by Sam Kean
In the 1890s, Marie and Pierre Curie began perhaps the most fruitful collaboration in science history. Radioactivity was the brilliant new field of the day, and Marie’s work on uranium, the heaviest natural element, provided a crucial early insight: its chemistry was separate from its physics. Atom for atom, pure uranium emitted just as many radioactive rays as uranium in minerals because the electron bonds between a uranium atom and the atoms surrounding it (its chemistry) did not affect if or when its nucleus went radioactive (its physics). Scientists no longer had to examine millions of chemicals and tediously measure the radioactivity of each (as they must do to figure out melting points, for instance). They needed to study only the ninety-some elements on the periodic table. This vastly simplified the field, clearing away the distracting cobwebs and revealing the wooden beam holding up the edifice. The Curies shared the 1903 Nobel Prize in Physics for making this discovery.
During this time, life in Paris satisfied Marie, and she had a daughter, Irène, in 1897. But she never stopped viewing herself as Polish. Indeed, Curie was an early example of a species whose population exploded during the twentieth century—the refugee scientist. Like any human activity, science has always been filled with politics—with backbiting, jealousy, and petty gambits. Any look at the politics of science wouldn’t be complete without examples of those. But the twentieth century provides the best (i.e., the most appalling) historical examples of how the sweep of empires can also warp science. Politics marred the careers of probably the two greatest women scientists ever, and even purely scientific efforts to rework the periodic table opened rifts between chemists and physicists. More than anything, politics proved the folly of scientists burying their heads in lab work and hoping the world around them figured out its problems as tidily as they did their equations.
Not long after her Nobel Prize, Curie made another fundamental discovery. After running experiments to purify uranium, she noticed, curiously, that the leftover “waste” she normally discarded was three hundred times more radioactive than uranium. Hopeful that the waste contained an unknown element, she and her husband rented a shed once used to dissect corpses and began boiling down thousands of pounds of pitchblende, a uranium ore, in a cauldron and stirring it with “an iron rod almost as big as myself,” she reported, just to get enough grams of the residue to study properly. It took years of oppressively tedious work, but the labor culminated in two new elements—and was consummated with, since they were elements far, far more radioactive than anything known before, another Nobel Prize in 1911, this one in chemistry.
It may seem odd that the same basic work was recognized in different prize categories, but back then the distinction between fields in atomic science wasn’t as clear as it is today. Many early winners in both chemistry and physics won for work related to the periodic table, since scientists were still sorting the table out. (Only by the time Glenn Seaborg and his crew created element ninety-six and named it curium in Marie’s honor was the work considered firmly chemistry.) Nevertheless, no one but Marie Curie emerged from that early era with more than one Nobel.
As discoverers of the new elements, the Curies earned the right to name them. To capitalize on the sensation these strange radioactive metals caused (not least because one of the discoverers was a woman), Marie called the first element they isolated polonium—from the Latin for Poland, Polonia—after her nonexistent homeland. No element had been named for a political cause before, and Marie assumed that her daring choice would command worldwide attention and invigorate the Polish struggle for independence. Not quite. The public blinked and yawned, then gorged itself on the salacious details of Marie’s personal life instead.
First, tragically, a street carriage ran over and killed Pierre* in 1906 (which is why he didn’t share the second Nobel Prize; only living people are eligible for the prize). A few years later, in a country still seething over the Dreyfus Affair (when the French army fabricated evidence of spying against a Jewish officer named Dreyfus and convicted him of treason), the prestigious French Academy of Sciences rejected Marie for admission for being a woman (which was true) and a suspected Jew (which wasn’t). Soon after, she and Paul Langevin, her scientific colleague—and, it turned out, lover—attended a conference in Brussels together. Miffed at their holiday, Mrs. Langevin sent Paul and Marie’s love letters to a scurrilous newspaper, which published all the juicy bits. A humiliated Langevin ended up fighting pistol duels to salvage Curie’s honor, though no one was shot. The only casualty resulted when Mrs. Langevin KO’d Paul with a chair.
The Langevin scandal broke in 1911, and the Swedish Academy of Sciences debated nixing Curie’s nomination for her second Nobel Prize, fearing the political fallout of attaching itself to her. It decided it couldn’t in good scientific conscience do that, but it did ask her not to attend the ceremony in her honor. She flauntingly showed up anyway. (Marie had a habit of flouting convention. Once, while visiting an eminent male scientist’s home, she ushered him and a second man into a dark closet to show off a vial of a radioactive metal that glowed in the dark. Just as their eyes adjusted, a curt knock interrupted them. One of the men’s wives was aware of Curie’s femme fatale reputation and thought they were taking a little long in there.)
Marie found a slight reprieve from her rocky personal life* when the cataclysm of World War I and the breakup of European empires resurrected Poland, which enjoyed its first taste of independence in centuries. But naming her first element after Poland contributed nothing to the effort. In fact, it turned out to have been a rash decision. As a metal, polonium is useless. It decays so quickly it might have been a mocking metaphor for Poland itself. And with the demise of Latin, its name calls to mind not Polonia but Polonius, the doddering fool from Hamlet. Worse, the second element, radium, glows a translucent green and soon appeared in consumer products worldwide. People even drank radium-infused water from radium-lined crocks called Revigators as a health tonic. (A competing company, Radithor, sold individual, pre-seeped bottles of radium and thorium water.)* In all, radium overshadowed its brother and caused exactly the sensation Curie had hoped for with polonium. Moreover, polonium has been linked to lung cancer from cigarettes, since tobacco plants absorb polonium excessively well and concentrate it in their leaves. Once incinerated and inhaled, the smoke ravishes lung tissue with radioactivity. Of all the countries in the world, only Russia, the many-time conqueror of Poland, bothers to manufacture polonium anymore. That’s why when ex–KGB spy Alexander Litvinenko ate polonium-laced sushi and appeared in videos looking like a teenage leukemia victim, having lost all his hair, even his eyebrows, his former Kremlin employers became the prime suspects.
The trendy Revigator, a pottery crock lined with nuclear radium. Users filled the flask with water, which turned radioactive after a night’s soak. Instructions suggested drinking six or more refreshing glasses a day. (National Museum of Nuclear Science and History)
Historically, only a single case of acute polonium poisoning has approached the drama of Litvinenko’s—that of Irène Joliot-Curie, Marie’s slender, sad-eyed daughter. A brilliant scientist herself, Irène and her husband, Frédéric Joliot-Curie, picked up on Marie’s work and soon one-upped her. Rather than just finding radioactive elements, Irène figured out a method for converting tame elements into artificially radioactive atoms by bombarding them with subatomic particles. This work led to her own Nobel Prize in 1935. Unfortunately, Joliot-Curie relied on polonium as her atomic bombardier. And one day in 1946, not long after Poland had been wrested from Nazi Germany, only to be taken over as a puppet of the Soviet Union, a capsule of polonium exploded in her laboratory, and she inhaled Marie’s beloved element. Though spared Litvinenko’s public humiliation, Joliot-Curie died of leukemia in 1956, just as her mother had twenty-two years before.
The helpless death of Irène Joliot-Curie proved doubly ironic because the cheap, artificial radioactive substances she made possible have since become crucial medical tools. When swallowed in small amounts,
radioactive “tracers” light up organs and soft tissue as effectively as X-rays do bones. Virtually every hospital in the world uses tracers, and a whole branch of medicine, radiology, deals exclusively in that line. It’s startling to learn, then, that tracers began as no more than a stunt by a graduate student—a friend of Joliot-Curie’s who sought revenge on his landlady.
In 1910, just before Marie Curie collected her second Nobel Prize for radioactivity, young György Hevesy arrived in England to study radioactivity himself. His university’s lab director in Manchester, Ernest Rutherford, immediately assigned Hevesy the Herculean task of separating out radioactive atoms from nonradioactive atoms inside blocks of lead. Actually, it turned out to be not Herculean but impossible. Rutherford had assumed the radioactive atoms, known as radium-D, were a unique substance. In fact, radium-D was radioactive lead and therefore could not be separated chemically. Ignorant of this, Hevesy wasted two years tediously trying to tease lead and radium-D apart before giving up.
Hevesy—a bald, droopy-cheeked, mustached aristocrat from Hungary—also faced domestic frustrations. Hevesy was far from home and used to savory Hungarian food, not the English cooking at his boardinghouse. After noticing patterns in the meals served there, Hevesy grew suspicious that, like a high school cafeteria recycling Monday’s hamburgers into Thursday’s beef chili, his landlady’s “fresh” daily meat was anything but. When confronted, she denied this, so Hevesy decided to seek proof.
Miraculously, he’d achieved a breakthrough in the lab around that time. He still couldn’t separate radium-D, but he realized he could flip that to his advantage. He’d begun musing over the possibility of injecting minute quantities of dissolved lead into a living creature and then tracing the element’s path, since the creature would metabolize the radioactive and nonradioactive lead the same way, and the radium-D would emit beacons of radioactivity as it moved. If this worked, he could actually track molecules inside veins and organs, an unprecedented degree of resolution.
Before he tried this on a living being, Hevesy decided to test his idea on the tissue of a nonliving being, a test with an ulterior motive. He took too much meat at dinner one night and, when the landlady’s back was turned, sprinkled “hot” lead over it. She gathered his leftovers as normal, and the next day Hevesy brought home a newfangled radiation detector from his lab buddy, Hans Geiger. Sure enough, when he waved it over that night’s goulash, Geiger’s counter went furious: click-click-click-click. Hevesy confronted his landlady with the evidence. But, being a scientific romantic, Hevesy no doubt laid it on thick as he explained the mysteries of radioactivity. In fact, the landlady was so charmed to be caught so cleverly, with the latest tools of forensic science, that she didn’t even get mad. There’s no historical record of whether she altered her menu, however.
Soon after discovering elemental tracers, Hevesy’s career blossomed, and he continued to work on projects that straddled chemistry and physics. Yet those two fields were clearly diverging, and most scientists picked sides. Chemists remained interested in whole atoms bonding to one another. Physicists were fascinated with the individual parts of atoms and with a new field called quantum mechanics, a bizarre but beautiful way to talk about matter. Hevesy left England in 1920 to study in Copenhagen with Niels Bohr, a major quantum physicist. And it was in Copenhagen that Bohr and Hevesy unwittingly opened the crack between chemistry and physics into a real political rift.
In 1922, the box for element seventy-two on the periodic table stood blank. Chemists had figured out that the elements between fifty-seven (lanthanum) and seventy-one (lutetium) all had rare earth DNA. Element seventy-two was ambiguous. No one knew whether to tack it onto the end of the hard-to-separate rare earths—in which case element hunters should sift through samples of the recently discovered lutetium—or to provisionally classify it as a transition metal, deserving its own column.
According to lore, Niels Bohr, alone in his office, constructed a nearly euclidean proof that element seventy-two was not a lutetium-like rare earth. Remember that the role of electrons in chemistry was not well-known, and Bohr supposedly based his proof on the strange mathematics of quantum mechanics, which says that elements can hide only so many electrons in their inner shells. Lutetium and its f-shells had electrons stuffed into every sleeve and cranny, and Bohr reasoned that the next element had no choice but to start putting electrons on display and act like a proper transition metal. Therefore, Bohr dispatched Hevesy and physicist Dirk Coster to scrutinize samples of zirconium—the element above number seventy-two on the table and its probable chemical analogue. In perhaps the least-sweat discovery in periodic table history, Hevesy and Coster found element seventy-two on their first attempt. They named it hafnium, from Hafnia, the Latin name for Copenhagen.
Quantum mechanics had won over many physicists by then, but it struck chemists as ugly and unintuitive. This wasn’t stodginess as much as pragmatism: that funny way of counting electrons seemed to have little to do with real chemistry. However, Bohr’s predictions about hafnium, made without setting foot in a lab, forced chemists to swallow hard. Coincidentally, Hevesy and Coster made their discovery just before Bohr accepted the 1922 Nobel Prize in Physics. They informed him by telegram in Stockholm, and Bohr announced their discovery in a speech. This made quantum mechanics look like the evolutionary science, since it dug deeper into atomic structure than chemistry could. A whispering campaign began, and as with Mendeleev before him, Bohr’s colleagues soon imbued Bohr—already inclined to scientific mysticism—with oracular qualities.
That’s the legend anyway. The truth is a little different. At least three scientists preceding Bohr, including a chemist who directly influenced Bohr, wrote papers as far back as 1895 that linked element seventy-two to transition metals such as zirconium. These men weren’t geniuses ahead of their time, but pedestrian chemists with little knowledge of or interest in quantum physics. It seems that Bohr poached their arguments when placing hafnium and probably used his quantum calculations to rationalize a less romantic, but still viable, chemical argument about its spot on the table.*
Yet, as with most legends, what’s important isn’t the truth but the consequences—how people react to a story. And as the myth was bruited about, people clearly wanted to believe that Bohr had found hafnium through quantum mechanics alone. Physics had always worked by reducing nature’s machines into smaller pieces, and for many scientists Bohr had reduced dusty, fusty chemistry to a specialized, and suddenly quaint, branch of physics. Philosophers of science also leapt on the story to proclaim that Mendeleevian chemistry was dead and Bohrian physics ruled the realm. What started as a scientific argument became a political dispute about territory and boundaries. Such is science, such is life.
The legend also lionized the man at the center of the brouhaha, György Hevesy. Colleagues had already nominated Hevesy for a Nobel Prize by 1924 for discovering hafnium, but there was a dispute over priority with a French chemist and dilettante painter. Georges Urbain—who had once tried and failed to embarrass Henry Moseley with his sample of rare earth elements—had discovered lutetium in 1907. Much later he claimed he had found hafnium—a rare earth flavor of hafnium—mixed in with his samples. Most scientists didn’t find Urbain’s work convincing, and unfortunately Europe was still divided by the recent unpleasantries in 1924, so the priority dispute took on nationalistic overtones. (The French considered Bohr and Hevesy Germans even though they were Danish and Hungarian, respectively. One French periodical sniffed that the whole thing “stinks of Huns,” as if Attila himself had discovered the element.) Chemists also mistrusted Hevesy for his dual “citizenship” in chemistry and physics, and that, along with the political bickering, prevented the Nobel committee from giving him the prize. Instead, it left the 1924 prize blank.
Saddened but unbowed, Hevesy left Copenhagen for Germany and continued his important experiments on chemical tracers. In his spare time, he even helped determine how quickly the human body recycles an average water molec
ule (nine days) by volunteering to drink special “heavy” water,* in which some hydrogen atoms have an extra neutron, and then having his urine weighed each day. (As with the landlady-meat incident, he wasn’t big on formal research protocol.) All the while, chemists such as Irène Joliot-Curie repeatedly and futilely nominated him for a Nobel Prize. Annually unrewarded, Hevesy grew a little despondent. But unlike with Gilbert Lewis, the obvious injustice aroused sympathy for Hevesy, and the lack of a prize strangely bolstered his status in the international community.
Nonetheless, with his Jewish ancestry, Hevesy soon faced direr problems than the lack of a Nobel Prize. He left Nazi Germany in the 1930s for Copenhagen again and remained there through August 1940, when Nazi storm troopers knocked on the front door of Bohr’s institute. And when the hour called for it, Hevesy proved himself courageous. Two Germans, one Jewish and the other a Jewish sympathizer and defender, had sent their gold Nobel Prize medals to Bohr for safekeeping in the 1930s, since the Nazis would likely plunder them in Germany. However, Hitler had made exporting gold a state crime, so the discovery of the medals in Denmark could lead to multiple executions. Hevesy suggested they bury the medals, but Bohr thought that was too obvious. So, as Hevesy later recalled, “while the invading forces marched in the streets of Copenhagen, I was busy dissolving [Max von] Laue’s and also James Franck’s medals.” To do this, he used aqua regia—a caustic mix of nitric and hydrochloric acids that fascinated alchemists because it dissolved “royal metals” such as gold (though not easily, Hevesy remembered). When the Nazis ransacked Bohr’s institute, they scoured the building for loot or evidence of wrongdoing but left the beaker of orange aqua regia untouched. Hevesy was forced to flee to Stockholm in 1943, but when he returned to his battered laboratory after V-E Day, he found the innocuous beaker undisturbed on a shelf. He precipitated out the gold, and the Swedish Academy later re-cast the medals for Franck and Laue. Hevesy’s only complaint about the ordeal was the day of lab work he missed while fleeing Copenhagen.