Travels abroad

Einstein visited New York City for the first time on 2 April 1921. When asked where he got his scientific ideas, Einstein explained 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. He also recommended theories with visualizable results.(Einstein 1954)

In 1922, he traveled throughout Asia and later to Palestine, as part of a six-month excursion and speaking tour. His travels included Singapore, Ceylon, and Japan, where he gave a series of lectures to thousands of Japanese. His first lecture in Tokyo lasted four hours, after which he met the emperor and empress at the Imperial Palace where thousands came to watch. Einstein later gave his impressions of the Japanese in a letter to his sons: "Of all the people I have met, I like the Japanese most, as they are modest, intelligent, considerate, and have a feel for art."

On his return voyage, he also visited Palestine for twelve days in what would become his only visit to that region. "He was greeted with great British pomp, as if he were a head of state rather than a theoretical physicist", writes Isaacson. This included a cannon salute upon his arrival at the residence of the British high commissioner, Sir Herbert Samuel. During one reception given to him, the building was "stormed by throngs who wanted to hear him". In Einstein's talk to the audience, he expressed his happiness over the event:

I consider this the greatest day of my life. Before, I have always found something to regret in the Jewish soul, and that is the forgetfulness of its own people. Today, I have been made happy by the sight of the Jewish people learning to recognize themselves and to make themselves recognized as a force in the world.

Emigration from Germany
Being protected in England after escaping Nazi Germany in 1933

In 1933, Einstein was compelled to immigrate to the United States due to the rise to power of the Nazis under Germany's new chancellor, Adolf Hitler. While visiting American universities in April, 1933, he learned that the new German government had passed a law barring Jews from holding any official positions, including teaching at universities. A month later, the Nazi book burnings occurred, with Einstein's works being among those burnt, and Nazi propaganda minister Joseph Goebbels proclaimed, "Jewish intellectualism is dead." Einstein also learned that his name was on a list of assassination targets, with a "$5,000 bounty on his head". One German magazine included him in a list of enemies of the German regime with the phrase, "not yet hanged".

Among other German scientists forced to flee were fourteen Nobel laureates and twenty-six of the sixty professors of theoretical physics in the country. Among the other scientists who left Germany, or the other countries it came to dominate, were Edward Teller, Niels Bohr, Enrico Fermi, Otto Stern, Victor Weisskopf, Hans Bethe, and Lise Meitner, many of whom made certain that the Allies would develop nuclear weapons first, before the Nazis. With so many other Jewish scientists now forced by circumstances to live in America, often working side by side, Einstein wrote to a friend, "For me the most beautiful thing is to be in contact with a few fine Jews—a few millennia of a civilized past do mean something after all." In another letter he writes, "In my whole life I have never felt so Jewish as now."

He took up a position at the Institute for Advanced Study at Princeton, New Jersey, an affiliation that lasted until his death in 1955. There, he tried unsuccessfully to develop a unified field theory and to refute the accepted interpretation of quantum physics. He and Kurt Gödel, another Institute member, became close friends. They would take long walks together discussing their work. His last assistant was Bruria Kaufman, who later became a renowned physicist.