London, 1930, autumn, night. The great and the good were gathering in their natural habitat, the Savoy Hotel. The grand ballroom was a sea of formal evening wear: white ties, tails, and elegant gowns. Baron Rothschild hosted the event, a charity dinner to benefit the tide of Eastern European Jewish refugees, already at risk from an increasingly hostile Germany. George Bernard Shaw was the master of ceremonies, although he had argued beforehand that he was insufficiently distinguished to introduce the night’s guest of honor. That duty, Shaw said, should rightly go to Britain’s prime minister, Ramsay MacDonald, but the P.M. was unavailable. In any event, the playwright gave a brilliant performance, the best brief explanation on record of why that night’s honoree remains the modern archetype of genius.
“Ptolemy,” Shaw said, “made a universe which lasted two thousand years. Newton made a universe which lasted for three hundred years. Einstein has made a universe, which I suppose you want me to say will never stop, but I don’t know how long it will last.”
Einstein laughed out loud, and the audience laughed with him. As was so often the case, Shaw’s wit had captured an essential truth. The latter two in his litany of greats had created scientific accounts that encompassed the entire cosmos. And Einstein himself was, Shaw concluded, “the greatest of our contemporaries.”
In response, Einstein tried to turn back the hype, gently chiding Shaw for praising his “mythical namesake, who makes life so difficult for me.” (Years later Einstein wrote that “the contrast between the popular estimate of my powers and achievements and the reality is simply grotesque.”)
Today there is no doubt that Shaw was right. Einstein is by broad consensus the greatest scientist of the modern era. The universe he made has lasted 100 years—so far. Whether or not someone else will come along someday and define another universe remains an open question, of course. But the passage of time allows us to bring what made Einstein such a genius into sharper focus—and to guess what it might take to produce another.
Another Einstein? A century ago, the question would have been, “Will there ever be another Newton?” The answer would surely have been, “Not likely.”
In 1904 the notion that a young Swiss patent examiner might be the next Isaac Newton would have been more than ridiculous; it would have been unthinkable, a joke so far-fetched it would have had no punch line. The 25-year-old Einstein was enjoying a perfectly good life—more or less the one he had sought as a somewhat rebellious university student. Valued at the patent office for his technical training, he was seemingly set for what would be the pleasant petit bourgeois life of a Swiss civil servant. He had published a handful of brief papers in a physics journal, none of them bad, none of them noteworthy. He appeared to be a bright amateur, a weekend physicist. In other words, he was no Newton. But that was no shame, for no one was.
Then, within a few months, everything changed. Over the first half of 1905, Einstein’s miracle year, he published major papers explaining Brownian motion and the reality of atoms, creating the quantum theory of light, and most famously, inventing the special theory of relativity. The famous equation E=mc2 came in an additional paper, a three-page note that appeared almost as an afterthought. Einstein was no longer an amateur. He would never again be unknown.
That’s not to say he ranked in the same league as Newton, not then. He would not extend relativity to encompass the entire universe for another decade—but already the miracle year reveals the critical common attribute the two men shared.
It wasn’t raw horsepower, surprisingly, and not pure ability. Newton’s mathematical skills were extraordinary. Einstein, although not a bad mathematician (for a physicist), never came close to Newton’s originality there. Nor was it personality. Beyond science, the two could not have been more different from each other. Newton was a virgin, a religiously driven obsessive who flirted with madness. Einstein was a relaxed, sensual man who found pleasure pleasurable and religious passion a waste of time. Still, the two men did share one critical skill: a profound gift for discovering the underlying simplicity of apparently intractably complicated problems.
The late Nobel-winning physicist Richard Feynman captured part of what made Newton different in a lecture about the proof that the planets must travel in elliptical orbits. Newton had achieved and Feynman re-created what he called an “elementary demonstration” of this proof. The word elementary, Feynman said, did not mean easy. Rather, it means that “very little is required to know ahead of time in order to understand it, except to have an infinite amount of intelligence.” It’s extraordinarily difficult, in other words, to abstract a problem to its simplest essence, the form in which it can be solved—and it was in this task that Einstein as well as Newton excelled beyond all peers.
Einstein used what were called thought experiments to achieve his radical simplifications. Special relativity emerged from a line of thinking that began when Einstein asked what would happen if he could chase a ray of light. His breakthrough realization of the relativity of time turned on a series of mental cartoons featuring trains and clocks. General relativity, his theory of gravity, started off as a meditation on what happens when a man falls off a roof.
What happens? He goes splat! of course—and that’s where most of us, including most scientists, would leave the image. Einstein didn’t. In what he called “the happiest thought of my life,” he focused on the time before the luckless roofer hit the ground. Almost immediately Einstein realized that as he fell, the man would not feel his own weight. To Einstein, that meant that the experience of free fall in a gravitational field and that of floating in a gravity-free region of space were the same, equivalent. That formed the basis of what he called the equivalence principle, which serves as the foundation of the general theory of relativity.
All of Einstein’s thought experiments turned on such simple, elementary ideas. The measure of Einstein’s genius is that he could both invent such absolutely stripped-down images and then go further, with seemingly infinite intelligence, to work out what those pictures actually meant.
A gift for simplification is not enough, certainly. Einstein, no monk in his personal life, displayed an almost monastic drive in his scientific career, a capacity for concentration that awed contemporaries. Abraham Pais, Einstein’s friend and biographer, commented that most physicists will stick with a problem for a year or two at the most. If they can’t solve it then, they give up and move on. Not Einstein. He credited his own success to his good nose for a problem and “the stubbornness of a mule.” He thought about special relativity for a decade, gravity for eight years, the quantum theory for almost all his professional life. On the day before he died, Einstein called for paper and began to calculate, working on his ideal of unification. He knew he was dying. He knew he would not be able to complete the calculation. He did it anyway. The problem still mattered, and he still cared.
So perhaps there was little more to Einstein’s genius than a version of the old Shaker virtue—“’tis a gift to be simple” as the song runs—combined with his own remarkable stamina and dedication.
Yet if insight and hard work were all it took to propel him, there would be no doubt that we would see another Einstein. But that leaves out a crucial term in the equation. Among other things, Einstein was a profoundly lucky man, in the same way that Newton had been fortunate. The 18th century mathematician Joseph-Louis Lagrange complained that there was only one universe and Newton had already uncovered its laws—a truth that at least partly explains why it took more than 200 years for a true rival to Newton to emerge. When Einstein appeared on the physics scene, it was at the very moment that his style of inquiry, his particular brilliance, faced the kinds of mysteries that he (and at that time, perhaps only he) could solve. The true measure of his genius in this light is the fact that he so precisely identified such problems—especially the problem of gravity, his general theory—at the time when the questions were ripe and his powers matched the task.
Einstein’s story demonstrates that such talents alone are still not enough. Some problems defy genius fixed in a particular era, a moment in historical time. Einstein achieved his great work in a 20-year span from 1905 to 1925. That in itself is remarkable, a measure of his exalted status, for most physicists, even the great ones, don’t produce top quality work for nearly that long. But not even Einstein could defy the ticking clock forever. From 1925 until his death in 1955—more than half his professional years—he devoted himself to an ultimately futile attempt to subsume relativity and quantum theory under a more general unified theory.
There are plenty of reasons why that vast generalization escaped Einstein. One was that he could not attack this new problem with the same techniques, the same style, that he had brought to bear on the earlier questions. The problems of quantum mechanics did not yield to the kind of infinitely intelligent simple arguments that marked his best work. Common sense was no guide—as Einstein himself acknowledged in a cowritten paper, complaining that “no reasonable definition of reality could be expected to permit” the irreducible absurdity of the quantum world. Absent his usual guides, Einstein launched himself on a kind of mathematical fishing expedition, seeking some body of increasingly exotic equations that might give him a hint, might help him find some way of expressing the physical ideas he wanted to believe in.
It was shocking, to some a tragic reversal, to see the great artist of the thought experiment give up on those visions of the real. Yet Einstein had no choice. He knew as well as anyone that the quantum world could not be captured in his pretty pictures, so he grabbed at whatever he could in his search for the next, grander theory. In a practical sense, he failed, producing almost nothing of scientific significance during the last three decades of his working life.
He didn’t seem to care. He asserted rather grandly that physicists generations hence would value his efforts to look for unification more than his contemporaries did—even if he never succeeded. He was right.
We have yet to see another Einstein. Not that there aren’t contenders, thinkers who see themselves as Einstein’s heirs. Theoretical physicists working in the general area of string theory are chasing his ultimate ambition, attempting to capture both quantum mechanics and relativity in a broader, more fundamental final theory. To those with the mathematical ability to grasp them, these theories provide visions of exquisite beauty, and they seem to be consistent with current observations. The creation of a single theory out of the current mass of ideas would meet the Shaw standard: The one or many who forged it would have made their universe, the one that would conquer Einstein’s.
Even so, it seems unlikely that the field will produce another Einstein in the sense of a broadly recognized emblem of genius. The sheer complexity of the models being explored confines almost all practitioners to parts of the problem. The final theory, should it ever emerge, seems certain to be the work of many minds. Contrast that with the cometlike blaze Einstein traced across the physics scene. There was no collaboration, no reliance on the work of others. It is still astonishing that Einstein’s special relativity paper contains no footnotes, no acknowledgement of prior work—as much for the chutzpah involved as for the bald fact of Einstein’s originality. General relativity was an almost equally solo triumph.
Since then, few, if any, significant breakthroughs of the 20th century have taken place in such near-perfect vacuums. Heisenberg and Schrödinger were first among equals when it came to quantum mechanics—but the quantum revolution as a whole was driven by an extraordinary group of physicists. Similarly, most accounts of string theory give Edward Witten pride of place, but if the field does finally deliver on its ambition of an ultimate explanation of physical reality, that epiphany will most likely be the work of dozens of contributors.
More deeply, beginning with the quantum revolution, physics has come to dwell at such a deep remove from everyday experience that it’s hard to say whether most of us would be able to recognize an Einstein-like accomplishment should it occur. Einstein became the symbol of greatest human accomplishment for a generation just emerged from the devastation of World War I, not just because he was brilliant but because what he did resonated far beyond the few hundred people who genuinely understood it on first reading. The image, even the sound of the word relativity connected at the gut level, not just to writers and artists but to everyone. When Einstein first came to New York in 1921, thousands lined the street for a motorcade. A decade later when he arrived in Los Angeles, cheerleaders from a local high school lined the pier, chanting “Einstein, Einstein! Rah! Rah!”
Try to imagine any theoretician today getting such a response. It’s impossible. The emotional connection between the physicist’s conception of reality and the popular imagination has weakened greatly since Einstein. People are still interested, certainly. There are best sellers every year providing the latest news from the frontier. But the new ideas, no matter how beautiful, no matter how powerful, do not offer the same kind of metaphoric possibility, the same sense of immediacy. Increasingly concerned with the ridiculously small, the unimaginably large, with extremes of time and space, the public face of physics is thrilling, perhaps terrifying. In the end, however, 11-dimensional strings do not lend themselves obviously to genuinely satisfying modern myths.
Seen through this lens, Einstein becomes a twice-lucky genius, fortunate first in the match between his talents and the specific problems at hand—and then blessed again to dominate at perhaps the last moment that a single mind could hope to tackle so much of physics by itself. That places Einstein at or near the end of a long and potent lineage. Since Newton, through Einstein, and for a few decades after, physicists were seen as the high priests of science, the ones with the purest connection to the underlying reality in which we live. A playwright like Shaw could say and believe that Einstein’s discoveries formed a new revelation, a kind of scripture. The notion rang true then. If it does not now, it is because the cutting edge of physics has left everyday reality so far behind.
So if there is to be another Einstein, then we should probably look for the kind of breakthroughs that might truly rock our sense of ourselves—and that may not come from physics anymore. Biology has already seen its Newton: Charles Darwin. It hasn’t yet found its Einstein, in the sense of a single figure who transforms both scientific ideas and popular imagination. Someone like Francis Crick comes close. Crick, after all, solved with James Watson the fundamental hardware problem in biology—how the DNA molecule works to store biological information—and then went on to make fundamental contributions to the software question, how that information gets coded and transmitted from generation to generation. Ultimately, Crick’s role in the molecular biological revolution is more akin to that of the top quantum theorists—he, too, is first among equals in a much larger community.
The next discoveries that will transform the way the rest of us think about ourselves seem much more likely to come from the study of how life works than from physics. The people who will solve the riddles of the brain, what consciousness is, how life first blossomed from inert, lifeless matter—they are hunting the big game now, the kind of problems that turn discoverers into heroes, into legends.
What defined Einstein, what made his apotheosis possible, was the grand ambition that enabled him to turn his extraordinary talents to the largest mysteries available. Ultimately, it’s impossible to predict when or if a similar nexus of personal brilliance, public reaction, and historic context will produce his like again. But two things are certain. In the world of science, there is never any shortage of ambition. And our ignorance of our place in the cosmos remains vast.