Titans of History

EINSTEIN

1879–1955

To raise new questions, new possibilities, to regard old problems from a new angle requires creative imagination and marks real advances in science.

Einstein on the essence of scientific creativity

It is no coincidence that Albert Einstein’s name has become all but synonymous with genius. He was the most important physicist of the 20th century—some would say of any century. His discoveries, both building on and supplanting the classical mechanics of Newton, marked a paradigm shift that radically transformed our understanding of the universe.

Einstein’s theory of relativity may be one of the most famous and fruitful scientific insights of all time, but the man behind it was far more than just a scientist. Throughout his life Einstein was committed to social issues and pacifism, speaking out against tyranny and persecution and despairing at the creation of the atomic bomb. Fifty years after his death, he remains an instantly recognizable figure, his face famously etched with wit and good humor.

Born into a family of secular middle-class Jews, Albert Einstein was brought up in Germany. As a child he was slow to develop (he was nicknamed der Depperte—the dopey one), but a magnetic compass given to him when he was five and a book on geometry he received when he was twelve pricked his intellectual curiosity in a way that the rigid German school system could not. Sent to boarding school in Munich, at the age of fifteen the boy ran away from both school and impending military service and joined his parents, who had moved to Italy in search of work.

Unimpressed by the arrival of their dissolute, draft-dodging son, the Einsteins welcomed Albert’s enrollment at university in Zurich, where he spent some of his happiest years. Here he met his first wife, Mileva Maric, a Serbian and fellow physicist whom he married in 1903. The same year he ended a long search for employment with an appointment to the patent office in Berne.

Analyzing patents was undemanding work that left Einstein time to apply his mind to mathematical and scientific problems. He was struck in particular by the apparent incompatibility of Newton’s laws of motion and James Clerk Maxwell’s equations describing the behavior of light. In 1905 he published a momentous series of scientific papers dealing with the movement and behavior of light, water and molecules. The most important proposal was the special theory of relativity, which has been described as the towering intellectual achievement of the 20th century, one that changed the way people understood the laws that govern the universe. According to this theory, nothing can move faster than light, the speed of which is constant throughout the universe. It also showed, via the famous equation E = mc², that energy (E) and mass (m) are equivalent and bound together in their relationship by the speed of light (c). Special relativity does away with the idea of absolute time; it proposes instead that time is relative, its measurement dependent on the motion of the observer. Space and time are all part of the same thing, a single continuum known as space–time.

What special relativity did not account for was the effect of gravity upon space–time. In 1915, in a series of lectures at the University of Göttingen, he finally resolved this problem by outlining his general theory of relativity.

According to this theory, the presence of objects of mass curves or warps space–time. Like a bowling ball placed in the middle of a trampoline, a large object such as a planet or star causes other objects to move through space–time toward it. So the earth, for instance, is not “pulled” toward the sun; rather, it follows the curve in space–time caused by the sun and is prevented from falling into it only by its own speed.

Einstein’s prediction that light from a star passing close to the sun’s gravitational field would be deflected, causing the star’s apparent position in the sky to change, was confirmed by observations during a solar eclipse in 1919. Another peculiar effect predicted by Einstein and later confirmed by observation is time dilation: the idea that time is not absolute but slows down at speeds approaching the speed of light. One upshot of time dilation is the bizarre twins paradox. If one of a pair of twins stays on earth while the other travels at close to the speed of light on a round trip to a distant star, the latter will have aged less than the stay-at-home sibling.

In this and numerous other ways, the theory of relativity continues to confound our common-sense ways of looking at and understanding the world around us. Nevertheless, it is today firmly established as the fundamental conceptual platform on which the physical sciences are built.

Few people noticed Einstein’s revolutionary theories until Max Planck, the German scientist and father of quantum theory, helped to publicize them. By 1913 Einstein had risen in the academic world to become director of the Institute of Physics at the University of Berlin.

While Einstein’s fame rocketed during this period, his personal life was in turmoil. After a lengthy separation he finally divorced Mileva in 1919 and promptly married his cousin Elsa Löwenthal. Einstein was now the most famous scientist in the world. He met and corresponded with many of the world’s leading scientists and artists, including Sigmund Freud, the Indian mystic Rabindranath Tagore and Charlie Chaplin. “The people applaud me,” Chaplin once told Einstein, “because everybody understands me; they applaud you because no one understands you.”

Though he was far from religiously orthodox and his theories seemed to cast doubt on religions, Einstein always believed in some form of higher principle or spirit. “The scientist is possessed by the sense of universal causation,” he wrote. “His religious feeling takes the form of a rapturous amazement at the harmony of natural law, which reveals an intelligence of such superiority that, compared with it, all the systematic thinking and acting of human beings is an utterly insignificant reflection.” He maintained a belief in what he called der Alte—the Old Man.

In 1931 the rising Nazi Party attacked Einstein and his “Jewish physics.” He left Germany forever the following year, realizing his life was in danger. He settled in the USA at the University of Princeton. His pacifism—which had led to his open opposition to the First World War—weakened in the face of Nazi tyranny. He supported rearmament against Hitler, and in 1939 he co-wrote a letter to President Franklin D. Roosevelt in which the dangers of the development of nuclear weapons by the Nazis were pointed out. This prompted the Allied powers to collaborate in the Manhattan Project in order to produce the first atomic bomb themselves.

When the Second World War ended in 1945 with the destruction of Hiroshima and Nagasaki, Einstein turned sharply and publicly against further nuclear development and favored international restrictions. He was even monitored by the FBI for his pacifist views. In 1952 he was offered the presidency of Israel; though he was a lifelong Zionist, he respectfully declined. When he died in 1955, Einstein had not achieved his long-term goal of finding a unified theory that would provide a comprehensive explanation of the fundamental forces governing the universe and so offer (as he figuratively put it) an insight into the mind of God. Such a goal has continued to elude succeeding generations of scientists, whose work has nevertheless been revolutionized by Einstein—a colossus of science and the most humane of men.