The Invisible Century: Einstein, Freud and the Search for Hidden Universes

DEDICATION

Once again, for Meg Wolitzer, with love

Epigraph

Q: “Is the invisible visible?”

A: “Not to the eye.”

—from an 1896 interview with

Wilhelm Conrad Röntgen,

the discoverer of the X-ray

CONTENTS

Cover

Title Page

Dedication

Epigraph

Prologue

I. MIND OVER MATTER

One: More Things in Heaven

Two: More Things on Earth

Three: Going to Extremes

II. MATTER OVER MIND

Four: A Leap of Faith

Five: The Descent of a Man

III. THE TREMBLING OF THE DEWDROP

Six: A Discourse Concerning Two New Sciences

Notes

Bibliography

Index

Acknowledgments

About the Author

Other Book by

Copyright

About the Publisher

PROLOGUE

They met only once. During the New Year’s holiday season of 1927, Albert Einstein called on Sigmund Freud, who was staying at the home of one of his sons in Berlin. Einstein, at forty-seven, was the foremost living symbol of the physical sciences, while Freud, at seventy, was his equal in the social sciences, but the evening was hardly a meeting of the minds. When a friend wrote Einstein just a few weeks later suggesting that he allow himself to undergo psychoanalysis, Einstein answered, “I regret that I cannot accede to your request, because I should like very much to remain in the darkness of not having been analyzed.” Or, as Freud wrote to a friend regarding Einstein immediately after their meeting in Berlin, “He understands as much about psychology as I do about physics, so we had a very pleasant talk.”

Freud and Einstein shared a native language, German, but their respective professional vocabularies had long since diverged, to the point that they now seemed virtually irreconcilable. Even so, Freud and Einstein had more in common than they might have imagined. Many years earlier, at the beginning of their respective scientific investigations, they both had reached what would prove to be the same pivotal juncture. Each had been exploring one of the foremost problems in his field. Each had found himself confronting an obstacle that had defeated everyone else exploring the problem. In both their cases, this obstacle was the same: a lack of more evidence. Yet rather than retreat from this absence and look elsewhere or concede defeat and stop looking, Einstein and Freud had kept looking anyway.

Looking, after all, was what scientists did. It was what defined the scientific method. It was what had precipitated the Scientific Revolution, some three centuries earlier. In 1610, Galileo Galilei reported that upon looking through a new instrument into the celestial realm he saw forty stars in the Pleiades cluster where previously everyone else had seen only six, five hundred new stars in the constellation of Orion, “a congeries of innumerable stars” in another stretch of the night sky, and then, around Jupiter, moons. Beginning in 1674, Antonius von Leeuwenhoek reported that upon looking at terrestrial objects through another new instrument he saw “upwards of one million living creatures” in a drop of water, “animals” numbering more than “there were human beings in the united Netherlands” in the white matter on his gums, and then, in the plaque from the mouth of an old man who’d never cleaned his teeth, “an unbelievably great number of living animalcules, a-swimming more nimbly than any I had ever seen up to this time.”

Such discoveries were not without precedent. They came, in fact, at the end of the Age of Discovery. If an explorer of the seas could discover a New World, then why should an explorer of the heavens not discover new worlds? And if those same sea voyages proved that the Earth could house innumerable creatures previously unknown, then why not earth itself or water or flesh?

What was without precedent in the discoveries of Galileo and Leeuwenhoek, however, was the means by which they reached them. Between 1595 and 1609, spectacle makers in the Netherlands had fit combinations of lenses together in two new instruments that performed similar, though distinct, optical tricks. The combination of lenses in one instrument made distant objects appear nearer, the combination in the other made small objects appear larger; and for the first time in history investigators of nature had at their disposal tools that served as an extension of one of the five human senses. As much as the discoveries themselves, what revolutionized science over the course of the seventeenth century was a new means of discovery and what it signified: There is more to the universe than meets the naked eye.

Who knew? After all, these instruments might easily have revealed nothing beyond what we already knew to be there, and what we already knew to be there might easily have been all there was to know. The naked eye alone didn’t have to be inadequate as a means of investigating nature; the invention of these instruments didn’t have to open two new frontiers. But it was; and they did.

For thousands of years, the number of objects in the heavens had been fixed at six thousand or so. Now, there were … more. Since the Creation, or at least since the Flood, the number of kinds of creatures on Earth, however incalculable as a practical matter, had nonetheless been fixed. Now, there were … more. “There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy”: When Shakespeare wrote these words in 1598 or 1599, at the very cusp of the turn of the seventeenth century, he was referring to the understandable assumption among practitioners of what would soon become the old philosophy that much of what was as yet unknown must remain unknown forever, and for the next three hundred years the practitioners of what they themselves came to call the New Philosophy frequently cited it as the last time in history that someone could have written so confidently about civilization’s continuing ignorance of, and estrangement from, the universe.

Because now all you had to do was look. Through the telescope you could see farther than with the naked eye alone and, by seeing farther, discover new worlds without. Through the microscope you could see deeper than with the naked eye alone and, by seeing deeper, discover new worlds within. By seeing more than meets the naked eye and then seeing yet more, you could discover more.

How much more? It was a logical question for natural philosophers to ask themselves, and the search for an answer that ensued over the next three centuries was nothing if not logical: a systematic pursuit of the truths of nature to the outermost and innermost realms of the universe, until by the turn of the twentieth century the search had reached the very limits of human perception even with the aid of optical instruments, and investigators of nature had begun to wonder: What now? What if there was no more more?

Specifically: Was the great scientific program that had begun three centuries earlier coming to a close? Or would an increasingly fractional examination of the existing evidence continue to reward investigators with further truths?

Some researchers, however, unexpectedly found themselves confronting a third option. Pushing the twin frontiers of scientific research—the inner universe and the outer—they had arrived at an impasse. Then, they’d spanned it. They’d kept looking until they discovered an entirely new kind of scientific evidence: evidence that no manner of mere looking was going to reveal; evidence that lay beyond the realm of the visible; evidence that was, to all appearances, invisible.

The invisible had always been part of humanity’s interactions with nature. Attempting to explain otherwise inexplicable phenomena, the ancients had invented spirits, forms and gods. In the Western world during the medieval era, those various causes of mysterious effects had coalesced into the idea of one God. Even after the inception of the modern era and the inauguration of the scientific method, investigators working at the two extremes of the universe had resorted to two new forms of the invisible. When Isaac Newton reached the limits of his understanding of the outer universe, he had invoked the concept of gravity. When René Descartes reached the limits of his understanding of the inner universe, he had invoked the concept of consciousness.

But by the turn of the twentieth century the kind of invisibility that certain investigators were beginning to invoke was new. These were scientists for whom any appeal to the supernatural, superstitious, or metaphysical would have been anathema. But now, here it was: evidence that was invisible yet scientifically incontrovertible, to their minds, anyway.

Although Einstein and Freud didn’t initiate this second scientific revolution all by themselves, they did come to represent it and in large measure embody it. This is the story of how their respective investigations reached unprecedented realms, relativity and the unconscious; how their further pursuits led to the somewhat inadvertent creation of two new sciences, cosmology and psychoanalysis; and how in Einstein’s case, a new way of doing science has become the dominant methodology throughout the sciences, while in Freud’s case, an alternative way of doing science has become the dominant exception, the key to the very question of what qualifies an intellectual endeavor as a science. This is also the story of what cosmology and psychoanalysis have allowed us to explore: universes, without and within, as vast in comparison to the ones they replaced as those had been to the ones they replaced.

And in that regard Einstein and Freud’s is a story, just as Galileo and Leeuwenhoek’s was, of a revolution in thought. The difference between our vision of the universe and its nineteenth-century counterpart has turned out to be not a question of what had distinguished each previous era from the preceding one for nearly three hundred years: of seeing farther or deeper, of seeing more—of perspective, of how much we see. Instead, it is a question of seeing itself—of perception, of how we see. It is also, then, a question of thinking about seeing—of conception, of how we think about how we see. As much as any discovery, this is what has changed the way we try to make sense of our existence in the twenty-first century—the way we struggle to investigate our circumstances as sentient creatures in a particular setting: Who are these creatures? What is this setting? It is a new means of discovery—the significance of which, a hundred years later, we are still only beginning to comprehend: that there is more to the universe than we would ever find, if all we ever did was look.

ONE MORE THINGS IN HEAVEN

Look.

And so the boy looked. His father had something to show him. It was small and round like a miniature clock, the boy saw, but instead of two hands pointing outward from the center of the face it had one iron needle. As the boy continued to look, his father rotated the object. He turned it first one way, then the other, and as he did so the most amazing thing happened. No matter how the boy’s father moved the object, the needle continued pointing in the same direction—not the same direction relative to the rest of the device, as the boy might have expected, but the same direction relative to … something else. Something out there, outside the device, that the boy couldn’t see. The needle was shaking now. It trembled with the effort. Some six decades later, when Albert Einstein recalled this scene, he couldn’t remember whether he had been four or five at the time, but the lesson he’d learned that day he could still summon and summarize crisply: “Something deeply hidden had to be behind things.”

Some things deeply hidden, actually. As the boy grew older, he learned what a few of those deeply hidden somethings were: magnetism, the subject of his father’s demonstration on that memorable day; electricity; and the relationship between the two. He learned that the existence of a relationship between magnetism and electricity was still so recent a discovery that nobody yet understood how it worked, and then he learned that within his lifetime physicists had demonstrated that this relationship manifested itself to our eyes as light. And he learned that even though nobody yet understood how light worked, what everybody did know was that it traveled along the biggest deeply hidden something of them all, one that had so far eluded the greatest minds of the age but one that was now, as a prominent physicist of the era proclaimed, “all but in our grasp.”

That something was the ether. Einstein himself sought it, in a paper he wrote in 1895, “Über die Untersuchung des Ätherzustandes im magnetischen Felde” (“On the Investigation of the State of the Ether in a Magnetic Field”). This contribution to the literature, however, wasn’t so much original scholarship as a five-finger exercise that wound up pretty much reiterating current thinking, since Einstein was only sixteen at the time and, as he cautioned prospective readers (such as the doting uncle to whom he sent the paper), “I was completely lacking in materials that would have enabled me to delve into the subject more deeply than by merely meditating on it.”

Still, it was a start. Over the following decade, Einstein would graduate from self-consciously precocious adolescent, speculating beyond his abilities, to willfully arrogant student at the Swiss Polytechnic in Zurich, to humble (if not quite humbled) clerk at the Swiss Office for Intellectual Property in Bern, where he wound up in part because his professors had refused to write letters of recommendation for someone so dismissive of their authority. As Einstein reported in a letter in May 1901, “From what I have been told, I am not in the good books of any of my former teachers.” Yet even as a patent clerk, Einstein continued to seek the ether, for the same reason that physicists everywhere were seeking the ether. When electromagnetic waves of light departed from a star that was there and hadn’t yet arrived here, they had to be traveling along something. So: What was it? Find that something, as physicists understood, and maybe electricity and magnetism and the relationship between the two wouldn’t seem so deeply hidden after all.

Among the seekers of the ether, one was without equal: the Scottish physicist William Thomson, eventually Baron Kelvin of Largs. As one of the most prominent and illustrious physicists of the century, Lord Kelvin had made the pursuit of the ether the primary focus of his scientific investigations for literally the entire length of his long career. He’d first thought he found it on November 28, 1846, during his initial term as a professor of natural history at the University of Glasgow. He was mistaken. As he wrote a friend in 1896, on the occasion of the golden jubilee of his service to the university, a three-day celebration that attracted two thousand representatives of scientific societies and academies of higher learning from around the world, “I have not had a moment’s peace or happiness in respect to electromagnetic theory since Nov. 28, 1846.”

Part of the problem with the ether was how to picture it. “I never satisfy myself unless I can make a mechanical model of a thing,” Kelvin once told a group of students. “If I can make a mechanical model, I can understand it.” In one such demonstration that was a perennial favorite of his students, he would draw geometrical shapes on a piece of india rubber, stretch the rubber across the ten-inch mouth of a long brass funnel, and, having hung the funnel upside down over a tub, direct water from a supply pipe into the thin tube at the top. As the water collected in the mouth of the funnel, the india rubber bulged, and it drooped, and it gradually assumed the shape of a globule. Soon the blob had expanded to a width nearly double the diameter of the mouth from which it appeared to be emerging, and just when the rubber seemed unable to stretch any thinner, it did anyway. All the while Kelvin continued to lecture, calmly commenting on the subject of surface tension as well as on the transformations the simple Euclidean shapes on the rubber were now undergoing. Then, at precisely the moment Kelvin calculated that neither india rubber nor the ten benches of physics students could endure any greater tension, he would raise his pointer, poke the gelatinous mass hanging before him, and, turning to the class, announce, “The trembling of the dewdrop, gentlemen!”

The trembling of the dewdrop, the angling of the gas molecule, the orbiting of a planet: the least matter in the universe to the greatest, and all operating according to the same unifying laws. Here was the whole of modern science, in one easy lesson. More than two hundred years earlier, René Descartes had expressed the philosophical hope that a full description of the material universe would require nothing but matter and motion, and several decades after that Isaac Newton had expressed the physical principles that described the motion of matter. The rest, in a way, had been a process of simply filling in the blanks—plugging measurements of matter into equations for motions, and watching the universe tumble out piecemeal yet unmistakably all of a single great mechanistic piece. The lecture hall where for half a century Kelvin demonstrated his models was a monument of sorts to this vision: the triple-spiral spring vibrator he’d hung from one end of the blackboard; the thirty-foot pendulum, consisting of a steel wire and a twelve-pound cannonball, that he’d suspended from the apex of the dome roof; two clocks, those universal symbols of the workings of the universe. Matter and motion, motion and matter, one acting upon the other; causes leading inexorably to effects that, by dint of more and more rigorous and precise examination, were equally predictable and verifiable to whatever degree of accuracy anyone might care to name: Here was a cosmos complete, almost.

The exception was the ether. When numerous experiments in the early nineteenth century began showing that light travels in waves, physicists naturally tried to describe a substance capable of carrying those waves. The consensus: an absolutely incompressible, or elastic, solid. For Cambridge physicist George Gabriel Stokes, that description suggested a combination of glue and water that would act as a conduit for rapid vibrations of waves and also allow the passage of slowly moving bodies. For British physicist Charles Wheatstone, it meant white beads, which he used in his Wheatstone wave machine of the early 1840s—a visual aid that vividly demonstrated how ether particles might move at right angles to a wave coursing through their midst and an inspiration for numerous similar teaching aids of the era.

And for Kelvin, “the nearest analogy I can give you,” as he once said during a lecture, “is this jelly which you see.” On other occasions, he might begin his demonstration with Scotch shoemakers’ wax. If he shaped the wax into a tuning fork or bell and struck it, a sound emanated. Then he would take that same sound-wave-conveying wax and suspend it in a glass jar filled with water. If he first placed corks under the substance, then laid bullets across the top of it, in time the positions of the objects would reverse themselves. The bullets would sink through the wax to the bottom while the corks would pop out the top. “The application of this to the luminiferous ether is immediate,” he concluded: a substance rigid enough to conduct waves traveling at fixed speeds in straight lines from one end of the universe to the other, if need be, yet porous enough not to block the passage of bullets, corks, or even—by the same application of scale that rendered minuscule dewdrops and giant rubber globules analogous—planets.

Not to block—but surely to impede? Surely at least to slow the passage of a planet? An elastic solid occupying all of space would have to present a degree of resistance to a (in the parlance of the day) “ponderable body” such as Earth. But to what degree precisely? In an effort to determine the exact extent of the luminiferous (or light-bearing) ether’s drag on Earth, the American physicist Albert A. Michelson devised an experiment that he first conducted in Berlin in 1881. His idea was to send two beams of light along paths at 90-degree angles to each other. Presumably the beam following one path would be fighting against the current as Earth plowed through the ether, while the beam on the other path would be swimming with the current. Michelson designed an ingenious instrument, which he called an interferometer, that he hoped would allow him to make measurements that, through a series of calculations, would determine the velocity of the Earth through the ether. The Berlin reading, however, suffered from the vibrations of the horse cabs passing outside the Physical Institute. So he moved his apparatus to the relative isolation of the Astrophysical Observatory in Potsdam, where he repeated the experiment. The reading, to his surprise, indicated nothing.

Which was impossible. An interaction between a massive planet and even the most elastic of solids surely couldn’t pass undetected or remain undetectable. “One thing we are sure of,” Kelvin told an audience in Philadelphia three years later, while on his way to lecture at Johns Hopkins University in Baltimore, “and that is the reality and substantiality of the luminiferous ether.” And if experiments of unprecedented refinement and sophistication failed to detect it, there was only one reasonable alternative course of action. As Kelvin wrote in his preface to the published volume of those Baltimore Lectures, “It is to be hoped that farther experiments will be made.”

They were. In 1887 Michelson tried again, this time with the help of the chemist Edward W. Morley. Together they constructed an interferometer far more elaborate and sensitive than the ones Michelson had used in Germany, secured it in an essentially tremor-free basement at the Case School of Applied Science in Cleveland, and set it floating on a bed of mercury for, literally, good measure. Michelson had in mind a specific number for the wavelength displacement he expected the ether would produce, and he further decided that a reading 10 percent of that number would conclusively indicate a null result. What he got was a reading of 5 percent of the displacement he thought the ether might produce—a blip attributable to observational error, if anything. Michelson found himself forced to reach the same conclusion he’d previously reported: “that the luminiferous ether is entirely unaffected by the motion of the matter which it permeates.”

“I cannot see any flaw,” said Kelvin of this experiment, in a lecture he delivered in the summer of 1900. “But a possibility of escaping from the conclusion which it seemed to prove may be found in a brilliant suggestion made independently by FitzGerald, and by Lorentz of Leiden.” Kelvin was referring to the physicists George Francis FitzGerald of Dublin, who had submitted a brief conjecture regarding the ether to the American journal Science in 1889, and Hendrik Antoon Lorentz, who in an 1892 paper and then in an 1895 book-length treatise had elaborated an entire argument along nearly identical lines: The ether compresses the molecules of the interferometer—as well as those of the Earth, for that matter—to the exact degree necessary to render a null result. In which case, the two beams of light in Cleveland actually did travel at two separate speeds, as the measurements of their multiple-mirror-deflected journeys would have shown, if only the machinery hadn’t contracted just enough to make up the difference. “Thus,” Lorentz concluded, “one would have to imagine that the motion of a solid body (such as a brass rod or the stone disc employed in the later experiments) through the resting ether exerts upon the dimensions of that body an influence which varies according to the orientation of the body with respect to the direction of motion.”