Einstein's Genius Club (24 page)

In 1925, when Einstein set aside his other work to find a unified theory, all seemed in place for success. General relativity provided the geometrizing approach he meant to extend to electromagnetism; he had been mulling the problem for seven years, since 1918; no physicist alive had a deeper intuition of what was physically possible or necessary, or the limits within which the new theory must work. He was still in his prime at forty-six. Max Born, no soft touch, predicted that “physics will be done in six months.”
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But unified theory was not to become another stroke of genius and insight. It was more like an aging engine fitfully turning over. Periodically, he would declare victory. After his first serious attempt in 1925, Einstein said: “I believe I have found the true solution.”
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He soon decided that he was wrong. He tried other approaches in 1927, and again in 1928—the latter broadcast as a victory by newspapers to eager readers. Einstein had to dampen the enthusiasm. In 1929, he again believed that he had prevailed, and even gave lectures in France and England. He retracted in 1931. In 1945, at age sixty-six, he published his final equations, but hardly with the overwhelming confidence he had expressed about general relativity. When queried by reporters, he said, “Come back and see me in twenty years.” He revised the equations in 1949 and 1954.
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Always, colleagues and friends bewailed his efforts. In 1932, Pauli was already complaining that Einstein's

never-failing inventiveness as well as his tenacious energy in the pursuit of [unification] guarantees us in recent years, on the average, one theory per annum.
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Einstein himself wondered how definitive even his final equations were. Perhaps, he said wryly, his critics were right, and the equations did not “correspond to nature”—the ultimate defeat.
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Pauli talked to him in 1954, and said that Einstein admitted

with his old directness and honesty, that he had not succeeded in proving the possibility of a pure field theory of matter. He regarded the problem as undecided.
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His final equations, appearing at last in 1945, had a muted reception. That year, the atom bombs exploded, the war ended, and physicists sought jobs in the booming field of particle physics. Einstein had become world famous for general relativity. As for unified field theory, it was beyond the horizon. He continued to work on unified field theory until the day he died.

Most physicists now see Einstein's theory as an intellectual feat but irrelevant to physics. A good theory should be able to predict important new insights and express earlier ones in some fertile new way, as general relativity did with Newton. Einstein's attempts do neither. Nor could he take into account the strong and weak nuclear forces. Today, the main contender for unifying all four forces is superstring theory. Most of its proponents pay homage to Einstein as a man “ahead of his time.” Still, his disdain for quantum mechanics might well have distanced him from today's unifiers. He tried to circumvent quantum physics by geometrizing electromagnetism in gravitation's image. String theorists have taken the inverse route by quantizing gravitation.

Meanwhile, Einstein's theory exists as a historical artifact in a scientific limbo. Physics does not linger over might-have-beens or maybes, unless they promise discoveries and insights. Careers are short, and the mainstream is where working theories are usually found. Einstein redirected the mainstream in his early work. But his attempts at a unified field theory banished him into the hinterland.

Postscript: The philosopher of science and theology Stanley Jaki, writing of current attempts to unify the forces, suggests that Gödel's theorem might apply. If so, says Jaki, such unification is impossible. Any consistent system, Gödel reminds us, cannot be complete in its own terms.
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As Einstein strolled to his Princeton
office with his friend Gödel, might they have mused about such a limitation on our knowledge of the world?

What might Russell have gleaned from his Princeton afternoons at Einstein's house? Much more than he let on, perhaps. Pauli and Gödel were quite biased in favor of metaphysics—as we know, their interests extended to archetypal mythology (Pauli) and the paranormal (Gödel). In a 1946 letter to his colleague Markus Fierz, Pauli spoke of “the idea of the reality of the symbol.”
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Psychology was his link to the “real” world of symbols. It would be difficult to imagine “premises” more distant from Russell's.

Yet Russell's quarrel with Einstein must have been by far the richest and the most important. In a “Note on Non-Demonstrative Inference and Induction,” which Russell dictated to his wife in 1959, he offers a tantalizing clue: “My beliefs about induction underwent important modifications in the year 1944, chiefly owing to the discovery that induction used without common sense leads more often to false conclusions than to true ones.” He goes on to distinguish between pure induction and what he calls “scientific common sense.” Induction, indeed, does not figure in the “extralogical postulates” required by scientific inference. Here, Russell shows himself to be an empiricist (as ever) with a difference: Induction is “invalid as a logical principle” because it so easily falls into fallacy. Russell's examples of induction going wrong include the following: “No man alive has died, therefore probably all men alive are immortal.”
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Had Russell in fact given up empiricism, Einstein would have been delighted. In his contribution to the Library of Living Philosophers volume on Russell, published in 1944, Einstein bluntly objected to the Humean “fear of metaphysics” in Russell. Of course, Einstein was quite right. After abandoning Plato in his youth, Russell never let go of the empirical impulse. In a way, the
gulf between Russell and Einstein was not enormous. Neither subscribed to what Einstein called the two illusions: “the unlimited penetrative power of thought” and “naïve realism, according to which things ‘are' as they are perceived through our senses.”
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Einstein agreed that “thought acquires material content only through its relationship with… sensory material”—a statement that sounds suspiciously acquiescent to empiricism. But he rejected any attempt to base thought upon material reality, arguing that the “free creations of thought” are sufficiently valid if they are merely “connected with sensory experiences.” That is, thought is not created out of material things or the perceptions of material things. But thought can contribute to knowledge only if it coincides with the “sense experience” that comes to us from what is material. Einstein was, to borrow his own words, on the thought side of the “gulf—logically unbridgeable—which separates the world of sensory experiences from the world of concepts and propositions.”
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The format of each volume of The Library of Living Philosophers requires that the subject “reply” to each essay. Russell dutifully replied to Einstein's contribution. Russell's few words are respectful and pointed. He agreed with Einstein that the “fear of metaphysics is the contemporary malady”—lamentable especially for the tendency of contemporary philosophers to swallow empiricism wholesale, without “prob[ing] questions to the bottom.” Still, Russell approached the “gulf” between metaphysics and empiricism with a “bias… towards empiricism.” He is thus quick to refute Einstein's assertion that number is an example of the “free creations of thought.”
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As one contrary instance, Russell offered the obvious correlation between the decimal system and our ten fingers. For Einstein, desperately clinging to the hope of a mathematical solution to his unified field theory, Russell's empirical bent must have been an unpleasant reminder of those abandoned “generalizable facts” upon which his relativity theories were based.
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In 1949, Russell wrote “Einstein and the Theory of Relativity” for a BBC broadcast. In it, Russell praised modern physics for its
“desire to avoid introducing into physics anything that, by its very nature, must be unobservable.” The consequence has been more abstraction in physics, as no longer are we permitted “to make pictures to ourselves of what goes on in atoms, or indeed of anything in the physical world.” The tongue-in-cheek of this quip aside, Russell put his finger on the paradox of evidence in physics. What Russell wanted was less of the unobservable to count as science: “[S]o long as the technique of science can survive, every diminution in the number of unobservables that are assumed is a gain. In this sense, Einstein took a long step forward.”
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Russell had recast Occam's razor
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to fit modern physics, but how that law of parsimony can be reconciled with scientific creativity, much less a “theory of everything,” is hard to know.

If Einstein did waver in his commitment to experience, he never fully gave it up. Asked by
Scientific American
to explain his most recent unified field theory in nontechnical terms, Einstein obliged. The result, a difficult and abstract article published in 1950, conceded as much:

The skeptic will say, “It may well be true that this system of equations is reasonable from a logical standpoint. But this does not prove that it corresponds to nature.” You are right, dear skeptic. Experience alone can decide on truth.
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William of Occam admonished, “Pluralitas non est ponenda sine necessitate,” which can be translated, loosely, as “Strip away unnecessary things.”

As Einstein and his friends in Princeton spoke quietly of philosophy and science, many of their colleagues were busy pushing physics toward brute power. In Los Alamos and in Germany, physicists raced to build the first atom bomb. Whoever succeeded would gain certain victory: The heart of London or Berlin could be destroyed in a moment. Neither Einstein nor his fellow physicist Pauli worked on the atom bomb, but both knew what their colleagues were doing. It was a small, tight-knit world. Oppenheimer, who directed the Los Alamos effort, had been Pauli's student. Werner Heisenberg, who led the German bomb project, was Pauli's closest collaborator. They had been friends since their college days in Munich. When it came down to the atom, everyone knew everyone else.

I
N DECEMBER 1943, WERNER HEISENBERG
paid a visit to Krakow at the invitation of Hans Frank, then the Nazi governor general of occupied Poland.
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Frank, a schoolmate of Heisenberg's brother, had extended the invitation in May 1943, having invented a “Copernicus
Prize” for Heisenberg as an enticement. Delayed for various reasons, Heisenberg finally accepted, with the promise, too, of a lecture for Frank's newly minted Institut fur Deutsche Ostarbeit (literally, Institute for German East Studies, a “think tank” for eastern colonization).

Frank had fallen from Nazi grace the previous year after a lecture critical of unconstitutional rule. That lecture saw him stripped of his prestigious title Reichskommissar, but left his governorship of Poland intact. In such disdain did Hitler hold Poland that he thought it punishment enough to let Frank languish there.

Exiled he might have been. But he did not languish. He had already appropriated for his living quarters the luxuriously appointed Wawel Castle, where he entertained lavishly and famously. Known as the “butcher of Poles” (later executed at Nuremburg in 1946), he extorted from his governorship all that he could: lavish feasts for friends, furs for his wife and his lover, money in the bank. (Among the charges of corruption floated during party infighting was the charge, easily documented, that Frank and his wife “shopped” in the Jewish ghetto, where discounts naturally abounded.) Frank despised Poles, whom he saw as fodder for slavery and extermination; and he exhorted his fellow Germans to exterminate Jews in a blunt, brutal 1941 speech.

In recollection, Heisenberg confided to the historian David Irving that he was struck by Frank's queries about a “miracle weapon, perhaps atomic bombs” in the possession of the Allies.
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Heisenberg seems to have recalled little about his own talk at Frank's Institut fur Deutsche Ostarbeit. Presumably, he lectured on quantum theory. Nor did he recall seeing or hearing anything untoward. Yet he must have listened to the outspoken Frank boast of his successes in dealing with the “Jewish question.” Frank's castle was about fifty miles from Auschwitz.

It was hardly surprising that Hans Frank might think to ask about an atomic bomb. Whether he had in mind a “miracle”
weapon for the fatherland or feared that the Allies might have their own, Frank, like most laypeople, would have heard all about “splitting the atom” and the possibilities of atomic energy.