Goebbels arrived in Berlin that November. He liked to recall it as a grand moment, something like Lenin’s arrival at the Finland Station with party members on hand to escort him before an eager audience. In reality, however, the Berlin Nazis were almost nonexistent. That was why Hitler had sent him there, to begin sowing and cultivating his lies as the new Gauleiter (director) of Berlin.

Elsewhere, optimists were feeling like they had found some truth. That same November, Max Born wrote to Einstein about his continuing pleasure with his probabilistic interpretation: “About me it can be told that physicswise I am entirely satisfied since my idea to look upon Schrödinger’s wave field as a ‘ghost field’ in your sense….”

Presumably Einstein winced at that “in your sense.” It was like Marx thanking Hegel for dialectical logic.

“Schrödinger’s achievement,” Born continued, “reduces itself to something purely mathematical; his physics is quite wretched.”

Born had every reason that autumn to be pleased with himself. He had cleaned up both main versions of quantum mechanics—putting Heisenberg on a clear mathematical footing and interpreting Schrödinger in a way that brought his equation in line with the practical views of the Göttingen physics department. As a proud papa, he

expected Einstein to share his enthusiasm and was quite unprepared for Einstein’s letter of early December.

“Quantum mechanics is certainly imposing,” Einstein granted, “but an inner voice tells me it is not yet the real thing.”

Born reports that he took this unexpected criticism “as a hard blow.”

“The theory says a lot, but does not really bring us any closer to the secret of the ‘Old One.’”

Max Born had known and chatted with Einstein for almost 20 years and yet appears to have spent the rest of his life feeling puzzled by what Einstein meant.

“I, at any rate,” Einstein proceeded, introducing what became the most famous metaphor in his canon, “am convinced that He is not playing at dice.”

By speaking so vividly, Einstein did his cause lasting damage. Born seems to have pictured God shooting dice and moving pieces across the universal game board and thought that Einstein objected to the randomness of things. Einstein’s mistrust actually focused on the alienation between dice throw and action. He found it as unsatisfactory as would a schoolboy who dislikes the board-game version of football. Throwing dice to determine player actions is no substitute for the reality of athletic competition.

In another letter, Einstein told Born, “You believe in God playing dice and I in perfect laws in the world of things existing as real objects.” There he made it as clear as language can allow that, for Einstein, the opposite of dice throwing was not a predetermined world, but one in which real things happen for real reasons.

Whenever a revolutionary refuses to accept the revolution’s outcome, former comrades-in-arms feel dismayed. The Soviet Union was developing a whole vocabulary to vilify revolutionaries who broke with the party line: right-wing Kautskyite, objectively counterrevolutionary, Trotskyist, and so forth. Nothing that terrible was likely to break out in the world of physics, but Einstein did find himself denigrated and scorned by those who embraced Max Born’s probabilistic settlement. Physicists had routinely scorned Einstein’s obsessions as windmill tilting and they continued the tradition this time.

“In the course of scientific progress,” Heisenberg later wrote, “it can happen that a new range of empirical data can be completely understood only when the enormous effort is made to enlarge [their philosophical] framework and to change the very structure of the thought process. In the case of quantum mechanics Einstein was apparently no longer willing to take this step, or perhaps no longer able to do so.”

Although more diplomatic, Bohr, too, dismissed Einstein’s objections in a way that relieved himself of any need to wonder whether his critic had a point: “In dealing with the task of bringing order into an entirely new field of experience, we could hardly trust in any accustomed principles, however broad, apart from the demand of avoiding logical inconsistencies.” It was a brazen statement for a thinker whose use of complementarity sounded to some like the embrace of inconsistency.

It sounds like Einstein was unwilling to consider the new statistical ideas, but Einstein knew as well as anyone in physics that action often results from chance. His explanation of Brownian motion had shown his very deep understanding of statistical fluctuations based on the perfectly random actions of atoms in fluid, and that great paper had built on previous work in which Einstein developed a statistical approach to unpredictable changes. Indeed, as Einstein fully understood, many classic concepts of physics, like temperature and pressure, have no meaning apart from a statistical one. But he also believed as fervently as Saint Anselm believed in the Almighty that the physical world was real and that physical outcomes result from physical inputs. If Brownian motion can be explained with statistical equations, it is because a real physical action underlies those statistics.

When Einstein wrote of coming closer to “the secret of the ‘Old One,’” he stayed with his belief that advances in science link rules to reality. Every step brings the world that much closer to discovering the invisible truth behind appearances. Max Born complained that Einstein had not rejected quantum mechanics “for any definite reason, but rather by referring to an ‘inner voice.’” But of course Einstein had immediately given his definite reason: it does not bring us any

closer to the secret of the “Old One.” He was still determined to see Truth’s face.

Born could have responded to that objection: “There is no ‘Old One,’ no physical givens whose properties and laws are to be discovered. At bottom, instead of nature and natural laws, there is only chaos.” But the striking fact is that Max Born never replied to Einstein’s objection, never seemed even to grasp what was at stake. Over the years, Born and Einstein had many more exchanges about quantum mechanics, with Born never clutching the nettle.

Born commented on Einstein’s initial response to quantum mechanics: “This rejection was based on a basic difference of philosophical attitude, which separated Einstein from the younger generation to which I felt that I belonged, although I was only a few years younger than Einstein.” Thus began the myth of Einstein as old fogey. It should immediately provoke suspicion to see how flattering this account is to its teller: all of three years younger than Einstein, Max Born the utterly married Herr Professor of Göttingen presents himself as so much younger at heart than Einstein the philandering man-about-town.

Born responded in a similar tone to another letter in which Einstein said we cannot understand clearly how quantum “machinery” works: “the same argument [about not understanding it clearly] was used by the opponents of the young Einstein…”. Born slips in the old-fogey-Einstein image as delicately as a prison hit-man slips in a shiv, “… who alleged that the consequences of the relativity theory did not make sense.”

This linkage of anti-relativity arguments with anti-quantum math became popular, but it misses the seriousness of Einstein’s objection. Complaints that relativity made no sense and was incomprehensible usually meant that Einstein thought reality was one way (in which time is relative) while the speaker was confident reality was another way (in which time is absolute). A philosophical opponent of relativity might have said, “I cannot imagine reality working the way you say it works.” Einstein’s objection to quantum mechanics went a step further, disputing the way the theory had taken reality out of the story altogether and replaced it with a mathematics. Einstein’s physics rested on the credo that physical reality exists all the way down to the small-

est part and flutter of the universe and that intelligible explanations of what happens must not stray from physical reality’s role.

Once, during the war years, Born came close to grasping Einstein’s point, “If God has made the world a perfect mechanism, he has at least conceded so much to our imperfect intellect that, in order to predict little parts of it, we need not solve innumerable differential equations but can use dice with fair success. That this is so I have learned, with many of my contemporaries, from Einstein himself. I think this situation has not changed much by the introduction of quantum statistics; it is still we mortals who are playing dice for our little purposes of prognosis—God’s actions are as mysterious in classical Brownian motion as in radioactivity and quantum radiation, or in life at large.”

How startling it is to find Max Born, even in the 1940s, asserting that thinking about physics was “not changed much by the introduction of quantum statistics.” The work of Galileo and Newton had enthroned natural explanation. Something new was afoot when scientists no longer believed that physical events lay behind physical laws.

The one who did grasp the importance of the change was Niels Bohr. His distaste for mathematics meant that he could not follow his colleagues into a world of pure mathematical meaning. He could understand the equations, but that was not where his creative strength lay. This unusual physical imagination might have pushed him out of the quantum story for good, but in his own way Bohr was as restless as Einstein.

Einstein’s way was reflected in the letter he wrote Max Born. After saying that God is not rolling dice, Einstein described his own approach to the problem. Its mathematical details are not important because they came to naught, but the approach matters. Einstein was returning to square one, looking for a new way to derive Schrödinger’s equation. That was the standard physicist’s approach to the mystery of Planck’s h—find some new insight into the physical world that leads to Planck’s equation. It was also Einstein’s approach to gravity where he found a new, relativistic world that led to Newton’s predictions. Bohr, however, came at it from the other end. Given quantum mechanics, what can we say about the world?