Einstein: His Life and Universe

by Walter Isaacson

A society’s competitive advantage will come not from how well its schools teach the multiplication and periodic tables, but from how well they stimulate imagination and creativity.

The value of creativity is shockingly important, not only seen from Einstein, but from Pixar. Fostering it, loving it to eliminate fear, is perhaps most important.

Almost a century earlier, the Italian scientist Amedeo Avogadro (1776–1856) had developed the hypothesis—correct, as it turned out—that equal volumes of any gas, when measured at the same temperature and pressure, will have the same number of molecules. That led to a difficult quest: figuring out just how many this was. The volume usually chosen is that occupied by a mole of the gas (its molecular weight in grams), which is 22.4 liters at standard temperature and pressure. The number of molecules under such conditions later became known as Avogadro’s number. Determining it precisely was, and still is, rather difficult. A current estimate is approximately 6.02214 × 1023. (This is a big number: that many unpopped popcorn kernels when spread across the United States would cover the country nine miles deep.)

“At the time atoms and molecules were still far from being regarded as real,” the theoretical physicist Max Born later recalled. “I think that these investigations of Einstein have done more than any other work to convince physicists of the reality of atoms and molecules.”

It became clear that light was the visible manifestation of a whole spectrum of electromagnetic waves. This includes what we now call AM radio signals (with a wavelength of 300 yards), FM radio signals (3 yards), and microwaves (3 inches). As the wavelengths get shorter (and the frequency of the wave cycles thus increases), they produce the spectrum of visible light, ranging from red (25 millionths of an inch) to violet (14 millionths of an inch). Even shorter wavelengths produce ultraviolet rays, X-rays, and gamma rays.

“We thus arrive at the important result: Events that are simultaneous with reference to the embankment are not simultaneous with respect to the train,” said Einstein. The principle of relativity says that there is no way to decree that the embankment is “at rest” and the train “in motion.” We can say only that they are in motion relative to each other. So there is no “real” or “right” answer. There is no way to say that any two events are “absolutely” or “really” simultaneous.43 This is a simple insight, but also a radical one. It means that there is no absolute time. Instead, all moving reference frames have their own relative time. Although Einstein refrained from saying that this leap was as truly “revolutionary” as the one he made about light quanta, it did in fact transform science. “This was a change in the very foundation of physics, an unexpected and very radical change that required all the courage of a young and revolutionary genius,” noted Werner Heisenberg, who later contributed to a similar feat with his principle of quantum uncertainty.

The obvious yet still astonishing conclusion: with no such thing as absolute simultaneity, there is no such thing as “real” or absolute time. As he later put it, “There is no audible tick-tock everywhere in the world that can be considered as time.”56 Moreover, this realization also meant overturning the other assumption that Newton made at the beginning of his Principia. Einstein showed that if time is relative, so too are space and distance: “If the man in the carriage covers the distance w in a unit of time—measured from the train—then this distance—as measured from the embankment—is not necessarily also equal to w.”

if you spent almost your entire life on an airplane, you would have aged merely 0.00005 seconds or so less than your twin on earth when you returned, an effect that would likely be counteracted by a lifetime spent eating airline food.

It is very important to note, however, that the theory of relativity does not mean that “everything is relative.” It does not mean that everything is subjective. Instead, it means that measurements of time, including duration and simultaneity, can be relative, depending on the motion of the observer. So can the measurements of space, such as distance and length. But there is a union of the two, which we call spacetime, and that remains invariant in all inertial frames. Likewise, there are things such as the speed of light that remain invariant.

“His conviction that the universe loves simplification and beauty, and his willingness to be guided by this conviction, even if it meant destroying the foundations of Newtonian physics, led him, with a clarity of thought that others could not match, to his new description of space and time.”

A kilogram of mass would convert into approximately 25 billion kilowatt hours of electricity. More vividly: the energy in the mass of one raisin could supply most of New York City’s energy needs for a day.

“The central idea of general relativity is that gravity arises from the curvature of spacetime,” says physicist James Hartle. “Gravity is geometry.”9 “I am now working exclusively on the gravitation problem and I believe that, with the help of a mathematician friend here, I will overcome all difficulties,” Einstein wrote to the physicist Arnold Sommerfeld. “I have gained enormous respect for mathematics, whose more subtle parts I considered until now, in my ignorance, as pure luxury!”

Einstein, at age 36, had produced one of history’s most imaginative and dramatic revisions of our concepts about the universe. The general theory of relativity was not merely the interpretation of some experimental data or the discovery of a more accurate set of laws. It was a whole new way of regarding reality.

Schwarzschild’s first calculations focused on the curvature of spacetime outside a spherical, nonspinning star. A few weeks later, he sent Einstein another paper on what it would be like inside such a star. In both cases, something unusual seemed possible, indeed inevitable. If all the mass of a star (or any object) was compressed into a tiny enough space—defined by what became known as the Schwarzschild radius—then all of the calculations seemed to break down. At the center, spacetime would infinitely curve in on itself. For our sun, that would happen if all of its mass were compressed into a radius of less than two miles. For the earth, it would happen if all the mass were compressed into a radius of about one-third of an inch.

Einstein began by noting that an absolutely infinite universe filled with stars and other objects was not plausible. There would be an infinite amount of gravity tugging at every point and an infinite amount of light shining from every direction. On the other hand, a finite universe floating at some random location in space was inconceivable as well. Among other things, what would keep the stars and energy from flying off, escaping, and depleting the universe? So he developed a third option: a finite universe, but one without boundaries. The masses in the universe caused space to curve, and over the expanse of the universe they caused space (indeed, the whole four-dimensional fabric of spacetime) to curve completely in on itself. The system is closed and finite, but there is no end or edge to it.

Einstein was acutely aware, even more than the assimilationists, that anti-Semitism was not the result of rational causes. “In Germany today hatred of the Jews has taken on horrible expressions,” he wrote in early 1920. Part of the problem was that inflation was out of control. The German mark had been worth about 12 cents at the beginning of 1919, which was half of its value from before the war but still manageable. But by the beginning of 1920, the mark was worth a mere 2 cents, and collapsing further each month. In addition, the loss of the war had been humiliating. Germany had lost 6 million men and then was forced into surrendering land containing half of its natural resources, plus all of its overseas colonies. Many proud Germans believed it must have been the result of betrayal. The Weimar Republic that had emerged after the war, though supported by liberals and pacifists and Jews such as Einstein, was disdained by much of the old order and even the middle class.

“The value of a college education is not the learning of many facts but the training of the mind to think,”

By the beginning of 1923, the price of a loaf went to 700 marks and by the end of that year cost 1 billion marks. Yes, 1 billion. In November 1923, a new currency, the Rentenmark, was introduced, backed by the government property; 1 trillion old marks equaled 1 new Rentenmark. The German people increasingly cast around for scapegoats. They blamed internationalists and pacifists who had forced a surrender in the war. They blamed the French and English for imposing what was in fact an onerous peace. And, no surprise, they blamed the Jews. So Germany in the 1920s was not a good place or time to be an internationalist, pacifist, intellectual Jew.

On 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.” Neither seemed to mind, for the conversation was so engrossing. “We rode to and fro,” according to Bohr, “and I can well imagine what the people thought about us.”43 More than just a friendship, their relationship became an intellectual entanglement that began with divergent views about quantum mechanics but then expanded into related issues of science, knowledge, and philosophy. “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?

“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.”

The idea of an impersonal God, whose hand is reflected in the glory of creation but who does not meddle in daily existence, is part of a respectable tradition in both Europe and America. It is to be found in some of Einstein’s favorite philosophers, and it generally accords with the religious beliefs of many of America’s founders, such as Jefferson and Franklin.

Unlike Sigmund Freud or Bertrand Russell or George Bernard Shaw, Einstein never felt the urge to denigrate those who believe in God; instead, he tended to denigrate atheists. “What separates me from most so-called atheists is a feeling of utter humility toward the unattainable secrets of the harmony of the cosmos,” he explained.

“The very fact that the totality of our sense experiences is such that, by means of thinking, it can be put in order, this fact is one that leaves us in awe,” he wrote. “The eternal mystery of the world is its comprehensibility… The fact that it is comprehensible is a miracle.”46

“Well, a priori, one should expect a chaotic world which cannot be grasped by the mind in any way,” he wrote. “There lies the weakness of positivists and professional atheists.”

Einstein had finally discovered what was fundamental about America: it can be swept by waves of what may seem, to outsiders, to be dangerous political passions but are, instead, passing sentiments that are absorbed by its democracy and righted by its constitutional gyroscope. McCarthyism had died down, and Eisenhower had proved a calming influence. “God’s own country becomes stranger and stranger,” Einstein wrote Hans Albert that Christmas, “but somehow they manage to return to normality. Everything—even lunacy—is mass produced here. But everything goes out of fashion very quickly.”

Planck and Poincaré and Lorentz all came close to some of the breakthroughs Einstein made in 1905. But they were a little too confined by dogma based on authority. Einstein alone among them was rebellious enough to throw out conventional thinking that had defined science for centuries.

There was a simple set of formulas that defined Einstein’s outlook. Creativity required being willing not to conform. That required nurturing free minds and free spirits, which in turn required “a spirit of tolerance.” And the underpinning of tolerance was humility—the belief that no one had the right to impose ideas and beliefs on others.