Einstein: His Life and Universe

at the grave of the greatest and noblest man of our times.” And in 1953, for the celebration of the hundredth anniversary of Lorentz’s birth, Einstein wrote an essay on his importance. “Whatever came from this supreme mind was as lucid and beautiful as a good work of art,” he wrote. “He meant more to me personally than anybody else I have met in my lifetime.”¹⁸

Mari was unhappy about moving to Prague. “I am not going there gladly and I expect very little pleasure,” she wrote a friend. But initially, until the city’s dirtiness and snobbishness became oppressive, their life there was nice enough. They had electric lighting in their home for the first time, and both the space and money for a live-in maid. “The people are haughty, shabby-genteel, or subservient, depending on their lot in life,” Einstein said. “Many of them possess a certain grace.”¹⁹

From Einstein’s office at the university he could look down on a beautiful park with shady trees and manicured gardens. In the morning, it would be filled just with women, and in the afternoon just with men. Some walked alone as if deep in thought, Einstein noticed, while others clustered in groups holding animated arguments. Eventually, Einstein asked what the park was. It belonged, he was told, to an insane asylum. When he showed his friend Philipp Frank the view, Einstein commented ruefully, “Those are the madmen who do not occupy themselves with the quantum theory.”²⁰

The Einsteins became acquainted with Bertha Fanta, a delightfully cultured woman who hosted at her home a literary and musical salon for Prague’s Jewish intelligentsia. Einstein was the ideal catch: a rising scholar who was willing, with equal gusto, to play the violin or discuss Hume and Kant, depending on the spirit of the occasion. Other habitues included the young writer Franz Kafka and his friend Max Brod.

In his book The Redemption of Tycho Brahe, Brod seemed to use (though he sometimes denied it) Einstein as the model for the character of Johannes Kepler, the brilliant astronomer who had been Brahe’s assistant in Prague in 1600. The character is devoted to his scientific work and is always willing to throw away conventional thinking. But in the realm of the personal, he is protected from “the aberrations of feeling” by his aloof and abstracted air. “He had no heart and therefore nothing to fear from the world,” Brod wrote. “He was not capable of emotion or love.” When the novel came out, a fellow scientist, Walther Nernst, said to Einstein, “You are this man Kepler.”²¹

Not really. Despite the image he sometimes cast as a loner, Einstein continued to establish, as he had back in Zurich and Bern, intimate friendships and emotional bonds, particularly with fellow thinkers and scientists. One such friend was Paul Ehrenfest, a young Jewish physicist from Vienna who was teaching at the University of St. Petersburg but feeling professionally stymied there because of his background. In early 1912, he embarked on a trip through Europe looking for a new job, and on his way toward Prague contacted Einstein, with whom he had been corresponding about gravity and radiation. “Do stay at my house so that we can make good use of the time,” Einstein responded.²²

When Ehrenfest arrived one rainy Friday afternoon in February, a cigar-puffing Einstein and his wife were at the train station to meet him. They all walked to a cafe, where they compared the great cities of Europe. When Mari left, the discussion turned to science, most notably statistical mechanics, and they continued talking as they walked to Einstein’s office. “On the way to the institute, first argument about everything,” Ehrenfest recorded in his diary of the seven days he spent in Prague.

Ehrenfest was a mousy and insecure man, but his eagerness for friendship and his love of physics made it easy for him to forge a bond with Einstein.²³ They both seemed to crave arguing about science, and Einstein later said that “within a few hours we were friends as if Nature created us for each other.”Their intense discussions continued the next day, as Einstein explained his efforts to generalize his theory of relativity. On Sunday evening, they relaxed a bit by performing Brahms, with Ehrenfest on piano, Einstein on violin, and 7-year-old Hans Albert singing. “Yes we will be friends,” Ehrenfest wrote in his diary that night. “Was awfully happy.”²⁴

Einstein was already thinking of leaving Prague, and he suggested Ehrenfest as a possible successor. But he “adamantly refuses to profess any religious affiliation,” Einstein lamented. Unlike Einstein, who was willing to relent and write “Mosaic” on his official forms, Ehrenfest had abandoned Judaism and would not profess otherwise. “Your stubborn refusal to acknowledge any religious affiliation really bugs me,” Einstein wrote him in April. “Drop it for your children’s sake. After all, after becoming a professor here you could revert to this strange hobby horse of yours.”²⁵

Matters eventually came to a happy resolution when Ehrenfest accepted an offer, which Einstein had earlier received but declined, to replace the revered Lorentz, who was cutting back from full-time teaching at the University of Leiden. Einstein was thrilled, for it meant he would now have two friends there to visit regularly. It became, for Einstein, almost a second academic home and a way to escape the oppressive atmosphere he later found in Berlin. Almost every year for the next two decades, until 1933 when Ehrenfest committed suicide and Einstein moved to America, Einstein would make regular pilgrimages to see him and Lorentz in Leiden or at the seaside resorts nearby.²⁶

The 1911 Solvay Conference

Ernest Solvay was a Belgian chemist and industrialist who reaped a fortune by inventing a method for making soda. Because he wanted to do something unusual yet useful with his money, and also because he had some odd theories of gravity that he wanted scientists to listen to, he decided to fund an elite gathering of Europe’s top physicists. Scheduled for the end of October 1911, it eventually spawned a series of influential meetings, known as Solvay Conferences, that were held sporadically over the ensuing years.

Twenty of Europe’s most famous scientists showed up at the Grand Hotel Metropole in Brussels. At 32, Einstein was the youngest. There was Max Planck, Henri Poincare, Marie Curie, Ernest Rutherford, and Wilhelm Wien. The chemist Walther Nernst organized the event and acted as chaperone for the quirky Ernest Solvay. The kindly Hendrik Lorentz served as the chairman, as his fan Einstein put it, “with incomparable tact and unbelievable virtuosity.”²⁷

The focus of the conference was “the quantum problem,” and Einstein was asked to present a paper on that topic, making him one of only eight “particularly competent members” thus honored. He expressed some annoyance, perhaps a bit more feigned than real, about the prestigious assignment. He dubbed the upcoming meeting “the witch’s Sabbath” and complained to Besso, “My twaddle for the Brussels conference weighs down on me.”²⁸

Einstein’s talk was titled “The Present State of the Problem of Specific Heats.” Specific heat—the quantity of energy required to increase the temperature of a specific amount of substance by a certain amount—had been a specialty of Einstein’s former professor and antagonist at the Zurich Polytechnic, Heinrich Weber. Weber had discovered some anomalies, especially at low temperatures, in the laws that were supposed to govern specific heat. Beginning in late 1906, Einstein had come up with what he called a “quantized” approach to the problem by surmising that the atoms in each substance could absorb energy only in discrete packets.

In his 1911 Solvay lecture, Einstein put these issues into the larger context of the so-called quantum problem. Was it possible, he asked, to avoid accepting the physical reality of these atomistic particles of light, which were like bullets aimed at the heart of Maxwell’s equations and, indeed, all of classical physics?

Planck, who had pioneered the concept of the quanta, continued to insist that they came into play only when