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Albert Einstein

Detalles Breves:
Fecha de Nacimiento: Marzo 14, 1879
Origen: Ulm, Baden-Wuerttemberg, Alemania
Nombre de Nacimiento: Albert Einstein
Altura: 1.75 m (5' 8.9")
Sexo: Masculino
Ocupación: Académico | Astronomía | Matemático/a | Física | Científico/a

A 17 personas les gusta
Por TM
Nombres Alternativos / Sobrenombres: 

Albert



Albert Einstein



Biografía

Born on March 14, 1879, in Ulm, Germany to Hermann Einstein, a salesman and engineer and Pauline Einstein (née Koch).

Albert Einstein the scientist considered as one of the greatest thinkers ever. He is best known for his theory of relativity but his contributions to physics also include relativistic cosmology, capillary action, critical opalescence, classical problems of statistical mechanics and their application to quantum theory, an explanation of the Brownian movement of molecules, atomic transition probabilities, the quantum theory of a monatomic gas, thermal properties of light with low radiation density (which laid the foundation for the photon theory), a theory of radiation including stimulated emission, the conception of a unified field theory, the geometrization of physics and the discovery of the law of the photoelectric effect. Einstein received the 1921 Nobel Prize in Physics "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect. Einstein published over 300 scientific works and over 150 non-scientific works.

Early life
Early career
1905, Annus Mirabilis
Photoelectric Effect
Special relativity theory
Mass energy equivalence
Post-1905 years - Einstein's early scientific career
General Theory of Relativity
Post-1915 years - Einstein's consolidated scientific career
Nuclear Age and World War II
The Cold War
Paternal family history
Maternal family history

Early life

Albert Einstein was born in Ulm, Württemberg, Germany on March 14, 1879 at 11.30 a.m., to Hermann Einstein and Pauline Einstein Koch. The address of his birth house was in Bahnhofstraße B 135, later renamed Bahnhofstraße 20.

Despite the Jewish origin of his family, the Einsteins were not observant of Jewish religious practices, and thus Albert attended a Catholic elementary school.

He spent his first year of life in Ulm from his birth in March 1879 until June 1880. In June 1880 the family moved to Munich where Hermann Einstein and his brother Jakob founded the electrical engineering company Einstein & Cie. Albert Einstein's sister Maria, called Maja, was born on November 18, 1881. The family would live in Munich until December 1894.

During his early childhood Albert had early speech difficulties, this gave birth to the term used to describe the syndrome which bears his name, the "Einstein syndrome". This term is used to describe exceptionally bright people with a slow development of speech, unlikely to have conversations before age four. Some common aspects given in this syndrome are: delayed speech development, usually happens in boys, highly educated parents, musically gifted families, puzzle solving abilities, lagging social development, delayed toilet training. Due to this slowness in learning how to speak. His parents even consulted a doctor.

Some researchers claim to detect in Einstein's childhood a mild manifestation of autism or Asperger's syndrome. Simon Baron-Cohen, the director of the autism research center at Cambridge University, is among those. He writes that autism is associated with a particularly intense drive to systemize and an unusually low drive to empathize. He also notes that this pattern explains the islets of ability that people with autism display in subjects like math or music or drawing -- all skills that benefit from systemizing. However this is not so convincing in the case of Einstein since as a teenager, Einstein made close friends, had passionate relationships, enjoyed collegial discussions, communicated well verbally and could empathize with friends and humanity in general, not to mention his social and political contribution to mankind during the difficult years of World War II and the Post-War years.

Einstein himself, decades later, said that one of his earliest memories was "the ambition to speak in whole sentences "so I would try each sentence out...saying it softly. Then, when it seemed alright, I said it out loud". Up to at least age seven, the habit of softly and slowly rehearsing his words persisted.

Beginning in 1884 he received private education in order to get prepared for school.

When someone reads his autobiography of Albert Einstein you will find in the description of his childhood and teenage years some hints pointing to two "wonders". These two "wonders" were, the encounter with a pocket compass that his father showed him when he was five years old; the other wonder was a geometry book. These two objects or wonders as he used to call them have strongly influenced his further way of life.

About the first "wonder" which deeply impressed him, the pocket compass, he wrote: "I encountered a wonder of such a kind as a child of 4 or 5 years when my father showed me a compass. That this needle behaved in such a determined way did not fit into the way of incidents at all which could find a place in the unconscious vocabulary of concepts (action connected with touch). I still remember – or I think I do – that this incident has left with me a deep impression. There must have been something behind things that was deeply hidden. To things which man sees from childhood on in front of him he does not respond to in such a way, he does not wonder about the falling of bodies, about wind and rain, not about the moon nor about the moon not falling down and not about the difference between the animate and inanimate".

Einstein realized that something in empty space was moving the needle. The needle's invariable northward swing, guided by an invisible force, profoundly impressed the child. The compass convinced him that there had to be "something behind things, something deeply hidden". Even as a small boy Einstein was self-sufficient and thoughtful.

During 1885, at his mother's insistence who adored music, he started learning to play violin, and although he disliked it and eventually quit, he later took great pleasure in Mozart's violin sonatas. That same year he started attending "Petersschule" (Peter’s School), a catholic public primary school in Munich, which he attended from October 1885 until 1888.

Einstein did not like the strict rules he had to follow in school and only really applied himself to the subjects that interested him, such as math and Latin.

He also had a cheeky rebelliousness toward authority. But these traits helped make him a genius. His cocky contempt for authority led him to question conventional wisdom. His slow verbal development made him curious about ordinary things such as space and time that most adults take for granted. As mentioned above the nature of the compass stamped such a deep impression on him that he puzzled over the nature of a magnetic field for the rest of his life. And he tended to think in pictures rather than words.

Young Albert had a quick temper, however, it vanished during his first school years. Albert’s sister Maja reports in Albert Einstein - Beitrag für sein Lebensbild (Albert Einstein – Contribution for his biography) the following: "In such moments his face became all yellow, however, the tip of his nose became snow-white, and he was no longer under control. At such an opportunity he once grabbed a chair and threw it after his home tutor, who was so terrified, that she ran away and never came back again. His little sister was once thrown a big skittles ball on the head and a third time a children’s pick served as a device for, hitting somebody on the head".

According with Maja, little Albert liked to play with "puzzles, jigsaw works, building complex constructions with a construction kit". He liked best building houses of cards, which he was able to build up to 14 stories high as a ten-year-old. He was less interested in wild and sportive games with other children. With increasing age he began to read very much and with much concentration. As he grew, Einstein built models and mechanical devices for fun, and began to show a talent for mathematics.

During primary school, Albert was self-assured and confidently found the way to solve difficult word problems. He did well, both in primary and high school, but the style of teaching in most subjects was repulsive to him.

Albert's intellectual growth was strongly fostered at home. As mentioned before his mother, a talented pianist, ensured the children's musical education. His father regularly read Schiller and Heine aloud to the family and his uncle Jakob challenged Albert with
mathematical problems, which he solved with a deep feeling of happiness.

In 1888 he changed over to the Luitpold-Gymnasium (Luitpold Grammar School), also in Munich, which he followed from October 1888 until 1894. However, this education was not to his liking and, in addition, he did not get along with his form-master. He did not enjoy his new school any more than his previous one, but he did love studying geometry and tackling mathematical problems.

In 1889 Max Talmud, a poor Jewish medical student from Poland, "for
whom the Jewish community had obtained free meals with the Einstein family" introduced the ten-year-old Albert to key science, mathematics, and philosophy texts. Albert's sister said "Talmud came on Thursday nights for about six years, and invested his whole person in examining everything that engaged Albert's interest". Talmud had Albert read and discuss many books with him. These included a series of twenty popular science books that convinced Albert "a lot in the Bible stories could not be true", Talmud even had Albert read Kant; as a result Einstein began preaching to his schoolmates about Kant, with
"forcefulness".

It's at age 12 that Talmud introduced him the second "wonder" of his life as he used to call it (the first was the compass); a textbook of plane geometry that launched Albert on avid self-study of mathematics, years ahead of the school curriculum. From Euclid, Einstein began to understand deductive reasoning, and by the age of twelve, he had learned Euclidean geometry. Soon thereafter he began to investigate calculus.

He said about it "At the age of 12 I experienced a second wonder of a very different kind: a booklet dealing with Euclidean plane geometry that came into my hands at the beginning of a school year. Here were assertions, as for example the intersection of the three altitudes of a triangle in one point which - though by no means evident - could nevertheless be proved with such certainty that any doubt appeared to be out of the question. This lucidity and certainty made an indescribable impression on me. That the axioms could not be proved did not annoy me. Actually I was completely satisfied when I was able to rely on such theorems whose validity were not doubtful to me. I remember for example that my uncle told me about Pythagoras’ Theorem before the holy geometry book came to my hands. After hard work I succeeded in proving this theorem due to the similarity of triangles; thereby it seemed evident to me, that the relations of the sides of a rectangular triangle must be completely defined by an acute angle. Only what did not seem evident to me in a similar way seemed to need evidence. Also the things that geometry is about did not seem to be of another kind than the things of sensual perception, which could be seen and touched".

However it cannot be said with certainty which book is Einstein’s "holy geometry book". There are three different titles as the possible ones:

  1. Theodor Spieker, 1890. Lehrbuch der ebenen Geometrie. Mit Übungsaufgaben für höhere Lehranstalten.
  2. Heinrich Borchert Lübsen, 1870. Ausführliches Lehrbuch der ebenen und sphärischen Trigonometrie. Zum Selbstunterricht. Mit Rücksicht auf die Zwecke des praktischen Lebens.
  3. Adolf Sickenberger, 1888. Leitfaden der elementaren Mathematik.

Young Albert Einstein owned all of these three books. The book by T. Spieker was given by Max Talmud. The book by H. B. Lübsen was from the library of his uncle Jakob Einstein and the one of A. Sickenberger was from his parents.

The Luitpold Gymnasium was a progressive school. His father intended for him to pursue electrical engineering, but Einstein clashed with authorities and resented the school regimen. He later wrote that the spirit of learning and creative thought were lost in strict rote learning. Although he got generally good grades (and was outstanding in mathematics), Einstein hated the academic high school, where success depended on memorization and obedience to arbitrary authority. His real studies were done at home with books on mathematics, physics, and philosophy.

Of his boyhood studies, Einstein recalled in his autobiographical notes; "At the age of 12-16 I familiarized myself with the elements of mathematics together with the principles of differential and integral calculus. In doing so I had the good fortune of hitting up books which made up for this by permitting the main thoughts to stand out clearly and synoptically. This occupation was, on the whole, truly fascinating: climaxes were reached whose impression could easily compete with that of elementary geometry - the basic idea of analytical geometry, the infinite series, the concepts of differential and integral. I also had the good fortune to know the essential results and methods of the entire field of the natural sciences in an excellent popular exposition, which limited itself almost throughout to qualitative aspects (Aaron Bernstein's People's Books on Natural Science, a work of 5 or 6 volumes), a work which I read with breathless attention".

Einstein also recalled that "at the age of 13 I read with entusiasm Ludwig Buchner's, Force and Matter, a book which I later found to be ratherchildish in its ingenous realism".

His school performance seemed already very promising, he received especially good marks in maths and the natural sciences, some worse marks in the languages, in drawing and in sports.

In 1894, when Einstein was fifteen, his father's business failed, and the Einstein family moved to Italy, first to Milan and then, after a few months, to Pavia. However Albert decided to stay in Germany to complete his studies at school.

Albert Einstein never had to "repeat a year" during his whole school time. However when he stayed behind to finish the school year, he did not last long on his own. A teacher suggested Einstein leave school, since his very presence destroyed the other students' respect for the teacher. So he withdrew to join his family in Pavia, convincing the school to let him go by using a doctor's note.

By law, a male German citizen could emigrate only before the age of 17 without having to return for military service. This was impetus for Albert's decision, made without consulting his parents, to conspire with a doctor for a medical release
from the Munich Gymnasium, join his family in Italy, and renounce German
citizenship. He left school before time in December 1894 without taking his exams.

When he moved to Italy, he had left the unpleasant rigors and discipline of the German Gymnasium, but had also left the school in Munich without a diploma. He spent a glorious period of nine months of freedom from work and anxiety with his parents in Italy, and during this time thought about pursuing higher education in theoretical physics. He would later think of gaining admission to the Swiss Federal Institute of Technology in Zurich by taking the entrance examination.

During this time he wrote his first scientific work, "The Investigation of the State of Aether in Magnetic Fields". Back in the days of early modern physics scientists proposed the existence of a medium called aether (also spelled ether), a space-filling substance or field, thought to be necessary as a transmission medium. The assorted aether theories embody the various conceptions of this "medium" and "substance". Essentially it was considered to be a physical medium occupying every point in space, including within material bodies. A second essential feature was that its properties give rise to the electric, magnetic and gravitational potentials and determines the propagation velocity of their effects. Therefore the speed of light and all other propagating effects are determined by the physical properties of the aether at the relevant location, analogous to the way that gaseous, liquid and solid media affect the propagation of sound waves. The Aether is considered the over-all reference frame for the Universe and thus velocities are all absolute relative to its rest frame.

He sent the essay, which is most probably his first scientific work, to his maternal uncle Cesar Koch who at the time was living in Antwerp, Belgium. It is quite evident from the letter that he wrote the essay during his stay in Italy.

Einstein's essay on the state of the aether in magnetic field, presented, refers to his familiarity with the experiments and deals rather vaguely with the connection between the aether and electromagnetic phenomena. In his essay Einstein proposed a method for detecting elastic deformations of the aether by sending light rays into the vicinity of the current-carrying wire. In his essay, Einstein raised the following main questions: (1) How does a magnetic field, which is generated when a current is turned on, affect the surrounding aether? (2) How does the magnetic field, in turn, affect the current itself? Einstein believed in the existence of aether at that time, and regarded it as an elastic medium; he wondered in particular how the three components of elasticity act on velocity of the aether wave which is generated when the current is turned on. His main conclusion was that "Above all, it ought to be experimentally shown that there exists a passive resistance to the electric current's ability for generating a magnetic field; this resistance is proportional to the length of the wire and independent of the cross section and the material of the conductor".

Thus the young Einstein independently discovered the qualitative properties of self-induction, and it seems clear that Einstein was not yet familiar with the earlier work on this phenomenon, though at that time he knew that light is an electromagnetic phenomenon but was not yet familiar with Maxwell's theory.

Without having completed high school, in 1895 he decided to apply for the Swiss Federal Institute of Technology in Zurich (the later Swiss Technical Academy, ETH). However because of lacking a high school diploma Albert was required to take an entrance examination.

He studied diligently on his own to prepare for the ETH entrance examinations. He was permitted to take the exams for the engineering department, although much younger than the prescribed entrance age of 18. He failed because he did poorly in modern languages and descriptive sciences, but he did very well in mathematics and physics. That led the ETH Director to urge Albert to enroll in the cantonal school in Aarau, a small town near Zurich, whose graduates were directly admitted to the ETH.

So to make up his graduation exam (Matur) he attended the business department of the Cantonal School in Aarau, Switzerland (Kantonsschule) from October 1895 until October 1896.

At Aarau, Albert had a happy year, both in the school and lodging in the home of Jost Winteler, one of the teachers. Long after, in contrasting Aarau with Munich, Einstein wrote: "By its liberal spirit and by the simple seriousness of its teachers. This school made me realize how much superior an education towards free action and personal responsibility is to one that relies on outward authority and ambition. True democracy is no empty illusion".

The Wintelers welcomed Albert into their large family. His congenial ties to them
proved durable; Maja married a Winteler son and Michele Besso, one of Einstein's
best friends, married a Winteler daughter. In an essay for his graduation exam,
written in "execrable French," Albert described with blithe confidence his ambitions: "If I am lucky enough to pass my examinations, I will attend the Polytechnic in Zurich. I will
stay there four years to study mathematics and physics. My idea is to become a teacher in these fields of natural science and I will choose the theoretical part of these sciences.
These are the reasons that have led me to this plan. It is primarily a personal gift for
abstract and mathematical thought and a lack of fantasy and practical talent. Moreover, my hopes lead me to the same resolution. This is quite natural; one always wishes to do the things one has the most talent for. Moreover, there is a certain independence in the profession of science that greatly appeals to me".

In Aarau, his thoughts turned to the theory of electromagnetism formulated by James Clerk Maxwell, seldom taught even in universities at the turn of the century.

He graduated from Cantonal School in Aarau leaving examination (Matur), in October 1896. The same month he enrolled at the Eidgenössische Polytechnische Schule, (Swiss Federal Institute of Technology in Zürich, the later Swiss Technical Academy, ETH) with the goal of becoming a teacher in Mathematics and Physics.

Perhaps with Jost Winteler as a model, Einstein entered ETH as a candidate for a specialist teacher diploma rather than as an engineering student. He enrolled in Department VI A, which dealt with mathematics, physics, and astronomy. It had only 23 students, 11 of them freshmen, a small fraction of the ETH student body of over 800 students, most of them in engineering fields.

Each of the VI A students had an individual study plan, decided at the start of each semester in consultation with the Department head. The program comprised a few core courses, which were graded, plus ungraded elective courses. At least one elective each semester had to be taken outside the student's Department.

Einstein's transcript shows he followed, at least nominally, a standard program within VI A. About half those courses were mathematics, extending beyond theory of functions, projective and differential geometry, and partial differential equations, to number theory and elliptic functions. About a quarter of the VI A courses were laboratory work. Einstein took more than the required minimum of electives outside VI A, among them courses on Goethe's works and worldview, Kant's philosophy, Prehistory of man, Geology of mountains, Politics and Cultural History of Switzerland, Banking and stock exchange, Social
consequences of free competition, Statistics and personal insurance, and Foundations
of national economy.

To graduate, VI A students had to pass two sets of oral exams on the core math and physics. One set was usually taken after the first two years, the other at the end of the fourth year. The final required also a written diploma thesis.

Einstein's view of his ETH years was bittersweet. Over 50 years later, he stressed that he lacked qualities expected of a "good" student: easy comprehension and docile focus on what was offered in lectures, but benefited from the freedom allowed by the Swiss system.

Typical comments: "Gradually I learned to arrange my studies to suit my intellectual somach and my interests. Some lectures I would follow with intense interest. Otherwise I played hooky a lot and studied the masters of theoretical physics with a holy zeal at home. I really could have gotten a sound mathematical education. However, I worked most of the time in the physical laboratory, fascinated by the direct contact with observation. In all there were only two examinations; for the rest one could do what one wanted a freedom, which I thoroughly enjoyed up to a few months before the examinations".

In his self-study of theory, Einstein embraced works almost entirely missing from the VI A courses. He read books by Kirchhoff, Hertz, Helmholtz, Mach, Boltzmann, and Drude, learned Maxwell's electromagnetism from a recent text, and studied papers by Lorentz. In the electrotechnical lab, Einstein's performance matched his zeal; he then "still expected to approach the major questions of physics by observation and experiment". However, he was not allowed to construct an apparatus that he designed to measure the earth's movement against the ether; "the skepticism of his teachers was too great". In coping with the exams, Einstein gratefully received crucial help from his classmate Marcel Grossmann, who
had prepared superb notes on the core courses.

Einstein deeply resented the exams: "It is, in fact, nothing short of a miracle that the modern methods of instruction have not yet entirely strangled the holy curiosity of inquiry; for this delicate little plant, aside from stimulation, stands mainly in need of freedom. It is a very grave mistake to think that the enjoyment of seeing and searching can be promoted by means of coercion and a sense of duty. I believe that it would be possible to rob even a healthy beast of prey of its voraciousness, with the aid of a whip, to force the beast to devour continuously, even when not hungry".

Despite his devotion to study, Einstein enjoyed some special social outlets in Zurich. He was regularly invited for weekly lunch or dinner by families (as Max Talmud had been by his family); in a letter of thanks, he wrote that "I often came to you in a dejected or bitter mood and there invariably found joy and an inner equilibrium". On Saturday nights and holidays he played his violin with chamber music groups.

Most special was his romance with Mileva Maric, his future wife. They studied together, and when apart exchanged many letters. In those from Einstein, usually both playful and ardent, he often reports what he is reading or research ideas he is hatching. His liaison with Mileva was opposed by his parents and puzzled friends, but that did not faze Einstein. Even when Mileva, having failed the diploma exam, was required to repeat it next year, Einstein presumed that she would also go on to get a doctorate.

In letters to her during summer vacation in 1900, he wrote: "Even my work seems to me pointless and unnecessary if I am not telling myself that you are happy with what I am and what I do...I am also looking forward very much to our new studies. You must now continue with your investigation --how proud I will be when maybe I'll have a little Ph.D.
for a sweetheart while I am myself still a totally ordinary man. So courage, little witch! I can hardly wait to be able to hug you and squeeze you and to live with you again. We'll happily get down to work right away, and money will be as plentiful as manure".

Einstein's antic hope for plentiful money was soon frustrated. During his four years at ETH, although his parents could not give him regular support, he had a monthly allowance from affluent relatives in Genoa, but that ended when he graduated.

He ended his studies successfully with a diploma degree in physics in July 1900.

He expected to be appointed at ETH as a teaching assistant. Because Department VI provided service courses for the large flux of engineering students, several assistants were needed. The few graduates in math or physics who wanted to be assistants usually were promptly appointed.

In 1900, Einstein was the only exception. He felt insulted when Professor Heinrich Weber, who had supervised Einstein's Diplomarbeit, hired two mechanical engineers as assistants. He was also rebuffed by other ETH faculty.

Despite these disappointments, Einstein returned to the ETH for the fall term to pursue an experimental doctoral thesis under Weber.

Shortly before, Einstein in a letter to Mileva had added a postscript: "For the investigation of the thermoelectric Thomson effect I have again resorted to another method, which has some similarities to yours for the determination of the dependence of heat conduction on temperature and which indeed presupposes such an investigation. If only we could already start tomorrow! With Weber we must try to get on good terms at all costs, because his laboratory is the best and the best equipped.

While preparing for her repeat try at the diploma exam, Mileva also intended to carry on experiments toward a doctoral thesis. Ever optimistic, Einstein expected her experiments would aid his project and he would complete his thesis by Easter of 1901.

The ETH did not grant doctoral degrees (until 1911), but ETH graduates could obtain a doctorate from the University of Zurich without further ado by merely submitting a dissertation. This policy naturally encouraged graduate students to work on projects proposed or endorsed by their faculty advisor, often related to their Diplomarbeit. The plans of Einstein and Mileva conformed to this pattern. By spring 1901, however, both had abandoned Weber's lab, and Einstein was convinced that a "poor reference" from Weber would foreclose prospects elsewhere.

Meanwhile, Einstein had submitted in December his first scientific paper, a theoretical analysis of capillarity as a means of characterizing attractive intermolecular forces in liquids. This most likely was stimulated by a lecture by Hermann Minkowski that Einstein had attended at ETH in the spring before his graduation. Minkowski had then just published an encyclopedia article on the subject and gave out reprints to his audience. Ruefully, Einstein remarked to another student: "This is the first lecture on mathematical physics we have heard at the Poly". He apparently undertook this work entirely on his own initiative.

He was proud and excited at contributing results that he took to be "entirely new despite their simplicity and might yield a law of nature". He had high hopes that this first paper, published in Annalen der Physik in early March of 1901, would help him get a job.

Within a few weeks, he had also decided to make intermolecular forces the subject of his doctoral thesis.

Einstein sent out during March and April more than a dozen letters or postcards (with postpaid return) pursuing job possibilities, all in vain.

This went to Wilhelm Ostwald: "Esteemed Herr Professor! Because your book on general chemistry inspired me to write the enclosed article, I am taking the liberty of sending you a copy of it. On this occasion permit me also to inquire whether you might have use for a mathematical physicist familiar with absolute measurements because I am without means, and only a position of this kind would offer me the possibility of additional education. Respectfully yours, Albert Einstein (gives Milan address of parents)".

Three weeks later, Einstein followed up with: "Esteemed Herr Professor! A few weeks ago I took the liberty of sending you from Zurich a short paper which I published in Wiedemann's Annalen. Because your judgment of it matters very much to me, and I am not sure whether I included my address in the letter, I am taking the liberty of sending you my address hereby. Respectfully yours, Albert Einstein".

Unknown to Einstein, on 13 April 1901 his father Hermann also wrote Ostwald: "Esteemed Herr Professor! Please forgive a father who is so bold as to turn to you in the interest of his son. I shall start by telling you that my son Albert is 22 years old, that he studied at the Zurich Polytechnikum for 4 years, and that he passed his diploma examinations in math and phys with flying colors last summer. Since then, he has been trying unsuccessfully to obtain a position as an Assistant, which would enable him to continue his education in theoretical & experimental physics. All those in position to give a judgment in the matter, praise his talents; in any case, I can assure you that he is extraordinarily studious and diligent and clings with great love to his science. My son therefore feels profoundly unhappy with his present lack of position, and his idea that he has gone off the tracks with his career & is now out of touch gets more and more entrenched each day. In addition, he is oppressed by the thought that he is a burden on us, people of modest means. Since it is you...whom my son seems to admire and esteem more than any other scholar currently active in physics I make the humble request to read his paper and to write him, if possible, a few words of encouragement, so that he might recover his joy in living and working".

Ostwald did not respond. Only nine years later, Ostwald made amends: right after he received the Nobel Prize, he became the first to nominate Einstein for it.

On the same day, 13 April 1901, Einstein received a hopeful message from Marcel Grossmann, his father, a friend of the director of the Swiss patent office in Bern, had recommended that Einstein be considered for the next vacancy.

Einstein responded gratefully: "Dear Marcel! When I found your letter yesterday, I was deeply moved by your devotion and compassion which did not let you forget your old luckless friend. I would be delighted to get such a nice sphere of activity and I would spare no effort to live up to your recommendation. I came here to my parents three weeks ago in order to search from here for an assistant's position at a university. I could have found one long ago had Weber had not played a dishonest game with me. All the same, I leave no stone unturned and do not give up my sense of humor...God created the donkey and gave him a thick hide. As for science, I have conceived a few marvelous ideas, which only have to be properly hatched. I now firmly believe that my theory of attractive forces between atoms can be extended also to gases and that the characteristic constants for nearly all elements will be determined without major difficulties. Then the question of the inner kinship of molecular forces and Newtonian forces will move a big step closer its solution. It is possible that experiments already done by others for other purposes will suffice for testing the theory. In that case I shall utilize everything achieved so far about molecular attraction in my doctoral thesis. It is a glorious feeling to recognize the unity of a complex of phenomena, which appear to direct sense perception as quite distinct things".

As things turned out, it was another 14 months before Einstein was actually hired at the patent office. During that stretch, he had only 6 months of salaried income from temporary jobs as a substitute teacher and as a private tutor. In May, 1901, he learned he had gotten Mileva pregnant and in late July, 1901 that she had again failed the diploma exam.

A few weeks before the exam, Einstein had sent her an earnest pledge: "Rejoice now in the irrevocable decision I have made! About our future I have decided the following: I’ll look for a position immediately, no matter how modest. My scientific goals and personal vanity will not prevent me from accepting the most subordinate role. As soon as I have such a position I will marry you and take you to live with me. Then no one can cast a stone upon
your dear head your parents and mine will just have to reconcile themselves to it as best they can.

In December, 1901; this pledge as yet unmet, Einstein made another earnest proposal that he would not manage to fulfill. Mileva was at home with her parents, waiting to give birth; she anticipated the baby would be a girl and had even named her Lieserl.

Einstein, having just heard that the patent office job was about to be advertised, wrote: "I’m even happier for you than for myself. We’ll be students as long as we live and won’t give a damn about the world. The only problem that still needs to be solved is the question of how we can take our Lieserl to us; I do not want us to have to give her up".

Einstein did carry out his plan to prepare a thesis dealing with molecular forces in gases. In November, 1901; he submitted this to Alfred Kleiner, the professor of physics at the University of Zurich, and wrote Mileva that "he won't dare reject my dissertation".

It was January, 1902 before Kleiner read the thesis and he did reject it, supposedly because Einstein had sharply criticized Boltzmann but likely also because theoretical results offered in the thesis lacked experimental confirmation.

Soon after withdrawing his thesis, to avoid forfeiting half the submission fee, Einstein heard from her father that Mileva had given birth to a daughter, Lieserl, after an exhausting labor. His letter in response includes curious comments: "You must suffer enormously if you cannot even write me yourself...our dear Lieserl too must get to know the world from this aspect right from the beginning! I would like once to produce a Lieserl myself, it must be so interesting!".

That Einstein had an illegitimate child has been only learned a few years ago when the above private letters mentioning this child were published. Nothing is known about the life of Einstein's daughter; probably she was released to become adopted or sent to live with relatives.

On February 21, 1901 he was given the naturalization of the city of Zurich and thus became a Swiss citizen. He remained a Swiss citizen until the end of his life. Since Einstein escaped the German military service by giving up the German citizenship as 17-year-old with the approval of his father. Einstein stayed stateless for the next 5 years. When he became a Swiss citizen he was summoned by the military officials for the medical examination one month later. At the medical examination on March 13, 1901 Einstein was attested varicosities, flat and sweaty feet. Thus he was declared "Unqualified A" ("Untauglich A") by the examination committee. The "A" means, that he could only be used for "helpers’ services" ("Hülfsdienste und Platzdienst"). However, the Swiss Army has never summoned Einstein to perform these services.

On October 10, 1902 Albert's father, Hermann died at the age of 55 in Milan on heart failure.

Early career

Einstein more than once gave up on the prospective patent office job. When it was finally advertised, he applied immediately, soon resigned incautiously from a salaried tutorial post, and in early February of 1902 moved to Bern. He advertised "private lessons...given most thoroughly...trial lessons free". There were few takers, but one led to a lifelong friendship. Maurice Solovine, a Romanian student, found Einstein was eager to discuss philosophy and literature as well as physics. Soon Conrad Habicht, a mathematics student Einstein had known in Zurich, joined their discussions. The trio decided to meet regularly as a book and debate club, which they dubbed the "Akademie Olympia" (The Olympia Academy) as a spoof of pompous societies.

For about two and a half years, they met regularly, often several evenings a week, had a modest dinner (sausage, cheese, fruit and tea), then indulged in intense, typically boisterous debate that sometimes "went on far into the night, to the annoyance of the neighbors". The reading was systematic and eclectic; in a memoir Solovine lists Karl Pearson's Grammar of Science, Ernst Mach's Mechanics, John Stuart Mill's Logic, David Hume's A Treatise on Human Nature, Spinoza's Ethics, as well as Sophocles’ Antigone, lectures by Helmholtz and Ampere on physics, and discussions by Riemann of the foundations of geometry and by Dedekind of the concept of number. Special attention was devoted to Henri Poincare's Science & Hypothesis, which "held us spellbound for weeks".

While waiting five more months for the patent office job, Einstein completed two more papers, again without a mentor. In an extension of his first paper, which he had anticipated a year earlier, he applied his theory of intermolecular forces to systems comprising metal electrodes immersed in dilute salt solutions. However, he concluded with an apology for "only setting out a meager plan for a demanding investigation" that required experimental solution and the hope his paper would "induce some researcher to attack the problem". In the other paper, possibly related to his rejected thesis, and likewise alluded to in a letter the previous year, his aim was to fill what he saw as a "gap" in Boltzmann's kinetic theory by providing a sounder derivation of the laws of thermal equilibrium and the second law of thermodynamics from statistical mechanics.

In late June, Einstein finally began work at the patent office. He was to continue there for more than 7 years, 8 hours a day, 6 days a week. Einstein enjoyed deciphering drawings and elaborate descriptions to decide whether the invention would work and was actually new. He found congenial the instructions issued to his dozen or so "patent slaves" by the Director, Friedrich Haller: "When you pick up an application, think that anything the inventor says is wrong...You have to remain critically vigilant". Indeed, from his boyhood on, Einstein was much interested in the design of machines and experiments, and he patented several devices of his own invention. He became so adept at processing patents
that he had time in the office to do some of his own calculations and writing, "guiltily hid in a drawer when footsteps approached". Ten years after his Bern era, Einstein recalled fondly "that temporal monastery, where I hatched my most beautiful ideas".

Soon after he entered his temporal monastery, Einstein was stunned when at age 55 his father suffered a fatal heart attack.

Einstein married Mileva on January 6, 1903, although Einstein's mother had objected to that relationship because she had a prejudice against Serbs and thought Marić was too old and "physically defective"; actually she was just three years older than Albert since she was born on December 19, 1875 in Titel, Serbia. However this marriage was against the wills of both families. Their relationship was for a time a personal and intellectual partnership. In a letter to her, Einstein called Marić "a creature who is my equal and who is as strong and independent as I am". There has been debate about whether Marić influenced Einstein's work; however, most historians do not think she made major contributions.

People in Bern did not know about Lieserl, and she was not brought there, perhaps for fear of offending propriety because Einstein's appointment was still provisional.

The Olympia Academy continued to meet, now usually in the Einstein's apartment. Solovine noted that Mileva, "intelligent and reserved, listened to us attentively without ever intervening in our discussions". Einstein himself noted that this academy was beneficial for his career and even when he already lived in the US, he remained a loyal member.

Einstein also now had congenial scientific interactions with colleagues at the University of Bern and the Natural Science Society as well as the patent office. Only three weeks after his wedding, Einstein wrote to Michele Besso about completing his fourth paper, which carried further his treatment of the foundations of thermodynamics: "On Monday I finally sent off my work, after many changes and corrections. Now it is perfectly clear and simple, so that I am quite satisfied with it. I have now decided to become a Privatdozent, provided of course I can get away with it. On the other hand, I won't become a Ph.D., as this doesn't help me much and the whole comedy has become a bore to me.

Michele Besso was a Swiss/Italian engineer, and a close friend of Albert Einstein during his years at the ETH of Zurich, and then at the patent office in Bern. Besso is credited with introducing Einstein to the works of Ernst Mach, the skeptical critic of physics who influenced Einstein's approach to the discipline. Einstein called Besso "the best sounding board in Europe" for scientific ideas.

He had learned that the University of Bern had an unusual policy, allowing a shortcut to the status of Privatdozent (unsalaried, but with the privilege to lecture at the university and collect fees from subscribing students). Scholars with "other outstanding achievements" could skip both a doctoral and habilitation thesis, submitting instead other published work. Einstein applied, offering his third and fourth papers. This ploy failed and soon he wrote Besso again: "The university here is a pigsty. I won't lecture there, it would be a waste of time".

More than a year later, Einstein submitted a fifth paper, completing a trilogy on statistical thermodynamics. He evaluated fluctuations of the internal energy about its average value. This, he emphasized, brought out the significance of Boltzmann's constant, which "determines the thermal stability of the system" because it sets the scale of the fluctuations.

On May 14, 1904, Albert and Mileva's first son, Hans Albert Einstein, was born in Berne, Switzerland. That summer, Einstein was joined at the patent office by his friend Michele Besso, whom he had encouraged to apply. In the fall, Einstein's provisional appointment, after 27 months, was made permanent. However, only after another 20 months was he promoted to Class II, in contrast to Besso, an engineer, who started at that rank. In late October, the Olympia Academy ended, as Habicht departed Bern.

He was employed as technical expert Class III with an annual salary of 3500 Swiss Francs in June 1902 and he was promoted to be technical expert second-class, with an annual salary of 4500 Swiss Francs in April 1906.

1905, Annus Mirabilis

In 1905, Einstein erupted in what history has come to call the Annus Mirabilis (in Latin, extraordinary year). During that year, he submitted six papers. The three most celebrated papers were submitted within a span of 15 weeks. Within that span he also completed a fourth paper which became his Ph.D. thesis.

Moreover, during the year Einstein contributed 21 reports to a scientific magazine, "Beiblätter zu den Annalen der Physik". These four articles contributed substantially to the foundation of modern physics and changed views on space, time, and matter. The Annus Mirabilis is often called the "Miracle Year" in English, in German, the "Wunderjahr".

His reviews, in the category "theory of heat" (Wärmelehre), summarized and commented on papers published in German, French, Italian, and English journals. Evidently he interleaved
writing his own papers with preparing these reviews, as 8 of his reviews appeared in March, 6 in June, 3 in September, and 4 in November. How much work Einstein had to do at the patent office is not known. In accord with policy, 18 years later his patent assessments were destroyed. However, it seems likely he would have had more to do in 1905 than earlier. As nearly all the other examiners were mechanical engineers, Einstein probably had to contend with a flood of electrical engineering patents, generated by the rapid development of electrical industry.

Einstein's creative outburst in 1905 is often said to be comparable only to that achieved by Newton in 1666. Both soared in their mid-20s, but otherwise what a contrast! With Cambridge University closed by the plague, Newton had retired to his mother's estate and, as a bachelor, was free to concentrate totally on science and mathematics. He is thought to have conceived several of his great ideas during the plague recess, but Newton published little until many years later. Einstein, with much else to do, must have labored mightily to bring forth so quickly his golden eggs. He never identified accelerating factors, but two speculative possibilities seem to me plausible. After the arrival of Hans Albert and the departure of Habicht, Einstein might have begun devoting more of his evenings to putting his ideas in writing. In lieu of the exuberant verbal sparring he'd enjoyed with his Olympia Academy, he had calmer stimulation in talking with Besso at the patent office and on the way home. Also, like the birthing urge induced by Lieserl, the presence of his infant son perhaps spurred Einstein to deliver his intellectual progeny.

Einstein loved his son, but he remained committed to science. Balancing the two, he sometimes rocked his son’s cradle with his foot while reading or prop his books on his son’s stroller while taking a walk.

Through these papers, Einstein tackles some of the era's most important physics questions and problems. In 1900, a lecture titled Nineteenth-Century Clouds over the Dynamical Theory of Heat and Light, by Lord Kelvin, suggested that physics was unsatisfactory in the explanations of two phenomena: the Michelson-Morley experiment (generally considered to be the first strong evidence against the theory of aether) and black body radiation (In physics, a black body is an object that absorbs all light that falls on it. No electromagnetic radiation passes through it and none is reflected. Because no light is reflected or transmitted, the object appears black when it is cold).

As introduced, special relativity provided an account for the results of the Michelson-Morley experiments. Einstein's theories for the photoelectric effect demonstrate some quantum mechanics, which also explain black body radiation.

The four Papers:

  • Photoelectric effect: The paper, "On a Heuristic Viewpoint Concerning the Production and Transformation of Light", proposed the idea of energy quanta. This idea, motivated by Max Planck's earlier derivation of the law of black body radiation, assumes that luminous energy can be absorbed or emitted only in discrete amounts, called quanta.

    Einstein states: "Energy, during the propagation of a ray of light, is not continuously distributed over steadily increasing spaces, but it consists of a finite number of energy quanta localised at points in space, moving without dividing and capable of being absorbed or generated only as entities".

    In explaining the photoelectric effect, the hypothesis that energy consists of discrete packets, as Einstein illustrates, can be directly applied to black bodies, as well.

    The idea of light quanta contradicts the wave theory of light that follows naturally from James Clerk Maxwell's equations for electromagnetic behavior and, more generally, the assumption of infinite divisibility of energy in physical systems.

    "A profound formal difference exists between the theoretical concepts that physicists have formed about gases and other ponderable bodies, and Maxwell's theory of electromagnetic processes in so-called empty space. While we consider the state of a body to be completely determined by the positions and velocities of an indeed very large yet finite number of atoms and electrons, we make use of continuous spatial functions to determine the electromagnetic state of a volume of space, so that a finite number of quantities cannot be considered as sufficient for the complete determination of the electromagnetic state of space. This leads to contradictions when applied to the phenomena of emission and transformation of light. According to the view that the incident light consists of energy quanta, the production of cathode rays by light can be conceived in the following way. The body's surface layer is penetrated by energy quanta whose energy is converted at least partially into kinetic energy of the electrons. The simplest conception is that a light quantum transfers its entire energy to a single electron".

    Einstein noted that the photoelectric effect depended on the wavelength, and hence the frequency of the light. At too low a frequency, even intense light produced no electrons. However, once a certain frequency was reached, even low intensity light produced electrons. He compared this to Planck's hypothesis that light could be emitted only in packets of energy given by hf, where h is Planck's constant and f is the frequency. He then postulated that light travels in packets whose energy depends on the frequency, and therefore only light above a certain frequency would bring sufficient energy to liberate an electron.

    Even after experiments confirmed that Einstein's equations for the photoelectric effect were accurate, his explanation was not universally accepted. Niels Bohr (a Danish physicist who made fundamental contributions to understanding atomic structure and quantum mechanics), in his 1922 Nobel address, stated, "The hypothesis of light-quanta is not able to throw light on the nature of radiation".

    By 1921, when Einstein was awarded the Nobel Prize and his work on photoelectricity was mentioned by name in the award citation, some physicists accepted that light quanta were possible. In 1923, Arthur Compton's X-ray scattering experiment helped more of the scientific community to accept this formula. The theory of light quanta was a strong indicator of wave-particle dual nature of light, a fundamental principle of quantum mechanics. A complete picture of the theory of photoelectricity was realized after the maturity of quantum mechanics.

  • Brownian motion:

    The random movement of particles suspended in a liquid or gas or the mathematical model used to describe such random movements, often called a particle theory. The mathematical model of Brownian motion has several real-world applications. An often quoted example is stock market fluctuations. Another example is the evolution of physical characteristics in the fossil record.

    The article "On the Motion Required by the Molecular Kinetic Theory of Heat of Small Particles Suspended in a Stationary Liquid" delineated a stochastic (random) model of Brownian motion.

    "In this paper it will be shown that, according to the molecular kinetic theory of heat, bodies of a microscopically visible size suspended in liquids must, as a result of thermal molecular motions, perform motions of such magnitudes that they can be easily observed with a microscope. It is possible that the motions to be discussed here are identical with so-called Brownian molecular motion; however, the data available to me on the latter are so imprecise that I could not form a judgment on the question".

    Brownian motion generates expressions for the root mean square displacement of particles. Using the kinetic theory of fluids, which at the time was controversial, the article established the phenomenon, which was lacking a satisfactory explanation even decades after the first observation provided empirical evidence for the reality of the atom. It also lent credence to statistical mechanics, which had been controversial at that time, as well. Before this paper, atoms were recognized as a useful concept, but physicists and chemists debated whether atoms were real entities. Einstein's statistical discussion of atomic behavior gave experimentalists a way to count atoms by looking through an ordinary microscope. Wilhelm Ostwald, one of the leaders of the anti-atom school, later told Arnold Sommerfeld that he had been convinced of the existence of atoms by Einstein's complete explanation of Brownian motion.

  • Special relativity: Einstein's "On the Electrodynamics of Moving Bodies", his third paper that year, was published on June 30, 1905. It reconciles Maxwell's equations for electricity and magnetism with the laws of mechanics, by introducing major changes to mechanics close to the speed of light. This later became known as Einstein's special theory of relativity.

    The paper mentions the name of only five other scientists, Isaac Newton, James Clerk Maxwell, Heinrich Hertz, Christian Doppler, and Hendrik Lorentz. This paper introduces a theory of time, distance, mass, and energy that was consistent with electromagnetism, but omitted the force of gravity.

    At the time, it was known that Maxwell's equations, when applied to moving bodies, led to asymmetries, and that it had not been possible to discover any motion of the Earth relative to the 'light medium'. Einstein puts forward two postulates to explain these observations. First, he applies the classic principle of relativity, which states that the laws of physics remain the same for any non-accelerating frame of reference (called an inertial reference frame), to the laws of electrodynamics and optics as well as mechanics. In the second postulate, Einstein proposes that the speed of light has the same value in all inertial frames of reference, independent of the state of motion of the emitting body.

    Special relativity is thus consistent with the result of the Michelson-Morley experiment, which had not detected a medium of conductance (or aether) for light waves unlike other known waves that require a medium (such as water or air).

    Einstein states: "The unsuccessful attempts to discover any motion of the earth relatively to the light medium, suggest that the phenomena of electrodynamics as well as of mechanics possess no properties corresponding to the idea of absolute rest".

    The speed of light is fixed, and thus not relative to the movement of the observer. This was impossible under Newtonian classical mechanics.

    Einstein argues: "The same laws of electrodynamics and optics will be valid for all frames of reference for which the equations of mechanics hold good. We will raise this conjecture (the purport of which will hereafter be called the Principle of Relativity) to the status of a postulate, and also introduce another postulate, which is only apparently irreconcilable with the former, namely, that light is always propagated in empty space with a definite velocity c which is independent of the state of motion of the emitting body. These two postulates suffice for the attainment of a simple and consistent theory of the electrodynamics of moving bodies based on Maxwell's theory for stationary bodies. The introduction of a luminiferous aether will prove to be superfluous in as much as the view here to be developed will not require an absolutely stationary space provided with special properties, nor assign a velocity-vector to a point of the empty space in which electromagnetic processes take place. The theory is based - like all electrodynamics - on the kinematics of the rigid body, since the assertions of any such theory have to do with the relationships between rigid bodies (systems of co-ordinates), clocks, and electromagnetic processes. Insufficient consideration of this circumstance lies at the root of the difficulties which the electrodynamics of moving bodies at present encounters".

    It had previously been conjectured, by George Fitzgerald in 1894 and by Lorentz 1895, independent of each other, that the Michelson-Morley result could be accounted for if moving bodies were contracted in the direction of their motion. Some of the paper's core equations, the Lorentz transforms, had been published by Joseph Larmor (1897, 1900), Hendrik Lorentz (1899, 1903, 1904) and Henri Poincaré (1905), in a development of Lorentz's 1904 paper. Einstein revealed the underlying causes for this geometrical oddity, which differed from the explanations given by FitzGerald, Larmor, and Lorentz, but were similar in many respects to the reasons given by Poincaré (1905).

    His explanation arises from two axioms. First, Galileo's idea that the laws of nature should be the same for all observers that move with constant speed relative to each other.

    Einstein writes: "The laws by which the states of physical systems undergo change are not affected, whether these changes of state be referred to the one or the other of two systems of co-ordinates in uniform translatory motion".

    The second is the rule that the speed of light is the same for every observer: "Any ray of light moves in the stationary system of co-ordinates with the determined velocity c, whether the ray be emitted by a stationary or by a moving body".

    The theory, now called the "special theory of relativity" distinguishes it from his later general theory of relativity, which considers all observers to be equivalent. Special relativity gained widespread acceptance remarkably quickly, confirming Einstein's comment that it had been "ripe for discovery" in 1905. Acknowledging the role of Max Planck in the early dissemination of his ideas, Einstein wrote in 1913: "The attention that this theory so quickly received from colleagues is surely to be ascribed in large part to the resoluteness and warmth with which he (Planck) intervened for this theory". In addition, the improved mathematical formulation of the theory by Hermann Minkowski in 1907 was influential in gaining acceptance for the theory. Also, and most importantly, the theory was supported by an ever-increasing body of confirmatory experimental evidence.

  • Matter and energy equivalence: A fourth paper, "Does the Inertia of a Body Depend Upon Its Energy Content?", was published on September 27 in "Annalen der Physik", in which Einstein developed an argument for one of the most famous equations in the field of physics: E = mc². Einstein considered the equivalency equation to be of paramount importance because it showed that a massive particle possesses an energy, the "rest energy", distinct from its classical kinetic and potential energies.

    The paper is based on James Clerk Maxwell's and Heinrich Rudolf Hertz's investigations and, in addition, the axioms of relativity.

    Einstein states: "The results of the previous investigation lead to a very interesting conclusion, which is here to be deduced. The previous investigation was based on the Maxwell-Hertz equations for empty space, together with the Maxwellian expression for the electromagnetic energy of space. The laws by which the states of physical systems alter are independent of the alternative, to which of two systems of coordinates, in uniform motion of parallel translation relatively to each other, these alterations of state are referred (principle of relativity)".

    The equation sets forth that energy of a body at rest (E) equals its mass (m) times the speed of light (c) squared, or E = mc².

    Einstein said: "If a body gives off the energy L in the form of radiation, its mass diminishes by L/c². The fact that the energy withdrawn from the body becomes energy of radiation evidently makes no difference, so that we are led to the more general conclusion that; the mass of a body is a measure of its energy-content; if the energy changes by L, the mass changes in the same sense by L/9 × 10^20, the energy being measured in ergs, and the mass in grammes. If the theory corresponds to the facts, radiation conveys inertia between the emitting and absorbing bodies".

    The mass-energy relation can be used to predict how much energy will be released or consumed by nuclear reactions; one simply measures the mass of all constituents and products and multiplies the difference by c2. The result shows how much energy will be released or consumed, usually in the form of light or heat. When applied to certain nuclear reactions, the equation shows that an extraordinarily large amount of energy will be released, much larger than in the combustion of chemical explosives, where the mass difference is hardly measurable at all. This explains why nuclear weapons produce such phenomenal amounts of energy, as they release binding energy during nuclear fission and nuclear fusion, and also convert a much larger portion of subatomic mass to energy.

All these four papers are recognized as a great contribution to the birth of modern physics, that's why 1905 is known as "Einstein's Annus Mirabilis" (Einstein's extraordinary year). At the time, however, they were not noticed by most physicists as being important, and many of those who did notice them rejected them outright.

Photoelectric Effect:

In March 1905 Einstein sent to the Annalen der Physik, the leading German physics magazine, a paper with a new understanding of the structure of light. He argued that light can act as though it consists of discrete, independent particles of energy, in some ways like the particles of a gas. A few years before, Max Planck's work had contained the first suggestion of a discreteness in energy, but Einstein went far beyond this. His revolutionary proposal seemed to contradict the universally accepted theory that light consists of smoothly oscillating electromagnetic waves. But Einstein showed that light quanta, as he called the particles of energy, could help to explain phenomena being studied by experimental physicists. For example, he made clear how light ejects electrons from metals.

These particles, or "light quanta," each carried a "quantum," or fixed amount, of energy, much as automobiles produced by an assembly plant arrive only as individual, identical cars—never as fractions of a car. The total energy of the light beam (or the total output of an assembly plant) is the sum total of the individual energies of these discrete "light quanta" (or automobiles), what are called today "photons." Theories of matter and electromagnetic radiation in which the total energy is treated as "quantized" are known as quantum theories. Although Einstein was not the first to break the energy of light into packets, he was the first to take this seriously and to realize the full implications of doing so.

Like the special theory of relativity, Einstein's quantum hypothesis arose from an experimental puzzle and an asymmetry or duality in physical theories. The duality consisted of the well-known distinction between material atoms and continuous ether, or, as Einstein wrote in the opening sentence of his light quantum paper, "between the theoretical conceptions that physicists have formed about gases and other ponderable bodies and the Maxwell theory of electromagnetic processes in so-called empty space". As noted earlier, Boltzmann and others conceived of gases as consisting of myriads of individual atoms, while Maxwell and Lorentz envisioned electromagnetic processes as consisting of continuous waves. Einstein sought a unification of these two viewpoints by removing the asymmetry in favor of a discontinuous, "atomic," or quantum, theory of light. Resolution of an experimental puzzle encouraged this approach.

The puzzle concerned so-called blackbody radiation, that is, the electro-magnetic radiation given off by a hot, glowing coal in a fireplace, or the radiation emerging from a small hole in a perfectly black box containing electromagnetic radiation at a high temperature. Scientists at the German bureau of standards in Berlin, who were interested in setting standards for the emerging electric lighting industry in Germany, had measured the distribution of the total electromagnetic energy in a black box—which would also apply to a glowing light bulb—among the different wavelengths of the light. But no one until Max Planck, at the turn of the century, was able to give a single mathematical formula for the observed distribution of the energy among the emitted wavelengths. Starting with the Maxwell-Lorentz theory of radiation and some natural assumptions about energy, Planck hoped to derive this formula from the second law of thermodynamics. Planck failed to attain the observed formula on these assumptions. Even Lorentz had to admit that his own electron theory could not account for blackbody radiation.

Only by reluctantly introducing a radical new assumption into his mathematics could Planck attain the correct formula. The assumption was that the energy of the radiation does not act continuously, as one would expect for waves, but exerts itself in equal discontinuous parcels, or "quanta," of energy. In essence Planck had discovered the quantum structure of electromagnetic radiation. But Planck himself did not see it that way; he saw the new assumption merely as a mathematical trick to obtain the right answer. Its significance remained for him a mystery. Thomas Kuhn has argued that it is not to Planck in 1900 but to Einstein in 1905 that we owe the origins of quantum theory.

Encouraged by his brief but successful application of statistical mechanics to radiation in 1904, in 1905 Einstein attempted to resolve the duality of atoms and waves by demonstrating that part of Planck's formula can arise only from the hypothesis that electromagnetic radiation behaves as if it actually consists of individual "quanta" of energy. The continuous waves of Maxwell's equations, which had been confirmed experimentally, could be considered only averages over myriads of tiny light quanta, essentially "atoms" of light.

With his light quantum hypothesis Einstein could not only derive part of Planck's formula but also account directly for certain hitherto inexplicable phenomena. Foremost among them was the photoelectric effect: the ejection of electrons from a metal when irradiated by light. The wave theory of light could not yield a satisfactory account of this, since the energy of a wave is spread over its entire surface. Light quanta, on the other hand, acting like little particles, could easily eject electrons, since the electron absorbs the entire quantum of energy on impact.

Einstein considered that light quanta, together with the equivalence of mass and energy, might result in a reduction of electrodynamics to an atom-based mechanics. But in 1907 he
discovered that atoms in matter are also subject to a quantum effect.

Here he made use of another galling experimental problem. Experimentalists had found that when solid bodies were cooled, the amount of heat they lost failed to fit a simple formula that followed from Newtonian mechanics. Einstein showed that the experiments could be explained only on the assumption that the oscillating atoms of the solid lattice can have only certain, specific energies, and nothing in between. In other words, even the motions of atoms—which are continuous in Newtonian mechanics—exhibit a quantum structure. Mechanics and electrodynamics both required radical revision, Einstein now concluded: neither could yet account for the existence of electrons or energy quanta.

Special relativity theory:

In June 1905 Einstein sent the Annalen der Physik a paper on electromagnetism and motion. Since the time of Galileo and Newton, physicists had known that laboratory measurements of mechanical processes could never show any difference between an apparatus at rest and an apparatus moving at constant speed in a straight line.

Objects behave the same way on a uniformly moving ship as on a ship at the dock; this is called the Principle of Relativity. But according to the electromagnetic theory, developed by Maxwell and refined by Lorentz, light should not obey this principle. Their electromagnetic theory predicted that measurements on the velocity of light would show the effects of motion. Yet no such effect had been detected in any of the ingenious and delicate experiments that physicists had devised: the velocity of light did not vary.

Einstein had long been convinced that the Principle of Relativity must apply to all phenomena, mechanical or not. Now he found a way to show that this principle was compatible with electromagnetic theory after all. As Einstein later remarked, reconciling these seemingly incompatible ideas required "only" a new and more careful consideration of the concept of time. His new theory, later called the special theory of relativity, was based on a novel analysis of space and time -- an analysis so clear and revealing that it can be understood by beginning science students.

In this paper, as in almost all subsequent accounts, Einstein bases SRT on two fundamental principles: the principle of relativity and the principle of the constancy of the velocity of light. The principle of relativity originated in Galilean-Newtonian mechanics: Any frame of reference in which Newton's law of inertia holds (for some period of time) is now called an inertial frame of reference. From the laws of mechanics it follows that, if one such inertial frame exists, then an infinity of them must: All frames of reference (and only such frames) moving with constant velocity with respect to a given inertial frame are also inertial frames. All mechanical experiments and observations proved to be in accord with the (mechanical) principle of relativity: the laws of mechanics take the same form in any of these inertial frames. The principle of relativity, as Einstein stated it in 1905, asserts that all the laws of physics take the same form in any inertial frame-in particular, the laws of electricity, magnetism, and optics in addition to those of mechanics.

The second of Einstein's principles is based on an important consequence of Maxwell's laws of electricity, magnetism, and optics, as interpreted by H. A. Lorentz near the end of the nineteenth century. Maxwell had unified optics with electricity and magnetism in a single theory, in which light is just one type of electromagnetic wave. It was then believed that any wave must propagate through some mechanical medium. Since light waves easily propagate through the vacuum of interstellar space, it was assumed that any vacuum, though empty of ordinary, ponderable matter, was actually filled by such a medium, to which our senses did not respond: the ether. The question then arose, how does this medium behave when ordinary matter is present? In particular, is it dragged along by the motion of matter? Various possible answers were considered in the course of the nineteenth century, but finally only one view seemed compatible with (almost) all the known experimental results, that of H. A. Lorentz: The ether is present everywhere. Ordinary matter is made up of electrically charged particles, which can move through the ether, which is basically immobile. These charged particles, then called "electrons" or "ions", produce all electric and magnetic fields (including the electromagnetic waves we perceive as light), which are nothing but certain excited states of the immovable ether. The important experimental problem then arose of detecting the motion of ponderable matter-the earth in particular-through the ether.

No other theory came remotely close to Lorentz's in accounting for so many electromagnetic and especially optical phenomena. In particular, Einstein again and again cites the abberration of starlight and the results of Fizeau's experiment on the velocity of light in flowing water as decisive evidence in favor of Lorentz's interpretation of Maxwell's equations.

A direct consequence of Lorentz's conception of the stationary ether is that the velocity of light with respect to the ether is a constant, independent of the motion of the source of light (or its frequency, amplitude, or direction of propagation in the ether, etc.).

Einstein adopted a slightly-but crucially-modified version of this conclusion as his second principle: There is an inertial frame in which the speed of light is a constant, independent of the velocity of its source. A Lorentzian ether theorist could agree at once to this statement, since it was always tacitly assumed that the ether rest frame is an inertial frame of reference and Einstein had "only" substituted "inertial frame" for "ether." But Einstein's omission of the ether was deliberate and crucial: by the time he formulated SRT he did not believe in its existence. For Einstein a principle was just that: a principle-a starting point for a process of deduction, not a deduction from any (ether) theory. (I am here getting ahead of my story and will return to this point later.) The Lorentzian ether theorist would add that there can only be one inertial frame in which the light principle holds. If the speed of light is a constant in the ether frame, it must be non-constant in every other inertial frame, as follows from the (Newtonian) law of addition of velocities. The light principle hence seems to be incompatible with the relativity principle. For, according to the relativity principle, all the laws of physics must be the same in any inertial frame. So, if the speed of light is constant in one inertial frame, and that frame is not physically singled out by being the rest frame of some medium (the ether), then the speed of light must be the same (universal) constant in every other inertial frame (otherwise the democracy of inertial frames is violated). As Einstein put it in 1905, his two principles are "apparently incompatible." Of course, if they really were incompatible logically or physically, that would be the end of Special Relativity Theory.

Einstein showed that they are not only logically compatible, but compatible with the results of all optical and other experiments performed up to 1905 (and since, we may add). He was able to show their logical compatibility by an analysis of the concepts of time, simultaneity, and length, which demonstrated that the speed of light really could have the privileged status, implied by his two principles, of being a universal speed, the same in every inertial frame of reference.

Let's put it in plain words:

The following explanation has been provided by The American Museum of Natural History; where a more precise guide about relativity can be found: http://www.amnh.org/exhibitions/einstein/energy/sun.php

The Special Relativity theory, which revolutionized our understanding of time and space, is based on Einstein's astonishing recognition that light always travels at a constant speed, regardless of how fast you're moving when you measure it. Einstein's explorations into the fundamental properties of light also laid the groundwork for his most impressive achievement, the General Theory of Relativity.

Einstein wondered about riding a beam of light-but another good question might have been about riding a wave of light. Light travels in waves that radiate outward from the source of light. Until Einstein, most scientists thought that light behaved like other waves, such as ocean or sound waves. According to this logic, light waves traveled through some sort of "medium," just as ocean waves traveled through the medium of water.

Nineteenth-century scientists didn't know much about the medium for light, which they dubbed the "luminiferous ether." No instrument could find the mysterious substance. But scientists of the day believed that the speed of light should be affected by how fast the source of light was moving through the ether. They believed that light from a source moving toward you (say, the headlight of an approaching train) would travel faster than light from a stationary source (a signal light next to the tracks).

For decades, physicists searched in vain for the ether and proposed elaborate explanations for why they couldn't detect it. Einstein suggested a more radical notion: the long-accepted theory that light moved through ether was simply wrong. He declared that there is no ether to speed up light or slow it down-in other words, the speed of light is constant. Einstein's bold proposal has survived all tests to date: every experiment to measure the speed of light in a vacuum (space devoid of all matter) shows that it is indeed constant for all observers.

No matter how you measure it, the speed of light is always the same.
Einstein's crucial breakthrough about the nature of light, made in 1905, can be summed up in a deceptively simple statement: The speed of light is constant. So what does this sentence really mean?

Surprisingly, the answer has nothing to do with the actual speed of light, which is 300,000 kilometers per second (186,000 miles per second) through the "vacuum" of empty space. Instead, Einstein had an unexpected—and paradoxical—insight: that light from a moving source has the same velocity as light from a stationary source. For example, beams of light from a lighthouse, from a speeding car's headlights and from the lights on a supersonic jet all travel at a constant rate as measured by all observers—despite differences in how fast the sources of these beams move.

The Special Theory of Relativity is based on Einstein's recognition that the speed of light does not change even when the source of the light moves. Although it might seem logical to add the speed of the light source and the speed of the light beam to determine the total speed, light does not work this way. No matter how fast Einstein rides his bike, the light coming from his headlight always moves at the same speed.

STATIONARY LIGHT
Light from a stationary source travels at 300,000 km/sec (186,000 miles/sec).

MOVING LIGHT
Light from a moving source also travels at 300,000 km/sec (186,000 miles/sec).

Speed of light 300,000 km/sec (in a vacuum) + Einstein's bike 30,000 km/sec (traveling at 10 percent the speed of light): Speed of light from Einstein's headlight ≠ (NOT equal) 330,000 km/sec

= 300,000 km/sec

The speed of light is constant and does not depend on the speed of the light source.

During the late 1800s and early 1900s, scientists struggled to understand the nature of light. Most physicists of the time believed that light traveled through what they called the "luminiferous ether." In 1887, two American scientists, Albert Michelson and Edward Morley, built a device known as an interferometer, which they hoped would enable them to prove the existence of the ether.

Michelson and Morley ran their interferometer experiment numerous times but never saw any evidence of the ether. Other scientists, sure that the ether theory was correct, continued searching for it. It wasn't until 1905, when Einstein published his Special Theory of Relativity, that the physics community began to accept that the ether does not exist.

The Michelson-Morley interferometer simulated here works by splitting a single beam of light in two. The two beams bounce off mirrors and arrive at a detector.

If the ether existed, it would remain still while the Earth moved through it. The ether would then change the speed of light depending on whether the light was moving in the direction of Earth's motion or at a right angle to that motion.

Michelson and Morley expected to find that two light beams arrived at the detector at different times. Instead they found that no matter which direction light traveled, it always moved at the same speed—indicating that the ether does not exist.

We believe that there is some "master clock" for the universe to which, in an ideal world, all clocks could be synchronized. The notion of the regular passage of time is so ingrained in human consciousness that our languages have developed special ways to distinguish events that occur in the past, present or future. And until Einstein, most physicists also accepted the idea of universal time without question.

When Einstein proposed that the speed of light is constant for all observers, he introduced a conundrum. How could different observers measure the same speed for light when the observers themselves were moving at different speeds? Speed is a measure of distance divided by time (for example, kilometers per hour or miles per hour). Einstein realized that for speed to remain constant, intervals of time and distance would have to change in a way that kept their ratio exactly the same.

Einstein's answer overturned long-held ideas about the nature of time as a steady, continuous progression of events from past to present to future. Although it's hard to believe, there is no single "master clock" for the entire universe. Time does not progress at the same rate for everyone, everywhere. Instead, Einstein showed that how fast time progresses depends on how fast the clock measuring time is moving. The faster an object travels, the more slowly time passes for that object, as measured by a stationary observer. Perhaps even more astonishing, one person's past could theoretically be another's future—which is why Einstein described the past, present and future as "persistent illusions."

Einstein said that everything is relative; How fast are you moving? Because you've stopped to read these words, you're not moving at all, right? Think again.

This room and everything else on Earth are traveling at 107,000 kilometers (67,000 miles) an hour around the Sun. You are standing still, but only in relation to Earth. Relative to the Sun, you are traveling through space very quickly. Physicists use the phrase "relative motion" to convey the idea that whether an object is at rest or in motion depends on your point of view—or your "frame of reference."

A "frame of reference" sounds complicated, but it's really just a physicist's way of describing someone's point of view. Different frames of reference are defined in part by speed. Someone in a parked car is in a different frame of reference than someone in a car traveling at a constant speed. The person in the moving car is in a different frame of reference than a person going even faster in an airplane.

Einstein was not the first to conceive of relative motion. The idea of "relativity" can be traced back to Galileo Galilei, the 17th-century Italian astronomer. Einstein's Theory of Relativity expanded and refined Galileo's idea of relative motion.

In a scenario, where a person with a ball is moving relative to an observer; although the person bounces the ball straight up and down, the observer sees the ball move in a zigzag path. Both are correct in their observations.

Now, if both the person with the ball and the observer are moving, but because they are traveling with the same velocity, they are not moving relative to one another—they are in the same frame of reference. Both see the ball going straight up and down.

In the Special Theory of Relativity, Einstein determined that time is relative—in other words, the rate at which time passes depends on your frame of reference. Just as observers in two different frames of reference don't always agree on how to describe the motion of a bouncing ball, they also don't always agree on when an event happened or how long it took. A second in one reference frame may be longer compared to a second in another reference frame.

The faster a clock moves, the slower time passes according to someone in a different frame of reference. To explain this bewildering result, physicists point to a thought experiment involving a clock that uses light to mark time. Although this "light clock" experiment is a hypothetical one, the same effects are true for any timepiece, from old-fashioned grandfather clocks to atomic clocks, the most accurate time-keeping devices available. Time is relative even for the human body, which is in essence a biological clock. The effect of time slowing down is negligible at speeds of everyday life, but it becomes very pronounced at speeds approaching that of light.

For instance imagine a flashlight into a spaceship that travels at the speed of light, that is 300,000 kms/sec. Now, imagine the light beam emitted by the flashlight, from the frame of reference of an observer in the spaceship the light beam travels at 300,000 kms/sec (the speed of light), so that means that in 1 second the light beam can make a distance of 300,000 kms.

Now from the frame of reference of a standing observer outside, that sees the spaceship and the light beam pass by; the spaceship travels at a speed of 300,000 kms/sec as stated before, so if inside it there is a traveller holding the flashlight, according to our human logic, the emitted light, from the outside standing observer frame of reference will travel at a speed of 600,000 kms/sec (the spaceship's speed plus that of the light); however this is not the case; since the speed of light is always 300,000 kms/sec; even the observer outside will perceive a speed of 300,000 kms/sec for the light beam, no matter the speed of the spaceship. So we conclude that in order to have a light beam traveling at the speed of light, into a spaceship that travels also at the speed of light, while in the spaceship ticks a second, for the observer outside there will be 2 seconds going by in order to have mathematically an equation that yields, 300,000 kms/sec.

For the traveller in the spaceship the equation to get the speed of the light beam is: 300,000/1 = 300,000 kms/sec (the speed of light).

For the observer standing outside the equation to get the speed of the light beam is:
600,000/2 = 300,000 kms/sec (the speed of light).

So, when for the traveller there has elapsed a second, for the observer outside 2 seconds have elapsed; since the speed of light is ALWAYS the same, 300,000 kms/sec (actually it's 299,792.458 kms/sec; but for matters of simplicity we rounded it up to 300,000).

The above example was somewhat intuitive to get an idea; however relativistic physics are not that simple, actually they are more complex, so now let's go a step further and let's be more precise.

So How long is a second?
The idea that a second is not always a second is one of the most surprising findings of Einstein's Special Theory of Relativity. Researchers have actually observed this effect, which is only detectable at high speeds. Scientists synchronized two highly accurate atomic clocks and then flew one around the Earth aboard an airplane. When the airborne clock returned to Earth, it was a tiny fraction of a second behind the one that remained on the ground. A thought experiment using a light clock reveals why this is so.

All moving clocks run slow-not just light clocks.
But the effect is insignificant except at speeds approaching that of light. Intriguingly, someone moving will not think that her clock is running slow, because everything in her frame of reference will have slowed down as well. According to a stationary observer in space watching Earth move around the Sun, all of the clocks on our planet are running slow, yet we don't notice anything out of the ordinary.

Thanks to Einstein, we know that the faster you go, the slower time passes—so a very fast spaceship is a time machine to the future. Five years on a ship traveling at 99 percent the speed of light (2.5 years out and 2.5 years back) corresponds to roughly 36 years on Earth. When the spaceship returned to Earth, the people onboard would come back 31 years in their future—but they would be only five years older than when they left. Indeed, Einstein himself could be alive today! If he could have hopped aboard a spaceship traveling at 99 percent the speed of light in 1879—the year of his birth—he would be only 17 years old upon his return to Earth today.

Slowing time
Imagine that each of the six clocks shown started measuring time on the day Einstein was born: March 14, 1879. Five of the clocks were placed in spaceships while one remains on Earth. Each spaceship travels at a different speed and as a result, time has been progressing at different rates on each spaceship. The faster the rate of travel, the more slowly time elapses.

If the people onboard the speeding ships returned to Earth now, they would travel in time from the date shown on the clocks to today—our present, but their future.

Einstein born: March 14, 1879
clock 1: 0% the speed of light
clock 2: 25% the speed of light
clock 3: 50% the speed of light
clock 4: 75% the speed of light
clock 5: 99% the speed of light
clock 6: 99.99999999% the speed of light

CLOCK 1: 0% speed of light (Earth)
Speed (relative to Earth): 0 kilometer/hour
Length of second (relative to Earth): 1.00 second

CLOCK 2: 25% speed of light
Speed (relative to Earth): 25% the speed of light
(75,000 km/sec or 47,000 miles/sec)
Length of second (relative to Earth): 1.03 seconds

CLOCK 3: 50% speed of light
Speed (relative to Earth): 50% the speed of light
(150,000 km/sec or 93,000 miles/sec)
Length of second (relative to Earth): 1.15 seconds

CLOCK 4: 75% speed of light
Speed (relative to Earth): 75% the speed of light
(225,000 km/sec or 140,000 miles/sec)
Length of second (relative to Earth): 1.51 seconds

CLOCK 5: 99% speed of light
Speed (relative to Earth): 99% the speed of light
(297,000 km/sec or 185,000 miles/sec)
Length of second (relative to Earth): 7.09 seconds

Einstein is 17 years old.

CLOCK 6: 99.99999999% speed of light
Speed (relative to Earth): 99.99999999% the speed of light
(299,999.997 km/sec or 185,999.998 miles/sec)
Length of second (relative to Earth): 19.6 hours

Einstein is one day old.

Much faster ships, traveling at a significant percentage of the speed of light, would shorten the journey. Space travelers could also take full advantage of the slowing down of time at high speeds. For example, a spaceship traveling at 75 percent the speed of light would reach Alpha Centauri in 5.7 "Earth years." But for the astronauts on the ship, the trip would take only 3.8 years.

Of course, the technology required for such high speeds is not available—and may not be for many, many years, if ever. The fastest spaceships of today travel at only 0.00004 percent the speed of light.

Cosmonaut Sergei Avdeyev spent a total of 748 days on the Russian space station Mir during three separate missions. Because Mir was moving relative to Earth, it was also a time machine. Avdeyev is 0.02 seconds younger than he would have been had he never traveled in space.

Mass energy equivalence:

In September 1905 Einstein finished a second, shorter article—essentially an addendum to his previous paper—describing a "very interesting conclusion" about energy. Einstein went on to present his findings mathematically: energy (E) equals mass (m) times the speed of light (c) squared (2), or E=mc2.

The secret the equation revealed—that mass and energy are different forms of the same thing—had eluded scientists for centuries. Einstein expected both of these revolutionary 1905 papers to arouse a lively debate among physicists. But for months, the often conservative scientific community was silent, and Einstein was disappointed by the lack of response. His isolation did not last long, however: by 1906, physicists from around Europe were journeying to Switzerland to discuss this intriguing new theory with the 27-year-old patent clerk.

Matter (or mass) is the physical stuff of the universe, while energy is what causes matter to move and change. There are different forms of matter (for example, solid, liquid and gas) as well as different forms of energy (such as electrical, chemical and nuclear energy). For centuries, scientists thought that matter could not be created or destroyed—it could only change form. The same idea seemed to apply to energy.

Einstein's work on the Special Theory of Relativity prompted him to rethink the fundamental laws of physics. He realized that one of the long-held views of nature—that matter could not be created or destroyed—was wrong. Einstein showed instead that matter can be destroyed and converted to energy. Conversely, energy can be converted to mass.

Einstein's equation E=mc2 demonstrates the unexpected finding that energy and mass are interrelated: mass is a form of energy, and energy is a form of mass. The equation also helps explain the energy source for a variety of physical phenomena, from stars to the atomic bomb—although initially Einstein did not anticipate any practical applications for his formula.

In Einstein's first paper about energy and mass, E=mc2 doesn't actually appear anywhere—he originally wrote the formula as m=L/c2. What happened? Einstein was using "L" (for Lagrangian, a general form of energy) instead of "E" for energy. Later, he replaced "L" with "E," rearranged the variables and the famous form of the equation emerged.

The implications of E=mc2 are profound. For centuries, scientists had considered energy and mass to be completely distinct and unrelated to each other. Einstein showed that in fact, energy and mass are different forms of the same thing. Einstein himself was surprised by the finding, calling it "amusing and enticing" and wondered "whether the Lord is laughing at it and has played a trick on me."

Einstein's equation shows that mass and energy are equivalent—so long as you multiply by the "conversion factor" of c2 (the speed of light multiplied by itself). This factor is huge: 90 billion kilometers2 per second2. So if you multiply a small amount of mass—say, the mass of a penny—by c2, you'll get a tremendous amount of energy.

If this penny could be converted entirely to energy, it would provide enough energy to power the New York City metropolitan area for at least two years.

Reality check
Converting a penny entirely to energy would require temperatures and pressures much greater than those found inside the Sun. So unfortunately, small coins are not a practical source of energy.

E=mc something?
Einstein's equation uses just three letters and one number. What do these symbols mean?

E = Energy
m = Mass
c = Speed of light
from the Latin term celeritas, which means "speed"
2 = Squared
when you "square" something, you multiply it by itself

As Einstein became better known in the scientific community, he began receiving requests to write about his new theory for journals and books. In 1912, he was asked to contribute several chapters on relativity to a book. The result is this 72-page manuscript. Because he did not save drafts of his 1905 papers, this manuscript is the earliest known description of relativity in Einstein's hand.

Einstein first published his Special Theory of Relativity—which describes his revolutionary ideas about light, time and energy—in 1905. He revisited the theory in this 1912 manuscript when he was asked to write several book chapters. The outbreak of World War I in 1914 delayed publication, and when the project resumed, Einstein considered this manuscript outdated and it was never published.

Nevertheless, the manuscript represents an important stage in Einstein's work. The draft focuses on the Special Theory of Relativity, which applies to the "special" circumstance in which observers making measurements do not change speed, or accelerate. But this draft also hints at how Einstein developed his more comprehensive General Theory of Relativity. That theory, finalized in 1916, applies to all observers, even those undergoing acceleration, and is actually a theory of gravity.

Each page of the 1912 Manuscript on the Special Theory of Relativity reveals an exacting mind at work. Mathematical equations have been altered, words have been crossed out and entire paragraphs have been rewritten.

When Einstein was asked to write these chapters, he decided to do more than simply summarize relativity. Instead, he derived from first principles the basic tenets of his influential theory about light, time and energy. In the process, he refined his ideas even further. For example, he adopted a novel four-dimensional mathematical system in this manuscript to explain portions of Special Relativity. Physicists refer to this four-dimensional system as "space-time"—the union of three-dimensional space with the fourth dimension of time.

Decades after Einstein published his famous equation, other scientists realized that it did explain a number of physical phenomena. One important discovery answered a question that had puzzled scientists for centuries: why does the Sun shine? Every star you can see in the night sky is powered by a process known as "fusion," in which atoms fuse together while some of their mass is converted to energy.

Perhaps most famously, E=mc2 helps explain the energy released by atomic bombs and produced by nuclear power plants. Under the right conditions, certain atoms can split apart in a process called "fission." During fission, some of the mass of the original atoms is converted to energy. Scientists have learned how to exploit fission for weapons as well as for peaceful applications, such as nuclear power.

The energy of an atomic bomb or a nuclear power plant is the result of the splitting, or "fission," of an atom. Most nuclear power plants today draw their energy from the fission of uranium atoms.

Under certain conditions, a uranium atom will split apart into two smaller atoms, such as barium and krypton. The combined mass of the two smaller atoms is less than the mass of the original uranium atom. Why? Because some of the mass of the uranium atom has been converted to energy. In a nuclear power plant, this energy is used to superheat water. The resulting steam powers a turbine and a generator, thereby producing electricity.

Atomic division: fission
Uranium can split apart into barium and krypton:

U = 235 units of mass
yields

Ba = 144 units of mass
plus
Kr = 90 units of mass

loss: 1 unit of mass

What happened to the missing unit of mass? During fission, particles known as neutrons are produced, accounting for some of the missing mass. The rest of the mass is converted to energy.

The above explanation has been provided by The American Museum of Natural History; where a more precise guide about relativity can be found: Einstein's theories.

Post-1905 years - Einstein's early scientific career:

In April 1906 Einstein was promoted to technical expert, second class, at the patent-office in Bern; with an increased annual salary of 4500 Swiss Francs.

That same year he applied to become a privatdozent, (private docent) at the University of Bern. A Private docent (abbreviates P.D. or Priv.-Doz.) is a title conferred in some European university systems, especially in German-speaking countries, for someone who wants to become a university professor. Privatedocentship is conferred to academics who have earned a doctorate (promotion) and then have written another thesis for habilitation and given a lecture before the respective department or faculty of a university. If they pass the vote after that lecture, they receive the venia legendi (or, rarely, venia docendi) and thus the status of P.D., roughly equivalent to the status of an associate professorship.

However his first application was turned down in 1907 by the university of Bern, he wasn't accepted and did not get his habilitation; but he would not give up that easy.

In early 1908, however, he was successful and at the end of the same year he gave his first lecture. Thus, he finally became a privatdozent at the University of Bern.

In 1907, he confronts the problem of gravitation, the same problem that Newton confronted and solved (almost). Einstein begins his work with one crucial insight: gravity and acceleration are equivalent, two facets of the same phenomenon. Where this "principle of equivalence" will lead remains obscure, but to Einstein, it offers the first hint of a theory that could supplant Newton's.

In July 1909 he handed in his notice to start a new job as extraordinary professor for theoretical physics at the university Zurich. Einstein had decided that he wanted to devote his time entirely to science; hence, he gave up his position at the patent-office in October 1909 and in the same month he started to work as "Ausserordentlicher Professor" (adjunct professor) of theoretical physics at the university of Zurich.

During 1909, Einstein published "Über die Entwicklung unserer Anschauungen über das Wesen und die Konstitution der Strahlung" ("The Development of Our Views on the Composition and Essence of Radiation"), on the quantization of light. A paper by Einstein reviewing the historical development of the wave and particle models of light and suggesting (for the first time) that light is simultaneously a wave and a particle. Einstein states clearly that the energy and momentum of light are concentrated in particles, and that the processes of emission and absorption should be modeled as inverse elementary processes. Einstein also shows that the particle and wave components of light produce independent pressure fluctuations in blackbody radiation. Contrary to modern physics, he speculates that the photon might carry with itself an oscillating field, a concept that may have led de Broglie to the "pilot wave" idea.

In this and in an earlier 1909 paper, Einstein showed that Max Planck's energy quanta must have well-defined momenta and act in some respects as independent, point-like particles. This paper introduced the photon concept (although the term itself was introduced by Gilbert N. Lewis in 1926) and inspired the notion of wave–particle duality in quantum mechanics.

Before anyone else, Einstein recognizes the essential dualism in nature, the coexistence of particles and waves at the level of quanta. In 1911, he declares resolving the quantum issue to be the central problem of physics.

Even the minor works resonate. For example, in 1910, Einstein answers a basic question: "Why is the sky blue?" His paper on the phenomenon called critical opalescence solves the problem by examining the cumulative effect of the scattering of light by individual molecules in the atmosphere.

On July 28 in 1910 Eduard, the second son of Albert Einstein (1879–1955) and Mileva Maric (1875–1948), was born in Zurich. From his mother he received the nickname “Tete”.

In 1911 Einstein was offered a chair at Charles University in Prague which he took on. Charles University in Prague (also simply Charles University; Czech: Univerzita Karlova v Praze; Latin: Universitas Carolina; German: Karls-Universität zu Prag) is the oldest and largest university in the Czech Republic. Being founded in 1348, it was the first one in the Holy Roman Empire and in Central Europe in general, and is one of the oldest universities in Europe.

Einstein’s chair for theoretical physics at the German University Prague lasted from April 1, 1911 until September 30, 1912; during this time he was connected with obtaining the Austrian citizenship but in 1912 Einstein returned to Switzerland to accept a professorship at his alma mater, the ETH.

In Prague ALbert Einstein met a visiting Austrian physicist, Paul Ehrenfest. "Within a few hours we were true friends," Einstein recalled, "as though our dreams and aspirations were made for each other."

While in Prague, Einstein published a paper about the effects of gravity on light, specifically the gravitational redshift and the gravitational deflection of light. The paper appealed to astronomers to find ways of detecting the deflection during a solar eclipse. German astronomer Erwin Finlay-Freundlich publicized Einstein's challenge to scientists around the world.

In physics, light or other forms of electromagnetic radiation of a certain wavelength originating from a source placed in a region of stronger gravitational field (and which could be said to have climbed "uphill" out of a gravity well) will be found to be of longer wavelength when received by an observer in a region of weaker gravitational field. If applied to optical wave-lengths this manifests itself as a change in the colour of the light as the wavelength is shifted toward the red (making it less energetic, longer in wavelength, and lower in frequency) part of the spectrum. This effect is called gravitational redshift and other spectral lines found in the light will also be shifted towards the longer wavelength, or "red," end of the spectrum. This shift can be observed along the entire electromagnetic spectrum. Light that has passed "downhill" into a region of stronger gravity shows a corresponding increase in energy, and is said to be gravitationally blueshifted. A rising star in the field of physics, Einstein was invited to the first ever Solvay Conference in Brussels in 1911. The event drew such notable scientists as Marie Curie, Paul Langevin, and Max Planck.

In 1912, Einstein returned to Switzerland to accept a professorship at the ETH. There he met mathematician Marcel Grossmann who introduced him to Riemannian geometry, and at the recommendation of Italian mathematician Tullio Levi-Civita, Einstein began exploring the usefulness of general covariance (essentially the use of tensors) for his gravitational theory. Although for a while Einstein thought that there were problems with that approach, he later returned to it and by late 1915 had published his general theory of relativity in the form that is still used today (Einstein 1915); that theory would explains gravitation as distortion of the structure of spacetime by matter, affecting the inertial motion of other matter.

In theoretical physics, general covariance (also known as diffeomorphism covariance or general invariance) is the invariance of the form of physical laws under arbitrary differentiable coordinate transformations. The essential idea is that coordinates do not exist a priori in nature, but are only artifices used in describing nature, and hence should play no role in the formulation of fundamental physical laws.

A physical law expressed in a generally covariant fashion takes the same mathematical form in all coordinate systems, and is usually expressed in terms of tensor fields. The classical (non-quantum) theory of electrodynamics is one theory that has such a formulation.

Albert Einstein proposed this principle for his special theory of relativity; however, that theory was limited to space-time coordinate systems related to each other by uniform relative motions only, the so-called "inertial frames." Einstein recognized that the general principle of relativity should also apply to accelerated relative motions, and he used the newly developed tool of tensor calculus to extend the special theory's global Lorentz covariance (applying only to inertial frames) to the more general local Lorentz covariance (which applies to all frames), eventually producing his general theory of relativity. The local reduction of the general metric tensor to the Minkowski metric corresponds to free-falling (geodesic) motion, in this theory, thus encompassing the phenomenon of gravitation.

Much of the work on classical unified field theories consisted of attempts to further extend the general theory of relativity to interpret additional physical phenomena, particularly electromagnetism, within the framework of general covariance, and more specifically as purely geometric objects in the space-time continuum.

Impressed by Einstein's achievements, Max Planck and the physical chemist Walther Nernst attempted to lure the young Einstein to Berlin, then stronghold of natural sciences. They wanted to make him a member of the Prussian Academy of Sciences, offer him a professorial position without teaching responsibilities at Berlin university and make him the head of the - still to be founded - Kaiser-Wilhelm-Institut of Physics. For Einstein this offer was so tempting that he accepted and in April 1914 moved to Berlin with his family. On July 2nd, 1914, he gave his inaugural lecture at the Prussian Academy.

When Einstein had left his native land as a youth, he had renounced German citizenship and all of the militarist German society. But Berlin -- with no teaching duties and a galaxy of top scientists for colleagues -- could not be resisted. It was the highest level a scientific career could ordinarily reach.

Einstein regained the German citizenship in April 1914 when he entered the German civil service, among other things as full member of the Prussian Academy of Sciences and professor at the University of Berlin.

"With such fame, not much time remains for his wife," Mileva complained. "I am very starved for love." Einstein felt suffocated in the increasingly strained and gloomy relationship. He found solace in a love affair with his cousin, Elsa Löwenthal. Mileva and Albert separated in 1914, in consequence, in June 1914 his wife and children returned to Zurich; after bitter arguments, they soon started divorce proceedings and finally divorced in 1919.

Einstein continued on alone to Berlin, where he became a member of the Prussian Academy of Sciences. As part of the arrangements for his new position, he also became a professor at the Humboldt University of Berlin, although with a special clause freeing him from most teaching obligations. From 1914 to 1932 he was also director of the Kaiser Wilhelm Institute for Physics; this institute being a German entity formally known as the Kaiser-Wilhelm-Gesellschaft zur Förderung der Wissenschaften e.V. (Kaiser Wilhelm Society for the Advancement of Science). The Kaiser Wilhelm Society was the umbrella organization for the institutes, testing stations, and units spawned under its authority.

Then, in 1915, Einstein completes the general theory of relativity, the product of eight years of work on the problem of gravity. In general relativity, Einstein shows that matter and energy—all the "stuff" in the universe—actually mold the shape of space and the flow of time. What we feel as the "force" of gravity is simply the sensation of following the shortest path we can through curved, four-dimensional space-time. It is a radical vision: space is no longer the box the universe comes in; instead, space and time, matter and energy are, as Einstein proves, locked together in the most intimate embrace.

General Theory of Relativity:

From 1909 to 1916 Albert Einstein worked on a generalization of his Special Theory of Relativity. The results of his efforts were published in March 1916 in the paper "The Foundation of the General Theory of Relativity". This theory investigates coordination systems which experience acceleration relative to each other and also the influence of gravitational fields to time and space.

As early as 1907, while Einstein and others explored the implications of his special theory of relativity, he was already thinking about a more general theory. The special theory had shown how to relate the measurements made in one laboratory to the measurements made in another laboratory moving in a uniform way with respect to the first laboratory. Could he extend the theory to deal with laboratories moving in arbitrary ways, speeding up, slowing down, changing direction? Einstein saw a possible link between such accelerated motion and the familiar force of gravity. He was impressed by a fact known to Galileo and Newton but not fully appreciated before Einstein puzzled over it. All bodies, however different, if released from the same height will fall with exactly the same constant acceleration (in the absence of air resistance). Like the invariant velocity of light on which Einstein had founded his special theory of relativity, here was an invariance that could be the starting point for a theory.

As he often did in his work, Einstein used a "thought experiment." Suppose that a scientist is enclosed in a large box somewhere, and that he releases a stone. The scientist sees the stone fall to the floor of the box with a constant acceleration. He might conclude that his box is in a place where there is a force of gravity pulling downward. But this might not be true. The entire box could be free from gravity, but accelerating upward in empty space on a rocket: the stone could be stationary and the floor rising to meet it. The physicist in the box cannot, Einstein noted, tell the difference between the two cases. Therefore there must be some profound connection between accelerated motion and the force of gravity. It remained to work out this connection.

Einstein began to search for particular equations -- ones that would relate the measurements made by two observers who are moving in an arbitrary way with respect to one another. The search was arduous, with entire years spent in blind alleys. Einstein had to master more elaborate mathematical techniques than he had ever expected to need, and to work at a higher level of abstraction than ever before. His friend Michele Besso gave crucial help here.

Success in his theoretical work was sealed in 1915. The new equations of gravitation had an essential logical simplicity, despite their unfamiliar mathematical form. To describe the action of gravity, the equations showed how the presence of matter warped the very framework of space and time. This warping would determine how an object moved. Einstein tested his theory by correctly calculating a small discrepancy in the motion of the planet Mercury, a discrepancy that astronomers had long been at a loss to explain.

Until Einstein the description of Newton about gravity was considered a Physical law. Newton had explained gravity as a force that instantaneously acts over a distance. The result is a pull between any two objects in the universe.

But unfortunately Newton's theory and Einstein's own Special Theory of Relativity could not be compatible. According to Newton's laws, for example, Earth's gravity immediately affects the Moon, so the the force travels 385,000 kilometers in an instant, that meaning it travels faster than the speed of light. But that's impossible in Einstein's theory, since nothing can exceed light's "cosmic speed limit".

So in his General Theory of Relativity, Einstein described gravity as not being a force.

Einstein showed that objects, like the stars and planets, bend "space-time", the four-dimensional entity in which all things in universe exist, including the univerese itself.

According with Einstein, space-time valleys or curves create the effect of gravity. So, the bowl-shaped warp created by a planet's mass, alters the course of an object. For instance that's the effect the Earth creates when an obeject like a satellite, travels into that warp.

According to Einstein anything with mass, including your small objects, bend this four-dimensional space-time. And thus this warp, creates the effect we call gravity, redirecting the path of objects that travel into it. The strength of gravity depends on the size of the space-time warp. Denser objects create larger distortions than those with a lower density. For example larger objects with little mass create smaller distortions than small objects with a huge mass.

According to Einstein we don't live in a 3-dimensional universe where everything expands only in 3 dimensions; that is in an up-down axis; a left-right axis and finally back-forth axis. Instead of that Einstein suggested that we live in a 4th dimensional universe where time and space are parts of the same nature. Thus, gravity would not only affect space but also the time, bending the whole 4-dimensional entity of space-time. Yes, according to Einstein time is bended too.

Thanks to Einstein's General Theory of Relativity we can explain blackholes. A black hole is the product of a star that collapses down to a tiny object; creating a high-density area (small size but big mass). This black hole can reach a so high level of density that creates a huge space-time warp bending it, and thus making a so strong gravitational field that nothing, including light, can escape from it.

Einstein's theory predicted that gravity can create a lense effect, where the path of light is redirected from objects to our eyes. Thus, distant galaxies and stars may appear displaced, duplicated or warped because the light emitted by them is bended somewhere by a strong gravitational field.

Whereas the Special Theory of Relativity was still intelligible to the layman, this did not apply to the General Theory of Relativity. Moreover, due to the relatively small relativistic effects, this theory was difficult to verify experimentally. Einstein - or his General Theory of Relativity - predicted the perihelion motion of mercury, the gravitational redshift as well as the deflection of light in a gravitational field. He was convinced that light deflection by the gravitational field of the sun could be observed during a total solar eclipse. After several failed observations of total solar eclipses proof came in 1919: On May 29 of that year the English astronomer Arthur Stanley Eddington confirmed Einstein's prediction of light deflection when he observed a total solar eclipse on the volcanic island of Principe in the Gulf of Guinea in western Africa. A second expedition, led by Andrew Crommelin, observed this eclipse in Sobral, Brazil.

The official result of these expeditions was announced on November 6, 1919 during a joint meeting of the Royal Society and the Royal Astronomical Society in London. Therby Einstein had become the successor of the great Isaac Newton. Joseph John Thomson, president of the Royal Society, stated solemnly "This is the most important result related to the theory of gravitation since the days of Newton...This result is among the greatest achievements of human thinking." This confirmation of the predictions made by the General Theory of Relativity made Einstein world-famous and not only among scientists. The perihelion motion of mercury and the gravitational redshift were also gloriously confirmed experimentally. Now Einstein and his Theory of Relativity were much talked of. He received invitations and honours from all the world. There was rarely a magazine which did not report on his achievements with the highest praise. On the other hand, since 1920 Einstein and his Theory of Relativity became subject to vigorous attacks which mostly were founded on anti-semitism. Even nobel-prize laureates like Philipp Lenard and Johannes Stark publicly took up a hostile attitude towards Einstein and his theory and pleaded for a "German physics".

Post-1915 years - Einstein's consolidated scientific career:

The new theory of relativity brought to the public a transformation of physics, by Einstein and others, that was overturning established views of time, space, matter, and energy. Einstein became the world's symbol of the new physics. Some journalists took a perverse delight in exaggerating the incomprehensibility of his theory, claiming that only a genius could understand it. More serious thinkers -- philosophers, artists, ordinary educated and curious people -- took the trouble to study the new concepts. These people too chose Einstein as a symbol for thought at its highest.

During World War I, the speeches and writings of Central Powers scientists were available only to Central Powers academics, for national security reasons. Some of Einstein's work did reach the United Kingdom and the United States through the efforts of the Austrian Paul Ehrenfest and physicists in the Netherlands, especially 1902 Nobel Prize-winner Hendrik Lorentz and Willem de Sitter of the Leiden University, the oldest university in the Netherlands located in the city of Leiden. After the end of the war, Einstein would maintain his relationship with the Leiden University, accepting a contract as an Extraordinary Professor; that would make him travel to Holland regularly to lecture there between 1920 and 1930.

During this times he would become also involved with politics. The outbreak of the World War I brought Einstein's pacifist sympathies into public view. Ninety-three leading German intellectuals, including physicists such as Planck, signed a manifesto defending Germany's war conduct. Einstein and three others signed an antiwar counter-manifesto. He helped to form a nonpartisan coalition that fought for a just peace and for a supranational organization to prevent future wars. As a Swiss citizen Einstein could feel free to spend his time on theoretical physics, but he kept looking for ways to reconcile the opposing sides. "My pacifism is an instinctive feeling," he said, "a feeling that possesses me because the murder of men is disgusting. My attitude is not derived from any intellectual theory but is based on my deepest antipathy to every kind of cruelty and hatred".

Along with Germany's military collapse in November 1918, chaotic workers' and soldiers' councils proliferated. One of Einstein's lectures at the University of Berlin was "canceled due to revolution". On November 16, 1918 Einstein was one of the original signers of a manifesto announcing the creation of a progressive middle-class party, the German Democratic Party. After a democratically elected assembly met in Weimar, Einstein formally accepted German citizenship as a gesture of support for the infant republic.

Back to his scientific activities, in 1917, Einstein published a paper that uses general relativity to model the behavior of an entire universe. But Einstein's paper is the starting point, the first in the modern field of cosmology—the study of the behavior of the universe as a whole. (It is also the paper in which Einstein makes what he would call his worst blunder—inventing a "cosmological constant" to keep his universe static. When Einstein learned of Edwin Hubble's observations that the universe is expanding, he promptly jettisoned the constant).

In 1917, Einstein published an article in Physikalische Zeitschrift that proposed the possibility of stimulated emission, the physical process that makes possible the maser and the laser. In optics, stimulated emission is the process by which, when perturbed by a photon, matter may lose energy resulting in the creation of another photon. The perturbing photon is not destroyed in the process (cf. absorption), and the second photon is created with the same phase, frequency, polarization, and direction of travel as the original. Stimulated emission is really a quantum mechanical phenomenon but it can be understood in terms of a "classical" field and a quantum mechanical atom. The process can be thought of as "optical amplification" and it forms the basis of both the laser and maser.

Returning to the quantum, by 1919, six years before the invention of quantum mechanics and the uncertainty principle, Einstein recognizes that there might be a problem with the classical notion of cause and effect. Given the peculiar dual nature of quanta as both waves and particles, it might be impossible, he warns, to definitively tie effects to their causes.

According to physicist Max Born, General Relativity was "the greatest feat of human thinking about nature, the most amazing combination of philosophical penetration, physical intuition, and mathematical skill". The two physicists corresponded from 1916 until Einstein's death.

Nobel laureate Paul Dirac, a British theoretical physicist, called General Relativity probably the greatest scientific discovery ever made.

When British eclipse expeditions in 1919 confirmed his predictions, Einstein was idolised by the popular press. The London Times ran the headline on 7 November 1919: "Revolution in science - New theory of the Universe - Newtonian ideas overthrown".

Apart from all his work Einstein still found time for playing music. Since his youth he played the violin and later he frequently was seen on the street carrying his violin case. He was an admirer of Bach and Mozart and, through continuous practice, he became a good violinist. Apart from his love for music he was a devoted sailor. Doing this just for fun, here did he find the time to think about problems of physics.

From 1917 on Einstein became sick, suffering from various diseases resulting in a general weekness which lasted until 1920. Throughout this time he was under the loving care of his cousin Elsa Loewenthal. They fell in love with each other and on June 2nd, 1919, he married Elsa who had already two daughters, Ilse and Margot, from her first marriage. The couple then moved to Haberlandstrasse 5 in Berlin.

In February 1920 Einstein's mother died in Berlin.

Einstein's close personal friend, Paul Ehrenfest (1880-1933), a professor of theoretical physics at Leiden University since 1912; invited Einstein to become "Bijzonder Hoogleraar" (special professor) at Leiden University. He was an Austrian physicist and mathematician, who obtained Dutch citizenship on March 24, 1922. He made major contributions to the field of statistical mechanics and its relations with quantum mechanics, including the theory of phase transition and the Ehrenfest theorem.

Ehrenfest in a letter he wrote to Einstein in 1919 says: "All of us are now in complete agreement that we must undertake to get you to Leiden. The business is extremely simple: if you just say yes to me, it will be possible - at least according to all human expectations - to arrange things extremely quickly according to your wishes. You can spend as much time as you want in Switzerland, or elsewhere, working, giving lectures, traveling, etc., provided only that one can say Einstein is in Leiden - in Leiden is Einstein. Bear in mind that you would be taken in here by a group of people who are really fond of you personally, and not just of the brain drippings that ooze out of you!".

This would bring him to Leiden regularly for a few weeks a year. Einstein liked the idea of such a "comet-like existence in Leiden". He began his official duties on October 27, 1920, with an inaugural lecture on "Ether and Relativity Theory" (where "ether" refers to the gravitational field, not the abandonded concept of the electromagnetic ether).

Einstein once wrote in a letter to Ehrenfest: "It's so remarkably good for both of us to be together more often, because it's just as though Nature had made us for each other... Each of us feels less of a stranger in this world because of the other". The friendship of Einstein and Ehrenfest made the cover of Physics Today. Ehrenfest's home in Leiden still evokes memories of Einstein's frequent visits. In 1921 Einstein gave Ehrenfest an unusual present: The fountain pen he had used to write down his research on general relativity. It is now on display in the Boerhaave Museum in Leiden. He also left behind a few of his manuscripts, including the one predicting Bose-Einstein condensation (his last major discovery).

With his scientific fame Einstein could act as unofficial spokesman for the Weimar Republic, and he protested the continued hostility of Germany's former enemies. In 1921 he refused to attend the third Solvay Congress in Belgium, since all other German scientists were excluded from it. In 1922 he joined a newly created Committee on Intellectual Cooperation set up under the League of Nations. The next year he resigned, distressed by the League's impotence when confronted with France's occupation of the German Ruhr. But with a revived belief in the ideals of this organisation Einstein re-joined the commission in May 1924. As a leading member of the German League for Human Rights, he worked hard for better relations with France. He also made numerous gestures against militarism.

Opposed to any kind of violence Einstein supported pacifist movements whenever he had the chance. In addition, he supported the cause of the Zionists.

Einstein traveled all around the world during 1920s, both as a spokesman for liberal causes and as an esteemed member of the physics community. He visited England, France, Austria, Czechoslovakia, and South America and traveled east as far as Japan, returning by way of Palestine and Spain.

During 1921 Einstein made his first visit to the United States. His main reason was to raise funds for the planned Hebrew University of Jerusalem, to which he later bequeathed his entire written legacy. However he received the Barnard Medal during his visit and lectured several times on relativity. He is reported to have commented to the chairman at the lecture he gave in a large hall at Princeton which was overflowing with people: "I never realised that so many Americans were interested in tensor analysis".

During his visti in America he was asked where he got his scientific ideas; he answered that he believed scientific work best proceeds from an examination of physical reality and a search for underlying axioms, with consistent explanations that apply in all instances and avoid contradicting each other.

Einstein received the Nobel Prize in 1921 but not for relativity rather for his 1905 work on the photoelectric effect. In fact he was not present in December 1922 to receive the prize being on a voyage to Japan. 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". This refers to his 1905 paper on the photoelectric effect: "On a Heuristic Viewpoint Concerning the Production and Transformation of Light", which was well supported by the experimental evidence by that time. The presentation speech began by mentioning "his theory of relativity, which had been the subject of lively debate in philosophical circles and also has astrophysical implications which are being rigorously examined at the present time". (Einstein 1923). Einstein gave the Nobel prize money to his first wife, Mileva Marić.

As anti-Semitism was growing in Germany and the Nazi party was emerging since 1919; Nazi physicists and their followers violently denounced Einstein's theory of relativity as "Jewish-Communist physics". At times his friends feared for his safety. Such anti-Semitism was one reason why Einstein, although he believed in world government rather than nationalism, gave public support to Zionism. He said: "In so far as a particular community is attacked as such, it is bound to defend itself as such, so that its individual members may be able to maintain their material and spiritual interests. In present circumstances the rebuilding of Palestine is the only object that has a sufficiently strong appeal to stimulate the Jews to effective corporate action". But he objected to a law that required him to join the official Jewish religious community in Berlin. Refusing, he said, "Much as I feel myself a Jew, I feel far removed from traditional religious forms".

Einstein attracted attention to a number of causes, such as the release of political prisoners and the defense of democracy against the spread of fascism. He spoke in public, made statements to the press, signed petitions. In 1924 he defended the radical Bauhaus School of Architecture; in 1927 he signed a protest against Italian fascism; in 1929 he appealed for the commutation of death sentences given to Arab rioters in British Palestine.

Around this time he made many international visits. He had visited Paris earlier in 1922 and during 1923 he visited Palestine. After making his last major scientific discovery on the association of waves with matter in 1924 he made further visits in 1925, this time to South America.

Among further honours which Einstein received were the Copley Medal of the Royal Society in 1925 and the Gold Medal of the Royal Astronomical Society in 1926.

Back to his main scientific activities; from 1920 onwards Einstein was working towards a unified field theory which, apart from gravitation, was also to include electrodynamics. This research would last until his death and remained unsuccessful. During the first decade of work towards the unified field theory he was still being supported by colleagues which, however, after having lost their faith in being able to resolve this mystery, turned to other problems such as the theory of the new microcosmos or quantum mechanics. Niels Bohr, founder of the so-called Copenhagen School, Max Born, and - from the then young generation - Werner Heisenberg and Wolfgang Pauli among others became the physicists to develop quantum mechanics. Einstein thus became a single fighter and gradually scientifically isolated which, however, did not seem to bother him much. His way into isolation was magnified as Einstein was unable to accept quantum mechanics and constantly exercised his criticism. In particular, he was opposed to the probabilities which were applied in this theory. In this context we have to understand his well-known quotation "God does not throw the dice". However, as far as quantum mechanics is concerned, Einstein was wrong because at present this theory is as widely applied in physics as are Einstein's theories of relativity.

In his pursuit of a unification of the fundamental forces, he ignored some mainstream developments in physics (and vice versa), most notably the strong and weak nuclear forces, which were not well understood until many years after Einstein's death. Einstein's goal of unifying the laws of physics under a single model survives in the current drive for the grand unification theory.

Beginning in 1925 a bold new quantum theory emerged, the creation of a whole generation of theoretical physicists from many nations. Soon scientists were vigorously debating how to interpret the new quantum mechanics. Einstein took an active part in these discussions. Heisenberg, Bohr, and other creators of the theory insisted that it left no meaningful way open to discuss certain details of an atom's behavior. For example, one could never predict the precise moment when an atom would emit a quantum of light. Einstein could not accept this lack of certainty; and he raised one objection after another. At the Solvay Conferences of 1927 and 1930 the debate between Bohr and Einstein went on day and night, neither man conceding defeat. Einstein had declined to give a paper at the conference and said "hardly anything beyond presenting a very simple objection to the probability interpretation". Then he fell back into silence.

By the mid 1930s, Einstein had accepted quantum mechanics as a consistent theory for the statistics of the behavior of atoms. He recognized that it was "the most successful physical theory of our time." This theory, which he had helped to create, could explain nearly all the physical phenomena of the everyday world. Eventually the applications would include transistors, lasers, a new chemistry, and more. Yet Einstein could not accept quantum mechanics as a completed theory, for its mathematics did not describe individual events. Einstein felt that a more basic theory, one that could completely describe how each individual atom behaved, might yet be found. By following the approach of his own general theory of relativity, he hoped to dig deeper than quantum mechanics. The search for a deeper theory was to occupy much of the rest of his life.

He said "I want to know how God created this world. I am not interested in this or that phenomenon, in the spectrum of this or that element. I want to know His thoughts; the rest are details".

In 1924, Einstein received a description of a statistical model from Indian physicist Satyendra Nath Bose which showed that light could be understood as a gas. Bose's statistics applied to some atoms as well as to the proposed light particles, and Einstein submitted his translation of Bose's paper to the Zeitschrift für Physik (Journal of Physics), a German academic journal published from 1920 until 1997. Einstein also published his own articles describing the model and its implications, among them the Bose–Einstein condensate phenomenon that should appear at very low temperatures. This condensate is a state of matter of bosons (particles with an integer spin, as opposed to fermions which have half-integer spin) confined in an external potential and cooled to temperatures very near to absolute zero (0 K, −273.15 °C, or −459 °F ). Under such supercooled conditions, a large fraction of the atoms collapse into the lowest quantum state of the external potential, at which point quantum effects become apparent on a macroscopic scale.

But only seventy years later, in 1995, the first gaseous condensate was produced by Eric Cornell and Carl Wieman at the University of Colorado at Boulder NIST-JILA lab, using a gas of rubidium atoms cooled to 170 nanokelvin (nK). Eric Cornell, Carl Wieman and Wolfgang Ketterle at MIT were awarded the 2001 Nobel Prize in Physics.

Bose–Einstein statistics are now used to describe the behaviors of any assembly of "bosons". Einstein's sketches for this project may be seen in the Einstein Archive in the library of the Leiden University. It was evidently used by Einstein to correct the page proofs in early 1925 and left behind in Leiden after his February, 1925 visit.

Einstein suggested to Erwin Schrödinger an application of Max Planck's idea of treating energy levels for a gas as a whole rather than for individual molecules, and Schrödinger applied this in a paper using the Boltzmann distribution to derive the thermodynamic properties of a semiclassical ideal gas. Schrödinger urged Einstein to add his name as co-author, although Einstein declined the invitation.

In 1926, Einstein and his former student Leó Szilárd, a Hungarian physicist who later worked on the Manhattan Project and is credited with the discovery of the chain reaction, co-invented the Einstein refrigerator, revolutionary for having no moving parts and using only heat, not ice, as an input. The Einstein refrigerator is an absorption-type refrigerator which has no moving parts and requires only a heat source to operate. It was patented in the US on November 11, 1930.

From 1926 until 1933 Einstein and Szilárd collaborated on ways to improve home refrigeration technology. The two were motivated by contemporary newspaper reports of a Berlin family who had been killed when a seal in their refrigerator broke and leaked toxic fumes into their home. Einstein and Szilard proposed that a device without moving parts would eliminate the potential for seal failure, and explored practical applications for different refrigeration cycles. Einstein used the experience he had gained during his years at the Swiss Patent Office to apply for valid patents for their inventions in several countries, the two eventually being granted 45 patents in their names for three different models. Then the Swedish company AB Electrolux to protect its refrigeration technology from competition bought up the patent. A few demonstration units were constructed from other patents. The invention of Freon in 1930 made the vapour compression process the standard for refrigeration; however, concerns about the effects of Freon as an ozone depleting agent may cause a reevaluation of Einstein and Szilard's design.

As for Einstein's trips around the world he toured Europe and North America, as well as distant lands like Japana and even South America.

Departing for Japan by the N. Y. K. (Nippon Yusen Kabushikikaisha) liner Kitanomaru which sailed from Marseille on October 8, 1922, Albert Einstein arrived in Kobe, Japan, on November 17, 1922 and stayed for forty-three days in this Far
East land, sparking off an "Einstein boom" in Taisho Japan (1912-1926). Sailing from Moji on the N. Y. K. liner
Harunamaru which departed on December 29, Einstein arrived on February 1 in the following year at Port Said, Egypt
where he went ashore and headed for Palestine. Including the time spent aboard ship on the outward and homeward voyages,
his visit to Japan lasted a full four months.

In a postcard to Mr. and Mrs. Max Born in Berlin written several days before he left Japan, Einstein described his impressions on Japan as follows. "Dear Borns, Splendid sunshine at Christmas. A happy, beautiful country, with a delicate, sensitive people." (23December 1922). In a letter to Niels Bohr in Copenhagen written aboard ship
near Singapore on the way home, he wrote, "The trip is splendid. I am charmed by Japan and the Japanese
and sure that you would be, too". (11 January 1923).

Prior to visiting Japan, Einstein had toured the Netherlands, Czechoslovakia, Austria, the United States and Britain in
1920 and 1921, and in the spring of 1922 he had also visited France. These visits, however, had mainly political significance in that he was acting as a cultural envoy or lending support to the Zionist movement, and culturally speaking, though he belonged to the European sphere, where the scars of World War I were still fresh, he was dogged by the Jewish issue. It must be emphasized the fact that at the same time as evoking an extraordinary response towards the Japanese scenery and people, as shown in the above remarks, this trip to Japan, where prejudice against Jews was virtually nonexistent, was Einstein’s first and last Asian experience, and heightened his awareness as a cosmopolitan.

Most Japanese viewed Einstein as the flower of German science, and treated him as a German scientist. In Germany he
was attacked as a non-German Jew, but his position in overseas as a representative German scientist was emphasized to
exaggeration. Einstein himself was forced to put up with this double-faced Janus-like position about which he could do
nothing. At a luncheon hosted by the mayor of Osaka, Einstein’s statement that he accepted the elaborate welcome
of the German national anthem and German flag not as an individual but in the name of science was probably his own
response to this ambivalent situation.

Apparently the manner, in which the Japanese made a cult out of German science, made a great impression on Einstein,
as his travel diary (unpublished) reveals. It was often said that only seven people in the world understood
the theory of relativity at that time. Nevertheless, the reason that many people gathered to hear it was because the general intellectual class which supported the wide-spread Taisho democracy movement had expectations of it not as an isolated physics theory, but as an idea opening up new horizons.

During his 43-day sojourn in Japan, an enthusiastic welcome was accorded to Einstein by both the government and
the people. Einstein delivered a total of seven general lectures. The admission fee was three yen for adults and two yen for students. This was equivalent to the cost of ten ordinary lunches, so it was a considerable sum. Two of them were in
Tokyo and one each in Sendai, Nagoya, Osaka, Kyoto and Fukuoka. Einstein spoke with flavor for five hours on occasion,
addressing a full house wherever he went. To give an idea of this wild enthusiasm: several dozens of people who had entrance tickets for the lecture at Kanda in Tokyo were unable to enter because of the great congestion, so Kaizosha Publishing Company paid their return fare to Sendai, the site of the next lecture. Einstein also had some contact, though slight, with ten of the sixteen universities in Japan at that time, attending welcome parties held by students at five universities, and his charm directly left a great impression on Japanese youth. As mentioned earlier, when Kaizosha’s Yamamoto Sanehiko asked Bertrand Russell who are the three greatest people in the world, Russell replied: "First Einstein, then Lenin. There is nobody else".

These words reveal Russell’s deep sympathy with Einstein’s selfless and courageous action because Einstein was aiming
at solidarity with the human race. This was one factor behind the fever of the Einstein boom. Here the theory of relativity is transformed into a weapon of social thought.

In 1925 Einstein visited Argentina, Uruguay and Brazil within his series of travels around the world. Even during trips with a distinctive scientific purpose, like his journeys to France or England, the political aspect was also strongly present. Einstein was the first German with public prominence to visit these nations after the war. He had the explicit aim of tightening the links between European nations, and attempted to show that science, as the art, could not be submitted to nationalism.

Einstein’s trip to South America is connected to all of these aspects: diffusion of his scientific theories and political ideas, and a strong interest in knowing new countries and cultures. He gave lectures about the Relativity Theory for both scientific and non specialized audiences. His theories were explained and discussed in the press, and his routine was reported daily on the front pages of the newspapers. He also had the opportunity to make contact with
local scientists, both in private speeches and in sessions of scientific academies. However, in the notes of his diary, he sometimes expressed his opinion on the lack of significance of these meetings, in contradiction to the opinion of local scientists.

The trip was partly financed and organized by the Latin-American Jewish communities. In the countries visited by Einstein, there were many Jewish institutions which participated in the organization of great receptions for him. He talked about the necessity of the Jews all over the world to join and support the movement for the foundation of the Hebrew University in Jerusalem. After his returning to Berlin, in a letter sent to Michele Besso, Einstein wrote: "In
everyplace where I arrived, I was celebrated by the Jews, because I am a symbol of union among them".

He published also in the Argentinean newspaper, La Prensa, in May 24, a paper entitled Pan-Europe, 9 where he defended the rebirth of the European community which had been destroyed during the World War. This paper was criticized by members of the German community in Argentina, and due to hostile manifestations, the German ambassador avoided the invitation of Germans for a reception at the Embassy.

Wondering at the tropical nature and different cultural traditions were constant aspects of Einstein’s attitude during the trip to South America. He agreed on taking a flight over Buenos Aires, and visited famous tourist spots in Rio de Janeiro such as Pão de Açucar and Corcovado, and took a day long tour by car in Rio’s surroundings. His notes about Rio de Janeiro make reference to the flora that “surpasses the 1001 night dreams”, to the "delicious ethnic mixture in the streets”, or to the influence of the warm and humid climate in the human behavior.11 From Rio, he sent a telegram to Ehrenfest, where he revealed his general impression: "It has already been two months since I’ve been wandering in this lost paradise as a traveler of the Relativity".

The formal invitation to visit Argentina was formulated by Buenos Aires University. Nevertheless, it was the result of a combination of efforts. In 1923, the Argentinean-German Cultural Institution, whose explicit purpose was to diffuse the German culture and science in Argentina, invited him but he declined. On the other hand, another cultural institution –
Asociacion Hebraica (Hebrew Association) – asked Max Straus, a commercial agent in Berlin, to personally deliver Einstein’s invitation.15 As Einstein was in Leiden, his wife, Elsa, talked about Einstein’s attitude of declining invitations which had not been formulated officially and by means of scientific institutions. Hebrew Association informed Buenos Aires University about Einstein’s wish to visit Argentina, since he had received the invitation from an academic institution. As some professors of the university had already manifested their interest in Einstein’s visit to Argentina, Buenos Aires University joined the Hebrew Association initiative. A pool of these institutions was created to finance Einstein’s trip: Buenos Aires University gave $4,000 Argentinean pesos, the Hebrew Association the amount of $4,660 pesos, and the Argentinean-German Institution contributed another $1,500 pesos. The invitation was the result of a confluence of several interests. For the scientists and professors of the university Einstein’s presence gave them, besides the prestige of succeeding in bringing Einstein to Argentina, the possibility of learning about the revolutionary relativity theory directly from the main author. For the Jews, who had just immigrated to South America, it was a good chance to exhibit the most celebrated scientist of the world as member of their people; for the Germans it
was the opportunity to make propaganda for German culture in the context of a cultural war with other European countries.

He reached Buenos Aires on March 24, after a stay of a few hours in Uruguay. In Buenos Aires, Einstein had an exhaustive agenda. He took part in receptions organized by scientists, the Jewish community and the German Ambassador. He was received by the President and State Ministers and visited a newspaper office and Jewish institutions. He gave eight conferences at the Faculty of Exact, Physical and Natural Sciences, a speech on “Positivism and Idealism: the geometry and the finite and infinite space of the General Theory” at the Philosophy and Literature Faculty, and a conference entitled "Some thoughts on the Jews situation” at the Hebrew Association. Einstein traveled also to La Plata and Córdoba, and attended conferences in both places. He had a reception at the National Academy of Exact Sciences where he answered several questions on relativity and quantum physics. But, generally, his scientific activity in Argentina was restricted to the diffusion and explanation of the relativistic ideas. Einstein left Argentina on April 24 and reached Montevideo on the same day. He had three conferences at the Engineering Faculty of the University and, as in Argentina, took part in many receptions and visited the President of the country and State Ministers. He stayed a week in Montevideo, and left on May 1, headed for Rio de Janeiro.

Indeed Einstein's life had been hectic and he was to pay the price of overworking in 1928 with a physical collapse brought on through overwork. He developed a heart disease which took him almost a year to recover from. However he made a full recovery despite having to take things easy throughout 1928.

In 1929 after his 50th birthday he built a summer house in the municipality of Caputh where he lived with his family each year between spring and late autumn until the December of 1932.

Over the years, Einstein kept in touch with his sons. Eduard suffered a mental breakdown in 1930. After visiting with Eduard in Switzerland, Einstein tried to find help for his troubled son. Eduard was later diagnosed with schizophrenia and spent most of adult life in mental health facilities.

By 1930 he was making international visits again, back to the United States. Between 1930 and 1933 he spent each winter in Pasadena at the California Institute of Technology, each spring in Berlin, and each summer near Berlin in a home at Caputh. A third visit to the United States in 1932 was followed by the offer of a post at Princeton. The idea was that Einstein would spend seven months a year in Berlin and five months at Princeton. Einstein accepted and left Germany in December 1932 for the United States, but before he would travel around Europe. The following month the Nazis came to power in Germany and Einstein was never to return there. His remaining property in Germany was confiscated, and his name appeared on the first Nazi list of people stripped of their citizenship.

During 1933 Einstein travelled in Europe visiting Oxford, Glasgow, Brussels and Zurich. Offers of academic posts which he had found it so hard to get in 1901, were plentiful. He received offers from Jerusalem, Leiden, Oxford, Madrid and Paris; but he had already accepted an offer to join the Institute for Advanced Study in Princeton, New Jersey. He arrived in the United States in October 1933

Due to the political power situation and thus the incidents in Nazi Germany he left civil service in 1933 and thus also lost the German citizenship. From 1933–1940 Einstein only possessed the Swiss citizenship; and was a resident of the United States of America.

In January 1933, Adolf Hitler was appointed Chancellor of Germany. One of the first actions of Hitler's administration was the Law for the Restoration of the Professional Civil Service which removed Jews and politically suspect government employees (including university professors) from their jobs, unless they had demonstrated their loyalty to Germany by serving in World War I.

The Einsteins bought a house in Princeton where in 1935 he and his wife bought a house in 112, Mercer Street. In December 1936 Einstein's wife Elsa died. In 1939 his sister Maja moved to his house where she stayed until her death in 1951. One of her daughters and Einstein's long-time secretary lived on with Einstein in Princeton and helped with housekeeping. Einstein remained an integral contributor to the Institute for Advanced Study until his death in 1955. During the 1930s and into World War II, Einstein wrote affidavits recommending United States visas for a huge number of Jews from Europe trying to flee persecution, raised money for Zionist organizations and was in part responsible for the formation, in 1933, of the International Rescue Committee, a leading non-sectarian, non-governmental international relief and humanitarian aid organization based in the United States for the help of those fleeing racial, religious and ethnic persecution, as well as those uprooted by war and violence.

Meanwhile in Germany, a campaign to eliminate Einstein's work from the German lexicon as unacceptable "Jewish physics" (Jüdische physik) was led by Philipp Lenard, a Hungarian-German physicist and winner of the Nobel Prize for Physics in 1905 for his research on cathode rays and the discovery of many of their properties; and Johannes Stark, a German physicist, and Physics Nobel Prize laureate.

Deutsche Physik activists published pamphlets and even textbooks denigrating Einstein, and instructors who taught his theories were blacklisted—including Nobel laureate Werner Heisenberg, who had debated quantum probability with Bohr and Einstein. Philipp Lenard claimed that the mass–energy equivalence formula needed to be credited to Friedrich Hasenöhrl, an Austro-Hungarian physicist, to make it an Aryan creation.

Einstein became a guest lecturer at Abraham Flexner's newly founded Institute for Advanced Study in Princeton, New Jersey; a center for theoretical research, though with no formal links to Princeton University or other educational institutions. However, since its founding, it has enjoyed close, collaborative ties with Princeton. The Institute is divided into four Schools: Historical Studies, Mathematics, Natural Sciences, and Social Science, with a more recent program in systems biology.

The Institute for Advanced Study was founded in 1930 by noted educator Abraham Flexner, with funding from department store magnate Louis Bamberger and his sister Mrs. Felix Fuld. Advised to begin this experiment with one field of study, Flexner chose mathematics because it was a fundamental subject which required the smallest investment in buildings or books; there was also greater agreement on the identity of the most eminent mathematicians than on leading scholars in other disciplines.

Flexner first recruited noted mathematicians from Princeton University to join the Institute, and Einstein accepted a faculty position in August, 1932. During the 1930s, Flexner broadened the scope of the Institute by including established scholars in economics, politics, and humanistic studies.

Throughout his tenure at the Institute, Einstein worked closely with numerous assistants on his unified field theory. Although Einstein officially retired from the Institute in 1945, he continued his research there until his death in 1955.

When the Einsteins established themselves in Princeton, Albert and his wife Elsa, along with his personal secretary Helen Dukas, spent ten days at the Peacock Inn, while Elsa looked for a suitable house and Einstein dodged reporters.

The Einsteins' first two years in Princeton were spent in a two-family house at 2 Library Place. By 1935 Einstein had decided to remain in Princeton and began the formal process of obtaining permanent residency in the United States. The family moved to the white, two-story house at 112 Mercer Street, which would become their permanent home.

After Einstein's death in 1955 (Elsa had died in 1936), his daughter Margot and Helen Dukas remained in the house until their deaths in 1986 and 1982, respectively. At Einstein's request the house has never been turned into a museum or public shrine; today it is owned by the Institute for Advanced Study and is used as a private residence.

After Elsa Einstein's death, Helen Dukas took charge of the household, which consisted of Einstein, his daughter Margot, and his sister Maja. Einstein was devoted to his sister, who lived with him from 1939 until her death in 1951, reading to her nightly after she was bedridden from a stroke.

In 1919 when ALbert married his cousin, Elsa Einstein Löwenthal, he adopted her two daughters, Ilse and Margot. (Ilse died of an illness in 1934.) Margot, an artist and sculptor, shared a deep love of nature with her father.

Devoting the majority of his time to scientific work, Einstein also found enjoyment in sailing, often taking advantage of Princeton's Lake Carnegie, and music, especially the work of Mozart. Einstein was a well-known figure in Princeton, due in no small part to his shock of white hair, his refusal to wear socks, and his total absorption in scientific problems. Many Princeton residents have fond memories of spotting the famous physicist, lost in thought, walking to and from his office at the Institute for Advanced Study.

Nuclear Age and World War II

In the 1930s, scientists could break apart the nuclear cores of atoms and thus confirmed Einstein's formula E=mc². The release of energy in a nuclear transformation was so great that it could cause a detectable change in the mass of the nucleus. But the study of nuclei -- in those years the fastest growing area of physics -- had scant effect on Einstein. Nuclear physicists were gathering into ever-larger teams of scientists and technicians, heavily funded by governments and foundations, engaged in experiments using massive devices. Such work was alien to Einstein's habit of abstract thought, done alone or with a mathematical assistant.

In 1939 Leó Szilárd, the Hungarian physicist who was an old friend of Einstein’s and co-inventor of the Einstein refrigerator, fled the Nazis, he made his way to England and then New York, where he worked at Columbia University on ways to create a nuclear chain reaction, an idea he had conceived while waiting at a stoplight in London a few years earlier. When he heard of the discovery of fission using uranium, Szilárd realized that element might be used to produce this phenomenon.

Szilárd discussed the possibility with his friend Eugene Wigner, another refugee physicist from Budapest, and they began to worry that the Germans might try to buy up the uranium supplies of the Congo, which was then a colony of Belgium. But how, they asked themselves, could two Hungarian refugees in America find a way to warn the Belgians? Then Szilárd recalled that Einstein happened to be friends with Belgium's Queen Elizabeth.

“We knew Einstein was somewhere on Long Island, but we didn’t know precisely where,” Szilárd recalled. So he phoned Einstein’s Princeton, New Jersey, office and was told he was renting the house of a Dr. Moore in the village of Peconic. On Sunday, July 16, 1939, they embarked on their mission with Wigner at the wheel (Szilárd, like Einstein, did not drive). But when they arrived, they couldn’t find the house, and nobody seemed to know Dr. Moore. Then Szilárd saw a young boy standing by the curb. “Do you, by any chance, know where Professor Einstein lives?” he asked. Like most people in town, the boy did, and he led them up to a cottage near the end of Old Grove Road, where they found Einstein lost in thought.

Sitting at a wooden table on the porch of the sparsely furnished cottage, Szi­lárd explained how an explosive chain reaction could be produced in uranium layered with graphite by the neutrons released from nuclear fission: Those neutrons would split more nuclei, and so on. “I never thought of that!” Einstein interjected. He asked a few questions and quickly grasped the implications. Instead of writing the Belgian queen, Einstein suggested, they should contact a Belgian minister he knew.

Wigner, showing some sensible propriety, suggested that three refugees should not be writing a foreign government about secret security matters without consulting the U.S. State Department. Perhaps, they decided, the proper channel was a letter from Einstein (the only one of them famous enough to be heeded) to the Belgian ambassador, with a cover letter to the State Department. With that plan in mind, Einstein dictated a draft in German. Wigner translated it, gave it to his secretary to be typed, and then sent it to Szilárd.

A few days later, a friend arranged for Szilárd to talk to Alexander Sachs, an economist at Lehman Brothers and a friend of President Roosevelt’s. Showing a bit more savvy than the three theoretical physicists, Sachs insisted that the letter go right to the White House, and he offered to hand-deliver it.

It was the first time Szilárd had met Sachs, but he found the bold plan appealing. "It could not do any harm to try this way", he wrote to Einstein. Einstein wrote back asking Szilárd to come back out to Peconic so they could revise the letter. By that point Wigner had gone to California for a visit. So Szilárd enlisted, as driver and scientific sidekick, another friend from the amazing group of Hungarian refugees who were theoretical physicists, Edward Teller.

Szilárd brought with him the original draft from two weeks earlier, but Einstein realized that they were now planning a letter that was far more momentous than one asking Belgian ministers to be careful about Congolese uranium exports. The world’s most famous scientist was about to tell the president of the United States that he should begin contemplating a weapon of almost unimaginable impact. "Einstein dictated a letter in German", Szilárd recalled, "which Teller took down, and I used this German text as a guide in preparing two drafts of a letter to the president".

According to Teller’s notes, Einstein’s dictated draft not only raised the question of the Congo’s uranium but also explained the possibility of chain reactions, suggested that a new type of bomb could result, and urged the president to set up formal contact with physicists working on this topic. Szilárd then prepared and sent back to Einstein a 45-line letter and a 25-line version—both dated August 2, 1939—“and left it up to Einstein to choose which he liked best.” Einstein signed them both in a small scrawl.

The scientists still had to figure out who could best get it into the hands of President Roosevelt. Einstein was unsure Sachs could do the job. When Szilárd sent back to Einstein the typed versions of the letter, he suggested that they use as their intermediary Charles Lindbergh, whose solo transatlantic flight 12 years earlier had made him a celebrity. All three refugee Jews were apparently unaware that the aviator had been spending time in Germany, had been decorated the year before by Hermann Göring with that nation’s medal of honor, and was becoming an isolationist and Roosevelt antagonist.

At the end of August 1939, the Nazis and Soviets stunned the world by signing a war-alliance pact and proceeded to carve up Poland. That prompted Britain and France to declare war.

Szilárd went to see Sachs in late September and was horrified to discover that he still had not been able to schedule an appointment with Roosevelt. "There is a distinct possibility Sachs will be of no use to us", Szilárd wrote to Einstein. "Wigner and I have decided to accord him ten days’ grace". Sachs barely made the deadline. On the afternoon of Wednesday, October 11, he was ushered into the Oval Office carrying Einstein’s letter, Szilárd’s memo, and an 800-word summary he had written on his own.

The president greeted him jovially: “Alex, what are you up to?”

Sachs worried that if he simply left Einstein’s letter and the other papers with Roosevelt, they might be glanced at and then pushed aside. The only reliable way to deliver them, he decided, was to read them aloud. Standing in front of the president’s desk, he read his summation of Einstein’s letter and parts of Szilárd’s memo.

"Alex, what you are after is to see that the Nazis don’t blow us up", the president said.

"Precisely", Sachs replied.

"This requires action", Roosevelt declared to his assistant.

The following week, Einstein received a polite and formal thank-you letter from the president. "I have convened a board", Roosevelt wrote, "to thoroughly investigate the possibilities of your suggestion regarding the element of uranium". Still, the effort’s slow pace and meager funding prompted Szilárd and Einstein to compose a second letter urging the president to consider whether the American work was proceeding quickly enough.

Despite helping to spur Roosevelt into action, Einstein never worked directly on the bomb project. J. Edgar Hoover, the director of the FBI even back then, wrote a letter to General Sherman Miles, who initially organized the efforts, that described Einstein’s pacifist activities and suggested that he was a security risk. In the end, Einstein played only a small role in the Manhattan Project. He was asked by Vannevar Bush, one of the project’s scientific overseers, to help on a specific problem involving the separation of isotopes that shared chemical traits. Einstein was happy to comply. Drawing on his old expertise in osmosis and diffusion, he worked for two days on a process of gaseous diffusion in which uranium was converted into a gas and forced through filters.

The scientists who received Einstein’s report were impressed, and they discussed it with Bush. In order for Einstein to be more useful, they said, he should be given more information about how the isotope separation fit in with other parts of the bomb-making challenge. Bush refused. He knew that Einstein didn’t have and couldn’t get the necessary security clearance. "I wish very much that I could place the whole thing before him and take him fully into confidence", Bush wrote, "but this is utterly impossible in view of the attitude of people here in Washington who have studied his whole history".

Thus the scientist who had explained the need for a bomb-making project was considered too risky to be told about it.

Transcriptions of Albert Einstein's letters to Roosvelt can be read at http://hypertextbook.com/eworld/einstein.shtml#first.

On October 1, 1940 Einstein was sworn in as American citizen, keeping however also his Swiss citizenship. In a public letter to the United Nations in 1946 Einstein would propose to install a world government in which he saw the only chance for a durable peace. In the following years he would intensify these endeavours.

By 1942 this effort had become the Manhattan Project, the largest secret scientific endeavor undertaken up to that time. By late 1945, the U.S. had developed operational nuclear weapons, and used them on the Japanese cities of Hiroshima and Nagasaki. Einstein himself did not play a role in the development of the atomic bomb other than signing the letter. He did help the United States Navy with some unrelated theoretical questions it was working on during the war.

BuOrd’s Lt. Stephen Brunauer solicited Einstein’s help in May 1943. The next month Einstein came up with his first suggestion, a way to make a torpedo detonate just as it passed beneath a ship’s keel. In Einstein’s scheme a pair of electromagnetic coils at the front and rear of the torpedo would be connected in series with an electromagnet between them. The two coils would have opposite magnetic polarity, so when the torpedo was far from the target ship, the induced current between them would be zero for reasons of symmetry. As the torpedo approached the ship, the hull’s magnetic field would start to be felt. Since the field would be stronger at the front of the torpedo than at the rear, it would induce a current. Then when the torpedo passed beneath the keel, the fields from either side of the hull would cancel each other out, and the current would briefly dip to zero, setting off the detonator.

In August Einstein turned his attention to torpedoes detonated by contact rather than magnetic impulses. He explained why the explosive charge in such torpedoes should be placed at the front instead of the rear and suggested a protruding hollow tip, possibly armed with a projectile, to increase the likelihood of puncturing the hull instead of just shaking it. But contact detonation raised a new problem: The force of a violent collision with the hull could crush the head of the torpedo before detonation was completed.

In October Einstein suggested a possible way around this difficulty: Put the explosive in the rear of the torpedo and rotate it after impact to bring the business end closer. At first he thought the increased water speed right next to a ship’s moving hull would do the trick. Two months later, though, he decided that even if his idea could be made to work, the turning forces would destroy the torpedo. Once again he proposed adding a small empty space at the front. It would crumple before the rest of the head, buying a few extra thousandths of a second to give the explosive time to detonate properly. (Navy engineers eventually solved the problem by redesigning the contact detonator’s firing pin.)

A few months after the weapon was used against Japan in 1945, Time put him on its cover with an explosion mushrooming behind him that had E = mc2 emblazoned on it. In a story overseen by an editor named Whittaker Chambers, the magazine noted with its typical prose from the period: "There will be dimly discernible, to those who are interested in cause & effect in history, the features of a shy, almost saintly, childlike little man with the soft brown eyes, the drooping facial lines of a world-weary hound, and hair like an aurora borealis. Albert Einstein did not work directly on the atom bomb. But Einstein was the father of the bomb in two important ways: 1) it was his initiative which started U.S. bomb research; 2) it was his equation (E = mc2) which made the atomic bomb theoretically possible".

Newsweek, likewise, did a cover on him, with the headline “The Man Who Started It All.” This was a perception fostered by the U.S. government. It had released an official history of the atom bomb project that assigned great weight to a letter Einstein had written to President Franklin Roosevelt warning of the destructive potential of an atomic chain reaction.

All of this troubled Einstein. "Had I known that the Germans would not succeed in producing an atomic bomb", he told Newsweek, "I never would have lifted a finger". He pointed out, correctly, that he had never actually worked on the bomb project. And he answered to a Japanese publication, Kaizo, a short essay to describe his limited involvement in the development of the atomic bomb. Einstein stated that his participation consisted of "a single act" - signing the 1939 letter to President Roosevelt. "I did not see any other way out, although I always was a convinced pacifist". The essay appeared in a special edition of Kaizo published in 1952

He added: "I was well aware of the dreadful danger for all mankind, if these experiments would succeed. But the probability that the Germans might work on that very problem with good chance of success prompted me to take that step. I did not see any other way out, although I always was a convinced pacifist. To kill in war time, it seems to me, is in no ways better than common murder. Only radical abolition of war and of danger of war can help. Toward this goal one should strive; in fact nobody should allow himself to be forced into actions contrary to this goal. This is a harsh demand for anyone who is aware of his social inter-relatedness; but it can be followed. Gandhi, the greatest political genius of our time has shown the way, and has demonstrated the sacrifices man is willing to bring if only he has found the right way. His work for the liberation of India is a living example that man's will, sustained by an indomitable conviction is stronger than apparently invincible material power".

In 1947, Einstein wrote an article for "The Atlantic Monthly" arguing that the United States should not try to pursue an atomic monopoly, and instead should equip the United Nations with nuclear weapons for the sole purpose of maintaining deterrence.

Einstein wrote: "Since the completion of the first atomic bomb nothing has been accomplished to make the world more safe from war, while much has been done to increase the destructiveness of war. I am not able to speak from any firsthand knowledge about the development of the atomic bomb, since I do not work in this field. But enough has been said by those who do to indicate that the bomb has been made more effective. Certainly the possibility can be envisaged of building a bomb of far greater size, capable of producing destruction over a larger area. It also is credible that an extensive use could be made of radioactivated gases which would spread over a wide region, causing heavy loss of life without damage to buildings".

He also added: "In refusing to outlaw the bomb while having the monopoly of it, this country suffers in another respect, in that it fails to return publicly to the ethical standards of warfare formally accepted previous to the last war. It should not be forgotten that the atomic bomb was made in this country as a preventive measure; it was to head off its use by the Germans, if they discovered it. The bombing of civilian centers was initiated by the Germans and adopted by the Japanese. To it the Allies responded in kind—as it turned out, with greater effectiveness—and they were morally justified in doing so. But now, without any provocation, and without the justification of reprisal or retaliation, a refusal to outlaw the use of the bomb save in reprisal is making a political purpose of its possession; this is hardly pardonable. I am not saying that the United States should not manufacture and stockpile the bomb, for I believe that it must do so; it must be able to deter another nation from making an atomic attack when it also has the bomb. But deterrence should be the only purpose of the stockpile of bombs. In the same way I believe that the United Nations should have the atomic bomb when it is supplied with its own armed forces and weapons. But it too should have the bomb for the sole purpose of deterring an aggressor or rebellious nations from making an atomic attack. It should not use the atomic bomb on its own initiative any more than the United States or any other power should do so. To keep a stockpile of atomic bombs without promising not to initiate its use is exploiting the possession of bombs for political ends. It may be that the United States hopes in this way to frighten the Soviet Union into accepting supranational control of atomic energy. But the creation of fear only heightens antagonism and increases the danger of war. I am of the opinion that this policy has detracted from the very real virtue in the offer of supranational control of atomic energy".

He also wrote: "I am in favor of inviting the Russians to join a world government authorized to provide security, and if they are unwilling to join, to proceed to establish supranational security without them. Let me admit quickly that I see great peril in such a course. If it is adopted it must be done in a way to make it utterly clear that the new regime is not a combination of power against Russia. It must be a combination that by its composite nature will greatly reduce the chances of war. It will be more diverse in its interests than any single state, thus less likely to resort to aggressive or preventive war. It will be larger, hence stronger than any single nation. It will be geographically much more extensive, and thus more difficult to defeat by military means. It will be dedicated to supranational security, and thus escape the emphasis on national supremacy which is so strong a factor in war. If a supranational regime is set up without Russia, its service to peace will depend on the skill and sincerity with which it is done. Emphasis should always be apparent on the desire to have Russia take part. It must be clear to Russia, and no less so to the nations comprising the organization, that no penalty is incurred or implied because a nation declines to join. If the Russians do not join at the outset, they must be sure of a welcome when they do decide to join. Those who create the organization must understand that they are building with the final objective of obtaining Russian adherence. I should like to see the authority of the supranational regime restricted altogether to the field of security. Whether this would be possible I am not sure. Experience may point to the desirability of adding some authority over economic matters, since under modern conditions these are capable of causing national upsets that have in them the seeds of violent conflict. But I should prefer to see the function of the organization altogether limited to the tasks of security. I also should like to see this regime established through the strengthening of the United Nations, so as not to sacrifice continuity in the search for peace".

The Cold War

In May 1946 he became chairman of the newly formed Emergency Committee of Atomic Scientists, joining their drive for international and civilian control of nuclear energy. He recorded fund-raising radio messages for the group, and wrote a widely read article on their work. Einstein's appeals for nuclear disarmament had an influence among both scientists and the general public. He also spoke out in opposition to German rearmament, defended conscientious objectors against military service, and criticized the Cold War policies of the United States.

An early and firm supporter of the United Nations, he was convinced that the solution to international conflict was world law, world government, and a strong world police force.

During the first days of McCarthyism, a term describing the intense anti-communist suspicion in the United States in a period that lasted roughly from the late 1940s to the late 1950s, Einstein was writing about a single world government; it was at this time that he wrote, "I do not know how the third World War will be fought, but I can tell you what they will use in the Fourth—rocks!"

Einstein was a member of several civil rights groups.

In 1946, Albert Einstein traveled to Lincoln University in Pennsylvania, the alma mater of Langston Hughes and Thurgood Marshall and the first school in America to grant college degrees to blacks. At Lincoln, Einstein gave a speech in which he called racism "a disease of white people", and added, "I do not intend to be quiet about it". He also received an honorary degree and gave a lecture on relativity to Lincoln students.

The reason Einstein’s visit to Lincoln is not better known is that it was virtually ignored by the mainstream press, which regularly covered Einstein’s speeches and activities. (Only the black press gave extensive coverage to the event.) Nor is there mention of the Lincoln visit in any of the major Einstein biographies or archives. That these omissions need to be recognized and corrected is the contention of Fred Jerome and Rodger Taylor, authors of "Einstein on Race and Racism" (Rutgers University Press, 2006).

According to Jerome and Taylor, Einstein’s statements at Lincoln were by no means an isolated case. Einstein, who was Jewish, was sensitized to racism by the years of Nazi-inspired threats and harassment he suffered during his tenure at the University of Berlin.

But while Einstein may have been grateful to have found a safe haven, his gratitude did not prevent him from criticizing the ethical shortcomings of his new home. "Einstein realized that African Americans in Princeton were treated like Jews in Germany,” said Taylor. “The town was strictly segregated. There was no high school that blacks could go to until the 1940s".

Einstein’s response to the racism and segregation he found in Princeton (Paul Robeson, who was born in Princeton, called it "the northernmost town in the South") was to cultivate relationships in the town’s African-American community. Jerome and Taylor interviewed members of that community who still remember Einstein strolling through their streets, stopping to chat with the inhabitants, and handing out candy to local children.

One woman remembered that Einstein paid the college tuition of a young man from the community. Another said that he invited Marian Anderson to stay at his home when the singer was refused a room at the Nassau Inn.

Einstein met Paul Robeson when the famous singer and actor came to perform at Princeton’s McCarter Theatre in 1935. The two found they had much in common. Both were concerned about the rise of fascism, and both gave their support to efforts to defend the democratically elected government of Spain against the fascist forces of Francisco Franco. Einstein and Robeson also worked together on the American Crusade to End Lynching, in response to an upsurge in racial murders as black soldiers returned home in the aftermath of World War II.

Einstein continued to support progressive causes through the 1950s, when the pressure of anti-Communist witch hunts made it dangerous to do so. Another example of Einstein using his prestige to help a prominent African American occurred in 1951, when the 83-year-old W.E.B. Du Bois; a civil rights activist, public intellectual, Pan-Africanist, sociologist, educator, historian, writer, editor, poet, and scholar and founder of the NAACP (National Association for the Advancement of Colored People), was indicted by the federal government for failing to register as a "foreign agent" as a consequence of circulating the pro-Soviet Stockholm Peace Petition. Einstein offered to appear as a character witness for Du Bois, which convinced the judge to drop the case.

In 1946 the Albert Einstein Foundation for Higher Learning, Inc. was formed to create a Jewish-sponsored secular university, open to all students, on the grounds of the former Middlesex University in Waltham, Massachusetts. It was created by Rabbi Israel Goldstein, Middlesex University heir C. Ruggles Smith, and activist attorney George Alpert and Albert Einstein collaborated with them. The main idea was to create a university "deeply conscious both of the Hebraic tradition of Torah looking upon culture as a birthright, and of the American ideal of an educated democracy."

However, when Einstein wanted to appoint British economist Harold Laski as the university's president, Alpert wrote that Laski was "a man utterly alien to American principles of democracy, tarred with the Communist brush." Einstein withdrew his support and barred the use of his name. Finally university opened its doors in 1948 and was named Brandeis University. In 1953, Brandeis offered Einstein an honorary degree, which he declined to accept.

In 1948 the State of Israel was founded. Chaim Weizmann (1874-1952), one of the co-founders of the State of Israel, became its first president in 1948. He died on November 9 in 1952.

That's when the Israeli government decided to offer Einstein the office of president. The Israeli minister-president David Ben Gurion (1886-1973) ordered his ambassador to the US in Washington, Abba Eban (1915-2002) to ask Einstein in Princeton whether he wanted to take over the office. In the telegram to Abba Eban it said: "Please find out immediately whether Einstein would accept the election (by parliament) to be Israeli president. Please telegraph his answer immediately. Ben Gurion."

Before the offer of the ambassador reached the Albert Einstein in Princeton, there was already a great disquiet in the household. Einstein had already been informed about the offer to become president of the State of Israel by the New York Times. There were subsequently many phone calls from people who wanted to know whether he would accept the offer. Finally the telegram of the ambassador arrived in Mercer Street 112 on the evening of November 17, 1952. Einstein was very excited and he found the offer unpleasant. He considered how to tell the ambassador he wanted to decline the offer and decided not to send a telegram but to phone the ambassador in Washington directly. In this conversation Einstein declined the offer in a friendly way and deeply moved. The ambassador asked Einstein for a written official statement. So Einstein fulfilled the ambassador's request.

The next morning he wrote the letter where he expressed his decline. Among other things he wrote: "I am deeply moved by the offer from our State of Israel (to serve as President), and at once saddened and ashamed that I cannot accept it. All my life I have dealt with objective matters, hence I lack both the natural aptitude and the experience to deal properly with people and to exercise official functions. Therefore I would also be an inappropriate candidate for this high task, even when my old age didn’t interfere with my forces more and more. I wish from the bottom of my heart that a man is found who will be able to take over the hard and responsible office due to his work and his personality."

This letter was handed over to the ambassador by an Israeli legate who had collected the it in Mercer Street.

Finally the successor to Chaim Weizmann was the Israeli politician Jitzchak Ben Zwi (1884-1963); he was later re-elected in 1957 and 1962. Ben Zwi died during his third period in office on April 23, 1963.

His interest in public affairs, however, did not end there. In 1955 he joined Bertrand Russell in urging scientists toward mediation between East and West and limitation of nuclear armament. Meanwhile he was writing a speech for the anniversary of Israel's independence. An incomplete draft of the speech was found at his bedside after he died.

In March 1950 he declared his will, making his secretary Helen Dukas and Dr. Otto Nathan jointly to his executors. On April 15, 1955 Einstein was transported to hospital in Princeton because he had severe pain. The diagnosis was a ruptured aneurysm of his abdominal aorta. As a consequence of this illness Albert Einstein died at the age of 76 at 1:15 a.m. on April 18, 1955. Following his wish his remains were cremated the same day and the ashes were put down at an unknown place.

However that was the beginning of Einstein's brain journey.

Thomas Harvey, the pathologist on call that evening, would later say, "I just knew we had permission to do an autopsy, and I assumed that we were going to study the brain." As reporters soon discovered, Harvey did not have permission. Nor did he have a legal right to remove and keep the brain for himself. When the fact came to light a few days later, Harvey managed to solicit a reluctant and retroactive blessing from Einstein's son, Hans Albert, with the now-familiar stipulation that any investigation would be conducted solely in the interest of science, and that any results would be published in reputable scientific journals. But Einstein's dignity had already been compromised. He had left behind specific instructions regarding his remains: cremate them, and scatter the ashes secretly in order to discourage idolaters. Yet not only did Harvey take the brain, he also removed the physicist's eyeballs and gave them to Henry Abrams, Einstein's eye doctor. They remain to this day in a safe deposit box in New York City, and are frequently rumored to be poised for the auction block.

A few months after the autopsy, Harvey was dismissed from Princeton Hospital for refusing to surrender his precious specimen, thus Harvey's tenure as a pathologist came to an end.

However, Thomas Harvey was not a brain specialist. His understanding of the brain did not extend beyond the postmortem diagnosis of disease, atrophy, or injury. Which is to say that he had neither the means nor the expertise to undertake the study he had proposed to Einstein's son. Although his accounts of the incident have varied considerably over the years, it seems that he removed the brain at the request of his mentor, Harry Zimmerman, who was Einstein's personal physician.

After losing his job, Harvey took the brain to a Philadelphia hospital, where a technician sectioned it into over two hundred blocks and embedded the pieces in celloidin using a variation of the Economo method. Harvey gave some of the pieces to Harry Zimmerman, and placed the remainder in two formalin-filled jars, which he stored in the basement of his house in Princeton. Occasionally, he would try to interest a brain researcher in his quest, but most of the inquiries he fielded came from reporters. Whenever they asked what was being done, Harvey would confidently proclaim that he was just one year away from publishing his results. He would continue to give the same answer for the next forty years.

For a time he worked as a medical supervisor in a biological testing lab in Wichita, Kansas, keeping the brain in a cider box stashed under a beer cooler. He moved again, to Weston, Missouri, and practiced medicine while trying to study the brain in his spare time, only to lose his medical license in 1988 after failing a three-day competency exam. He then relocated to Lawrence, Kansas, took an assembly-line job in a plastic-extrusion factory, moved into a second-floor apartment next to a gas station, and befriended a neighbor, the beat poet William Burroughs. The two men routinely met for drinks on Burroughs's front porch. Harvey would tell stories about the brain, about cutting off chunks to send to researchers around the world. Burroughs, in turn, would boast to visitors that he could have a piece of Einstein any time he wanted.

In the early 1990s, Harvey returned to Princeton, his wanderings not quite over. What had merely verged on the absurd in the early days crossed the line in 1997 when he embarked on a cross-country road trip with a freelance magazine writer named Michael Paterniti. Harvey wanted to meet Einstein's granddaughter in California. Paterniti eagerly signed on as a driver, and the two men set off from New Jersey with Einstein's brain in the trunk of Harvey's Buick Skylark. When he met the granddaughter, Harvey toyed with the idea of giving her the brain. He even left it at her house accidentally. But she didn't want it. In the end, the two men and the brain parted ways: Paterniti to seek fame and fortune with his story, Harvey to seek peace of mind at his girlfriend's house in Princeton, and the brain to end its days at the pathology lab where it had all started some forty years earlier.

Paternal family history

Albert Einstein's father was Hermann Einstein, born on August 30, 1847 in Buchau, Wurttemberg (currently is part of the German state of Bavaria) to Abraham Einstein and Helene Moos. Hermann Einstein had three brothers (August Ignaz, Heinrich and Jakob) and two sisters (Jette and Friederike). At the age of 14 Hermann attended the secondary school in the regional capital Stuttgart successfully. He had a strong affection for mathematics and had liked to study in this or another related area. But as the financial situation of the family opposed a study he decided to become a merchant and made an apprenticeship in Stuttgart.

He married Pauline Koch (1858–1920) who was only 18 years old then in Cannstatt, Wuerttemberg on August 8, 1876. After their marriage the young couple lived in Ulm, where Hermann became joint partner in the bed feathers shop of his cousin Moses and Hermann Levi. In Ulm their son Albert (1879–1955) was born on March 14, 1879. On initiative of Hermann’s brother Jakob, the family moved to Munich in the summer of 1880. The two brothers founded there a company for electrical engineering. Hermann was the merchant and Jakob the technician in this company. The second child of Hermann and Pauline, their daughter Maria – called Maja – (1881–1951) was born in Munich on November 18, 1881.

The two brothers moved their company to Pavia, Italy in 1894. Hermann, Pauline and Maja moved to Milan in the same year and one year later also to Pavia. Albert stayed with relatives in Munich to complete his education there.

Due to the bad business situation Hermann and Jakob had to abandon their factory in 1896. Though the Hermann family had lost most of their money he founded, without his brother, again an electrical engineering company in Milan. He was in this connection supported financially by his relatives. Though business was better this time Hermann was steadily occupied with "worries due to the vexatious money". These worries didn’t pass him traceless. His health had suffered a lot from this in the last years. He died on October 10, 1902 at the age of 55 in Milan on heart failure.

Hermann's father (Albert's paternal grandfather) was Abraham Einstein who was born on April 16, 1808 in Buchau, Wurttemberg, Germany to Ruppert Einstein and Rebecka Obernauer (Einstein). He lived in Buchau on the Federsee, a lake located just north of Bad Buchau in the region of Upper Swabia; and is said to have enjoyed a great and widespread reputation as an intelligent and upright man. Abraham married with Helene Moos (Albert's paternal grandmother) who was born on July 3rd, 1814. They married in Buchau on April 15, 1839 and had five children; Raphael Einstein, born on December 3rd, 1839; August Ignatz Einstein born on December 23rd, 1841; Jette Einstein, born on January 13th, 1844; Heinrich Einstein, born on October 12th, 1845; Hermann Einstein (Albert Einstein's father, read the previous paragraphs for more info about him); Jacob Einstein, born on November 25th, 1850, and Friederike (Rika) Einstein, known as Rika, born on March 15th, 1855; all of them were born in Buchau Federsee, Donaukreis, Wuttemberg, Germany.

Abraham died at the age of 60 on November 21st, 1868; his grandson, Albert, never knew him. Helene Moos died at the age of 73 on August 20th, 1887; during Albert's childhood.

Abraham's father, Ruppert (Albert's great-grandfather) was born in July, 1759 in Wurttemberg, Germany to Naftali Einstein and Helene Sttepach. He married with Rebekka Overnauer, born on 22 May 1770 in Buchau, Wurttenberg, Germany. They married on January 20, 1797 and had six children; Hirsch born on February 18, 1799; Judith Einstein born on May 28, 1802; Samuel Rupert, born on February 12, 1804; Raphael born on June 18, 1806 (Raphael was the grandfather of Elsa Einstein, Albert's second wife); Abraham (Albert's grandfather) born on April 16, 1808; and David born on August 11, 1810. Rupert died on 4 April 1834 in Wurttemberg, Germany; while Rebekka Overnauer died on 24 Feb 1853 in Germany.

Albert Einstein great great grandfather Naftali Einstein was born about 1733 in Buchau, Württemberg, Germany and he married with Helene Sttepach who was born about 1737 in Steppach, Germany.

The Einstein was a fairly widespread Jewish family in southern Germany, especially in Württemberg and Bavaria. Particularly the Albert Einstein's family-tree has a long tradition in the city of Buchau in Württemberg, Germany; where all the scientist's paternal ancestors were born at least, as far back as the fifth generation in the 18th century.

Maternal family history

Pauline Einstein, nee Koch, the mother of the great physicist Albert Einstein, was born in Cannstatt, Wuerttemberg, on February 8, 1858. She was Jewish and had an older sister, Fanny, and two older brothers, Jacob and Caesar. Her parents were Julius Derzbacher, who had accepted the family name Koch in 1842 and Jette Bernheimer. They had married in 1847. Pauline’s father was from Jebernhausen (now part of Göppingen a city in southern Germany, part of the Stuttgart Region of Baden-Württemberg) and came from simple circumstances. Later he lived in Cannstatt and he succeeded together with his brother Heinrich to make a considerable fortune with corn trade. They even became "Royal Wuerttemberg Purveyor to the Court"; purveyors are Royal Warrants of Appointment which have been issued for centuries to those who supply goods or services to a royal court or certain royal personages. The warrant enables the supplier to advertise the fact that they supply to the royal family, so lending prestige to the supplier. Their mother was from Cannstatt and was a quiet and caring person.

The 18-year-old Pauline married the merchant Hermann Einstein (1847–1902) who lived in Ulm, in Cannstatt on August 8, 1876. After the marriage the young couple lived in Ulm, where Hermann Einstein became joint partner in a bed feathers company. Their son Albert (1879–1955) was born on March 14, 1879. On the initiative of Hermann’s brother Jakob the family moved to Munich in the summer of 1880, where the two brothers together founded an electrical engineering company. The second child of Hermann and Pauline, their daughter Maria – called Maja – (1881–1951) was born in Munich on November 18, 1881.

Pauline Einstein was a very well educated and quiet woman who had an inclination towards the arts. When her duties in the household allowed it she was an assiduous and good piano player. She made her son Albert begin with violin lessons at the age of five. Her patience was one of her characteristics.

The factory of Hermann and Jakob was moved to Pavia, Italy in 1894. Hermann, Pauline and Maja moved first to Milan in the same year and one year later to Pavia. Albert stayed with relatives in Munich to complete his education there. The separation from her son was certainly difficult for Pauline.

Due to the bad business situation the brothers had to abandon their factory in 1896. Though the Hermann's and Pauline's family had lost most of their money, Hermann founded, without his brother, again an electrical engineering company in Milan. This time business was better. But Hermann’s health had suffered a lot in the last years and he died on October 10, 1902 in Milan on heart failure.

From 1903 on Pauline lived with her sister Fanny and her husband Rudolf Einstein in Hechingen, Wuerttemberg. Her daughter Elsa became the second wife of Albert Einstein in 1919.

In 1910 Pauline moved with her sister Fanny and her family to Berlin. She took on a job as housekeeper in Heilbronn, Wuerttemberg in 1911. She had lived with her brother Jacob Koch and his family in Zurich since 1914. During World War I Pauline fell ill with cancer.

In 1918, when visiting her daughter Maja and her husband Paul Winteler in Luzern, Pauline was taken to the sanatorium Rosenau there due to her illness. At the end of 1919 Albert got his terminally ill mother out of the sanatorium in Luzern and took her to himself and his second wife Elsa to Berlin, to a house in Haberlandstrasse 5 where she died a few month later on February 20, 1920.

Julius Derzbacher (Albert's maternal grandfather) was born on 19 February 1816 in Jebenhausen (now part of Göppingen, a city in southern Germany, part of the Stuttgart Region of Baden-Württemberg), Wurttenberg, Germany; to Zadok Loeb Doerzbacher and Blumle Sintheimer. In 1842 he accepted the family name Koch. In Jebenhausen he practiced his trade as a baker, at first in modest circumstances. Later he lived together with his brother in Cannstatt, and together they managed to build a considerable fortune in the grain trade. The brothers and their families shared a single
household under the same roof.

As his commercial abilities showed, Julius Koch possessed a distinctly practical intelligence and great energy. Theorizing was completely foreign to him. With wealth came a desire to be a patron of the arts, which he undertook, however, in a petty manner, and in
accord with the principles of his trade, that is, spending as little as possible on it. As a result, he often ended up buying copies rather than authentic paintings. He once took in a poor artist he happened to meet on one of his walks for the purpose of laying the foundation of a future ancestral portrait gallery. This was the origin of a
childhood portrait of Albert Einstein, still in the possession of the
author. It is doubtful that the poor painter ever earned more than a free room and board under this arrangement. On the other hand, it was quite all right with grandfather Koch if technical skill, in this case a "likeness," took the place of genuine art.

Later he lived in Cannstatt and he succeeded together with his brother Heinrich to make a considerable fortune with corn trade. They became "Royal Wuerttemberg Purveyor to the Court".

Jette Bernheimer (Albert's maternal grandmother) was born in 1825 in Jebenhausen, Wurttemberg, Germany. Julius Derbacher (Koch) and Jette Bernheimer were married in 1847 and had four children; Fanny Koch born on March 25, 1852, and who was the mother of Elsa Einstein, the second wife of Albert Einstein. The other three children include; Jacob Koch, Caesar Koch and Pauline Koch (Albert's mother).

Jette, Albert's maternal grandmother, had a quiet and solicitous nature, and was also clearheaded and methodical, as is apparent from surviving school essays. She handled the difficulties sometimes produced by grandfather Koch's choleric disposition with
disarming humor. She was truly the soul of that odd household of the two brothers and their families.

Jette died in 1886 and Julius Derzbacher (Koch) died in 1895, both in Canstatt, Wurttemberg, Germany.

Julius Derzbacher's father (Albert's maternal great grandfather) Zadok Loeb Doerzbacher was born in 1783 in Dorzbach, Wurttemberg, Germany to Loeb Samuel Doerzbacher and Golies. He married Blumle Sintheimer (Albert's maternal great grandmother) born in 1786 in Jebenhausen, Wurttemberg, Germany.

Zadok Loeb Doerbacher's father (Albert's great great grandfather) was born about 1757. He married Golies who was born about 1761. Loeb and Golies had two children Samuel Loeb Doerzbacher, born on January 28, 1781 and Zadok Loeb Doerzbacher (Albert's great grandfather) born in 1783.


Curiosidades: 
  • His affiliation with the Jewish people was the strongest bond in his life, even though he did not adhere to the rituals of the religion. There was an anti-Semitic reaction both to the publicity he got and to the abstract and seemingly heretical nature of relativity theory. But the rise in anti-Semitism made him identify with the Jewish people even more. His first trip to America was to raise money for the Zionist movement, and in 1933 he fled Hitler and moved to Princeton.
  • He defined God in an impersonal, deistic fashion, but he deeply believed that God's handiwork was reflected in the harmony of nature's laws and the beauty of all that exists. He often invoked God, such as by saying He wouldn't play dice, when rejecting quantum mechanics. Einstein's belief in something larger than himself produced in him a wondrous mixture of confidence and humility. As he famously declared: A spirit is manifest in the laws of the Universe "a spirit vastly superior to that of man, and one in the face of which we with our modest powers must feel humble. In this way the pursuit of science leads to a religious feeling of a special sort."
  • His great breakthroughs came from visual experiments, pictures in his mind rather than words performed in his head rather than the lab. They were called Gedankenexperiment -- thought experiments. At age 16, he tried to picture in his mind what it would be like to ride alongside a light beam. If you reached the speed of light, wouldn't the light waves seem stationery to you? But Maxwell's famous equations describing electromagnetic waves didn't allow that. For the next ten years he wrestled with this thought experiment until he came up with the special theory of relativity.
  • In 1918 Supported the new Weimar Republic in Germany.
  • In 1894 his Parents moved to Milan; six months later, Einstein left the Gymnasium without completing his schooling and joins his family in Pavia, Italy.
  • He retook the studies at cantonal school in Aarau, Switzerland in 1895 where he graduated.
  • Studied Physics at the Polytechnic (later the Federal Institute of Technology), Zurich where he graduated with a degree in Physics in 1900.
  • He had a daughter, Lieserl, who was never mentioned born to Mileva Marić in Novi Sad, Serbia. It's is said that she probably was given into adoption. Her existence was discovered by the love letters Einstein sent to Mileva.
  • His relationship with Mileva Marić was disapproved by his mother and Mileva's parents as well.
  • Einstein chaged his nationality many times. Albert Einstein became German citizen with his birth in Ulm (Baden-Wuerttemberg) on March 14, 1879. 17 years later, on January 28, 1896 when left Germany and accordingly avoided military service he lost his German citizenship; thus Einstein stayed stateless for the next 5 years. On February 21, 1901 he became a Swiss citizen. Einstein’s chair for theoretical physics at the German University Prague from April 1, 1911 until September 30, 1912 appointed him for the Austrian citizenship; but he soon left Prague and never got that citizenship. Einstein regained the German citizenship in April 1914 when he entered the German civil service, as full member of the Prussian Academy of Sciences and professor at the University of Berlin. Due to the incidents in Nazi Germany he left the country in March 1933 and thus he lost the German citizenship. From 1933–1940 Einstein only possessed the Swiss citizenship. On October 1, 1940 Einstein became an American citizen. So he was a Swiss and an American citizen and stayed like that until his death on April 18, 1955.
  • The Riverside Church in New York, USA which was built in 1929 immortalized Einstein at the west portal next to personalities such as Euclid, Pythagoras, Archimedes, Galileo, Kepler, Newton, Faraday, Darwin and Pasteur, to only mention a few. In 1930, during a stay in New York, Albert Einstein and his wife visited the Riverside Church, too. During the detailed guided tour through the church Einstein was also shown the sculptures at the west portal. He was told that only one of the sculptures there represented a living person, and that was he himself. Contemporaries reported that he looked at the sculpture calmly and thoughtfully. But it would also be thinkable that there was a mischievous smile on his face and an ironic remark.
  • As a child he liked best building houses of cards, which he was able to build up to 14 stories high as a ten-year-old.
  • Albert Einstein never had to “repeat a year” during his whole school time.
  • Albert Einstein was married two times. He married Mileva Maric (1875-1948) in January 1903, a former fellow student from his time as a student at the Polytechnic in Zurich. They were divorced in February 1919. 4 months later, in June 1919, he married his cousin Elsa Löwenthal (1876-1936).
  • With Mileva Maric, his first wife, he had three children. Lieserl (1902-?), who was probably given into adoption, Hans Albert (1904-1973) and Eduard (1910-1965).
  • His second wife, Elsa Löwenthal, nee Einstein, had two daughters from her first marriage, Ilse Löwenthal (1897-1934) and Margot Löwenthal (1899-1986); Albert adopted both of them.
  • According to his Swiss passport Einstein's height was 175 cm.
  • Einstein was right-handed.
  • Einstein enjoyed playing the violin and the piano.
  • According to Ze'ev Rosenkranz; Albert liked to scoff at his 'incompetence' playing the violin, which he rarely found "impressing", however, this did not reduce his joy in playing the violin. Supposedly he was a good amateur musician with an own intuitive understanding of the music. In his later years he didn’t like the notes produced by himself any more; in the end he stopped playing the violin and only fantasized on the piano."
  • His favorite musician was Mozart followed by Vivaldi, Bach, Schubert and Corelli.
  • Einstein enjoyed sailing; he had a boat in Caputh, near Potsdam, named Tümmler, which was confiscated during the national socialist seizure of power in 1933 and sold one year later. In the US he had a sailing boat of his own called Tinnef.
  • About the famous tongue picture of Einstein, it was taken on Einstein’s 72nd birthday in Princeton on March 14, 1951 by Arthur Sasse, a press photographer. The original picture shows Einstein sitting on the backseat of a car between Dr Frank Aydelotte, the former head of the Institute for Advanced Study, and his wife. Albert Einstein and the Aydelottes were just returning from an event which had taken place in honour of Einstein. Einstein was bullied by reporters and photographers. They didn’t let him be and he is said to have shouted: "That’s enough, that’s enough!" However, the photographers didn't stop taking some more pictures of Einstein and his companions. And when he still was asked to pose for a birthday picture he grew tired of the journalists and the photographers and as encouraging words didn’t help any more, he stuck out his tongue to his "prosecutors". Later Einstein liked the picture very much, so he cut it into shape so only he can still be seen and made several copies of it and started using it as a greeting card to friends.
  • Despite his passion for sailing he could not swim. He even denied to use swim vests. This led to his family always worrying very much when he was out sailing.
  • Albert Einstein never learned how to drive. So he was driven by friends or relatives.
  • He was a cigar and pipe smoker, despite his wife Elsa and his doctors forbid him to smoke.
  • Albert Einstein drank only few alcohol. If at all, a glass of wine or a little glass of cognac. Mostly he only sipped on the alcoholics served to him.
  • There is one case when he got drunk in summer 1905 when he wrote in a postcard to Conrad Habicht: "Totally drunk unfortunately both of us (meaning him and his wife Milefa) under the table".
  • He very much liked to read Don Quijote by Cervantes Saavedra and The Karamasow Brothers by Dostojewski. David Humes Traktat about human nature had according to Einstein’s own words quite an influence on his development. Among other things he liked to read Kant, Poincaré, Mach, Tolstoi, Heine, Brecht, Shaw, Sinclair, Schopenhauer and Spinoza.
  • During his trips around the world he wrote a diary; which today is exhibited at the Albert Einstein Archives in Jerusalem.
  • The papers on Brownian motion, the photoelectric effect and special relativity contained explanations and ideas that changed the way we all view the world. That got him a proper job in a university.
  • In his paper on Brownian Motion, Einstein proved the existence of atoms by identifying why pollen grains in water jiggle around - the so-called Brownian motion. The invisible atoms in the water bounce around the pollen grains kicking them like footballers kick a ball. The discovery paved the way for other scientists to identify methods for measuring the size of atoms, on the basis of how fast they move.
  • The photoelectric effect reversed the thinking that light came in "waves", identifying instead that it is made up of packages of energy or photons. This explained anomalies in the energy contained in different colours of light which had long puzzled Einstein's predecessors. His discovery paved the way for other scientists to unravel the mysteries of quantum physics.
  • In 1933, Einstein escaped the persecution of Jews in Nazi Germany by accepting a position at the Institute for Advanced Study at Princeton in the United States, where he spent the rest of his life.
  • Einstein spent much of his later career searching for a unified field theory, but was unsuccessful.
  • In 1939 pointed out, in a letter to President Roosevelt, the possibility that an extremely powerful bomb might be constructed using atomic chain reactions in uranium, and suggested that the Germans might be working on such a bomb.
  • He owned more then twenty patents. Among them the Einstein refrigerator, revolutionary for having no moving parts and using only heat, not ice, as an input.
  • Einstein was not a religious man and he wrote: "The word god is for me nothing more than the expression and product of human weaknesses, the Bible a collection of honourable, but still primitive legends which are nevertheless pretty childish. No interpretation no matter how subtle can (for me) change this." Einstein, who was Jewish, also rejected the idea that the Jews are God's favoured people, about this he said: "For me the Jewish religion like all others 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. As far as my experience goes, they are no better than other human groups, although they are protected from the worst cancers by a lack of power. Otherwise I cannot see anything 'chosen' about them." His parents were not religious but he attended a Catholic primary school and at the same time received private tuition in Judaism. This prompted what he later called, his "religious paradise of youth", during which he observed religious rules such as not eating pork. This did not last long though and by 12 he was questioning the truth of many biblical stories. In his later years he referred to a "cosmic religious feeling" that permeated and sustained his scientific work. In 1954, a year before his death, he spoke of wishing to "experience the universe as a single cosmic whole". He was also fond of using religious flourishes, in 1926 declaring that "God does not throw dice" when referring to randomness thrown up by quantum theory. John Brooke of Oxford University said: "It is clear for example that he had respect for the religious values enshrined within Judaic and Christian traditions, but what he understood by religion was something far more subtle than what is usually meant by the word in popular discussion".
  • When he was employed in Swiss Office for Intellectual Property in Bern as technical expert third-class he had an annual salary of 3500 Swiss Francs in June 1902 and he was promoted to be technical expert second-class, with an annual salary of 4500 Swiss Francs in April 1906.
  • Einstein’s office in the back Bern Patent Office has been rebuilt. The building, which is not open to the public, is used no longer as patent office today and except for a commemorative plaque in the foyer nothing indicates that Einstein has worked there.
  • The German version of the film about Einstein’s special theory of relativity, which was first shown on April 2, 1922, is no longer available. Today only the English version of the film from the year 1923 is preserved. However, this is a short version of the German original.
  • Einstein has grandchildren and great grandchildren as descendants.
  • The American news magazine Time declared Albert Einstein "Person of the Century" at the end of 20th century. The former American president Franklin Delano Roosevelt (1882-1945) took second place; while Mahatma Gandhi (1869-1948) took the third place.
  • Einstein declined the presidency of the state of Israel when it was offered to him in 1952 by state leaders.
  • The element einsteinium, discovered in 1952, was named in honor of Albert Einstein.

Frases Personales: 
  • Any intelligent fool can make things bigger, more complex, and more violent. It takes a touch of genius -- and a lot of courage -- to move in the opposite direction.
  • Imagination is more important than knowledge.
  • Gravitation is not responsible for people falling in love.
  • I want to know God's thoughts; the rest are details.
  • The hardest thing in the world to understand is the income tax.
  • Reality is merely an illusion, albeit a very persistent one.
  • The only real valuable thing is intuition.
  • A person starts to live when he can live outside himself.
  • I am convinced that He (God) does not play dice.
  • God is subtle but he is not malicious.
  • Weakness of attitude becomes weakness of character.
  • I never think of the future. It comes soon enough.
  • The eternal mystery of the world is its comprehensibility.
  • Sometimes one pays most for the things one gets for nothing.
  • Science without religion is lame. Religion without science is blind.
  • Anyone who has never made a mistake has never tried anything new.
  • Great spirits have often encountered violent opposition from weak minds.
  • Everything should be made as simple as possible, but not simpler.
  • Common sense is the collection of prejudices acquired by age eighteen.
  • Science is a wonderful thing if one does not have to earn one's living at it.
  • The secret to creativity is knowing how to hide your sources.
  • The only thing that interferes with my learning is my education.
  • God does not care about our mathematical difficulties. He integrates empirically.
  • The whole of science is nothing more than a refinement of everyday thinking.
  • Technological progress is like an axe in the hands of a pathological criminal.
  • Peace cannot be kept by force. It can only be achieved by understanding.
  • The most incomprehensible thing about the world is that it is comprehensible.
  • We can't solve problems by using the same kind of thinking we used when we created them.
  • Education is what remains after one has forgotten everything he learned in school.
  • The important thing is not to stop questioning. Curiosity has its own reason for existing.
  • Do not worry about your difficulties in Mathematics. I can assure you mine are still greater.
  • Equations are more important to me, because politics is for the present, but an equation is something for eternity.
  • If A is a success in life, then A equals x plus y plus z. Work is x; y is play; and z is keeping your mouth shut.
  • Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe.
  • As far as the laws of mathematics refer to reality, they are not certain, as far as they are certain, they do not refer to reality.
  • Whoever undertakes to set himself up as a judge of Truth and Knowledge is shipwrecked by the laughter of the gods.
  • I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones.
  • In order to form an immaculate member of a flock of sheep one must, above all, be a sheep.
  • The fear of death is the most unjustified of all fears, for there's no risk of accident for someone who's dead.
  • Too many of us look upon Americans as dollar chasers. This is a cruel libel, even if it is reiterated thoughtlessly by the Americans themselves.
  • Heroism on command, senseless violence, and all the loathsome nonsense that goes by the name of patriotism -- how passionately I hate them!
  • No, this trick won't work...How on earth are you ever going to explain in terms of chemistry and physics so important a biological phenomenon as first love?
  • My religion consists of a humble admiration of the illimitable superior spirit who reveals himself in the slight details we are able to perceive with our frail and feeble mind.
  • Yes, we have to divide up our time like that, between our politics and our equations. But to me our equations are far more important, for politics are only a matter of present concern. A mathematical equation stands forever.
  • The release of atom power has changed everything except our way of thinking...the solution to this problem lies in the heart of mankind. If only I had known, I should have become a watchmaker.
  • Great spirits have always found violent opposition from mediocrities. The latter cannot understand it when a man does not thoughtlessly submit to hereditary prejudices but honestly and courageously uses his intelligence.
  • The most beautiful thing we can experience is the mysterious. It is the source of all true art and all science. He to whom this emotion is a stranger, who can no longer pause to wonder and stand rapt in awe, is as good as dead: his eyes are closed.
  • A man's ethical behavior should be based effectually on sympathy, education, and social ties; no religious basis is necessary. Man would indeeded be in a poor way if he had to be restrained by fear of punishment and hope of reward after death.
  • The further the spiritual evolution of mankind advances, the more certain it seems to me that the path to genuine religiosity does not lie through the fear of life, and the fear of death, and blind faith, but through striving after rational knowledge.
  • Now he has departed from this strange world a little ahead of me. That means nothing. People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion.
  • You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat.
  • One had to cram all this stuff into one's mind for the examinations, whether one liked it or not. This coercion had such a deterring effect on me that, after I had passed the final examination, I found the consideration of any scientific problems distasteful to me for an entire year.
  • One of the strongest motives that lead men to art and science is escape from everyday life with its painful crudity and hopeless dreariness, from the fetters of one's own ever-shifting desires. A finely tempered nature longs to escape from the personal life into the world of objective perception and thought.
  • He who joyfully marches to music rank and file, has already earned my contempt. He has been given a large brain by mistake, since for him the spinal cord would surely suffice. This disgrace to civilization should be done away with at once. Heroism at command, how violently I hate all this, how despicable and ignoble war is; I would rather be torn to shreds than be a part of so base an action. It is my conviction that killing under the cloak of war is nothing but an act of murder.
  • A human being is a part of a whole, called by us _universe_, a part limited in time and space. He experiences himself, his thoughts and feelings as something separated from the rest... a kind of optical delusion of his consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty.
  • Not everything that counts can be counted, and not everything that can be counted counts." (Sign hanging in Einstein's office at Princeton).
  • Science without religion is lame, religion without science is blind.
  • I do not consider myself the father of the release of atomic energy. Atomic War or Peace, 1945.
  • We are in the position of a little child entering a huge library filled with books in many languages. The child knows someone must have written those books. It does not know how. It does not understand the languages in which they are written. The child dimly suspects a mysterious order in the arrangement of the books but doesn't know what it is. That, it seems to me, is the attitude of even the most intelligent human being toward God. We see the universe marvelously arranged and obeying certain laws but only dimly understand these laws.

Trabajos Realizados / Logros: 

Studies:

  • Graduated in October 1896 from Cantonal School in Aarau, Switzerland.
  • Graduated in 1900 from Polytechnic (the later Swiss Technical Academy, ETH or Swiss Federal Institute of Technology) with a degree in Physics.

Career:

  • Technical expert third-class in the Swiss Office for Intellectual Property in Bern in June, 1902.
  • Technical expert second-class in the Swiss Office for Intellectual Property in Bern in April, 1906.
  • Chair for theoretical physics at the Charles University of Prague from April 1, 1911 until September 30, 1912.
  • Professor in Physics of ETH (Swiss Technical Academy) in Zurich October, 1912 - April, 1914.
  • Professor of the Prussian Academy of Sciences. July, 1914 - Decmber, 1932.
  • Director of the Kaiser Wilhelm Institute for Physics. July, 1914 - Decmber, 1932.
  • Extraordinary Professor of Leiden University, Netherlands. 1920 - 1930.
  • Professor at the California Institute of Technology in Pasadena, California, USA. (Winters 1930-1933)
  • Professor of Physics and Mathematics at the Institute for Advanced Studies in Princeton, New Jersey, USA. (1933-1945).

Scientific feats:

  • The Photoelectric Effect. The paper, "On a Heuristic Viewpoint Concerning the Production and Transformation of Light", proposed the idea of energy quanta.
  • Brownian motion. In the article "On the Motion Required by the Molecular Kinetic Theory of Heat of Small Particles Suspended in a Stationary Liquid", it will be shown that, according to the molecular kinetic theory of heat, bodies of a microscopically visible size suspended in liquids must, as a result of thermal molecular motions, perform motions of such magnitudes that they can be easily observed with a microscope. Einstein's statistical discussion of atomic behavior gave experimentalists a way to count atoms by looking through an ordinary microscope.
  • Special relativity explained in Einstein's third paper of 1905 (the annus-mirabilis) "On the Electrodynamics of Moving Bodies".
  • Matter and energy equivalence, E = mc². Explained in his fourth 1905 paper, "Does the Inertia of a Body Depend Upon Its Energy Content?", published on September 27, 1905 in Annalen der Physik.
  • General theory of relativity. Explained in his paper "The Foundation of the General Theory of Relativity", published on March, 1916.
  • In 1917, Einstein published an article in Physikalische Zeitschrift that proposed the possibility of stimulated emission, the physical process that makes possible the maser and the laser.
  • Bose–Einstein statistics. Co-worked with Indian physicist Satyendra Nath Bose on a statistical model that describes a state of matter of bosons confined in an external potential and cooled to temperatures very near to absolute zero (0 K, −273.15 °C, or −459 °F ). Under such supercooled conditions, a large fraction of the atoms collapse into the lowest quantum state of the external potential, at which point quantum effects become apparent on a macroscopic scale.
  • Schrödinger gas model. Einstein suggested to Erwin Schrödinger an application of Max Planck's idea of treating energy levels for a gas as a whole rather than for individual molecules, and Schrödinger applied this in a paper using the Boltzmann distribution to derive the thermodynamic properties of a semiclassical ideal gas. Schrödinger urged Einstein to add his name as co-author, although Einstein declined the invitation.
  • In 1926 co-invented with Leó Szilárd the Einstein refrigerator, revolutionary for having no moving parts and using only heat, not ice, as an input. It was patented in 1930.
  • Co-invented with the industrial Hermann Anschütz-Kaempfe gyroscopic compass.
  • Co-invented with Rudolf Goldschmidt, a professor for mechanical engineering and electrical engineering, a hearing device.
  • Co-invented with the doctor Gustav Bucky a patent for an automatic camera.
  • Einstein owned more then twenty patents. However, always together with a partner.
  • Einstein's findings resulted in the base of technologies used in Nuclear power plants, particles accelerators. His relativity theories are also used in astrophysics, space exploration and communications.
  • Today Einstein’s findings are also applied in technical systems. Such for example in laser technology, which includes among its applications, the CD player and the DVD player; his findings also are the base of the technologies behind the digital camera, the solar cell and in the "Global Positioning System" (GPS).

Awards and Honors:

  • The 1921 Nobel Prize in Physics awarded in 1922, for "his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect".
  • University of Rostock Honorary doctorate in 1919.
  • Princeton University Honorary doctorate in 1921.
  • Order "Pour le mérite" Admission to the order in 1923.
  • Royal Society of London Copley Medal in 1925.
  • Royal Astronomical Society Gold Medal in 1926.
  • German Physical Society Max-Planck-Medal in 1929.
  • ETH (Eidgenoessische Technische Hochschule), Zurich Honorary doctorate in 1930.
  • Oxford University Honorary doctorate in 1931.
  • Franklin Institute, Philadelphia Benjamin Franklin Medal in 1935.
  • Harvard University Honorary doctorate in 1935.
  • In 1999, Albert Einstein was named "Person of the Century" by Time magazine
  • The Gallup poll recorded him as the fourth most admired person of the 20th century.
  • The 100: A Ranking of the Most Influential Persons in History, named Einstein as "the greatest scientist of the twentieth century and one of the supreme intellects of all time."
  • Scientific and mathematical concepts:
    1. Higher-dimensional Einstein gravity.
    2. Einstein solid.
    3. Einstein force.
    4. Einstein's constant.
    5. Einstein relation (kinetic theory).
    6. Stark-Einstein law.
    7. Einstein–Hilbert action.
    8. Einstein–Cartan theory.
    9. Bose–Einstein condensate.
    10. Bose–Einstein statistics.
    11. Einstein field equations.
    12. Einstein's radius of the universe.
    13. Einstein coefficients.
    14. Einstein synchronisation.
    15. Einstein notation.
    16. Einstein tensor.
    17. Einstein manifold.
    18. Einstein ring.
    19. Einstein Cross.
    20. Einstein radius.
    21. Einstein (unit).
    22. Einstein refrigerator.
    23. Einsteinium.
    24. Einstein's Puzzle.
    25. EPR paradox.
    26. Einstein syndrome.
  • Places and institutions named after Albert Einstein:
    1. Albert Einstein Academy Charter School.
    2. Einstein Tower.
    3. Albert Einstein Institution.
    4. Albert Einstein College of Medicine at Yeshiva University.
    5. Einsteinova ulica, a major road in Bratislava, Slovakia.
    6. Einstein street and within the Einstein Primary School at the city of Haifa in Israel.
    7. Albert Einstein Hospital in São Paulo, Brazil.
    8. Einsteinstraße, Munich, Germany.
  • Different aspects of life that have been named after Einstein:
    1. Bohr-Einstein debates, a series of epistemological challenges and responses by Albert Einstein and Niels Bohr.
    2. Russell-Einstein Manifesto, issued in 1955 by Bertrand Russell in the midst of the Cold War.
    3. Einstein-Szilárd letter, a letter sent to President Franklin Delano Roosevelt in August 1939.
    4. Albert Einstein Medal, presented to people who have "rendered outstanding services" in connection with Albert Einstein, since 1979.
    5. Einstein's Dreams, a 1992 novel by Alan Lightman.
    6. Einstein's Monsters, a collection of short stories by Martin Amis.
    7. Einstein Symposium, on the centennial of "Annus Mirabilis".
    8. Little Einsteins, an animated television series.
    9. Tatung Einstein, an eight-bit home/personal computer.
    10. Einsteinium an Actinide on the Periodic Table of Elements.
    11. The Einstein Factor, an Australian TV game show hosted by Peter Berner.
    12. The Albert Einstein Mathematics Institute at the Hebrew University in Jerusalem.
    13. The International Union of Pure and Applied Physics named 2005 the "World Year of Physics" in commemoration of the 100th anniversary of the publication of the Annus Mirabilis Papers.
    14. The Albert Einstein Memorial by Robert Berks.
    15. A unit used in photochemistry, the einstein.
    16. The asteroid 2001 Einstein.
    17. The Albert Einstein Peace Priz.

Books:

  • A New Determination of Molecular Dimensions (1906).
  • About the special and the general theory of relativity (intelligible to everybody) (1916).
  • On the Special and General Theory of Relativity (A Popular Account) (1917).
  • On the Special and General Theory of Relativity (A Popular Account) (1918).
  • On the Special and General Theory of Relativity (A Popular Account) (1920).
  • Aether and Relativity Theory: A Talk Given on 5 May 1920 at the University of Leiden (1920).
  • Geometry and Experience: Expanded Edition of the Celebratory Lecture Given at the Prussian Academy (1921).
  • Four Lectures on Relativity Theory, Given in May 1921 at Princeton University (1922).
  • Investigations of Brownian Motion (1922).
  • Fundamental Ideas and Problems of Relativity Theory (1923).
  • On the Method of Theoretical Physics (1933).
  • Origins of the General Theory of Relativity (1933).
  • Foundations of the General Theory of Relativity (1933).
  • The Evolution of Physics: The Growth of Ideas from Early Concepts to Relativity and Quanta (1938).
  • Physics as an Adventure of the Mind (1938).
  • The Meaning of Relativity (1945).
  • My World of View.
  • From my later years.

Característica Personal: 

He was a real pragmatist, who didn't base his thoughts on religious or superstitious views. His great breakthroughs came from visual experiments, pictures in his mind. He was a fervent pacifist.


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