Einstein: His Life and Universe by Walter Isaacson. Simon & Schuster, $32, 704 pages.

The News & Observer

April 15, 2007

The full equation

By PHILLIP MANNING

In 1905, a brash and free-spirited young patent clerk in Switzerland published three papers that turned physics upside down. The first paper toppled the wave theory of light that had prevailed for a century. The second paper conclusively established the existence of atoms and molecules. The third proposed the special theory of relativity, which led to the best known equation in the world, E=mc². 

The story of Albert Einstein’s annus mirablis is an eye-popping science story. And Walter Isaacson’s touching and exceptionally well-rendered biography of Einstein (1879-1955) captures the all of the excitement stirred up by those seminal papers. But Isaacson, whose previous books include a best selling biography of Benjamin Franklin, also takes the reader into less familiar territory, probing not only Einstein the scientist but also Einstein the man.

To many people, Einstein was the saintly, sad-eyed man with frizzy hair peering out from photographs taken after he moved to the United States. The younger Einstein was not sad-eyed, did not have frizzy hair and certainly was not a saint. He was a complex rebel, a handsome Bohemian — and occasional philanderer — who had no trouble attracting women. 
Isaacson shows how Einstein’s rebellious nature galvanized him to make the greatest advances in physics since Isaac Newton formulated his laws of motion and gravity two centuries earlier.

All his life, Einstein railed against authority, against militarism and against established science. This antiauthoritarian streak enabled him to discard Newton’s laws of absolute space and time and formulate the special theory of relativity. The theory states that measurements of time are relative and depend on the motion of the observers. Other scientists had similar ideas but had not pursued them because they contradicted Newton’s laws, the bedrock of classical physics. Einstein had no problem setting Newton aside. He was an outsider and a born revolutionary.

In his personal life, Einstein showed a similar disregard for convention. He fathered a child out of wedlock, then married the mother, divorced her, and married his cousin, with whom he had lived for years. His relationships with his children were bumpy. He never saw his first child, a girl who was (presumably) put up for adoption. He was sometimes aloof with his younger sons, too. This might have been due in part to Einstein's powers of concentration. “One of his strengths as a thinker, if not as a parent,” Isaacson writes, “was that he had the ability, and the inclination to tune out all distractions, a category that to him sometimes included his children and family.” It wasn’t that Einstein didn’t care for his family: he was generous and loving most of the time. But he hated being tied down and chafed under the demands of family life, often seeking refuge in his science.

Einstein’s scientific achievements landed him a prestigious professorship at the University of Berlin just as a rising tide of nationalism was pushing Germany into World War I. As usual, Einstein did not go along with the crowd. Calling himself a “militant pacifist,” he wrote tracts opposing the war, all to no avail. Germany entered the war in 1915, leaving Einstein to wonder, “What drives people to kill and maim each other so savagely?” 
After the war, with a 1921 Nobel prize in his pocket and his theory of relativity capturing the public’s imagination, Einstein became a celebrity. Isaacson puts his finger on why: “He gave interviews readily, peppered them with delightful aphorisms, and knew exactly what made for a good story.“ But Einstein was ambivalent about fame. “He was attracted and repelled by the cameras, loved publicity and loved to complain about it,” Isaacson writes. 

By 1933, when the Nazis drove him from Germany to the United States, he was as famous as any movie star. Isaacson recounts Einstein’s later years in detail — his work to create the state of Israel, his support of almost any worthwhile humanitarian cause, his reconciliation with his first wife and oldest son, his efforts to maintain contact with his many friends. But he was a working scientist, too. Settling at the Institute for Advanced Study at Princeton, he devoted the rest of his life in a gallant, but ultimately futile, attempt to unite quantum mechanics and relativity. Fittingly, Isaacson ends his biography with the line of equations scribbled by the 76-year-old Einstein in 1955 as he lay dying in a hospital.

Though Einstein’s personality and personal life are fascinating, any biography of him must revolve around his science because his approach to it was unique. Isaacson does a good job of explaining the science and Einstein’s ideas about it. Instead of proposing theories to explain experimental data, Einstein thought about how the universe ought to work and, as Isaacson puts it, made “predictions that experimenters could proceed to test.” This way of thinking is especially apparent in his work on general relativity, the crown jewel of Einstein’s career.

The special theory of relativity is special because it applies only to bodies in steady, unaccelerated motion, which includes bodies at rest. Einstein felt that in a properly designed universe, the laws of physics should hold for all bodies, even those in accelerated motion. As he explored the nature of accelerating systems, Einstein realized that that gravity and acceleration were equivalent forces. This led him to the conclusion that both gravity and acceleration must be “manifestations of the same structure ...”

This insight led Einstein into years of mathematical groping to develop a new picture of the universe. The work was exhausting; Isaacson paints a picture of a man waging a solitary intellectual struggle, “eating and working at whatever hours suited him, sleeping when he had to.” When he was done, our understanding of gravity — the mysterious force that had baffled every scientist since Newton — was forever changed. 

Gravity, Einstein said, was the warping of the fabric of space-time by matter. The warping of four-dimensional space-time is not easy to visualize, but, as Isaacson writes, “that’s why we’re no Einstein and he was.”. As one physicist put it, “Matter tells space-time how to curve, and curved space tells matter how to move.” Gravity was no longer a spooky, unexplainable force acting between distant bodies. In the words of Nobel laureate Paul Dirac, the general theory was “greatest scientific discovery ever made.” 

Typically, Einstein threw in predictions about some consequences of general relativity. Chief among these was the bending of starlight by the gravitational field of the sun. Four years after Einstein published his theory, scientists measured the sun’s deflection of light. The results were as predicted by the general theory. Einstein received the good news calmly. “I knew the theory was correct,” he said. 
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