Science: Exile in Princeton

(See front cover)

The sun was shining, the air was like early summer last week on the campus of Princeton University. The duckboards which protect the feet of undergraduates and teachers from the mud and slosh of New Jersey winters were still in place along the paths, but earth smells arose from the drying ground, excited birds skittered in the shrubbery, squirrels chattered in the trees. Students went to classes without neckties, and in the afternoons an elderly man with soft, inquisitive eyes and a flowing halo of white hair ambled in & out of Fine Hall, pausing to admire the changing season. He had always felt close to Nature—ever since his unhappy childhood in Munich, his happy youth in Italy, his placid days in Switzerland when he worked for the Berne patent office and pondered the structure of the world.

On the bulletin board in Fine Hall this elderly man was listed as “A. Einstein,” occupant of Room No. 215. A small brick building with heavy-paneled doors and antique lamps glowing dimly in the linoleum-floored corridors, Fine Hall-houses the mathematical contingent of Princeton’s Institute for Advanced Study. The Institute, which soon will have buildings of its own, is a group of distinguished scholars who are subsidized so that they may pursue their own researches without the distraction of giving courses, preparing examinations, grading papers. Many of the Institute’s members are Jewish exiles from Germany. Directed by Dr. Abraham Flexner, the Institute was started in 1933 with a $5,000,000 endowment from Louis Bamberger, retired Newark department store tycoon, and his sister, Mrs. Felix Fuld.

In Fine Hall last week there were whispered conferences and quiet telephone conversations. A surprise party was being planned for A. Einstein and another member of the Institute, Dr. Leopold Infeld. The mathematicians made great efforts to keep the party a secret from Dr. Infeld. It was not so difficult to keep it a secret from Dr. Einstein. On the day of the party this week a book† will be published of which Drs. Einstein & Infeld are coauthors, the first “popular” book on physics to which Albert Einstein has ever lent his name.

Collaborators. Co-author Infeld is a distinguished theoretical physicist in his own right. A tall, jovial man with irregular teeth and the lumpy physique of a sedentary scholar, he speaks English with a heavy accent, but fluently and well. Born 40 years ago in Cracow, Poland, he studied at Cracow’s ancient university and in Berlin, lectured in Lwów, spent some years in England’s Cambridge as a Rockefeller fellow, joined the Institute at Princeton in 1936. In Cambridge he helped Physicist Max Born, another German exile (now at Edinburgh), in the formulation of a field theory which bridges modern Quantum Mechanics and the 19th-Century electro-magnetic wave equations of Scotland’s brilliant James Clerk Maxwell (TIME, Sept. 11, 1933).

The idea of an explanation for laymen of modern physics and its origins was first suggested by Infeld. But Albert Einstein had been long fondling such a notion, readily agreed. Although he now speaks English quite well, Einstein is still reluctant to write in this new language. So the actual writing was done by Infeld. But it is not simply a ghostwritten job. Their friends, who did not know about the book for some time after it was actually under way, say that it is a “real project of collaboration.” The scope, form and content of the book were agreed on and mapped out in careful detail.

It does not appear whether Einstein’s readiness for the project was due to a prickly dissatisfaction with the existing popularizations of Relativity and Quantum Mechanics. These have appeared in a steady stream since—to his complete bewilderment—his newspaper fame flowered in the 1920s. It is noteworthy that Einstein’s book contains none of the mystical discursions of Sir Arthur Eddington and Sir James Jeans. The cast of characters in The Evolution of Physics does not include God.

Lucid But Not Light. The Evolution of Physics does not contain a single mathematical equation or formula, but it is studded with a number of helpful diagrams. Co-author Infeld writes with lucid, straightforward simplicity, not devoid of patches of whimsey—as, for example, having shown how modern physics banished the concept of a jelly-like ether which carries light waves, he thereafter refers to the ether, when necessary, as if it were a swearword: “e—r.” The authors admit that the avoidance of mathematical languages involves a certain loss of precision. But the loss is held to a minimum because they try not to paraphrase mathematical procedure, but to follow trains of physical thought, trace the origins from which they sprang, show the ends to which they lead.

Some weeks ago Gossip Walter Winchell announced in his syndicated column that Einstein was writing a book on physics “which you, you and you can understand.” It is doubtful whether many of Columnist Winchell’s “you’s” will find The Evolution of Physics light reading. The Book-of-the-Month Club considered the manuscript at length, finally rejected it as a club selection, fearing an avalanche of returns from readers who would find it too difficult. Yet the U. S. publishers have turned out a first printing of 5,000 copies. Cambridge University Press, which is handling the English publication, has printed 10,000 copies. The English publishers and U. S. publishers are both trying to get the book on required reading lists in schools. The book is also being published in Dutch translation in Holland.

Evolution. In tracing the roots of modern physics, the authors found il necessary to go back to Galileo and Newton, and even to mention Aristotle. The great Greek philosopher, whose shadow dominated scholastic thought in Medieval Europe, declared that a continuous push had to be exerted on a body to keep it in motion. Galileo, who shocked cloistered thinkers by making uncouth experiments, concluded that this was not so—that if a moving body was not acted upon by any forces it would continue in uniform motion indefinitely. This was one of the laws formulated by Newton a generation later. When Newton formulated the principle that the force of gravity is inversely proportional to the square of the distance, he had the key to the orbits of the planets, and what looked like the key to the operation of the whole universe. The universe, in operation, was a multitude of masses acting instantaneously on one another at a distance—the forces being exerted along straight lines connecting the masses.

Early experiments with electricity and magnetism disturbed this mechanical view. Faraday and Oersted showed that a moving magnet produces an electric field, that a moving electric charge produces a magnetic field. The lines of force in these fields were not arranged in Newtonian straight lines but in curves. After curved fields in space came waves of energy. The wave theory of light, which had been opposed by Newton, was picked up again because it was the only way to explain certain phenomena—for example, the diffraction rings produced when light passes through a small aperture. Before electro-magnetic waves (e.g., wireless waves) were ever demonstrated experimentally, Maxwell distilled them out of his mathematical equations, then showed that their velocity was equal to the velocity of light. Therefore, light appeared to be an electro-magnetic wave. This was one of the greatest achievements in the history of science. Physicists speak of Maxwell’s equations as if they were a beautiful painting hung in a museum.

Electromagnetic waves were supposed to be transported through space in a jelly-like medium called the ether. But the difficulty of constructing a coherent mathematical picture of the ether proved insuperable. Furthermore, the famed Michelson-Morley experiment showed fairly conclusively that the ether did not exist.

Relativity. Astronomical observations of double stars revolving around each other indicate that the velocity of light is not affected by the motion of its source. Einstein made this a fundamental assumption of Relativity—that the velocity of light in empty space is always the same, whatever the motion of the source or that of an observer. A corollary of this was that there could be no such thing as absolute time, that two events which are simultaneous to one observer may not be simultaneous to another.

When the idea of absolute time is abandoned, every body moving relative to another must have its own time specification as well as length, breadth, and thickness. Thus time becomes a fourth dimension added to the three dimensions of space. The consequences of the theory, when worked out mathematically, are that absolute motion, absolute mass and absolute dimensions must also be shelved. When a body is in motion relative to an observer, he would see (if he had instruments fine enough) that its length in the direction of motion is shortened, that its mass is increased. The increased mass must be due to energy of motion; therefore energy and mass are the same. Light, which is energy, must be influenced by gravitational fields. All these pieces of the Theory of Relativity fit into place as neatly as the pieces of a jigsaw puzzle. The completed puzzle is a coherent picture of the universe which has stood up under the test of numerous experiments.

The first experimental confirmation was the bending of starlight in the gravitational field of the sun, observed during a solar eclipse in 1919. Others are the “stretching” (increased wave length) of light from heavy stars, the conversion of mass into energy in the laboratory, the recoil of a body which emits light. Relativity also explains eccentricities in Mercury’s orbit, which had remained a mystery under Newtonian mechanics. Atom-smashers who build cyclotrons (machines in which atomic projectiles are whirled by electric and magnetic fields) take into careful consideration the Relativistic increase in mass of fast particles. In brief, Relativity has become an everyday tool of astronomers and physicists.

Quanta. Having traced the evolution of physics through Relativity, the co-authors close their volume with a discussion of the Quantum Theory. Max Planck provided the first experiments and Einstein the early theory which regards energy as released and received not in continuous flow but in separate little bundles called quanta. A quantum of light is called a photon. Einstein used early Quantum Theory to explain photoelectric action—the ability of photons to knock electrons out of metals.

In The Evolution of Physics, Drs. Einstein & Infeld admit that modern Quantum Theory has thrown a very powerful searchlight on the atom, but they are dissatisfied with it as a picture of reality. Quantum Theory makes use of old-fashioned absolute time, with three separate space dimensions. But each particle requires its own three space coordinates. So to describe two particles six dimensions are needed; a description of ten particles require’s 30 dimensions. That is too abstract for Dr. Einstein. He thinks four dimensions are enough.

Unity? The Quantum Theory is incapable of dealing with the large-scale cosmos. Relativity can treat individual particles only as “singularities” (i.e., anomalies) in the space-time field—a far feebler picture than that provided by Quantum Theory. Many years ago Einstein said he would devote the rest of his life to the research for a Unified Field Theory which would comprehend all natural phenomena. He knows that such a fantastically ambitious goal will never be reached by a straight frontal attack. He has been probing around it, looking for avenues of approach, circuitously groping toward unity. Nearly a decade ago he actually announced a Unified Field Theory, but discarded it when flaws were detected. Later he found a way to handle particles as bridges connecting two contiguous “sheets” of space. His associates now cough sadly behind their hands when the space-sheets are mentioned, and Einstein has not pursued the matter any further. Not yet, however, has he given any sign of abandoning his search for a Unified Field Theory.

Universe? At present, Einstein does not know whether the universe is finite or infinite. The Relativistic picture of the cosmos is a four-dimensional sphere—or, more exactly, a “hypersphere,” since an ordinary sphere can have only three dimensions. The hypersphere is curved, so it must close back on itself and therefore be finite—but only if the curvature is positive. It may be negative, that is, somewhat less curved than a straight line. Negative curvature, which in mathematics simply involves a minus sign, cannot of course be visualized; but if such is the shape of the hypersphere, the universe must be “open”—i.e., infinite. Some theorists have suggested that the universe may not be spherical but hyperbolic—closed at one end, open at the other. The erection of Caltech’s 200-inch telescope in California may possibly settle the question.

Peace. Meanwhile the man who is generally regarded as the world’s greatest living scientist lives placidly in a white frame house on Princeton’s Mercer Street. He chose it for two dimensions, the height of its ceilings and the length of its flower garden in the back. He lives there with Margot, his late wife’s daughter by a previous marriage, and his secretary, Fraulein Helen Dukas, who since Frau Einstein’s death last year has looked after his bank account, his clothes and other things which to him are equally trivial. In the morning he works at home with his assistant, Dr. Peter G. Bergmann, a member of the Institute for Advanced Study. In the afternoons he goes to his office in Fine Hall. In the evenings he goes to concerts whenever possible, once in a long while to the cinema.

The Albert Einstein of today is no longer the timid bewildered man who visited the U. S. in 1930. He has acquired considerable poise in public, is not so afraid of the world as he used to be, entertains frequently. He has learned that it is not necessary to associate with anyone whom he does not like and trust. His telephone number is not listed and the telephone company will not furnish it. He leads the kind of life he likes and the U. S. suits him very well.

An accounting of Frau Elsa Einstein’s estate filed last week in Trenton revealed that she left $52,689. Since she died intestate, only one-third will go to Widower Einstein, the rest to her daughter. This means nothing to Einstein. He has enough money for living expenses and wants no more. When he first joined the Institute, its officials asked him to name the salary he expected. His figure was so low that the officials had to raise it to preserve Institute standards. But if he is indifferent about his own money, Albert Einstein has a strict moral sense about other people’s. His associates were amused last week because he had put his foot down against too many free copies of The Evolution of Physics being scattered around Princeton. It did not seem fair to the publishers.

*Named for the late Henry Burchard Fine, famed Princeton mathematician.

†THE EVOLUTION OF PHYSICS—Simon & Schuster ($2.50).