Einstein: His Life and Universe

by Walter Isaacson

At a party following one of these lectures, Einstein uttered one of his most memorable and self-revealing quotes. Someone excitedly informed him that word had just arrived of a new set of experiments improving on the Michelson-Morley technique that seemed to show that the ether existed and the speed of light was variable. Einstein simply refused to accept it. He knew that his theory was correct. And so he calmly responded, “Subtle is the Lord, but malicious he is not.”* The mathematics professor Oswald Veblen, who was standing there, heard the remark and, when a new math building was built a decade later, asked Einstein for the right to carve the words on the stone mantel of the fireplace in the common room. Einstein happily sent back his approval and further explained to Veblen what he had meant: “Nature hides her secret because of her essential loftiness, but not by means of ruse.”49 The building, neatly enough, later became the temporary home of the Institute for Advanced Study, and Einstein would have an office there when he immigrated to Princeton in 1933. Near the end of his life, he was in front of the fireplace at a retirement party for the mathematician Hermann Weyl, a friend who had followed him from Germany to Princeton when the Nazis took power. Alluding to his frustration with the uncertainties of quantum mechanics, Einstein nodded to the quote and lamented to Weyl, “Who knows, perhaps He is a little malicious.”

The Times called it “the ever-present Edison questionnaire controversy,” and of course Einstein ran into it. A reporter asked him a question from the test. “What is the speed of sound?” If anyone understood the propagation of sound waves, it was Einstein. But he admitted that he did not “carry such information in my mind since it is readily available in books.” Then he made a larger point designed to disparage Edison’s view of education. “The value of a college education is not the learning of many facts but the training of the mind to think,” he said.

“This business of quietude is an illusion,”

One evening at a dinner, Murray’s wife asked him why he remained so cheerful given the depravity of the world. “We must remember that this is a very small star,” he responded, “and probably some of the larger and more important stars may be very virtuous and happy.”

“Dull-minded tribal companions are praying, faces turned to the wall, rocking their bodies forward and back,” he recorded in his diary. “A pitiful sight of men with a past but without a future.”

There was a dark irony in using the photoelectric effect as a path to get Einstein the prize. His “law” was based primarily on observations made by Philipp Lenard, who had been the most fervent campaigner to have him blackballed.

“Anything truly novel is invented only during one’s youth,” Einstein lamented to a friend after finishing his work on general relativity and cosmology. “Later one becomes more experienced, more famous—and more blockheaded.”

Among other things, Mach’s idea that inertia is caused by the presence of all of the distant bodies in the universe implied that these bodies could instantly have an effect on an object, even though they were far apart. Einstein’s theory of relativity did not accept instant actions at a distance. Even gravity did not exert its force instantly, but only through changes in the gravitational field that obeyed the speed limit of light.

Bohr made a refinement based on the fact that these electrons did not collapse into the nucleus and emit a continuous spectrum of radiation, as classical physics would suggest. In Bohr’s new model, which was based on studying the hydrogen atom, an electron circled a nucleus at certain permitted orbits in states with discrete energies. The atom could absorb energy from radiation (such as light) only in increments that would kick the electron up a notch to another permitted orbit. Likewise, the atom could emit radiation only in increments that would drop the electron down to another permitted orbit. When an electron moved from one orbit to the next, it was a quantum leap. In other words, it was a disconnected and discontinuous shift from one level to another, with no meandering in between. Bohr went on to show how this model accounted for the lines in the spectrum of light emitted by the hydrogen atom.

That was not necessarily a problem. But here was the rub: there was no way to determine which direction an emitted photon might go. In addition, there was no way to determine when it would happen. If an atom was in a state of higher energy, it was possible to calculate the probability that it would emit a photon at any specific moment. But it was not possible to determine the moment of emission precisely. Nor was it possible to determine the direction. No matter how much information you had. It was all a matter of chance, like the roll of dice. That was a problem. It threatened the strict determinism of Newton’s mechanics. It undermined the certainty of classical physics and the faith that if you knew all the positions and velocities in a system you could determine its future. Relativity may have seemed like a radical idea, but at least it preserved rigid cause-and-effect rules. The quirky and unpredictable behavior of pesky quanta, however, was messing with this causality.

“I find the idea quite intolerable that an electron exposed to radiation should choose of its own free will not only its moment to jump off but also its direction,” he despaired to Born a few years later. “In that case, I would rather be a cobbler, or even an employee of a gaming house, than a physicist.”

his journey home from delivering his acceptance speech in Sweden the following summer, Einstein stopped in Copenhagen to see Bohr, who met him at the train station to take him home by streetcar. On the ride, they got into a debate. “We took the streetcar and talked so animatedly that we went much too far,” Bohr recalled. “We got off and traveled back, but again rode too far.”

“In all the history of human thought, there is no greater dialogue than that which took place over the years between Niels Bohr and Albert Einstein about the meaning of the quantum,” says the physicist John Wheeler, who studied under Bohr. The social philosopher C. P. Snow went further. “No more profound intellectual debate has ever been conducted,” he proclaimed.44 Their dispute went to the fundamental heart of the design of the cosmos: Was there an objective reality that existed whether or not we could ever observe it? Were there laws that restored strict causality to phenomena that seemed inherently random? Was everything in the universe predetermined?

On one of the many occasions when Einstein declared that God would not play dice, it was Bohr who countered with the famous rejoinder: Einstein, stop telling God what to do!

Louis de Broglie,

Using Einstein’s law of the photoelectric affect, de Broglie showed that the wavelength associated with an electron (or any particle) would be related to Planck’s constant divided by the particle’s momentum. It turns out to be an incredibly tiny wavelength, which means that it’s usually relevant only to particles in the subatomic realm, not to such things as pebbles or planets or baseballs.

But there was a twist: Bose said that any two photons that had the same energy state were absolutely indistinguishable, in theory as well as fact, and should not be treated separately in the statistical calculations.

Einstein had a similar conversation with his friend in Prague, Philipp Frank. “A new fashion has arisen in physics,” Einstein complained, which declares that certain things cannot be observed and therefore should not be ascribed reality. “But the fashion you speak of,” Frank protested, “was invented by you in 1905!” Replied Einstein: “A good joke should not be repeated too often.”

“It is wrong to think that the task of physics is to find out how nature is,” Bohr declared. “Physics concerns what we can say about nature.”

Of the remaining twenty-six attendees, more than half had won or would win Nobel Prizes as well. The boy wonders of the new quantum mechanics were all there, hoping to convert or conquer Einstein: Werner Heisenberg, 25; Paul Dirac, 25; Wolfgang Pauli, 27; Louis de Broglie, 35; and from America, Arthur Compton, 35. Also there was Erwin Schrödinger, 40, caught between the young Turks and the older skeptics. And, of course, there was the old Turk, Niels Bohr, 42, who had helped spawn quantum mechanics with his model of the atom and become the staunch defender of its counterintuitive ramifications.

He was also bothered—and later would become even more so—by the way quantum mechanics seemed to permit action at a distance. In other words, something that happened to one object could, according to the Copenhagen interpretation, instantly determine how an object located somewhere else would be observed. Particles separated in space are, according to relativity theory, independent. If an action involving one can immediately affect another some distance away, Einstein noted, “in my opinion it contradicts the relativity postulate.” No force, including gravity, can propagate faster than the speed of light, he insisted.

At the Gare du Nord they had a farewell talk on the platform. Einstein told de Broglie that all scientific theories, leaving aside their mathematical expressions, ought to lend themselves to so simple a description “that even a child could understand them.”

Einstein’s thought experiment involved a box with a shutter that could open and shut so rapidly that it would allow only one photon to escape at a time. The shutter is controlled by a precise clock. The box is weighed exactly. Then, at a certain specified moment, the shutter opens and a photon escapes. The box is now weighed again. The relationship between energy and mass (remember, E=mc2) permitted a precise determination of the energy of the particle. And we know, from the clock, its exact time of departing the system. So there!

When he was struggling to find a foothold for a unified theory, he captured the essence of this process in a letter to Hermann Weyl: “I believe that, in order to make any real progress, one would again have to find a general principle wrested from Nature.”

the red shift of the stars’ spectra (which is the light wave counterpart to the Doppler effect for sound waves),

It was a sunny day, and Einstein merrily played with the telescope’s dials and instruments. Elsa came along as well, and it was explained to her that the equipment was used to determine the scope and shape of the universe. She reportedly replied, “Well, my husband does that on the back of an old envelope.”

course, it would have been even more exciting if Einstein had trusted his original equations and simply announced that his general theory of relativity predicted that the universe is expanding. If he had done that, then Hubble’s confirmation of the expansion more than a decade later would have had as great an impact as when Eddington confirmed his prediction of how the sun’s gravity would bend rays of light. The Big Bang might have been named the Einstein Bang, and it would have gone down in history, as well as in the popular imagination, as one of the most fascinating theoretical discoveries of modern physics.

From around the world came other gifts and greetings. The ones that moved him the most were from ordinary people. A seamstress had sent him a poem, and an unemployed man had saved a few coins to get him a small packet of tobacco. The latter gift brought tears to his eyes and was the first for which he wrote a thank-you letter.

“Here is the proof: 1) What one enjoys and doesn’t harm others, one should do. 2) What one doesn’t enjoy and only aggravates others, one should not do. Because of #1, she came with me, and because of #2 she didn’t tell you anything about it. Isn’t that impeccable behavior?”

He had let it be known that he believed that men and women were not naturally monogamous.

Einstein assumed that his son had been ensnared because he was shy and inexperienced with women. “She was the one to grab you first, and now you consider her to be the embodiment of femininity,” he wrote Hans Albert. “That is the well-known way that women take advantage of unworldly people.” So he suggested that an attractive woman would remedy such problems.

Einstein expressed his dismay about Hans Albert’s marriage in letters to Eduard. “The deterioration of the race is a serious problem,” Einstein wrote. “That is why I cannot forgive [Hans] Albert his sin. I instinctively avoid meeting him, because I cannot show him a happy face.”

“People who fill their time with intellectual work bring into the world sickly, nervous at times even completely idiotic children (for example, you me).”

“Einstein understands as much about psychology as I do about physics,” Freud wrote to a friend.

Einstein never asked Freud to meet or treat his son, nor did he seem impressed by the idea of psychoanalysis. “It may not always be helpful to delve into the subconscious,” he once said. “Our legs are controlled by a hundred different muscles. Do you think it would help us to walk if we analyzed our legs and knew the exact purpose of each muscle and the order in which they work?” He certainly never expressed any interest in undergoing therapy himself. “I should like very much to remain in the darkness of not having been analyzed,” he declared.

“There is no meaning to life outside of life itself,” Eduard declared in one of these aphorisms. Einstein replied politely that he could accept this, “but that clarifies very little.” Life for its own sake, Einstein went on, was hollow. “People who live in a society, enjoy looking into each other’s eyes, who share their troubles, who focus their efforts on what is important to them and find this joyful—these people lead a full life.”

Military training is the education of the mind and body in the technique of killing. It thwarts the growth of man’s will for peace.”

“At the top there appears to be a personal struggle in which the foulest means are used by power-hungry individuals acting from purely selfish motives. At the bottom there seems to be complete suppression of the individual and freedom of speech. One wonders whether life is worth living under such conditions.”

Despite his association with the Zionist cause, Einstein’s sympathies extended to the Arabs who were being displaced by the influx of Jews into what would eventually be Israel. His message was a prophetic one. “Should we be unable to find a way to honest cooperation and honest pacts with the Arabs,” he wrote Weizmann in 1929, “then we have learned absolutely nothing during our 2,000 years of suffering.”

He proposed, both to Weizmann and in an open letter to an Arab, that a “privy council” of four Jews and four Arabs, all independent-minded, be set up to resolve any disputes. “The two great Semitic peoples,” he said, “have a great common future.” If the Jews did not assure that both sides lived in harmony, he warned friends in the Zionist movement, the struggle would haunt them in decades to come.78 Once again, he was labeled naïve.

“I’m enough of an artist to draw freely on my imagination. Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.”

The most beautiful emotion we can experience is the mysterious. It is the fundamental emotion that stands at the cradle of all true art and science. He to whom this emotion is a stranger, who can no longer wonder and stand rapt in awe, is as good as dead, a snuffed-out candle. To sense that behind anything that can be experienced there is something that our minds cannot grasp, whose beauty and sublimity reaches us only indirectly: this is religiousness. In this sense, and in this sense only, I am a devoutly religious man.

This public blast from a cardinal prompted the noted Orthodox Jewish leader in New York, Rabbi Herbert S. Goldstein, to send a very direct telegram: “Do you believe in God? Stop. Answer paid. 50 words.” Einstein used only about half his allotted number of words. It became the most famous version of an answer he gave often: “I believe in Spinoza’s God, who reveals himself in the lawful harmony of all that exists, but not in a God who concerns himself with the fate and the doings of mankind.”

I do not at all believe in free will in the philosophical sense. Everybody acts not only under external compulsion but also in accordance with inner necessity. Schopenhauer’s saying, “A man can do as he wills, but not will as he wills,”19 has been a real inspiration to me since my youth; it has been a continual consolation in the face of life’s hardships, my own and others’, and an unfailing wellspring of tolerance.20

“The most important human endeavor is the striving for morality in our actions,” he wrote a Brooklyn minister. “Our inner balance and even our existence depend on it. Only morality in our actions can give beauty and dignity to life.”

When a ferocious storm, far greater than any he had ever witnessed, seized his ship, he recorded his thoughts in his travel diary. “One feels the insignificance of the individual,” he wrote, “and it makes one happy.”

As a result, he was dismissive when his friend Ehrenfest in Leiden wrote to ask for his help in getting a job in America. “I must tell you honestly that in the long term I would prefer to be in Holland rather than in America,” Einstein replied. “Apart from the handful of really fine scholars, it is a boring and barren society that would soon make you shiver.”

The entire dispute was becoming moot. Early in April 1933, the German government passed a law declaring that Jews (defined as anyone with a Jewish grandparent) could not hold an official position, including at the Academy or at the universities. Among those forced to flee were fourteen Nobel laureates and twenty-six of the sixty professors of theoretical physics in the country.

Planck tried to temper the anti-Jewish policies, even to the extent of appealing to Hitler personally. “Our national policies will not be revoked or modified, even for scientists,” Hitler thundered back. “If the dismissal of Jewish scientists means the annihilation of contemporary German science, then we shall do without science for a few years!”

Born took it all rather well, and he developed, like Einstein, a deeper appreciation for his heritage. “As regards my wife and children, they have only become conscious of being Jews or ‘non-Aryans’ (to use the delightful technical term) during the last few months, and I myself have never felt particularly Jewish,” he wrote in his letter back to Einstein. “Now, of course, I am extremely conscious of it, not only because we are considered to be so, but because oppression and injustice provoke me to anger and resistance.”