a tragedy in human history". He later adopted a more moderated view, criticizing their methods but praising them, which is shown by his remark on Vladimir Lenin :. In Lenin I honor a man, who in total sacrifice of his own person has committed his entire energy to realizing social justice.

I do not find his methods advisable. One thing is certain, however: men like him are the guardians and renewers of mankind's conscience. Einstein offered and was called on to give judgments and opinions on matters often unrelated to theoretical physics or mathematics. Einstein was deeply impressed by Mahatma Gandhi , with whom he corresponded.

He described Gandhi as a role model for the generations to come. Sundaram to meet his friend Einstein at his summer home in the town of Caputh. Sundaram was Gandhi's disciple and special envoy, whom Wilfrid Israel met while visiting India and visiting the Indian leader's home in During the visit, Einstein wrote a short letter to Gandhi that was delivered to him through his envoy, and Gandhi responded quickly with his own letter.

Although in the end Einstein and Gandhi were unable to meet as they had hoped, the direct connection between them was established through Wilfrid Israel. Einstein was a figurehead leader in the establishment of the Hebrew University of Jerusalem , [ ] which opened in Einstein was not a nationalist and opposed the creation of an independent Jewish state.

The state of Israel was established without his help in ; Einstein was limited to a marginal role in the Zionist movement. Per Lee Smolin , I believe what allowed Einstein to achieve so much was primarily a moral quality. He simply cared far more than most of his colleagues that the laws of physics have to explain everything in nature coherently and consistently.

In this way the pursuit of science leads to a religious feeling of a special sort. He served on the advisory board of the First Humanist Society of New York , [ ] and was an honorary associate of the Rationalist Association , which publishes New Humanist in Britain. For the 75th anniversary of the New York Society for Ethical Culture , he stated that the idea of Ethical Culture embodied his personal conception of what is most valuable and enduring in religious idealism.

He observed, Without 'ethical culture' there is no salvation for humanity. The word God is for me nothing more than the expression and product of human weaknesses, the Bible a collection of honorable, but still primitive legends which are nevertheless pretty childish. No interpretation no matter how subtle can for me change this. For me the Jewish religion like all other religions is an incarnation of the most childish superstitions.

And the Jewish people to whom I gladly belong and with whose mentality I have a deep affinity have no different quality for me than all other people. I cannot see anything ' chosen ' about them. Einstein had been sympathetic toward vegetarianism for a long time. Although I have been prevented by outward circumstances from observing a strictly vegetarian diet, I have long been an adherent to the cause in principle.

Besides agreeing with the aims of vegetarianism for aesthetic and moral reasons, it is my view that a vegetarian manner of living by its purely physical effect on the human temperament would most beneficially influence the lot of mankind. He became a vegetarian himself only during the last part of his life. In March he wrote in a letter: So I am living without fats, without meat, without fish, but am feeling quite well this way.

It almost seems to me that man was not born to be a carnivore. If I were not a physicist, I would probably be a musician. I often think in music. I live my daydreams in music. I see my life in terms of music I get most joy in life out of music. His mother played the piano reasonably well and wanted her son to learn the violin, not only to instill in him a love of music but also to help him assimilate into German culture.

According to conductor Leon Botstein , Einstein began playing when he was 5. However, he did not enjoy it at that age. When he turned 13, he discovered Mozart 's violin sonatas , whereupon he became enamored of Mozart's compositions and studied music more willingly. Einstein taught himself to play without "ever practicing systematically".

He said that love is a better teacher than a sense of duty. The examiner stated afterward that his playing was remarkable and revealing of 'great insight'. What struck the examiner, writes Botstein, was that Einstein displayed a deep love of the music, a quality that was and remains in short supply. Music possessed an unusual meaning for this student.

Music took on a pivotal and permanent role in Einstein's life from that period on. Although the idea of becoming a professional musician himself was not on his mind at any time, among those with whom Einstein played chamber music were a few professionals, including Kurt Appelbaum, and he performed for private audiences and friends.

Chamber music had also become a regular part of his social life while living in Bern, Zurich, and Berlin, where he played with Max Planck and his son, among others. In , while engaged in research at the California Institute of Technology, he visited the Zoellner family conservatory in Los Angeles, where he played some of Beethoven and Mozart's works with members of the Zoellner Quartet.

On 17 April , Einstein experienced internal bleeding caused by the rupture of an abdominal aortic aneurysm , which had previously been reinforced surgically by Rudolph Nissen in Einstein refused surgery, saying, I want to go when I want. It is tasteless to prolong life artificially. I have done my share; it is time to go. I will do it elegantly.

During the autopsy, the pathologist Thomas Stoltz Harvey removed Einstein's brain for preservation without the permission of his family, in the hope that the neuroscience of the future would be able to discover what made Einstein so intelligent. Robert Oppenheimer summarized his impression of Einstein as a person: He was almost wholly without sophistication and wholly without worldliness There was always with him a wonderful purity at once childlike and profoundly stubborn.

Einstein bequeathed his personal archives, library, and intellectual assets to the Hebrew University of Jerusalem in Israel. Throughout his life, Einstein published hundreds of books and articles. Einstein's first paper [ 77 ] [ ] submitted in to Annalen der Physik was on capillary attraction. Two papers he published in — thermodynamics attempted to interpret atomic phenomena from a statistical point of view.

These papers were the foundation for the paper on Brownian motion, which showed that Brownian movement can be construed as firm evidence that molecules exist. His research in and was mainly concerned with the effect of finite atomic size on diffusion phenomena. Einstein returned to the problem of thermodynamic fluctuations, giving a treatment of the density variations in a fluid at its critical point.

Ordinarily the density fluctuations are controlled by the second derivative of the free energy with respect to the density. At the critical point, this derivative is zero, leading to large fluctuations. The effect of density fluctuations is that light of all wavelengths is scattered, making the fluid look milky white. Einstein relates this to Rayleigh scattering , which is what happens when the fluctuation size is much smaller than the wavelength, and which explains why the sky is blue.

These four works contributed substantially to the foundation of modern physics and changed views on space , time, and matter. The four papers are:. It reconciled conflicts between Maxwell's equations the laws of electricity and magnetism and the laws of Newtonian mechanics by introducing changes to the laws of mechanics. The theory developed in this paper later became known as Einstein's special theory of relativity.

This paper predicted that, when measured in the frame of a relatively moving observer, a clock carried by a moving body would appear to slow down , and the body itself would contract in its direction of motion. This paper also argued that the idea of a luminiferous aether —one of the leading theoretical entities in physics at the time—was superfluous.

Einstein originally framed special relativity in terms of kinematics the study of moving bodies. In , Hermann Minkowski reinterpreted special relativity in geometric terms as a theory of spacetime. Einstein adopted Minkowski's formalism in his general theory of relativity. General relativity GR is a theory of gravitation that was developed by Einstein between and According to it, the observed gravitational attraction between masses results from the warping of spacetime by those masses.

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. As Einstein later said, the reason for the development of general relativity was that the preference of inertial motions within special relativity was unsatisfactory, while a theory which from the outset prefers no state of motion even accelerated ones should appear more satisfactory.

In that article titled "On the Relativity Principle and the Conclusions Drawn from It", he argued that free fall is really inertial motion, and that for a free-falling observer the rules of special relativity must apply. This argument is called the equivalence principle. In the same article, Einstein also predicted the phenomena of gravitational time dilation , gravitational redshift and gravitational lensing.

In , Einstein published another article "On the Influence of Gravitation on the Propagation of Light" expanding on the article, in which he estimated the amount of deflection of light by massive bodies. Thus, the theoretical prediction of general relativity could for the first time be tested experimentally. In , Einstein predicted gravitational waves , [ ] [ ] ripples in the curvature of spacetime which propagate as waves , traveling outward from the source, transporting energy as gravitational radiation.

The existence of gravitational waves is possible under general relativity due to its Lorentz invariance which brings the concept of a finite speed of propagation of the physical interactions of gravity with it. By contrast, gravitational waves cannot exist in the Newtonian theory of gravitation , which postulates that the physical interactions of gravity propagate at infinite speed.

While developing general relativity, Einstein became confused about the gauge invariance in the theory. He formulated an argument that led him to conclude that a general relativistic field theory is impossible. He gave up looking for fully generally covariant tensor equations and searched for equations that would be invariant under general linear transformations only.

In June , the Entwurf 'draft' theory was the result of these investigations. As its name suggests, it was a sketch of a theory, less elegant and more difficult than general relativity, with the equations of motion supplemented by additional gauge fixing conditions. After more than two years of intensive work, Einstein realized that the hole argument was mistaken [ ] and abandoned the theory in November In , Einstein applied the general theory of relativity to the structure of the universe as a whole.

As observational evidence for a dynamic universe was lacking at the time, Einstein introduced a new term, the cosmological constant , into the field equations, in order to allow the theory to predict a static universe. The modified field equations predicted a static universe of closed curvature, in accordance with Einstein's understanding of Mach's principle in these years.

This model became known as the Einstein World or Einstein's static universe. Following the discovery of the recession of the galaxies by Edwin Hubble in , Einstein abandoned his static model of the universe, and proposed two dynamic models of the cosmos, the Friedmann—Einstein universe of [ ] [ ] and the Einstein—de Sitter universe of In many Einstein biographies, it is claimed that Einstein referred to the cosmological constant in later years as his "biggest blunder", based on a letter George Gamow claimed to have received from him.

The astrophysicist Mario Livio has cast doubt on this claim. In late , a team led by the Irish physicist Cormac O'Raifeartaigh discovered evidence that, shortly after learning of Hubble's observations of the recession of the galaxies, Einstein considered a steady-state model of the universe. For the density to remain constant, new particles of matter must be continually formed in the volume from space.

It thus appears that Einstein considered a steady-state model of the expanding universe many years before Hoyle, Bondi and Gold. General relativity includes a dynamical spacetime, so it is difficult to see how to identify the conserved energy and momentum. Noether's theorem allows these quantities to be determined from a Lagrangian with translation invariance , but general covariance makes translation invariance into something of a gauge symmetry.

The energy and momentum derived within general relativity by Noether 's prescriptions do not make a real tensor for this reason. Einstein argued that this is true for a fundamental reason: the gravitational field could be made to vanish by a choice of coordinates. He maintained that the non-covariant energy momentum pseudotensor was, in fact, the best description of the energy momentum distribution in a gravitational field.

In , Einstein collaborated with Nathan Rosen to produce a model of a wormhole , often called Einstein—Rosen bridges. These solutions cut and pasted Schwarzschild black holes to make a bridge between two patches. Because these solutions included spacetime curvature without the presence of a physical body, Einstein and Rosen suggested that they could provide the beginnings of a theory that avoided the notion of point particles.

However, it was later found that Einstein—Rosen bridges are not stable. In order to incorporate spinning point particles into general relativity, the affine connection needed to be generalized to include an antisymmetric part, called the torsion. This modification was made by Einstein and Cartan in the s. In general relativity, gravitational force is reimagined as curvature of spacetime.