Albert Einstein

Einstein Biography

Childhood, youth and education

Albert Einstein’s life began on March 14, 1879, in Ulm, within the Kingdom of Württemberg of the German Empire. He was the son of Hermann Einstein, an engineer and salesman, and Pauline Koch, both secular Ashkenazi Jews. A year after his birth, the family relocated to Munich, where his father and uncle Jakob founded Elektrotechnische Fabrik J. Einstein & Cie, a firm specializing in direct-current electrical equipment.

In his earliest years, Einstein’s delayed speech development led his parents to suspect a learning disability. However, his intellectual curiosity was ignited at age five when his father showed him a compass while he was ill in bed; the realization that an unseen force directed the needle convinced him that something deeply hidden governed physical reality. He started his education at St. Peter's Catholic elementary school at five and moved to the Luitpold Gymnasium at eight for his secondary studies.

The family business faced a crisis in 1894 when it lost a major Munich lighting contract because it lacked the capital to switch from direct current to the increasingly dominant alternating current. This failure forced a move to Italy—first Milan, then Pavia—while the fifteen-year-old Einstein remained in Munich to complete his schooling. He grew to resent the Gymnasium’s rigid, rote-learning methods, which he believed destroyed creativity. By December 1894, he used a doctor’s note to leave the school and reunite with his family in Pavia. During this period in Italy, he composed an early scientific essay titled "On the Investigation of the State of the Ether in a Magnetic Field."

Einstein demonstrated exceptional mathematical talent from a young age, teaching himself algebra, Euclidean geometry, and calculus by age twelve. He produced an original proof of the Pythagorean theorem before turning thirteen and claimed to have mastered complex calculus by fourteen. His intellectual interests were further expanded by his tutor Max Talmud, who introduced him to Kant’s Critique of Pure Reason when he was thirteen; despite the difficulty of the text, Einstein found its arguments remarkably clear.

At sixteen, Einstein attempted to enter the federal polytechnic school in Zurich but failed the general portion of the entrance exam, despite outstanding results in math and physics. Following the principal's advice, he finished his secondary education at the Argovian cantonal school in Aarau, graduating in 1896. During this time, he lived with the family of Jost Winteler and fell in love with his daughter, Marie. In early 1896, with his father's consent, he renounced his German citizenship to avoid military service. He earned his Matura in September 1896 with highest marks in history and mathematics, subsequently enrolling in the four-year teaching diploma program at the Zurich polytechnic. There, he befriended Marcel Grossmann, who would later assist him with the mathematical foundations of his theories.

His cohort at the polytechnic included Mileva Marić, the only woman in the program. The two became close friends and eventually lovers, spending much of their time studying advanced physics topics outside the official curriculum. While some historians speculate that Marić significantly contributed to the groundbreaking papers Einstein published in 1905, citing his letters about their shared work, the scientific community remains divided on the actual extent of her influence on his intellectual output.

Marriages, relationships and children

The private life of Albert Einstein was marked by complex emotional ties and a series of turbulent relationships. In 1987, the publication of correspondence between Einstein and Mileva Marić revealed the existence of a daughter, Lieserl, born in early 1902 while Marić was in Novi Sad. The child's ultimate fate remains a historical mystery; a September 1903 letter suggests she was either placed for adoption or succumbed to scarlet fever in her infancy.

Einstein and Marić officially wed in January 1903, subsequently having two sons: Hans Albert, born in May 1904, and Eduard, born in July 1910. Despite the expansion of his family, Einstein harbored deep regrets. Letters written to his former flame, Marie Winteler, shortly before Eduard’s birth, reveal him describing his marriage as "misguided" and expressing profound unhappiness over a perceived "missed life" without her.

By 1912, Einstein began an affair with his cousin, Elsa Löwenthal. This infidelity led to a permanent rupture with Marić shortly after the family moved to Berlin in 1914; she returned to Zurich with their sons. Their marriage legally ended on February 14, 1919. A notable condition of their divorce settlement was Einstein’s promise to transfer any future Nobel Prize funds to Marić—a commitment he fulfilled after winning the prize in 1921.

Einstein married Elsa in 1919, yet his patterns of extramarital involvement continued. He entered a relationship with his secretary, Betty Neumann, in 1923, and later correspondence released in 2006 identified several other women—including Margarete Lebach, Estella Katzenellenbogen, Toni Mendel, and Ethel Michanowski—with whom he was involved during his second marriage. Elsa remained with him through their emigration to the United States in 1933 but died in December 1936 following heart and kidney complications. Later in life, Einstein was involved with Margarita Konenkova, a woman suspected by some of being a Russian spy.

The lives of his children also faced significant hardship. His son Eduard suffered a mental breakdown in his early twenties and was diagnosed with schizophrenia. He spent his life moving between his mother’s care and psychiatric institutions, eventually being permanently committed to the Burghölzli hospital in Zurich following Marić's death.

Einstein assistant at the Swiss Patent Office (1902–1909)

After graduating from the Zurich polytechnic in 1900 with a teaching certificate in mathematics and physics, Einstein faced a period of professional uncertainty. Although he gained Swiss citizenship in February 1901, he was spared military service after being declared medically unfit. Despite nearly two years of applications, he was unable to secure a teaching post. It was only through the personal intervention of Marcel Grossmann’s father that he finally obtained a position in Bern at the Swiss Patent Office, where he began work as a level III assistant examiner.

His responsibilities involved evaluating a wide array of inventions, ranging from gravel sorters to electric typewriters. While his superiors were satisfied enough to grant him a permanent contract in 1903, they delayed his promotion, citing his need to further master "machine technology." Historically, it is suggested that this environment was instrumental in the birth of special relativity. His daily work evaluating inventions often involved the synchronization of clocks and the transmission of electrical signals—practical problems that mirrored the very thought experiments he used to redefine the nature of space and time.

During his time in Bern, Einstein also cultivated his intellectual life outside the office. In 1902, he and a small circle of friends founded the "Olympia Academy," an ironically named club dedicated to the rigorous discussion of science and philosophy. While Mileva Marić occasionally attended as a silent observer, the group focused on the works of influential thinkers like Henri Poincaré, Ernst Mach, and David Hume. The philosophical foundations laid during these meetings would eventually become the bedrock of Einstein's own scientific worldview.

First scientific papers (1900–1905)

Einstein’s publishing career began in 1901 with the paper "Conclusions drawn from the phenomena of capillarity," published in Annalen der Physik. In this debut, he proposed a model for intermolecular attraction, though he would later dismiss the work as entirely worthless. His academic focus on molecular physics continued with his doctoral dissertation, "A New Determination of Molecular Dimensions." Dedicated to his friend Marcel Grossmann, the 24-page thesis was completed on April 30, 1905, and received approval from Professor Alfred Kleiner at the University of Zurich that July. He was officially granted his PhD on January 15, 1906.

The year 1905 stands as a singular turning point in scientific history, often compared to Isaac Newton’s "miracle year" of 1666. Beyond his dissertation, Einstein produced four legendary papers that year, covering the photoelectric effect, Brownian motion, the special theory of relativity, and the equivalence of mass and energy. Collectively, these works earned 1905 the title of annus mirabilis, or miracle year, leaving a profound and lasting impression on the global scientific community.

Academic career in Europe (1908–1933)

Einstein's transition from the patent office to academia began in 1908 with a junior teaching role at the University of Bern. His reputation grew rapidly; a 1909 lecture on relativistic electrodynamics so impressed Alfred Kleiner that the University of Zurich created an associate professorship specifically to recruit him. By April 1911, he attained a full professorship at the German Charles-Ferdinand University in Prague. Although this appointment required him to initiate the process of becoming an Austrian citizen within the Austro-Hungarian Empire, the paperwork was never finalized. During his brief tenure in Prague, he authored eleven research papers and attended the inaugural Solvay Conference on Physics in late 1911.

In July 1912, Einstein returned to ETH Zurich as a chair in theoretical physics. While teaching thermodynamics and analytical mechanics, he focused his research on the molecular theory of heat and the development of a relativistic theory of gravitation. For the latter, he relied heavily on the mathematical expertise of his friend Marcel Grossmann. In early 1913, Max Planck and Walther Nernst visited Zurich to recruit Einstein for Berlin. They offered him an elite package: membership in the Prussian Academy of Sciences, the directorship of the future Kaiser Wilhelm Institute for Physics, and a research professorship at Humboldt University with no teaching obligations. The offer was particularly enticing as it allowed him to be near Elsa Löwenthal. He accepted, joining the Academy in July 1913 and moving to Berlin in April 1914.

The start of World War I in July 1914 sparked Einstein's political alienation from Germany. He was one of only a few intellectuals to refuse to sign the "Manifesto of the Ninety-Three," which supported German militarism, choosing instead to endorse the pacifist "Manifesto to the Europeans." Despite his dissent, he remained a central figure in the scientific community, serving as president of the German Physical Society from 1916 to 1918. In 1917, he finally assumed his role as the founding director of the Kaiser Wilhelm Institute for Physics.

The 1920s brought global acclaim. He was elected to the Royal Netherlands Academy of Arts and Sciences in 1920 and the Royal Society in 1921. In 1922, he received the 1921 Nobel Prize in Physics, primarily for the photoelectric effect, as the committee remained cautious regarding general relativity. His theory of light particles was only fully embraced by the scientific community after S. N. Bose’s work in 1924. Einstein’s prestige continued to grow with his election to the American Academy of Arts and Sciences (1924), the receipt of the Copley Medal (1925), and membership in the American Philosophical Society (1930). His era in Berlin—marked by the completion of general relativity, the discovery of the Einstein–de Haas effect, and work on Bose–Einstein statistics—ended in March 1933, when he resigned from the Prussian Academy.

Putting general relativity to the test (1919)

By 1907, Einstein achieved a critical breakthrough by formulating the equivalence principle, which posited that an observer in a freely falling elevator would be unable to detect the presence of a gravitational field. This realization marked the beginning of his transition from special relativity to a revolutionary theory of gravity. In 1911, he applied this principle to predict gravitational lensing, estimating the degree to which the Sun's mass would bend light from distant stars.

His mathematical framework evolved significantly by 1913, when he began utilizing the Riemann curvature tensor to represent gravity as the curvature of a non-Euclidean, four-dimensional spacetime. By the autumn of 1915, Einstein finalized this reimagining of gravity through Riemannian geometry. He successfully applied his finished theory to explain the precession of the perihelion of Mercury—resolving a long-standing mystery regarding the planet's shifting elliptical orbit—and refined his predictions for how the Sun would act as a gravitational lens.

The ultimate validation came during the total solar eclipse of May 29, 1919. Observations led by Sir Arthur Eddington confirmed that the bending of starlight matched Einstein’s specific calculations rather than traditional Newtonian physics. This triumph was broadcast globally; notably, on November 7, 1919, the British newspaper The Times announced a "Revolution in Science," declaring that Newtonian ideas had been overthrown and a new theory of the universe had arrived.

Coming to terms with fame (1921–1923)

The widespread press coverage of Eddington’s observations transformed Einstein into a global icon, arguably making him the world's first "celebrity scientist." By overturning the Newtonian paradigm that had dominated physics since the 17th century, he achieved a level of fame that transcended academia.

On April 2, 1921, Einstein arrived in the United States to begin his life as an international intellectual figure. Mayor John Francis Hylan welcomed him to New York City, launching a three-week tour of lectures and receptions at prestigious institutions like Columbia University and Princeton. In Washington, he visited the White House alongside representatives of the National Academy of Sciences. He returned to Europe through London, where he stayed with Viscount Haldane and engaged with the British intellectual and political elite, including delivering a lecture at King’s College. In July 1921, he published his reflections on the American character in an essay titled "My First Impression of the U.S.A.," praising Americans for their "joyous, positive attitude to life" and their lack of envy.

In 1922, Einstein embarked on a six-month tour of Asia, visiting Singapore, Sri Lanka, and Japan. His arrival in Tokyo was met with massive public interest; thousands lined the streets for a glimpse of him, and he was received by Emperor Yoshihito at the Imperial Palace. While his letters to his sons spoke highly of the Japanese people's modesty and artistic sense, his private diaries revealed a more critical and prejudiced perspective. He expressed uncomplimentary views regarding the "intellectual needs" of the Japanese and wrote disparagingly about the Chinese people, expressing a "dreary" concern about the prospect of them "supplanting all other races."

The final leg of this 1922 journey took him to Mandatory Palestine. The British High Commissioner, Sir Herbert Samuel, received him with the ceremony typically reserved for a head of state, complete with a cannon salute. During a crowded reception, Einstein expressed his pride in the growing recognition of the Jewish people as a significant global force.

Because of his travels in the East, Einstein was absent from the Nobel Prize ceremony in Stockholm in December 1922. A German diplomat represented him at the banquet, delivering a speech that honored both his scientific achievements and his dedication to peace. His travels continued into 1923 with a two-week visit to Spain. There, he was inducted into the Spanish Academy of Sciences by King Alfonso XIII and met the renowned neuroanatomist Santiago Ramón y Cajal.

Serving the League of Nations (1922–1932)

Between 1922 and 1932, Einstein served as a member of the International Committee on Intellectual Cooperation of the League of Nations in Geneva, with only brief interruptions in 1923 and 1924. This organization was created by the League to encourage global collaboration among scientists, artists, and scholars, helping them work more effectively across national borders.

His appointment involved significant political friction. Although he held Swiss citizenship, he was designated as a delegate for Germany rather than Switzerland due to the actions of two Catholic activists, Oskar Halecki and Giuseppe Motta. They influenced Secretary General Eric Drummond to deny Einstein the Swiss seat, which instead went to Gonzague de Reynold, who used the platform to advance Catholic doctrine. Despite these complications, Einstein served on the committee alongside distinguished colleagues, including his former professor Hendrik Lorentz and the chemist Marie Curie.

Touring South America (1925)

During March and April 1925, Einstein and his wife traveled to South America for an extensive tour that included a week-long stay in Brazil, another week in Uruguay, and a full month in Argentina. The journey was initiated by Jorge Duclout and Mauricio Nirenstein, gaining further backing from several prominent Argentine scholars such as Julio Rey Pastor, Jakob Laub, and Leopoldo Lugones. The funding for the trip was provided largely by the Council of the University of Buenos Aires and the Argentine Hebraic Association, with additional financial support coming from the Argentine-Germanic Cultural Institution.

Touring the US (1930–1931)

In December 1930, Einstein returned to the United States for a two-month research fellowship at the California Institute of Technology. Seeking to avoid the intense media frenzy that had defined his 1921 visit, he requested a more private experience. Consequently, he turned down numerous invitations for awards and public speeches, though he still occasionally made time for his many admirers.

His arrival in New York City was marked by a series of high-profile events, including a visit to Chinatown and a lunch with the editorial staff of The New York Times. When he attended a performance of Carmen at the Metropolitan Opera, the audience greeted him with a standing ovation. During his stay, Mayor Jimmy Walker presented him with the keys to the city, and Nicholas Murray Butler, the president of Columbia University, referred to him as a monarch of the mind. Einstein also visited Riverside Church, where he was shown a life-size statue of himself at the entrance, and joined a massive Hanukkah celebration at Madison Square Garden with 15,000 people.

Upon traveling to California, Einstein met with the president of Caltech, Robert A. Millikan. Their relationship was somewhat strained due to their conflicting ideologies; Millikan held strong militaristic views, while Einstein was a committed pacifist. This perspective was evident when Einstein addressed the students at Caltech, warning that science could often be used to cause more harm than good.

His pacifist beliefs drew him toward like-minded individuals, such as the writer Upton Sinclair and the actor Charlie Chaplin. After a tour of Universal Studios, Einstein met Chaplin, and the two formed an immediate bond. Chaplin, who invited Einstein and his wife Elsa to dinner, observed that Einstein’s calm exterior seemed to mask a deeply emotional nature that fueled his immense intellectual drive.

The two icons appeared together at the Hollywood premiere of the film City Lights. This public appearance became a legendary moment in the history of celebrity culture. As the crowd cheered them both, Chaplin famously remarked that the people cheered him because they understood him, but they cheered Einstein because no one understood him. Later, Chaplin visited Einstein in Berlin and recalled his modest apartment, wondering if the piano Einstein used while developing his theories had eventually been destroyed by the Nazis.

Emigration to the US (1933)

In February 1933, during a visit to the United States, Einstein realized that the ascent of the Nazi party and the appointment of Adolf Hitler as chancellor made it impossible for him to return to Germany. At the time, he was completing his third two-month term as a visiting professor at the California Institute of Technology. While he was in Pasadena, the Gestapo conducted several raids on his family's Berlin apartment.

In March 1933, Einstein and his wife Elsa sailed back toward Europe. During the voyage, they received news that the Reichstag had passed the Enabling Act on March 23, effectively establishing a legal dictatorship and blocking their return to Berlin. They soon learned that Nazi forces had also raided their summer cottage and seized Einstein’s personal sailboat.

Upon docking in Antwerp, Belgium, on March 28, Einstein proceeded directly to the German consulate. There, he surrendered his passport and formally renounced his German citizenship for the second time in his life. The Nazi regime subsequently sold his confiscated boat and repurposed his private cottage into a camp for the Hitler Youth.

Refugee status

In April 1933, Einstein learned that the new German administration had enacted legislation prohibiting Jews from holding official posts, including university professorships. As noted by historian Gerald Holton, this occurred with almost no public opposition from their non-Jewish colleagues. Consequently, thousands of Jewish scientists were abruptly stripped of their positions, and their names were purged from institutional records.

The following month, Einstein’s publications were targeted during the state-sponsored book burnings organized by the German Student Union. Nazi propaganda minister Joseph Goebbels declared the end of Jewish intellectualism, while a German magazine labeled Einstein an enemy of the state, noting he was "not yet hanged" and placing a 5,000 dollar bounty on his life. In correspondence with his friend Max Born, who had already fled to England, Einstein admitted he was surprised by the sheer extent of the regime's brutality and cowardice. Later, in the United States, he characterized the book burnings as an outburst by those who feared the influence of independent thinkers and sought to suppress public enlightenment.

Now homeless and uncertain of his future, Einstein was also deeply concerned for the safety of colleagues remaining in Germany. He was assisted by the Academic Assistance Council, an organization established by British politician William Beveridge to help persecuted scholars. Einstein initially stayed in De Haan, Belgium, before accepting an invitation from Commander Oliver Locker-Lampson to visit England in July 1933. To ensure his safety, he was housed in a secluded cabin in Norfolk under the protection of armed bodyguards.

During his time in Britain, Locker-Lampson arranged meetings for Einstein with influential political figures, including Winston Churchill, Austen Chamberlain, and Lloyd George. Einstein urged them to facilitate the escape of Jewish scientists from Germany. Churchill responded by sending physicist Frederick Lindemann to Germany to recruit these scholars for British universities. Churchill later remarked that by expelling its Jewish intellectuals, Germany had severely degraded its own technical standards, inadvertently giving the Allies a technological advantage.

Einstein continued his efforts globally, writing to leaders such as Turkey’s Prime Minister, İsmet İnönü. His intervention led to the relocation of over 1,000 individuals to Turkey. Although Locker-Lampson attempted to pass a bill in Parliament to grant Einstein British citizenship and described him as a "citizen of the world," the effort was unsuccessful. Ultimately, Einstein accepted a prior offer to become a resident scholar at the Institute for Advanced Study in Princeton, New Jersey.

Resident scholar at the Institute for Advanced Study

On 3 October 1933, Einstein addressed a capacity crowd at the Royal Albert Hall in London, delivering a powerful speech on the vital necessity of academic freedom. His words were met with enthusiastic cheers from the audience. Four days later, he departed for the United States to join the Institute for Advanced Study in Princeton. At that time, the Institute served as a critical sanctuary for scientists escaping Nazi Germany, a stark contrast to many major American universities like Harvard, Princeton, and Yale, which maintained restrictive quotas on Jewish students and faculty until the late 1940s.

Despite having established himself in New Jersey, Einstein initially remained uncertain about his long-term future. He received several prestigious offers from European institutions, including a five-year research fellowship at Christ Church, Oxford, where he had already spent several short periods as a guest. However, by 1935, he made the definitive choice to stay in the United States permanently and began the process of applying for American citizenship.

Einstein’s tenure at the Institute for Advanced Study continued for the remainder of his life. He was among the first four faculty members selected for the new institution, alongside John von Neumann, Kurt Gödel, and Hermann Weyl. He formed a particularly deep bond with Gödel, and the two were frequently seen taking long walks together to discuss their complex theories. During these years, Einstein dedicated himself to developing a unified field theory and challenged the prevailing interpretations of quantum mechanics, though these specific pursuits did not reach the conclusions he sought. From 1935 until his death in 1955, he resided in his home in Princeton, which was later designated a National Historic Landmark in 1976.

World War II and the Manhattan Project

In 1939, a group of Hungarian scientists, including the physicist Leó Szilárd, grew increasingly concerned that Nazi Germany was making progress in atomic bomb research. After their initial warnings to the American government were ignored, Szilárd and fellow refugees Edward Teller and Eugene Wigner turned to Einstein. They believed it was their duty to warn the United States that German scientists might develop a nuclear weapon first, and that Hitler would certainly use it. In July 1939, just before the outbreak of World War II, Szilárd and Wigner visited Einstein to explain the mechanics of such a bomb. Einstein, a lifelong pacifist, admitted he had not previously considered the possibility of an atomic explosion, but he agreed to help.

Einstein and Szilárd drafted a letter to President Franklin D. Roosevelt, urging the United States to monitor German developments and begin its own nuclear research. This document is widely regarded as the primary catalyst that pushed the American government to take the threat of nuclear weaponry seriously. To ensure the message reached the highest levels of power, Einstein also utilized his personal connection with the Belgian royal family to secure a direct channel to the Oval Office. Many historians believe this intervention was the spark that led to the Manhattan Project, mobilizing the vast scientific and financial resources of the United States.

While Einstein viewed war as a disease and consistently advocated for peaceful resistance, his decision to sign the Roosevelt letter appeared to contradict his pacifist principles. However, he felt the existential threat posed by a Nazi-controlled atomic bomb left him no choice. In 1954, shortly before his death, he remarked to his friend Linus Pauling that signing the letter was the one great mistake of his life, though he noted the justification was the terrifying possibility that Germany might succeed first.

In his final years, Einstein became a vocal critic of the nuclear arms race. In 1955, he joined Bertrand Russell and other prominent intellectuals in signing a manifesto that warned of the catastrophic dangers of nuclear weapons. Following his death, he was honored as a charter member of the World Academy of Art and Science, an organization dedicated to ensuring that scientific progress is pursued with ethical responsibility.

US citizenship

Einstein officially became an American citizen in 1940. Shortly after starting his work at the Institute for Advanced Study, he noted his admiration for the meritocratic nature of American society. He valued the freedom of individuals to think and speak without the rigid social barriers common in Europe, believing this environment fostered the creativity he had prized since his youth.

However, Einstein also identified significant flaws in his new home, labeling racism as the most persistent and destructive disease in America. He viewed it as a cycle passed down through generations. To combat this, he joined the Princeton chapter of the NAACP and actively campaigned for the civil rights of African Americans. His commitment was demonstrated through his relationship with W. E. B. Du Bois; in 1951, Einstein offered to serve as a character witness for Du Bois during his trial as a suspected foreign agent. This offer was so significant that the judge ultimately dismissed the case.

In 1946, Einstein traveled to Lincoln University, the first institution in the United States to grant degrees to African Americans. While receiving an honorary degree there, he delivered a speech explicitly denouncing American racism, stating his refusal to remain silent on the matter. His support was often personal; he is known to have quietly paid the university tuition for a Black student.

Drawing on his own experiences as a Jew, Einstein expressed a deep empathy for those facing discrimination. This empathy translated into tangible action in 1937 when the famed Black singer Marian Anderson was denied a room at the Nassau Inn in Princeton due to her race. Einstein invited her to stay in his own home, a gesture of friendship that continued for nearly two decades. Anderson remained a regular guest at his house whenever she visited the area, making her final visit only two months before his death in 1955.

Personal views

Political views

In 1918, Einstein helped establish the German Democratic Party, a liberal organization, by signing its founding proclamation. Over time, however, his political stance shifted toward socialism. In his writings, most notably the essay titled Why Socialism, he articulated a critique of capitalism and argued for a more equitable economic structure. His perception of the Bolsheviks also evolved; while in 1925 he condemned their rule as a tragic regime of terror lacking proper governance, by 1929 his tone had moderated. He expressed admiration for Vladimir Lenin's personal sacrifice and dedication to social justice, even though he remained critical of the violent methods employed by the Soviet leader.

Einstein frequently used his platform to speak on global issues far removed from physics. He was a staunch proponent of creating a democratic world government, believing that a global federation was the only way to curb the dangerous impulses of individual nation-states and prevent human catastrophe. These vocal political opinions did not go unnoticed by authorities; the FBI maintained a secret file on him beginning in 1932, which grew to over 1,400 pages by the end of his life.

A significant influence on Einstein’s world view was Mahatma Gandhi, whom he considered a primary role model for future generations. Although the two never met in person, they maintained a respectful correspondence that began in September 1931. This connection was facilitated by Wilfrid Israel, who brought Gandhi’s envoy to Einstein’s summer home in Caputh. Through this intermediary, the two men exchanged letters and established a mutual intellectual bond centered on the principles of non-violence and moral leadership.

Relationship with Zionism

Einstein played a central role as a symbolic leader in the founding of the Hebrew University of Jerusalem, which opened its doors in 1925. His involvement began years earlier in 1921, when biochemist and Zionist leader Chaim Weizmann recruited him to help secure funding for the institution. Einstein took a practical interest in the university's focus, advocating for the creation of institutes dedicated to agriculture, chemistry, and microbiology. He viewed these fields as essential for combating epidemics like malaria, which he described as a major obstacle to the region's development. He also suggested establishing an Institute of Oriental Studies that would offer instruction in both Hebrew and Arabic to foster better understanding.

Despite his support for these cultural and educational initiatives, Einstein was not a nationalist and remained opposed to the formation of a sovereign Jewish state. He envisioned a future where Jewish immigrants and the existing Arab population could coexist peacefully in Palestine. When the State of Israel was established in 1948, it was done without his direct assistance, as his influence within the Zionist movement remained limited to the periphery.

Following the death of President Chaim Weizmann in November 1952, Prime Minister David Ben-Gurion offered Einstein the presidency of Israel. While the position was primarily ceremonial, the offer was intended to signify the highest possible respect from the Jewish people. Einstein expressed that he was deeply moved by the gesture but ultimately declined, feeling both saddened and ashamed that he could not accept. In reality, while Ben-Gurion felt a moral obligation to extend the invitation, he privately worried about the complications that might arise if a man of Einstein's independent mind actually accepted the role.

Religious and philosophical views

According to Lee Smolin, Einstein’s immense achievements were rooted in a specific moral quality: a profound commitment to the idea that the laws of physics must explain nature in a completely coherent and consistent manner. Einstein detailed his spiritual perspective across many works, expressing an affinity for the pantheistic God described by Baruch Spinoza—an impersonal force represented by the harmony of the universe. He rejected the notion of a personal deity who intervenes in human affairs, labeling such a belief as naive. However, he was careful to distinguish his views from atheism, preferring to identify as an agnostic or a deeply religious nonbeliever. He felt that the laws of the universe revealed a spirit vastly superior to that of humanity, inspiring a unique sense of scientific humility.

In both the United Kingdom and the United States, Einstein aligned himself with non-religious humanist and ethical organizations. He served on the advisory board of the First Humanist Society of New York and was an honorary associate of the Rationalist Association in Britain. He held the movement for Ethical Culture in high regard, suggesting that humanity’s salvation depended on these ethical principles, which he viewed as the most valuable core of religious idealism.

Despite his appreciation for his heritage, Einstein’s private correspondence revealed a sharp critique of traditional religion. In a 1954 letter to philosopher Eric Gutkind, he described the word God as a product of human weakness and dismissed the Bible as a collection of primitive, though honorable, legends. He viewed the Jewish religion, like all others, as a manifestation of superstition and stated that while he felt a deep affinity for the Jewish people, he did not believe they were chosen or inherently superior to any other group.

Einstein’s personal ethics also extended to his diet. For decades, he supported vegetarianism on moral and aesthetic grounds, believing it would beneficially influence the human temperament. While external circumstances prevented him from following this path strictly for most of his life, he finally adopted a vegetarian diet during his final years. By 1954, he reported feeling well living without meat or fish, concluding that humans were perhaps not intended to be carnivores. Additionally, his intellectual curiosity led him to explore various philosophical and esoteric ideas, including the works of Helena Blavatsky and the lectures of Rudolf Steiner.

Love of music

Einstein possessed a profound and lifelong connection to music, once remarking that a career as a musician would have been his likely path had he not pursued physics. He experienced his thoughts and daydreams through musical structures, viewing his entire life through the lens of harmony and rhythm. His journey with the violin began at age five, encouraged by his mother to foster both artistic appreciation and cultural integration. Although he initially lacked interest, his perspective changed entirely at thirteen when he discovered Mozart’s violin sonatas. This encounter sparked a deep passion, leading him to become largely self-taught, as he firmly believed that love for a craft was a far superior motivator than a mere sense of duty.

By the age of seventeen, his talent was evident to outside observers. An examiner in Aarau, after hearing him perform Beethoven, noted that his playing showed remarkable emotional depth and a rare, genuine affection for the music. While Einstein never sought to become a professional performer, music became an essential pillar of his social existence. Throughout his time in Bern, Zurich, and Berlin, he frequently engaged in chamber music sessions with friends and professional colleagues, including the physicist Max Planck. Although sometimes confused with the musicologist Alfred Einstein who edited the catalog of Mozart's works, Albert’s own involvement remained centered on active performance.

Mozart remained his primary favorite, as Einstein felt his music possessed a celestial purity that seemed to exist naturally within the universe. However, he held an even deeper reverence for Bach, often prioritizing his compositions over those of Beethoven. This dedication to the violin persisted throughout his global travels and into his final years in Princeton. Whether playing with the Zoellner Quartet in Los Angeles or the young members of the Juilliard Quartet later in life, he continued to impress audiences with his technical precision and the expressive clarity of his playing.

Death

On April 17, 1955, Einstein suffered internal bleeding following the rupture of an abdominal aortic aneurysm, a condition that had been surgically addressed years earlier. Even as he was taken to the hospital, he remained dedicated to his work, carrying with him the draft of a speech intended for the seventh anniversary of the State of Israel.

When faced with the option of additional surgery, Einstein firmly declined. He expressed a desire to leave life on his own terms, stating that it was distasteful to prolong existence through artificial means. Having felt that he had fulfilled his purpose, he chose to face the end with elegance. He passed away at Princeton Hospital the following morning at the age of seventy-six.

Following his death, a controversial event occurred during the autopsy when the pathologist, Thomas Stoltz Harvey, removed Einstein's brain without the family’s consent. Harvey hoped that future scientific advancements might eventually reveal the biological secrets behind Einstein’s extraordinary intelligence. Einstein’s body was cremated, and his ashes were scattered in a private, undisclosed location to prevent his resting place from becoming a site of morbid veneration.

Reflecting on his life years later, the physicist J. Robert Oppenheimer described Einstein as a man of remarkable purity, noting that he possessed a character that was simultaneously childlike and deeply stubborn, entirely lacking in worldly sophistication. In accordance with his wishes, Einstein’s personal archives, extensive library, and intellectual property were all bequeathed to the Hebrew University of Jerusalem.

The Family of Albert Einstein: Roots and Relations

The life of Albert Einstein was shaped not only by his immense intellect but also by a family background rooted in the German-Jewish middle class of the late 19th century.

Parents and Siblings

Albert grew up in a supportive, secular environment where music and education were highly valued.

Hermann Einstein (Father): A salesman and engineer. He was a kind-hearted man who ran an electrochemical business. Though he often faced financial difficulties, he encouraged Albert’s early interest in science by giving him his first compass.

Pauline Einstein (Mother) Koch: A talented pianist who instilled a lifelong love of music in Albert. She was a strong-willed woman who ensured her children received a well-rounded education.

Maria "Maja" Einstein (Sister): Albert’s only sibling, born two years after him. They remained exceptionally close throughout their lives. Maja earned a PhD in Romance languages and was one of the few people who truly understood Albert's private nature.

Spouses

Mileva Marić: His first wife and a fellow physicist. Their relationship was a blend of passion and science. However, the pressures of domestic life and Mileva's struggle with depression eventually led to their divorce in 1919.

Elsa Einstein: Albert’s second wife and first cousin. Elsa provided the stability and care he needed as his global fame grew. She managed his schedule and protected his privacy until her death in 1936.

Children

Lieserl: The mysterious first daughter of Albert and Mileva, whose existence only became known to historians in the 1980s.

Hans Albert: A successful professor of hydraulic engineering in the United States. He carried on the family name and professional legacy.

Eduard: A sensitive and brilliant soul who dreamed of becoming a psychiatrist but spent much of his life battling mental illness.

Scientific career

Einstein authored hundreds of books and articles, including over three hundred scientific papers and one hundred fifty non-scientific works. In 2014, a massive archive of his legacy was released, containing more than thirty thousand unique documents. While known for his solo work, he also collaborated on projects like the Bose-Einstein statistics and the Einstein refrigerator.

Statistical mechanics

Thermodynamic fluctuations and statistical physics

In 1900, Einstein submitted his first paper to the journal Annalen der Physik, focusing on the mechanics of capillary attraction. Published the following year, this work examined conclusions drawn from capillarity phenomena. Between 1902 and 1903, he turned his attention to thermodynamics, using a statistical approach to interpret atomic behavior. These early studies provided the necessary groundwork for his 1905 paper on Brownian motion, which offered definitive evidence for the existence of molecules. During 1903 and 1904, his research focused primarily on how the finite size of atoms influenced the process of diffusion.

Theory of critical opalescence

Einstein revisited the challenge of thermodynamic fluctuations, focusing on how density varies within a fluid at its critical point. Under normal conditions, these variations are stable, but at the critical point, they become significant enough to scatter light across all wavelengths, giving the fluid a milky appearance. Einstein connected this phenomenon to Rayleigh scattering, which explains why the sky appears blue when fluctuations are smaller than the wavelength of light. By providing a quantitative derivation of critical opalescence, he demonstrated that both this effect and Rayleigh scattering are direct results of the underlying atomic structure of matter.

1905 – Annus Mirabilis papers

In 1905, Einstein published a series of four groundbreaking articles in the journal Annalen der Physik, a period now referred to as his miracle year. These works introduced the photoelectric effect, which laid the cornerstones for quantum theory, and provided an explanation of Brownian motion. He also established the special theory of relativity and the world's most famous equation, E=mc2. Collectively, these papers fundamentally reshaped the landscape of modern physics by altering our understanding of the relationships between space, time, and matter.

Special relativity

Einstein’s landmark work on the electrodynamics of moving bodies, submitted and published in 1905, effectively harmonized the discrepancies between Newtonian mechanics and Maxwell’s electromagnetic equations. This was achieved by fundamentally revising the laws of mechanics, with the most significant effects occurring at velocities approaching the speed of light. This framework eventually became established as the special theory of relativity.

The paper introduced several revolutionary predictions, most notably that a clock in motion would appear to slow down when viewed by a stationary observer, and that objects would undergo physical contraction along their path of travel. Furthermore, Einstein demonstrated that the widely accepted concept of a luminiferous ether was entirely unnecessary to explain the behavior of light.

As a direct result of his special relativity equations, Einstein derived the principle of mass-energy equivalence, represented by E=mc2. While these ideas remained a subject of intense debate for a considerable period, they eventually gained acceptance among the scientific elite, with Max Planck being one of the first major proponents. Although Einstein initially approached the theory through the study of moving bodies, it was later given a geometric interpretation by Hermann Minkowski, who introduced the concept of four-dimensional spacetime. Einstein later integrated this mathematical structure into his 1915 general theory of relativity.

General relativity

General relativity and the equivalence principle

Developed by Einstein between 1907 and 1915, general relativity serves as a revolutionary theory of gravitation. It proposes that the gravitational pull observed between masses is actually the result of those masses warping the very fabric of spacetime. This framework has become a cornerstone of modern astrophysics, providing the essential theoretical basis for understanding black holes—regions where gravity is so intense that even light is trapped.

Einstein was motivated to create this theory because he found the focus on constant, inertial motion in special relativity to be incomplete. He sought a more comprehensive system that could account for all forms of motion, including acceleration. In 1907, he introduced the equivalence principle, arguing that an observer in free fall is effectively in an inertial state where the rules of special relativity still apply. Within this same period, he predicted several key phenomena: the slowing of time due to gravity, the shifting of light toward the red end of the spectrum, and the bending of light by massive objects, known as gravitational lensing.

By 1911, Einstein expanded these ideas to calculate exactly how much light would be deflected when passing near a massive body. This provided the first concrete opportunity to move his theories from the realm of abstract mathematics to experimental testing, allowing the scientific community to verify general relativity through direct observation.

Gravitational waves

In 1916, Einstein proposed the existence of gravitational waves, which are ripples in the fabric of spacetime that travel outward from their source, carrying energy as gravitational radiation. This phenomenon is a direct consequence of general relativity and its principle of a finite speed for physical interactions. This stands in sharp contrast to Newtonian theory, which assumed that gravity acts instantaneously across any distance, making such waves impossible under the old laws.

The first indirect evidence of these waves surfaced in the 1970s through the study of a binary neutron star system. Scientists observed a gradual decay in the stars' orbital period, a change that could only be explained by the energy lost through the emission of gravitational radiation. Einstein's foresight was definitively validated on February 11, 2016. Researchers at the LIGO observatory announced the first direct detection of gravitational waves, which had reached Earth in September 2015—marking the confirmation of his theory nearly a century after it was first written.

Hole argument and Entwurf theory

During the development of general relativity, Einstein struggled with the concept of gauge invariance, leading him to a false conclusion that a general relativistic field theory was mathematically impossible. Consequently, he paused his search for fully covariant equations and instead focused on those that remained invariant only under linear transformations.

This period of uncertainty resulted in the "Entwurf" or draft theory in June 1913. This version was considerably less refined and more complex than the final theory of general relativity, requiring extra conditions to function. However, after two years of rigorous effort, Einstein identified the flaw in his previous logic. In November 1915, he abandoned the draft theory and returned to the correct path that would lead to his completed masterpiece.

Physical cosmology

In 1917, Einstein expanded the application of general relativity to encompass the structure of the entire universe. His initial field equations suggested a dynamic cosmos that was either expanding or contracting. Since there was no observational evidence for such motion at the time, he introduced the cosmological constant to force the equations to predict a stable, static universe. This model, characterized by closed curvature, became known as the Einstein World and is now recognized as the beginning of modern theoretical cosmology.

This perspective shifted in 1929 when Edwin Hubble discovered that galaxies were actually moving away from each other. Consequently, Einstein discarded his static model in favor of dynamic alternatives, such as the Friedmann–Einstein and Einstein–de Sitter models. In these new versions, he removed the cosmological constant, viewing it as a theoretically unsatisfactory addition. Although popular biographies often claim he later called the constant his "biggest blunder," some historians have questioned the authenticity of that specific remark.

Recent findings also reveal that in early 1931, Einstein briefly explored a steady-state model. In this discarded manuscript, he proposed that as the universe expands, its density remains constant through the continuous creation of new matter. This shows that he considered the steady-state theory long before it was popularized by other scientists, though he quickly abandoned the idea after identifying a fundamental flaw in the logic.

Energy momentum pseudotensor

Within the framework of general relativity, the dynamic nature of spacetime makes it difficult to define conserved energy and momentum. While Noether's theorem typically allows these quantities to be determined through translation invariance, general covariance essentially turns this into a gauge symmetry. Consequently, the energy and momentum derived in this context do not function as a true tensor.

Einstein argued that this difficulty arises from a fundamental principle: the gravitational field can be made to disappear simply by choosing a specific set of coordinates. He maintained that using a non-covariant energy-momentum pseudotensor was the most accurate way to describe how energy and momentum are distributed in a gravitational field. Although this approach was criticized by Erwin Schrödinger for its lack of covariance, it was later supported by prominent physicists such as Lev Landau and Evgeny Lifshitz.

Wormholes

In 1935, Einstein and Nathan Rosen developed a theoretical model known as Einstein–Rosen bridges, or wormholes. Their primary objective was to represent charged elementary particles as solutions to gravitational field equations, seeking to understand if gravity played a fundamental role in the internal structure of matter.

To create these models, they mathematically joined two separate regions of a Schwarzschild black hole solution, effectively creating a bridge between two distinct patches of spacetime. Since these configurations described spacetime curvature without requiring a physical body, Einstein and Rosen proposed them as a possible way to develop a theory that did not rely on the problematic concept of point-like particles. However, subsequent research revealed that these Einstein–Rosen bridges are inherently unstable and would collapse before any matter could pass through them.

Einstein–Cartan theory

To integrate the concept of spinning point particles within the framework of general relativity, it became necessary to expand the affine connection. This generalization involved adding an antisymmetric component known as torsion. This significant theoretical modification was developed through a collaboration between Einstein and the mathematician Elie Cartan during the 1920s, resulting in what is now recognized as the Einstein-Cartan theory.

Equations of motion

In general relativity, the traditional concept of gravitational force is replaced by the curvature of spacetime. Within this framework, an orbit is not seen as a path being diverted by an external force, but rather as an object’s natural attempt to move freely through a landscape that has been warped by the presence of mass. This relationship is famously captured by John Archibald Wheeler’s summary: "Spacetime tells matter how to move; matter tells spacetime how to curve."

The Einstein field equations define how matter and energy create this curvature, while the geodesic equation explains how freely falling bodies navigate these curved paths. Einstein initially viewed the geodesic equation as an independent assumption needed to complete the theory. However, he eventually saw this as a deficiency and sought to derive the motion of objects directly from the field equations themselves.

Because the equations are non-linear, Einstein proposed that the movement of a concentrated region of energy, such as a black hole, should be dictated by the field equations rather than a separate law. He argued that the equations should naturally force such singular solutions to follow a geodesic path. While many physicists and philosophers continue to claim that the geodesic equation can be derived by applying the field equations to gravitational singularities, this assertion remains a subject of ongoing debate in the scientific community.

Old quantum theory

Photons and energy quanta

In his 1905 paper, Einstein proposed the revolutionary idea that light is composed of localized particles, which he referred to as quanta. This concept was met with nearly universal skepticism from the scientific community, including prominent figures like Max Planck and Niels Bohr. It was not until 1919, following Robert Millikan’s rigorous experiments on the photoelectric effect and the observation of Compton scattering, that the existence of light particles gained widespread acceptance.

Einstein determined that for a wave of a given frequency f, the energy of each associated photon is defined by the product hf, where h represents Planck's constant. At the time, he remained cautious about how these discrete particles related to the nature of waves, yet he correctly predicted that this model would explain specific experimental phenomena, most notably the photoelectric effect. These light quanta were eventually given the name "photons" by Gilbert N. Lewis in 1926.

Quantized atomic vibrations

In 1907, Einstein introduced a model of matter where every atom within a lattice is viewed as an independent harmonic oscillator. Each of these atoms vibrates on its own, moving through a sequence of quantized energy states that are equally spaced. Although Einstein realized that determining the precise frequency of these oscillations would be a challenge, he moved forward with the theory. He did so because it clearly proved that quantum mechanics could resolve the specific heat issues found in classical physics. This model was subsequently improved by Peter Debye.

Bose–Einstein statistics

In 1924, Einstein was presented with a statistical model by the Indian physicist Satyendra Nath Bose. This model utilized a counting method that treated light as a gas composed of particles that were indistinguishable from one another. Einstein recognized that Bose's statistics were applicable not only to light particles but also to certain atoms. He translated Bose's work for publication and began exploring the implications of this model himself.

Through his own research, Einstein predicted the existence of the Bose–Einstein condensate. He theorized that at extremely low temperatures, a group of particles would collapse into a single quantum state. This phenomenon remained purely theoretical for decades, until it was finally produced in a laboratory setting in 1995. Today, Bose–Einstein statistics serve as the standard framework for describing the behavior of bosons.

Wave–particle duality

In 1906, the patent office promoted Einstein to Technical Examiner Second Class, yet his commitment to academia remained firm. By 1908, he had secured a position as a Privatdozent at the University of Bern. During this period, he produced influential work regarding the quantization of light, specifically in his 1909 papers on the nature of radiation.

Einstein demonstrated that the energy quanta proposed by Max Planck possessed specific momentum and behaved, in several ways, like independent and point-like particles. This work was crucial in establishing the concept of the photon and laid the groundwork for the theory of wave–particle duality in quantum mechanics. For Einstein, the fact that radiation could exhibit both wave and particle characteristics was clear evidence that the existing laws of physics required a completely new and unified foundation.

Zero-point energy

Between 1911 and 1913, Max Planck revised his original quantum theory, introducing the concept of zero-point energy. This new development quickly captured the interest of Einstein and his assistant, Otto Stern. They decided to test the validity of this idea by applying it to the rotation of diatomic molecules.

By incorporating zero-point energy into their calculations, they analyzed the theoretical specific heat of hydrogen gas and found that it aligned closely with experimental results. Despite this successful match, their confidence in the underlying concept faltered. Shortly after their findings were published, Einstein and Stern withdrew their support for the study, as they had become skeptical of the actual existence of zero-point energy.

Stimulated emission

In 1917, while deeply immersed in his work on relativity, Einstein published a paper that introduced the concept of stimulated emission. This physical process is the fundamental principle that later allowed for the creation of the maser and the laser.

Einstein demonstrated that the statistics governing how atoms absorb and emit light would only align with Planck's distribution law if the presence of existing photons enhanced the likelihood of further emission into that same state. This discovery was a landmark in the development of quantum mechanics, as it provided the first evidence that the transitions of electrons within atoms follow simple, predictable statistical laws.

Matter waves

Einstein discovered Louis de Broglie's work and supported his ideas, which were initially met with skepticism. In a major paper, Einstein observed that de Broglie waves could explain the quantization rules of Bohr and Sommerfeld. This work later inspired Schrödinger's research in 1926.

Quantum mechanics

Einstein objections to quantum mechanics

Einstein played a major role in developing quantum theory, beginning with his 1905 paper on the photoelectric effect. However, he became displeased with modern quantum mechanics as it evolved after 1925, despite its acceptance by other physicists. He was skeptical that the randomness of quantum mechanics was fundamental rather than the result of determinism, famously stating that God "is not playing at dice." Until the end of his life, he continued to maintain that quantum mechanics was incomplete.

Bohr versus Einstein

The Bohr–Einstein debates were a series of public disputes about quantum mechanics between Einstein and Niels Bohr, two of its founders. These exchanges are remembered primarily for their profound importance to the philosophy of science. Their debates would eventually shape and influence later interpretations of quantum mechanics.

Einstein–Podolsky–Rosen paradox

Einstein never fully accepted quantum mechanics. While he recognized its correct predictions, he believed a more fundamental description of nature was possible. His preferred argument, dating to a 1930 debate with Bohr, involved two objects that interact and move far apart. Because of quantum entanglement, measuring one object instantaneously changes the wavefunction of the other. Einstein reasoned that no influence can propagate instantaneously, and since the state of the second object cannot be immediately altered by an action on the first, the wavefunction must be an incomplete description of reality.

In 1935, Einstein, Boris Podolsky, and Nathan Rosen published the EPR paradox. They argued that if you can predict a particle's position or momentum with certainty without disturbing it, then those values must be "elements of reality." Since quantum mechanics cannot assign definite values to both simultaneously, they concluded the theory was incomplete. They maintained that any instantaneous influence between particles would violate relativity.

In 1964, John Stewart Bell showed that if hidden variables determined the outcomes for entangled particles, there would be a mathematical limit on their correlations, known as Bell's inequality. Quantum physics predicts correlations that violate this limit. Bell concluded that any hidden variable explanation would require "nonlocality"—an instantaneous interaction that Einstein rejected. While the EPR paper was complex, it became a foundation for quantum information theory.

Unified field theory

Encouraged by his success with general relativity, Einstein sought an even more ambitious geometrical theory that would treat gravitation and electromagnetism as aspects of a single entity. In 1950, he described his unified field theory in an article titled "On the Generalized Theory of Gravitation". His attempt to find the most fundamental laws of nature won him praise but not success. A particularly conspicuous blemish of his model was that it did not accommodate the strong and weak nuclear forces, neither of which was well understood until many years after his death. Although most researchers now believe that Einstein's approach to unifying physics was mistaken, his goal of a theory of everything is one to which his successors still aspire.

Other investigations

Einstein conducted other investigations that were unsuccessful and eventually abandoned. These projects pertained to the nature of force, the phenomenon of superconductivity, and various other research topics. Despite his immense intuition, these specific paths did not lead to the breakthroughs he sought during his career.

Collaboration with other scientists

In addition to longtime collaborators such as Leopold Infeld, Nathan Rosen, and Peter Bergmann, Einstein engaged in several one-shot collaborations with various other scientists. These brief partnerships allowed him to explore a wide range of specialized topics outside of his primary research focus.

Einstein–de Haas experiment

In 1908, Owen Willans Richardson predicted that a change in the magnetic moment of a body would cause it to rotate. This phenomenon, rooted in the conservation of angular momentum, is particularly observable in ferromagnetic materials. In 1915, Einstein and Wander Johannes de Haas published research claiming the first experimental observation of this occurrence.

These measurements prove that magnetization results from the alignment of electron angular momenta along a specific axis. The experiment also allows for a distinction between the contributions of electron spin and orbital motion to total magnetization. Notably, this remains the only experiment that Einstein personally conceived, executed, and published.

The original experimental equipment was donated to the Ampère Museum in Lyon, France, in 1961. After being lost within the museum's extensive collections for decades, it was rediscovered in 2023 and is now on display.

Einstein as an inventor

In 1926, Einstein and his former student Leó Szilárd co-invented an absorption refrigerator, which they patented in 1930. This device was revolutionary because it contained no moving parts and required only heat as an input to operate. On November 11, 1930, U.S. patent 1,781,541 was awarded to Einstein and Leó Szilárd for the refrigerator.

Although it was not immediately produced for the commercial market, several of their most promising patents were purchased by the Swedish company Electrolux. Beyond this, Einstein also invented an electromagnetic pump, a sound reproduction device, and various other household appliances.

Legacy

Non-scientific

While traveling, Einstein wrote daily to his wife Elsa and adopted stepdaughters Margot and Ilse. These letters were bequeathed to the Hebrew University of Jerusalem. Margot Einstein requested that these personal letters remain private until twenty years after her death. Barbara Wolff of the Einstein Archives noted there are approximately 3,500 pages of private correspondence written between 1912 and 1955.

In his final four years, Einstein helped establish the Albert Einstein College of Medicine in New York City. In 1979, the Albert Einstein Memorial was unveiled in Washington, D.C., for his centenary. The statue by Robert Berks depicts Einstein holding a paper with his equations for the photoelectric effect, general relativity, and mass-energy equivalence.

Einstein's right of publicity was litigated in 2015. While a lower court initially claimed the right had expired, that decision was vacated, and the Hebrew University of Jerusalem remains the exclusive representative of his image and name. Mount Einstein in Alaska was named in 1955, and another peak in New Zealand's Paparoa Range was named after him in 1970. In 1999, Time named him Person of the Century.

Scientific

In 1999, a survey of the top 100 physicists voted Einstein as the greatest physicist ever. A parallel survey of rank-and-file physicists placed him second, with Isaac Newton taking the top spot.

Physicist Lev Landau used a logarithmic scale from 0 to 5 to rank genius and productivity. He placed Newton and Einstein in a "super league," assigning Newton a 0 and Einstein a 0.5. For comparison, pioneers of quantum mechanics like Werner Heisenberg and Paul Dirac were ranked 1, while Landau ranked himself a 2.

Eugene Wigner observed that while John von Neumann possessed the quickest and most acute mind he had ever known, Einstein's mind was more penetrating and original. Wigner noted that Einstein took extraordinary pleasure in invention, and neither von Neumann nor any other modern physicist produced anything as original as the Special and General Theories of Relativity.

In recognition of his "miracle year" in 1905, the International Union of Pure and Applied Physics and the United Nations declared 2005 the World Year of Physics, also known as Einstein Year.

In popular culture

Einstein became one of the most famous scientific celebrities after the confirmation of his general theory of relativity in 1919. Although most of the public had little understanding of his work, he was widely recognized and admired. In the period before World War II, The New Yorker published a vignette saying that Einstein was so well known in America that he would be stopped on the street by people wanting him to explain "that theory". Eventually, he came to cope with unwanted enquirers by pretending to be someone else, saying: "Pardon me, sorry! Always I am mistaken for Professor Einstein."

Einstein has been the subject of or inspiration for many novels, films, plays, and works of music. He is a favorite model for depictions of absent-minded professors; his expressive face and distinctive hairstyle have been widely copied and exaggerated. Time magazine's Frederic Golden wrote that Einstein was "a cartoonist's dream come true". His intellectual achievements and originality made Einstein broadly synonymous with genius.

To add to this, Strategist, his influence extends into unexpected areas:

• The iconic character Yoda from Star Wars had his eyes and wrinkles partially modeled after Einstein to convey a look of wisdom.
• The chemical element 99, discovered in the debris of the first hydrogen bomb explosion in 1952, was named Einsteinium in his honor.
• One of the most famous photographs of the 20th century—Einstein sticking out his tongue—was taken on his 72nd birthday. He liked the photo so much that he ordered nine prints for his personal use.

Awards and honors

Einstein received numerous awards and honors. In 1922, he was awarded the 1921 Nobel Prize in Physics for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect. Since none of the nominations in 1921 met the specific criteria set by Alfred Nobel, the prize was carried forward and awarded to him a year later.

Einsteinium, a synthetic chemical element, was named in his honor in 1955, just a few months after his death.

• Barnard Medal for Meritorious Service to Science (1920)
• Matteucci Medal (1921)
• Copley Medal (1925) – the oldest and most prestigious award of the Royal Society.
• Gold Medal of the Royal Astronomical Society (1926)
• Max Planck Medal (1929) – awarded by the German Physical Society.
• Franklin Medal (1935) – for his contributions to theoretical physics.
• Honorary Doctorate from Princeton University (1933) and many other global institutions.

Publications

This is not the complete list. These are only the most famous pillars of his work. In total, Einstein published more than 300 scientific papers and over 150 non-scientific works.

Early Foundations and Statistical Mechanics (1901–1904)

1. 1901: Conclusions Drawn from the Phenomena of Capillarity Einstein’s first paper, investigating intermolecular forces through the lens of liquid surfaces.
2. 1902: Thermodynamic Theory of the Potential Difference between Metals and Completely Dissociated Solutions of Their Salts An investigation into molecular forces and the thermodynamics of electrolytes.
3. 1902: Kinetic Theory of Thermal Equilibrium and of the Second Law of Thermodynamics A foundational paper in statistical mechanics, developed independently of Josiah Willard Gibbs.
4. 1903: A Theory of the Foundations of Thermodynamics An attempt to define the foundations of the second law of thermodynamics using kinetic theory.
5. 1904: On the General Molecular Theory of Heat A study of energy fluctuations which served as the precursor to his work on Brownian motion.

Annus Mirabilis — The Miracle Year (1905)

1. 1905: On a Heuristic Viewpoint Concerning the Production and Transformation of Light The proposal of the light quanta (photon) to explain the photoelectric effect.
2. 1905: A New Determination of Molecular Dimensions His doctoral thesis providing a mathematical method to determine the size of atoms.
3. 1905: On the Motion of Small Particles Suspended in a Stationary Liquid The theoretical explanation of Brownian motion, proving the existence of atoms.
4. 1905: On the Electrodynamics of Moving Bodies The introduction of Special Relativity, redefining space and time.
5. 1905: Does the Inertia of a Body Depend Upon Its Energy Content? The derivation of the equivalence of mass and energy, resulting in E=mc2.

Quantum Theory and the Path to General Relativity (1906–1915)

1. 1906: On the Theory of Light Production and Light Absorption A deeper dive into Planck’s radiation law and quantum energy.
2. 1907: Planck’s Theory of Radiation and the Theory of Specific Heat Applied quantum theory to the specific heat of solids, solving a long-standing thermodynamic puzzle.
3. 1907: On the Relativity Principle and the Conclusions Drawn from It The first introduction of the Equivalence Principle and the prediction of gravitational redshift.
4. 1909: On the Development of Our Views Concerning the Nature and Constitution of Radiation The first prediction of the wave-particle duality of light.
5. 1910: Theory of the Opalescence of Homogeneous Fluids and Liquid Mixtures near the Critical State Explained why the sky turns white/opaque near critical temperatures (critical opalescence).
6. 1911: On the Influence of Gravitation on the Propagation of Light Predicted the bending of starlight by the Sun's gravity.
7. 1913: Project of a Generalized Theory of Relativity and a Theory of Gravitation Co-authored with Marcel Grossman; the "Entwurf" paper that introduced the metric tensor.
8. 1914: Formal Foundations of the General Theory of Relativity A massive 100-page summary of the mathematical tools needed for the final theory.

General Relativity and Cosmology (1915–1920)

1. 1915: On the General Theory of Relativity The series of four papers delivered to the Prussian Academy of Sciences.
2. 1915: Explanation of the Perihelion Motion of Mercury from the General Theory of Relativity Proved OTO by solving the mystery of Mercury's orbit.
3. 1915: The Field Equations of Gravitation The final derivation of the Einstein Field Equations.
4. 1915: Experimental Proof of Ampère's Molecular Currents Co-authored with de Haas, describing the Einstein–de Haas effect.
5. 1916: The Foundation of the General Theory of Relativity The definitive, comprehensive paper on the finalized theory of gravity.
6. 1916: Quantum Theory of Radiation Introduced stimulated emission (the basis for the laser) and the concept of "probability" in transitions.
7. 1917: Cosmological Considerations in the General Theory of Relativity Founded modern cosmology and introduced the Cosmological Constant (Λ).
8. 1918: On Gravitational Waves The first formal prediction of ripples in the fabric of spacetime.

Bose-Einstein Statistics and Unified Field Theory (1921–1955)

1. 1922: The Meaning of Relativity The core textbook based on his lectures at Princeton University.
2. 1923: On the General Theory of Relativity Early attempts to expand the geometric framework of gravity.
3. 1924: Quantum Theory of the Monatomic Ideal Gas Applied Bose's statistics to atoms, founding Bose-Einstein statistics.
4. 1925: Quantum Theory of the Monatomic Ideal Gas: Second Communication Predicted the existence of the Bose-Einstein Condensate (BEC).
5. 1927: On Kaluza's Theory of the Connection between Gravitation and Electricity Explored the five-dimensional theory to unify gravity and light.
6. 1935: Can Quantum-Mechanical Description of Physical Reality Be Considered Complete? The EPR paper (with Podolsky and Rosen) regarding entanglement and hidden variables.
7. 1935: The Particle Problem in the General Theory of Relativity Co-authored with Rosen; introduced the concept of "wormholes" (Einstein–Rosen bridges).
8. 1938: The Evolution of Physics Co-authored with Leopold Infeld; a revolutionary look at the conceptual history of physics.
9. 1938: Gravitational Equations and the Problem of Motion A rigorous derivation of the motion of stars and planets directly from field equations.
10. 1950: On the Generalized Theory of Gravitation His late-stage work published in Scientific American regarding the Unified Field Theory.
11. 1955: The Meaning of Relativity (5th Edition) Contained "Appendix II," the final mathematical iteration of his search for a Unified Field Theory.

Einstein Metaphysical Portrait: Astrology, Numerology, and the Pythagorean Square

To understand the persona of Albert Einstein beyond his formulas, one can explore his life through the lens of ancient symbolic systems. These frameworks provide a unique perspective on the internal tensions between his intuitive nature and his rigorous intellectual discipline.

Scientific Disclaimer: It is critical to note that astrology and numerology are not sciences. They are classified as pseudosciences because they lack empirical evidence, reproducibility, and the objective validity of the scientific method. While they offer a symbolic lens for character analysis, they are not based on the physical reality that Einstein dedicated his life to measuring.

Astrological Profile

Albert Einstein’s identity as a Pisces explains the intuitive and "boundary-breaking" nature of his intellect, which allowed him to visualize the universe as a fluid fabric rather than a rigid machine. Born on March 14, he fell under the influence of Neptune, the planet of illusions, dreams, and the infinite. This astrological placement suggests that his primary tool for discovery was not cold calculation, but a profound, almost mystical intuition. He famously stated that "imagination is more important than knowledge," a sentiment that perfectly captures the Piscean essence—the ability to perceive a reality that exists beyond the reach of the five senses.

In practice, this manifested through his "Gedankenexperiments" (thought experiments). While his contemporaries were stuck in laboratories, Einstein was "dreaming" of what it would be like to ride alongside a beam of light. However, his chart contains a fascinating internal contradiction: the presence of Saturn (the planet of structure and discipline) provided a "grounding" force. While a typical Pisces might get lost in dreams, Einstein’s Saturnian influence forced him to translate those dreams into the rigorous language of mathematics. This explains why he spent decades stubbornly pursuing the "Unified Field Theory," refusing to accept that the universe could be governed by the chaotic randomness of quantum mechanics. He was a dreamer who demanded that his dreams be mathematically perfect.

Numerology

The numbers 5 and 33 shaped Einstein’s life by defining him as a lifelong rebel who ultimately became a global teacher for humanity. To arrive at these conclusions, we look at two primary calculations: the day of birth (Soul Number) and the total sum of the birth date (Destiny Number). Einstein was born on the 14th, which in numerology reduces to 5 (1+4=5). The number 5 is the vibration of the "eternal student" and the "revolutionary." It gave him an inherent distaste for the rigid, Prussian-style education of his youth and the courage to challenge Sir Isaac Newton’s 200-year-old laws. Without the disruptive energy of the 5, Einstein might have remained a patent clerk, too afraid to question the scientific status quo.

As he matured, the "higher octave" of his life path emerged: the Master Number 33 (derived from the sum: 1+4+0+3+1+8+7+9=33). While 33 usually reduces to 6—the number of family, harmony, and local responsibility—the double digits signify a "Master Teacher" whose responsibility extends to the entire human race. We see this transition clearly in Einstein’s biography: after establishing the laws of the universe, he shifted his focus to the fate of the world. He became an advocate for global government and nuclear disarmament, using his immense intellectual authority to teach humanity how to survive the atomic age he helped create.

The Pythagorean Square

The Pythagorean Square reveals that Einstein’s mind was architecturally built for intellectual excess and scientific hypersensitivity, specifically through a rare concentration of the number 3. In the Pythagorean system (a 3x3 grid based on birth numbers), the "3" represents logic, technology, and the understanding of the material world. Einstein possessed an "overload" of four 3s (3333), a configuration so rare it is often called the "sign of a discoverer." This gave him a specialized form of perception, allowing him to see the internal logic of the cosmos as clearly as one might see the gears of a clock.

Another vital revelation of his matrix is the complete absence of the number 2. In this numerological school, "2" represents vital physical energy and the ability to interact with the external world. A person with "No 2s" is like a high-powered computer with a small battery—they must be extremely selective about how they spend their energy. This perfectly explains Einstein’s legendary detachment: he was often seen as "absent-minded" or socially distant because his brain was consuming 99% of his available energy to solve cosmic puzzles. He didn't have the energy for small talk, matching socks, or social niceties. Furthermore, his Character Score of 111 indicates a "Golden Mean"—he had exactly enough ego to believe in his own revolutionary ideas against the rest of the world, but not so much that he became a dogmatic tyrant.

Question and Answers

1. What is the fundamental difference between Special and General Relativity?

Special Relativity (1905) focuses on objects moving at constant high speeds and introduces time dilation. General Relativity (1915) includes gravity, explaining it as the curvature of spacetime caused by mass and energy.

2. What does the equation E=mc2 actually represent?

It expresses mass-energy equivalence, stating that energy (E) equals mass (m) times the speed of light (c) squared. This implies that even a small amount of matter contains a vast amount of energy.

3. Why did Einstein win the Nobel Prize in Physics?

He was awarded the 1921 Nobel Prize specifically for his discovery of the law of the photoelectric effect, which proved that light consists of particles called photons, laying the groundwork for quantum mechanics.

4. What was Einstein's "Miracle Year"?

The year 1905 (Annus Mirabilis), during which he published four groundbreaking papers on the photoelectric effect, Brownian motion, Special Relativity, and mass-energy equivalence.

5. What are gravitational waves?

These are "ripples" in the fabric of spacetime caused by massive accelerating objects (like merging black holes), predicted by Einstein in 1916 and directly detected for the first time in 2015.

6. Why did Einstein famously say "God does not play dice"?

He used this phrase to express his discomfort with the inherent randomness and uncertainty of quantum mechanics, believing that the universe must follow strict, deterministic laws.

7. Did Einstein really fail mathematics in school?

No, this is a myth. He was an exceptional student in mathematics and physics from a young age, mastering differential and integral calculus by age 15.

8. What was his involvement with the Manhattan Project?

Einstein did not work on the project. However, he signed a letter to President Roosevelt warning that Germany might develop an atomic bomb, which catalyzed the US nuclear program.

9. Why is he often pictured with his tongue out?

The photo was taken on his 72nd birthday. Tired of smiling for photographers, he stuck his tongue out in an attempt to ruin the shot, but it became his most iconic image.

10. Was Einstein offered a presidency?

Yes, in 1952, he was offered the presidency of the State of Israel. He declined, stating he lacked the "natural aptitude" to deal with people and formal duties.

11. What musical instrument did he play?

He was an avid violinist. He once said that if he were not a physicist, he would probably be a musician, as he often used music as a way to clear his mind for scientific problems.

12. Why didn't he wear socks?

Einstein found socks unnecessary and annoying because they eventually developed holes. He preferred the simplicity and freedom of going without them.

13. What was his "Greatest Blunder"?

The introduction of the "Cosmological Constant" into his equations to maintain a static universe. He removed it after Hubble proved the universe is expanding.

14. What happened to his brain after he died?

It was removed by pathologist Thomas Harvey for scientific study. Research later suggested that certain areas related to mathematical and spatial reasoning were larger than average.

15. What were his religious views?

He described himself as an agnostic or a "religious non-believer." He believed in Spinoza's God—a god revealed in the harmony of the universe—rather than a personal deity.

16. What is the Unified Field Theory?

This was Einstein's unfinished attempt to merge all fundamental forces of nature (specifically gravity and electromagnetism) into a single master equation.

17. How did Einstein view imagination?

He famously stated: "Imagination is more important than knowledge. For knowledge is limited, whereas imagination embraces the entire world."

18. Did he support vegetarianism?

He became a strict vegetarian late in life, believing that the transition to a vegetarian diet would greatly benefit the health and survival of humanity.

19. What was his view on the "mystery" of the world?

He believed that "The most beautiful thing we can experience is the mysterious," citing it as the source of all true art and science.

20. What were his last words?

His last words were spoken in German to a nurse who did not understand the language. Consequently, his final thoughts remain a mystery.

Einstein 20 facts

1. Late Talker: He didn’t start speaking comfortably until he was about four years old, leading his parents to fear he had a learning disability.
2. The "Love Letters" Scandal: Einstein’s private letters revealed he had a tumultuous love life, including a secret daughter (Lieserl) whose fate remains a mystery.
3. Harsh Marriage Rules: He gave his first wife, Mileva Marić, a list of brutal conditions to stay married, including: "You will expect no affection from me" and "You must leave my bedroom or study immediately without protest if I request it."
4. Marrying His Cousin: After divorcing Mileva, he married his first cousin, Elsa Löwenthal.
5. The Nobel Prize Divorce Settlement: He was so confident he would win the Nobel Prize that he promised the prize money to his first wife as a divorce settlement years before he actually won it.
6. He Hated Socks: Einstein considered socks a nuisance because they often got holes in them. He famously stopped wearing them altogether, even to formal events.
7. FBI Surveillance: Because of his pacifist and civil rights activism, J. Edgar Hoover’s FBI kept a secret file on him for 22 years, which eventually grew to over 1,400 pages.
8. The "Atomic" Regret: Although a pacifist, he signed a letter to FDR urging the development of the atomic bomb (fearing the Nazis would get it first). He later called it the "one great mistake" of his life.
9. Refused the Presidency: In 1952, he was offered the presidency of Israel but declined, stating he lacked the "aptitude and experience" to deal with people.
10. The Brain Thief: After his death, the pathologist Thomas Harvey stole Einstein’s brain during the autopsy without permission, keeping it in jars for decades to study it.
11. Violin Therapy: He loved his violin (named "Lina") and said he often thought in music. If he was stuck on a theory, he would play until the solution came to him.
12. The Iconic Tongue Photo: That famous photo was taken on his 72nd birthday because he was tired of smiling for photographers and wanted to ruin the shot. He ended up loving the photo himself.
13. Bad Memory for Names: Despite his genius, he was notoriously forgetful about everyday things like names, dates, and phone numbers.
14. Sailing "Expert": He loved sailing but was famously terrible at it. He frequently got lost or capsized his boat, but refused to wear a life jacket because he couldn't swim.
15. No Car: He never learned to drive and never owned a car. He preferred walking or being driven.
16. Cigarette Smoke as a Tool: He was a life member of the Montreal Pipe Smokers' Club and believed pipe smoking contributed to a "calm and objective judgment."
17. Civil Rights Advocate: Long before the movement went mainstream, he called racism America’s "worst disease" and was a close friend of W.E.B. Du Bois.
18. The "Miracle Year": In 1905, while working as a humble patent clerk, he published four papers that fundamentally changed modern physics.
19. He Failed a College Entrance Exam: Contrary to the myth, he was great at math, but he failed the general section (botany, zoology, and languages) of his first entrance exam to the Swiss Federal Polytechnic.
20. Last Words Lost: He spoke his final words in German to a nurse who didn't understand the language, so his last thoughts are lost to history forever.

Sources

1. Falk, Dan (2 April 2021). "One Hundred Years Ago, Einstein Was Given a Hero's Welcome by America's Jews". Smithsonian Magazine. Retrieved 14 March 2025.
2. Public Domain Day 2026 Is Coming: Here’s What to Know