For many of us, the name "Einstein" calls to mind two things: genius, and unruly white hair. (Unruly white hair now almost evokes "genius" on its own.) But behind the iconic name and image, of course, are the man himself and his revolutionary work. This year marks an anniversary for both: fifty years ago, on April 18, 1955, Einstein died in Princeton, New Jersey, where he had spent the final two decades of his life. And one hundred years ago, in 1905, the then-twenty-six-year-old Einstein published five papers in the prestigious German science journal Annals of Physics. One of those papers, which explained how light can behave as both a particle and a wave, earned him a Nobel Prize. Two others explained the nature and motion of atoms and molecules. Yet another introduced the world's most famous equation, E=mc2.
But it was a fifth paper, describing his theory of relativity, that made him an international celebrity, a synonym for brilliance. His theory—which suggested, among other things, that it was possible for space-traveling twins to age at different rates—captured the imagination of non-scientists in a way his other work hadn't, because it upended our very concepts of space and time.
One recent Atlantic article, a review by physicist Alan Lightman of a republication of Einstein's 1905 papers, puts the nature and dramatic scope of Einstein's accomplishments that year into perspective. Lightman points out that in 1905, many scientists were convinced that the world's mysteries had already been solved. Since the seventeenth century, for example, Newton's laws of motion had successfully accounted for everything from "the bouncing of balls to the orbits of planets." And more recently, physicists had published detailed theories on the nature of light and heat.
But there were cracks in the façade. Physicists had long believed that time and space were of an absolute nature. Five seconds meant five seconds, no matter who measured it or where. And space was thought to be filled with a colorless substance called ether—a fixed reference against which all measurements could be made and through which light waves traveled. (It was assumed that light, like sound, could only propagate through a medium.) The trouble was, hard as they tried, physicists couldn't find this so-called ether. And the speed of light, which was thought to vary depending on the speed of the object emitting the light, always turned out to measure the same.
Einstein's paper on relativity, published in June of 1905, was modestly titled "On the Electrodynamics of Moving Bodies," but it was universe-shattering. He eliminated the untraceable ether (calling it "superfluous"), and said that space and time measurements are not absolute, as previously thought, but depend on who is doing the measuring. Without absolute space and time, Einstein determined there is only one fixed entity: the speed of light. If it doesn't change in experiments, he asked, why don't we assume it never changes? From these postulates Einstein derived his special theory of relativity. (A decade later he published an expanded version—the "general theory of relativity"—which took gravity into account.)
Lightman suggests that to a significant extent, it was Einstein's attitude of open-mindedness that enabled him to conceive of such revolutionary ideas. "Einstein regarded all concepts as subject to revision based on experiment," Lightman writes. "There were no sacred cows—everything was open to question. A few pages into his paper he began questioning the meaning of time with the profound innocence of a child."
At the time Einstein's groundbreaking work first became known, many laypeople vaguely understood that he had wrought some kind of momentous transformation in the way science made sense of the world, but the specifics of his theories seemed utterly confusing and counterintuitive. The first Atlantic article about Einstein and his ideas appeared in October of 1920, four years after the publication of his general theory of relativity. Called "In Defense of Science," the short, unsigned piece offered a humorous take on how Einstein's strange theories about space and time might apply in the real world.
Do Bolsheviki attempt to agitate a peaceful community? Let our velocity be —dv(An), and presto! these uncomfortable characters won't have been born for a century and a half yet; and we may confidently leave their treatment to posterity. Do some of our enthusiastic officials suppress certain of the rights of man? Let us apply the formula Xdp = Y2, and whoof! they find themselves in the seventeenth century, where they may hunt the fearsome witch and wily Quaker to their hearts' content. Does my revered wife's uncle read aloud items from the Daily Transcript? Q = Pz, and lo! it's four o'clock, and the paper hasn't yet arrived.
"This is Truth," the anonymous author wrote, referring to Einstein's new theories—but a truth understood only by a "benevolent intellectual aristocracy" who can perform the necessary mental acrobatics to bend the laws of the universe to its will. In tones of mock solemnity, the author proclaimed the significance of this development:
And now, little children and reverend theologians, gather about and let us consider the situation. Do you realize what is really meant by Einstein's Idea? Why, bless your orthodox hearts, this is no less than a scientific Doctrine of Free Will! ... mind has assumed its dominion over matter; Man has come into his kingdom.
Less than a year later, Alexander McAdie, a meteorology professor at Harvard, published "Relativity and the Absurdities of Alice" (June 1921), which touched on many of Einstein's discoveries, including both special and general relativity. McAdie described ways in which Einstein's work had helped turned fantasy into reality. "Alice in dreamland underwent remarkable transformations," he wrote, "but the physicists are changing substances and analyzing structure of atoms in a way that makes Lewis Carroll's wildest flight of fancy seem humdrum."
Today any budding physicist can tell you without cracking a smile that 'a conception of the physical world in its objective four-dimensional scheme would merely be an abridged statement of the correspondence of the subjective time-space experiences in the realm of the various senses, and nothing more.' Remember, it is not the Hatter speaking now, but the average serious-minded young man or woman at college, who has been taking notes of the lectures on Relativity given by the Professor of Mathematical Physics.
By the time McAdie wrote his article, Einstein's relativity theory had been put to practical tests by astronomers and had succeeded. For example, general relativity had been able to account for a discrepancy in Mercury's placement in its orbit when closest to the sun. Discoveries like this one were a spectacular blow to pre-existing theories of physics, and helped to make Einstein a household name.