When I was a 12-year-old living in Chicago, my school class went on a field trip to a museum, and at one point our teacher started talking about how great Albert Einstein was. We were all impressed. Then I remember Melissa Gorman, who was quite attentive, asking our teacher what exactly it was that Einstein invented.
The teacher had no idea.
Einstein loved to tinker with precision gadgets and was granted more than two dozen patents for various devices, including a gyrocompass, a hearing aid, and an electromagnetic pump. In 1930 he and Leo Szilard, a Hungarian physicist, invented a cooling mechanism for a refrigerator that was bought by AB Electrolux but never manufactured. Andy Delano, a mechanical engineer, built this prototype of Einstein and Szilard’s design as part of his doctoral thesis at the Georgia Institute of Technology.
I was shocked, and not just because I still believed that teachers knew everything. I found it hard to imagine that someone could be so famous without having invented something, or pitched in a World Series, or in some other way actually done something concrete. I knew that Einstein was smart: Several parents in my neighborhood had a picture of him taped up on their refrigerator. A lot of Jewish families in the 1950s and 1960s had photos of Einstein hanging in the house. In those photos it was always clear that Einstein was thinking deeply and perhaps even that he was sad. I wondered, What exactly had he done?
When I was an undergraduate at the University of Chicago, I learned more about Einstein’s great theories and read some of his comments about the impersonality of what he’d achieved—his feeling that although he had been granted the opportunity to see something of how our universe was built, his own role would in time be forgotten. As a teenager, I found Einstein’s acknowledgment of his own mortality hard to accept. But years later when I was teaching at Oxford, I had an epiphany while watching the rowing teams out on the river early one morning. I realized that as one generation of undergraduates took over from the next, they were beginning to blur in my mind. I was startled, and at the same moment pleased, by the thought that my contributions to their education would also blur in their minds, just as on a far higher level we have begun to take for granted Einstein’s role in expanding our understanding of the universe.
Decades after that childhood museum field trip roused my curiosity about Einstein and his work, I was surprised to discover that he did invent something—actually quite a few things, including a refrigerator with no moving parts. Over the years I had also come to recognize that Einstein’s theories are so far-reaching that he literally helped invent our modern world.
Spend the better part of a day pondering the technological marvels that are now an integral part of ordinary life and you’ll encounter Einstein wherever you turn.
OH, WHAT A BEAUTIFUL MORNING
As you head to the kitchen for your coffee, pause for a moment and contemplate the smoke detector operating silently overhead, a small quantity of the radioactive substance americium-241 pouring out energy to create a thin beam of charged particles. Any smoke from a fire would interfere with that beam, setting off an alarm. The nucleus of the americium atom is unstable. When it breaks apart, mass seems to disappear, for the fragments weigh less than the original nucleus. But it’s not truly lost, and we know that because of Einstein.
In one of the seminal papers Einstein published in 1905, he destroyed a central belief of 19th-century science: the notion that there was a domain of energy and a domain of mass, and ne’er the twain shall meet. Instead, he showed that any mass whatsoever could be considered a very compressed form of energy. To find out exactly how much energy can pour out from a given amount of mass, one measures the disappearing mass and simply multiplies it by c squared, the speed of light multiplied by itself—a truly enormous number.
Chemists and engineers use calculations based on Einstein’s famous E = mc2 equation to design even our humble smoke detectors. But it goes further. Medical specialists use similar calculations when giving cancer patients radiation treatments or when they need to estimate how much damage X-rays might produce in DNA. And, of course, when Manhattan Project physicists were computing blast powers for the atomic bombs to be dropped over Japan, they used Einstein’s E = mc2.
Even beyond medical and military technology, our world is suffused by Einstein’s insights into the relationship between mass and energy. Look up at the sky from your kitchen window and the sun you see is actually a great pumping station, converting millions of tons of mass into billowing energy at a rate prodigious enough to light up our planet. Go for a morning jog over hilly terrain and the very landscape is likely to be the result of tectonic plate movements, powered deep under our feet in great part by radioactive decays like that of the humble americium writ large.
ON THE ROAD AGAIN
The Global Positioning System satellites that guide us—on the highways we drive along to work as well as in the passenger jets overhead and on boats at sea—depend on more of Einstein’s insights. In another of his 1905 papers, Einstein showed that the conventional definition of time “is indeed sufficient if a time is to be defined exclusively for the place at which [a] watch is located, but the definition is no longer satisfactory when series of events occurring at different locations have to be linked temporally.” GPS satellites are equipped with precision atomic clocks, but the GPS signals beamed down to us would veer well over a mile out of kilter each day unless they were adjusted for the relative difference in time measured by atomic clocks on the ground.
The roads under our wheels also depend on Einstein’s work. Einstein had failed to get an academic job after he graduated from his technical university in Switzerland, not, as myth would have it, because he was a poor student—he actually got good grades—but because he couldn’t resist telling his professors what he thought about their teaching dry, out-of-date facts from the books, rather than trying to explore the implications of the latest research. This is how he got stuck in his patent office job while he wrote his Ph.D. thesis.
The thesis introduced ingenious ways of measuring molecules in diverse solutions, and that became fundamental to the chemistry of colloids. When cement engineers fabricate the roads we drive on, they’re using Einstein’s results.